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SDLRC - Scientific Articles all years by Author - Po+


The Sheahan Diamond Literature Reference Compilation
The Sheahan Diamond Literature Reference Compilation is compiled by Patricia Sheahan who publishes on a monthly basis a list of new scientific articles related to diamonds as well as media coverage and corporate announcementscalled the Sheahan Diamond Literature Service that is distributed as a free pdf to a list of followers. Pat has kindly agreed to allow her work to be made available as an online digital resource at Kaiser Research Online so that a broader community interested in diamonds and related geology can benefit. The references are for personal use information purposes only; when available a link is provided to an online location where the full article can be accessed or purchased directly. Reproduction of this compilation in part or in whole without permission from the Sheahan Diamond Literature Service is strictly prohibited. Return to Diamond Resource Center
Sheahan Diamond Literature Reference Compilation - Scientific Articles by Author for all years
A-An Ao+ B-Bd Be-Bk Bl-Bq Br+ C-Cg Ch-Ck Cl+ D-Dd De-Dn Do+ E F-Fn Fo+ G-Gh Gi-Gq Gr+ H-Hd He-Hn Ho+ I J K-Kg Kh-Kn Ko-Kq Kr+ L-Lh
Li+ M-Maq Mar-Mc Md-Mn Mo+ N O P-Pd Pe-Pn Po+ Q R-Rh Ri-Rn Ro+ S-Sd Se-Sh Si-Sm Sn-Ss St+ T-Th Ti+ U V W-Wg Wh+ X Y Z
Sheahan Diamond Literature Reference Compilation - Media/Corporate References by Name for all years
A B C D-Diam Diamonds Diamr+ E F G H I J K L M N O P Q R S T U V W X Y Z
Tips for Users
Posted/Published Reference CodesThe SDLRC provides 3 types of references identified in the reference code. DS for scientific article, DM for a media article, and DC for a corporate announcement. Consider DS0512-0001. The DS stands for "diamond scientific". 05 stands for 2005, the year the reference was posted. 12 represents the month the reference was posted. For all years prior to 2015 the default month is 12. -0001 is the reference's identifier and it does not mean anything. The number below the refence code, ie 2015, is the year the article was published. Note that the posted year may sometimes be later than the published year.
Sort OrderReferences are sorted by the "author" name and when the reference was posted to the compilation.
Most RecentIf the reference code is highlighted yellow, the reference was made available through the most recent monthly compilation of new literature. Use this to check out new references. When new references are posted, we make it our priority to track down an online link and obtain an abstract. With regard to older references, tracking down an abstract and an online link is a work in progress.
Link to external location of article: If the title has a link, it means we have found a location online where you can either retrieve the full article free, or purchase access to it. The Sheahan Diamond Literature Service is not a technical article procurement service; if you want a restricted article, you must deal directly with the vendor who controls the copyright to the article.
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Author Index
A-An Ao+ B-Bd Be-Bk Bl-Bq Br+ C-Cg Ch-Ck Cl+ D-Dd De-Dn Do+ E F-Fn Fo+ G-Gh Gi-Gq Gr+ H-Hd He-Hn Ho+ I J K-Kg Kh-Kn Ko-Kq Kr+ L-Lh
Li+ M-Maq Mar-Mc Md-Mn Mo+ N O P-Pd Pe-Pn Po+ Q R-Rh Ri-Rn Ro+ S-Sd Se-Sh Si-Sm Sn-Ss St+ T-Th Ti+ U V W-Wg Wh+ X Y Z
Sheahan Diamond Literature Reference Compilation - Scientific Articles by Author for all years - Po+
Posted/
Published
AuthorTitleSourceRegionKeywords
DS1994-1565
1994
Poage, M.A.Sears, J.W., Jacob, J.P., Poage, M.A., Sims, J.L., Skinner, L.L.Mid-continent rift analog for middle Proterozoic belt basinGeological Society of America Abstracts, Vol. 26, No. 6, April p. 62. Abstract.GlobalTectonics, Midcontinent
DS1970-0176
1970
Poberezhskiy, V.A.Ponamarenko, A.I., Pankratov, A.A., Poberezhskiy, V.A.Occurrence of Kimberlite Magmatism on the Southern Slope Of the Anabar Anticlise (uplift).In: Geology, Petrography And Mineralogy of Magmatic Formatio, PP. 33-47.RussiaBlank
DS1981-0338
1981
Poberezhskiy, V.A.Poberezhskiy, V.A. , Kharkiv, A.D., Smirnov, G.I., Nikishov, K.Xenoliths of the Spinel Pyroxene Depth Facies from Kimberlitic Rocks.Doklady Academy of Science USSR, Earth Science Section., Vol. 248, No. 1-8, PP. 99-102.RussiaGenesis
DS1988-0274
1988
Poberezhskiy, V.A.Gritsik, V.V., Dyakov, A.G., Poberezhskiy, V.A.Carbon isotope composition of diamonds from different diamond bearing provinces of the world.(Russian)Mineral. Sbornik (L'Vov), (Russian), Vol. 42, No. 1, pp. 68-70Russia, GlobalGeochronology, Diamonds, Carbon isotope
DS1989-0553
1989
Poberezhskiy, V.A.Gritsik, V.V., Hashchak, M.S., Poberezhskiy, V.A.The insignificant role of parental carbon fractionation during the synthesis of native impact and synthetic diamonds.(Russian)Mineralogischeskiy Sbornik, (L'vov), (Russian), Vol. 43, No. 1, pp. 95-96RussiaMineral chemistry
DS202008-1434
2020
Pobric, V.Pobric, V., Korolev, N., Kopylova, M.Eclogites of the North Atlantic Craton: insights from Chidliak eclogite xenoliths ( S. Baffin Island, Canada).Contributions to Mineralogy and Petrology, Vol. 175, 8, 25p. PdfCanada, Baffin Islanddeposit - Chidliak

Abstract: The 156-138 Ma Chidliak kimberlites on the Eastern Hall peninsula (EHP) of Baffin Island entrained mantle xenoliths interpreted to have been a part of the Archean North Atlantic Craton (NAC) lithospheric mantle. We studied 19 Chidliak eclogite xenoliths that comprise 10 bimineralic, 5 rutile-bearing, 3 orthopyroxene-bearing and 1 kyanite-bearing eclogites. We report major and trace element compositions of the minerals, calculated bulk compositions, pressures and temperatures of the rock formation and model melt extraction from viable protoliths. The eclogite samples are classified into three groups of HREE-enriched, LREE-depleted and metasomatized based on their reconstructed whole-rock REE patterns. PT parameters of the eclogites were calculated by projecting garnet-clinopyroxene temperatures onto the local P-T arrays for 65 Chidliak peridotite xenoliths. All Chidliak eclogites are equilibrated in the diamond P-T field and cluster in two groups, low-temperature (n?=?5, 840-990 °C at 4.1-5.0 GPa) and high-temperature (n?=?11, T?>?1320 °C at P?>?7.0 GPa). The reconstructed Mg-rich major element bulk compositions and trace elements patterns are similar to Archean basalts from the North Atlantic and Superior cratons and the oceanic gabbros. The LREE-depleted Chidliak eclogites could be residues after 15-55% partial melting of Archean basalt at the eclogite facies of metamorphism that led to extraction of a tonalite-trondhjemite-granodiorite melt from the EHP. The HREE-depleted eclogites may have experienced a lower degree (<10%) of partial melting. Two eclogites may have formed after the gabbro protolith based on the presence of kyanite, high Sr content of garnet and positive Eu anomalies in garnet and bulk eclogite compositions. The metasomatism is reflected in higher Ce/Yb, Sr/Y, TiO2 or MgO of the eclogites. The average contents of MgO, FeO and CaO in NAC eclogites are statistically distinct from those in Slave craton eclogites with a probability of?>95%. The former are more magnesian, less ferrous and calcic, contain more magnesian and less calcic garnets, and lower proportions of group C eclogites. The contrast may relate to the stronger NAC metasomatism by silicate-carbonate melt observed in Chidliak peridotitic mantle, or to the different formation ages of the eclogites beneath the two cratons.
DS202008-1435
2020
Pobric, V.Pobric, V., Korolev, N., Kopylova, M.Eclogites of the North Atlantic Craton: insights from Chidliak eclogite xenoliths ( S. Baffin Island, Canada).Goldschmidt 2020, 1p. AbstractCanada, Baffin Islanddeposit - Chidliak
DS1993-1246
1993
Pochtarev, V.I.Pochtarev, V.I.Magnetic properties of the upper mantleRussian Geology and Geophysics, Vol. 34, No. 2, pp. 126-131.RussiaMantle, Geophysics
DS1996-1125
1996
Pockley, P.Pockley, P.Shifting ground, rock solid or dead boring: public perceptions ofgeoscienceAustralia Geologist, pp. 29-34AustraliaInformation, Geoscience -perception
DS200512-0667
2004
Pocock, J.Mabuza, N.T., Pocock, J., Loveday, B.K.The use of surface active chemicals in heavy medium viscosity reduction.Minerals Engineering, Vol. 18, pp. 25-31.Africa, South AfricaDMS, magnetite, viscosity
DS201903-0531
2019
Podborodnikov, I.V.Martirosayan, N.S., Shatskiy, A., Chanyshev, A.D., Litasov, K.D., Podborodnikov, I.V., Yoshino, T.Effect of water on the magnesite-iron interaction, with implications for the fate of carbonates in the deep mantle.Lithos, Vol. 326-327, pp. 435-445.Mantleperidotite

Abstract: The subduction of carbonates beyond 250-300?km, where redox conditions favour the presence of metallic iron (Fe), will result in redox reactions with the Fe dispersed in the silicate rocks. Here, we studied the effect of water on the carbonate-Fe interaction in the hydromagnesite-Fe system at 6, 8 and 16?GPa and the peridotite-CO2-H2O-Fe system at 8?GPa, using a multianvil apparatus. In all of the studied samples, we observed the formation of magnesiowüstite, graphite and carbide. Additionally, in the peridotite-CO2-H2O-Fe system, magnesiowüstite reacted with pyroxenes, resulting in olivine enrichment. Kinetic calculations performed at 8?GPa showed that, at the pressure-temperature (P-T) parameters of the ‘hot’, ‘medium’ and ‘cold’ subduction, about 40, 12 and 4?vol% of carbonates, respectively, would be reduced in the hydrous system within 1 Myr, assuming direct contact with Fe. Based on the present results, it is suggested that carbonates will largely be consumed during the characteristic subduction time to the mantle transition zone by reaction with the reduced mantle in the presence of hydrous fluid.
DS201903-0539
2019
Podborodnikov, I.V.Podborodnikov, I.V., Shatskiy, A., Arefiev, A.V., Litasov, K.D.Phase relations in the system Na2COs-CaCO3 at 3 Gpa with implications for carbonatite genesis and evolution.Lithos, in press available 43p.Mantlecarbonatite

Abstract: The phase relations in the system Na2CO3?CaCO3?MgCO3 have been studied at 3?GPa and 700-1285?°C using a Kawai-type multianvil press. At 700?°C, the system has five intermediate compounds: dolomite, Mg-bearing Na2Ca4(CO3)5 burbankite, Na2Ca3(CO3)4, Na4Ca(CO3)3, and eitelite. As temperature increases to 800?°C, the system is complicated by an appearance of Ca-dolomite and Mg-bearing shortite, while Na2Ca4(CO3)5 disappears. At 850?°C, Na4Ca(CO3)3 decomposes to produce Na carbonate and nyerereite. The latter melts incongruently at 875?±?25?°C to form Na2Ca3(CO3)4. Incongruent melting of eitelite to magnesite and liquid, occurs at 925?±?25 °C. Mg-bearing shortite melts incongruently at 950?±?50?°C, producing Na2Ca3(CO3)4 and liquid. Na2Ca3(CO3)4 disappears at 1000?°C via incongruent melting to calcite and liquid. The liquidus projection of the studied ternary system has seven primary solidification phase regions for magnesite, dolomite-calcite solid solutions, Na2Ca3(CO3)4, Mg-bearing shortite, nyerereite, eitelite, and Na carbonate. The primary solidification regions are separated by five peritectic and three cotectic monovariant lines. The system has six ternary peritectic points and one minimum on the liquidus at 850?°C and 52Na2CO3?48(Ca0.62Mg0.38)CO3. The minimum point resembles a eutectic controlled by a four-phase reaction, by which, on cooling, a liquid transforms into three solid phases: shortite, Na carbonate, and eitelite. Since the system has a single eutectic at 3?GPa, there is no thermal barrier preventing continuous liquid fractionation from Na-poor toward Na-rich dolomitic compositions more alkaline than eitelite and nyerereite. Considering the present results and previous data, a range of Na-Ca-Mg double carbonates changes in the following sequence upon pressure and temperature increase: Na2Ca2(CO3)3 (Amm2) shortite, Na2Ca(CO3)2 (P21ca) nyerereite, Na2Mg(CO3)2 () eitelite (0.1?GPa)???Na2(Ca0.97-0.98Mg0.02-0.03)4(CO3)5 (P63mc), Na2(Ca?0.91Mg?0.09)3(CO3)4 (P1n1), Na2(Ca???0.81?Mg0?0.19)(CO3)2 () nyerereite, Na2(Ca0.77-0.93Mg0.07-0.23)2(CO3)3 (Amm2) shortite, Na4(Ca0.90-0.98Mg0.02-0.10)(CO3)3 (Ia3d), Na2(Mg?0.9Ca0?0.1)(CO3)2 (P21ca) eitelite (3?GPa)???Na2(Ca?0.87Mg0?0.13)4(CO3)5 (P63mc), Na2(Ca?0.89Mg?0.11)3(CO3)4 (P1n1), Na4(Ca???0.7?Mg0?0.3)(CO3)3 (Ia3d), Na2(Mg?0.92Ca0?0.08)(CO3)2 (P21ca) eitelite (6?GPa). Using the present results at 3?GPa and previous data at 6?GPa in the Na2CO3?CaCO3?MgCO3 system, we constrained isopleths of the Na2CO3 content in melt coexisting with Ca-Mg carbonates. We found that the cratonic geotherms cross the isopleths so that the carbonatite melt percolating upward via the continental mantle lithosphere should become progressively enriched in Na, evolving from alkali-poor dolomitic composition at depths exceeding 200?km toward sodic dolomitic with the ~52?mol% Na2CO3 at 80-120?km depths.
DS201905-1067
2019
Podborodnikov, I.V.Podborodnikov, I.V., Shatskiy, A., Arefiev, A.V., Litasov, K.D.Phase relations in the system Na2CO3-CaCO3-MgCO3 at 3 GPa with implications for carbonatite genesis and evolution.Lithos, Vol. 330-331, pp. 74-89.Mantlecarbonatite

Abstract: The phase relations in the system Na2CO3?CaCO3?MgCO3 have been studied at 3?GPa and 700-1285?°C using a Kawai-type multianvil press. At 700?°C, the system has five intermediate compounds: dolomite, Mg-bearing Na2Ca4(CO3)5 burbankite, Na2Ca3(CO3)4, Na4Ca(CO3)3, and eitelite. As temperature increases to 800?°C, the system is complicated by an appearance of Ca-dolomite and Mg-bearing shortite, while Na2Ca4(CO3)5 disappears. At 850?°C, Na4Ca(CO3)3 decomposes to produce Na carbonate and nyerereite. The latter melts incongruently at 875?±?25?°C to form Na2Ca3(CO3)4. Incongruent melting of eitelite to magnesite and liquid, occurs at 925?±?25 °C. Mg-bearing shortite melts incongruently at 950?±?50?°C, producing Na2Ca3(CO3)4 and liquid. Na2Ca3(CO3)4 disappears at 1000?°C via incongruent melting to calcite and liquid. The liquidus projection of the studied ternary system has seven primary solidification phase regions for magnesite, dolomite-calcite solid solutions, Na2Ca3(CO3)4, Mg-bearing shortite, nyerereite, eitelite, and Na carbonate. The primary solidification regions are separated by five peritectic and three cotectic monovariant lines. The system has six ternary peritectic points and one minimum on the liquidus at 850?°C and 52Na2CO3?48(Ca0.62Mg0.38)CO3. The minimum point resembles a eutectic controlled by a four-phase reaction, by which, on cooling, a liquid transforms into three solid phases: shortite, Na carbonate, and eitelite. Since the system has a single eutectic at 3?GPa, there is no thermal barrier preventing continuous liquid fractionation from Na-poor toward Na-rich dolomitic compositions more alkaline than eitelite and nyerereite. Considering the present results and previous data, a range of Na-Ca-Mg double carbonates changes in the following sequence upon pressure and temperature increase: Na2Ca2(CO3)3 (Amm2) shortite, Na2Ca(CO3)2 (P21ca) nyerereite, Na2Mg(CO3)2 () eitelite (0.1?GPa)???Na2(Ca0.97-0.98Mg0.02-0.03)4(CO3)5 (P63mc), Na2(Ca?0.91Mg?0.09)3(CO3)4 (P1n1), Na2(Ca???0.81?Mg0?0.19)(CO3)2 () nyerereite, Na2(Ca0.77-0.93Mg0.07-0.23)2(CO3)3 (Amm2) shortite, Na4(Ca0.90-0.98Mg0.02-0.10)(CO3)3 (Ia3d), Na2(Mg?0.9Ca0?0.1)(CO3)2 (P21ca) eitelite (3?GPa)???Na2(Ca?0.87Mg0?0.13)4(CO3)5 (P63mc), Na2(Ca?0.89Mg?0.11)3(CO3)4 (P1n1), Na4(Ca???0.7?Mg0?0.3)(CO3)3 (Ia3d), Na2(Mg?0.92Ca0?0.08)(CO3)2 (P21ca) eitelite (6?GPa). Using the present results at 3?GPa and previous data at 6?GPa in the Na2CO3?CaCO3?MgCO3 system, we constrained isopleths of the Na2CO3 content in melt coexisting with Ca-Mg carbonates. We found that the cratonic geotherms cross the isopleths so that the carbonatite melt percolating upward via the continental mantle lithosphere should become progressively enriched in Na, evolving from alkali-poor dolomitic composition at depths exceeding 200?km toward sodic dolomitic with the ~52?mol% Na2CO3 at 80-120?km depths.
DS201906-1336
2019
Podborodnikov, I.V.Podborodnikov, I.V., Shatskiy, A., Arefiev, A.V., Bekhtenova, A.New data on the system Na2CO3-CaCO3-MgCO3 at 6 Gpa with implications to the composition and stability of carbonatite melts at the base of continental lithosphere.Chemical Geology, Vol. 515, pp. 50-60.Russiadeposit - Udachnaya-East

Abstract: Subsolidus and melting phase relationships in the system Na2CO3-CaCO3-MgCO3 have been studied at 6?GPa and 900-1250?°C using a Kawai-type multianvil press. At 900 and 1000?°C, the system has four intermediate compounds: Na2Ca4(CO3)5 burbankite, Na2Ca3(CO3)4, Na4Ca(CO3)3, and Na2Mg(CO3)2 eitelite. The Na-Ca compounds dissolve noticeable amounts of Mg component, whereas eitelite dissolves a few percents of Ca component: Na2(Ca?0.91Mg?0.09)4(CO3)5, Na2(Ca?0.94Mg?0.06)3(CO3)4, Na4(Ca?0.67Mg?0.33)(CO3)3, and Na2(Mg?.93Ca?0.07)(CO3)2. At 1050?°C, the system is complicated by an appearance of dolomite. Na-Ca burbankite decomposes at 1075?±?25?°C to aragonite plus Na2Ca3(CO3)4. Na4Ca(CO3)3 and eitelite disappear via congruent melting between 1200 and 1250?°C. Na2Ca3(CO3)4 remains stable through the whole studied temperature range. The liquidus projection of the studied ternary system has eight primary solidification phase regions for magnesite, dolomite, calcite-dolomite solid solutions, aragonite, Na2Ca3(CO3)4, Na4Ca(CO3)3, and Na2CO3 solid solutions. The system has five ternary peritectic reaction points and one minimum on the liquidus at 1050?°C and 48Na2CO3•52(Ca0.75Mg0.25)CO3. The minimum point resembles a eutectic controlled by a four-phase reaction, by which a liquid transforms into three solid phases upon cooling: Na2(Ca0.94Mg0.06)3(CO3)4, Na4(Ca0.67Mg0.33)(CO3)3, and Na2(Mg0.93Ca0.07)(CO3)2 eitelite. Since at 6?GPa, the system has a single eutectic, there is no thermal barrier preventing continuous liquid fractionation from alkali-poor toward Na-rich dolomitic compositions. Cooling of the Na-Ca-Mg carbonatite melt from 1400 to 1100?°C within the lherzolite substrate will be accompanied by magnesite crystallization and wehrlitization keeping calcium number of the melt at 40 and shifting the Na2CO3 content to ?40?mol%. In the case of the eclogitic wall rock, the cooling will be accompanied by dolomite crystallization keeping calcium number of the melt at 60-65 and shifting the Na2CO3 content to ?30?mol%.
DS201908-1812
2019
Podborodnikov, I.V.Shatskiy, A., Arefiev, A.V., Podborodnikov, I.V., Litasov, K.D.Origin of K-rich diamond-forming immscible melts and CO2 fluid via partial melting of carbonated pelites at depth of 180-200 km.Gondwana Research, Vol. 75, pp. 154-171.Mantlediamond genesis

Abstract: Melt inclusions in kimberlitic and metamorphic diamonds worldwide range in composition from potassic aluminosilicate to alkali-rich carbonatitic and their low-temperature derivative, a saline high-density fluid (HDF). The discovery of CO2 inclusions in diamonds containing eclogitic minerals are also essential. These melts and HDFs may be responsible for diamond formation and metasomatic alteration of mantle rocks since the late Archean to Phanerozoic. Although a genetic link between these melts and fluids was suggested, their origin is still highly uncertain. Here we present experimental results on melting phase relations in a carbonated pelite at 6?GPa and 900-1500?°C. We found that just below solidus K2O enters potassium feldspar or K2TiSi3O9 wadeite coexisting with clinopyroxene, garnet, kyanite, coesite, and dolomite. The potassium phases react with dolomite to produce garnet, kyanite, coesite, and potassic dolomitic melt, 40(K0.90Na0.10)2CO3•60Ca0.55Mg0.24Fe0.21CO3?+?1.9?mol% SiO2?+?0.7?mol% TiO2?+?1.4?mol% Al2O3 at the solidus established near 1000?°C. Molecular CO2 liberates at 1100?°C. Potassic aluminosilicate melt appears in addition to carbonatite melt at 1200?°C. This melt contains (mol/wt%): SiO2?=?57.0/52.4, TiO2?=?1.8/2.3, Al2O3?=?8.5/13.0, FeO?=?1.4/1.6, MgO?=?1.9/1.2, CaO?=?3.8/3.2, Na2O?=?3.2/3.0, K2O?=?10.5/15.2, CO2?=?12.0/8.0, while carbonatite melt can be approximated as 24(K0.81Na0.19)2CO3•76Ca0.59Mg0.21Fe0.20CO3?+?3.0?mol% SiO2?+?1.6?mol% TiO2?+?1.4?mol% Al2O3. Both melts remain stable to at least 1500?°C coexisting with CO2 fluid and residual eclogite assemblage consisting of K-rich omphacite (0.4-1.5?wt% K2O), almandine-pyrope-grossular garnet, kyanite, and coesite. The obtained immiscible alkali?carbonatitic and potassic aluminosilicate melts resemble compositions of melt inclusions in diamonds worldwide. Thus, these melts entrapped by diamonds could be derived by partial melting of the carbonated material of the continental crust subducted down to 180-200?km depths. Given the high solubility of chlorides and water in both carbonate and aluminosilicate melts inferred in previous experiments, the saline end-member, brine, could evolve from potassic carbonatitic and/or silicic melts by fractionation of Ca-Mg carbonates/eclogitic minerals and accumulation of alkalis, chlorine and water in the residual low-temperature supercritical fluid. Direct extraction from the hydrated marine sediments under conditions of cold subduction would be another possibility for the brine formation.
DS201909-2085
2019
Podborodnikov, I.V.Shatskiy, A., Arefiev, A.V., Podborodnikov, I.V., Litasov, K.D.Origin of K-rich diamond forming immiscible melts and CO2 fluid via partial melting of carbonated pelites at a depth of 180-200km.Gondwana Research, Vol. 75, pp. 154-171.Mantlediamond genesis

Abstract: Melt inclusions in kimberlitic and metamorphic diamonds worldwide range in composition from potassic aluminosilicate to alkali-rich carbonatitic and their low-temperature derivative, a saline high-density fluid (HDF). The discovery of CO2 inclusions in diamonds containing eclogitic minerals are also essential. These melts and HDFs may be responsible for diamond formation and metasomatic alteration of mantle rocks since the late Archean to Phanerozoic. Although a genetic link between these melts and fluids was suggested, their origin is still highly uncertain. Here we present experimental results on melting phase relations in a carbonated pelite at 6?GPa and 900-1500?°C. We found that just below solidus K2O enters potassium feldspar or K2TiSi3O9 wadeite coexisting with clinopyroxene, garnet, kyanite, coesite, and dolomite. The potassium phases react with dolomite to produce garnet, kyanite, coesite, and potassic dolomitic melt, 40(K0.90Na0.10)2CO3•60Ca0.55Mg0.24Fe0.21CO3?+?1.9?mol% SiO2?+?0.7?mol% TiO2?+?1.4?mol% Al2O3 at the solidus established near 1000?°C. Molecular CO2 liberates at 1100?°C. Potassic aluminosilicate melt appears in addition to carbonatite melt at 1200?°C. This melt contains (mol/wt%): SiO2?=?57.0/52.4, TiO2?=?1.8/2.3, Al2O3?=?8.5/13.0, FeO?=?1.4/1.6, MgO?=?1.9/1.2, CaO?=?3.8/3.2, Na2O?=?3.2/3.0, K2O?=?10.5/15.2, CO2?=?12.0/8.0, while carbonatite melt can be approximated as 24(K0.81Na0.19)2CO3•76Ca0.59Mg0.21Fe0.20CO3?+?3.0?mol% SiO2?+?1.6?mol% TiO2?+?1.4?mol% Al2O3. Both melts remain stable to at least 1500?°C coexisting with CO2 fluid and residual eclogite assemblage consisting of K-rich omphacite (0.4-1.5?wt% K2O), almandine-pyrope-grossular garnet, kyanite, and coesite. The obtained immiscible alkali?carbonatitic and potassic aluminosilicate melts resemble compositions of melt inclusions in diamonds worldwide. Thus, these melts entrapped by diamonds could be derived by partial melting of the carbonated material of the continental crust subducted down to 180-200?km depths. Given the high solubility of chlorides and water in both carbonate and aluminosilicate melts inferred in previous experiments, the saline end-member, brine, could evolve from potassic carbonatitic and/or silicic melts by fractionation of Ca-Mg carbonates/eclogitic minerals and accumulation of alkalis, chlorine and water in the residual low-temperature supercritical fluid. Direct extraction from the hydrated marine sediments under conditions of cold subduction would be another possibility for the brine formation.
DS202009-1659
2020
Podborodnikov, I.V.Shatskiy, A., Arefiev, A.V.,Podborodnikov, I.V., Litasov, K.D.Liquid immiscibility and phase relations in the system KAlSi0308-CaMg ( CO3)2+- NaAiSi2O6+- Na2CO3 at Gpa: implications for diamond forming melts.Chemical Geology, Vol. 550, 17p. PdfMantlemelting

Abstract: To evaluate the effect of Na on the carbonate-silicate liquid immiscibility in the diamond stability field, we performed experiments along some specific joins of the system KAlSi3O8-CaMg(CO3)2 ± NaAlSi2O6 ± Na2CO3 at 6 GPa. Melting in all studied joins begins at 1000-1050 °C. The melting in the Kfs + Dol system is controlled by the reaction 6 KAlSi3O8 (K-feldspar) + 6 CaMg(CO3)2 (dolomite) = 2 (Can,Mg1-n)3Al2Si3O12 (garnet) + Al2SiO5 (kyanite) + 11 SiO2 (coesite) + 3 K2(Ca1-n,Mgn)2(CO3)3 (carbonatitic melt) + 3 CO2 (fluid), where n ~ 0.3-0.4. A temperature increasing to 1300 °C yields an appearance of the silicic immiscible melt in addition to carbonatitic melt via the reaction K2CO3 (carbonatitic melt) + Al2SiO5 (kyanite) + 5 SiO2 (coesite) = 2 KAlSi3O8 (silicic melt) + CO2 (fluid or solute in melts). The silicic melt composition is close to KAlSi3O8 with dissolved CaMg(CO3)2 and molecular CO2. An addition of NaAlSi2O6 or Na2CO3 to the system results in partial decomposition of K-feldspar and formation of K-bearing carbonates, (K, Na)2Mg(CO3)2 and (K, Na)2Ca3(CO3)4. Their melting produces carbonatite melt with the approximate composition of 4(K, Na)2CO3•6Ca0.6Mg0.4CO3 and magnesite. Besides, the presence of NaAlSi2O6 in the studied system shifts the lower-temperature limit of immiscibility to 1500°?, while the presence of Na2CO3 eliminates the appearance of silicic melt by the following reaction: 2 KAlSi3O8 (in the silicic melt) + Na2CO3 = 2 NaAlSi2O6 (in clinopyroxene) + K2CO3 (in the carbonatitic melt) + SiO2 (coesite). Thus, an increase of the Na2O content in the system Na2O-K2O-CaO-MgO-Al2O3-SiO2-CO2 consumes Al2O3 and SiO2 from silicic melt to form clinopyroxene. We found that grossular-pyrope and diopside-jadeite solid solutions can coexist with CO2 fluid at 900-1500 °C and 6 GPa. Thus, CO2 fluid is stable in the eclogitic suite in the diamond stability field under temperature conditions of the continental lithosphere and subducting slabs. Variations in the Na2O content observed in carbonatitic melts trapped by natural in diamonds exceed those derived by the pelite melting. The present experiments show that an addition of NaAlSi2O6 to the Kfs + Dol system does not cause an increase of the Na2O content in the carbonatitic melt, whereas the addition of Na2CO3 at Na2O/Al2O3 > 1 yields the formation of the melts with the Na2O contents covering the entire range of natural compositions. Thus, only the presence of additional salt components can explain the elevated Na2O content in the melts trapped in lithospheric diamonds. In addition to carbonates, sodium can be hosted by chlorides, sulfates, etc.
DS202009-1660
2020
Podborodnikov, I.V.Shatskiy, A., Bekhtenova, A., Podborodnikov, I.V., Arefiev, A.V., Litasov, K.D.Metasomatic interaction of the eutectic Na- and K-bearing carbonate melts with natural garnet lherzolite at 6 Gpa and 1100-1200 C: toward carbonatite melt composition in SCLM.Lithos, Vol. 374-375, 17p. PdfMantlemetasomatism

Abstract: The range of carbonatite melts in equilibrium with the subcontinental lithospheric mantle (SCLM) under geothermal conditions is limited by alkali-rich near-eutectic compositions. Therefore, here we employed eutectic Na/K-Ca-Mg-Fe carbonate mixtures to model the interaction of a metasomatic carbonatite melt with natural garnet lherzolite. The experiments were performed at 1100 and 1200 °C and 6 GPa in graphite capsules using a multianvil press. The run duration was 111 and 86 h, respectively. To verify achieving an equilibrium, a synthetic mixture identical to natural lherzolite was also employed. We have found that both Na- and K-bearing carbonatite melts cause wehrlitization accompanying by the elimination of orthopyroxene and an increase of CaO in garnet at a constant Cr2O3. Interaction with the K?carbonatite melt alters clinopyroxene composition toward lower Na2O (0.2-0.3 wt%), and higher K2O (0.5-1.0 wt%), whereas the Na?carbonatite melt revealed the opposite effect. The resulting melts have a following approximate composition [40(Na, K)2CO3?60Ca0.5Mg0.4Fe0.1CO2 + 0.6-1.4 wt% SiO2] displaying a decrease in Ca# at a nearly constant alkali content relative to the initial composition, where Ca# = 100?Ca/(Ca + Mg + Fe). We have also found that alkali-poor (? 20 mol% (Na, K)2CO3) carbonate mixtures do not melt completely but yield magnesite and alkali- and Ca-rich melts like those in the systems with eutectic mixtures. Under SCLM P-T conditions the range of carbonatite melt compositions is restricted by the full melting field of alkali-rich carbonates in the corresponding Na/K-Ca-Mg carbonate systems. Infiltration of less alkaline higher-temperature carbonatite melt in SCLM and its subsequent cooling to the ambient mantle temperature, 1100-1200 °C at 6 GPa, should cause crystallization of magnesite and shift the melt composition to [30(Na, K)2CO3?70Ca0.6Mg0.3Fe0.1CO3]. Owing to its high Ca#, this melt is not stable in equilibrium with orthopyroxene yielding its disappearance by CaMg exchange reaction producing clinopyroxene, magnesite, and shifting the melt composition toward higher alkali content. The melts containing 40-45 mol% of alkaline carbonates have no limitation in Ca# because the corresponding binary NaMg and KMg carbonate eutectics are located near 1200 °C. Therefore, these melts can achieve Ca# ? 30-40 and, be in equilibrium with garnet lherzolites and harzburgites under the geothermal condition of SCLM. Considering the present results and previous experimental data the following ranges of carbonatite melt compositions can be expected in equilibrium with garnet peridotites at the base of SCLM: Ca# < 30 and > 30 mol% (K, Na)2CO3 in equilibrium with harzburgite; Ca# 30-40, >25 mol% (K, Na)2CO3 in equilibrium with lherzolite; and Ca# 40-60 and >20 mol% (K, Na)2CO3 in equilibrium with wehrlite.
DS202103-0407
2021
Podborodnikov, I.V.Shatskiy, A., Arefiev, A.V., Podborodnikov, I.V., Litasov, K.D.Effect of water on carbonate-silicate liquid immiscibility in the system KAlSi3O8-CaMgSiO6-NaAlSiO6-CaMg(CO3)2 at 6 Pa: implications for diamond forming melts.American Mineralogist, Vol. 106, pp. 165-173. pdfMantlemelting

Abstract: To evaluate the effect of Na on the carbonate-silicate liquid immiscibility in the diamond stability field, we performed experiments along some specific joins of the system KAlSi3O8-CaMg(CO3)2 ± NaAlSi2O6 ± Na2CO3 at 6 GPa. Melting in all studied joins begins at 1000-1050 °C. The melting in the Kfs + Dol system is controlled by the reaction 6 KAlSi3O8 (K-feldspar) + 6 CaMg(CO3)2 (dolomite) = 2 (Can,Mg1-n)3Al2Si3O12 (garnet) + Al2SiO5 (kyanite) + 11 SiO2 (coesite) + 3 K2(Ca1-n,Mgn)2(CO3)3 (carbonatitic melt) + 3 CO2 (fluid), where n ~ 0.3-0.4. A temperature increasing to 1300 °C yields an appearance of the silicic immiscible melt in addition to carbonatitic melt via the reaction K2CO3 (carbonatitic melt) + Al2SiO5 (kyanite) + 5 SiO2 (coesite) = 2 KAlSi3O8 (silicic melt) + CO2 (fluid or solute in melts). The silicic melt composition is close to KAlSi3O8 with dissolved CaMg(CO3)2 and molecular CO2. An addition of NaAlSi2O6 or Na2CO3 to the system results in partial decomposition of K-feldspar and formation of K-bearing carbonates, (K, Na)2Mg(CO3)2 and (K, Na)2Ca3(CO3)4. Their melting produces carbonatite melt with the approximate composition of 4(K, Na)2CO3•6Ca0.6Mg0.4CO3 and magnesite. Besides, the presence of NaAlSi2O6 in the studied system shifts the lower-temperature limit of immiscibility to 1500°?, while the presence of Na2CO3 eliminates the appearance of silicic melt by the following reaction: 2 KAlSi3O8 (in the silicic melt) + Na2CO3 = 2 NaAlSi2O6 (in clinopyroxene) + K2CO3 (in the carbonatitic melt) + SiO2 (coesite). Thus, an increase of the Na2O content in the system Na2O-K2O-CaO-MgO-Al2O3-SiO2-CO2 consumes Al2O3 and SiO2 from silicic melt to form clinopyroxene. We found that grossular-pyrope and diopside-jadeite solid solutions can coexist with CO2 fluid at 900-1500 °C and 6 GPa. Thus, CO2 fluid is stable in the eclogitic suite in the diamond stability field under temperature conditions of the continental lithosphere and subducting slabs. Variations in the Na2O content observed in carbonatitic melts trapped by natural in diamonds exceed those derived by the pelite melting. The present experiments show that an addition of NaAlSi2O6 to the Kfs + Dol system does not cause an increase of the Na2O content in the carbonatitic melt, whereas the addition of Na2CO3 at Na2O/Al2O3 > 1 yields the formation of the melts with the Na2O contents covering the entire range of natural compositions. Thus, only the presence of additional salt components can explain the elevated Na2O content in the melts trapped in lithospheric diamonds. In addition to carbonates, sodium can be hosted by chlorides, sulfates, etc.
DS202105-0789
2021
Podborodnikov, I.V.Shatskiy, A., Podborodnikov, I.V., Arefiev, A.V., Bekhtenova, A., Vinogradova, Y.G., Stepanov, K.M., Litasov, K.D.Pyroxene-carbonate reactions in the CaMgSi206+-NaAlSi206+MgC03+-Na2C03+-K2C03 system at 3-6 Gpa: implications for partial melting of carbonated peridotite.Contributions to Mineralogy and Petrology, Vol. 176, 34 21p. PdfMantlecarbonatites

Abstract: The reactions between pyroxenes and carbonates have been studied in the CaMgSi2O6 + MgCO3 (Di + 2Mgs), CaMgSi2O6 + NaAlSi2O6 + 2MgCO3 (Di + Jd + 2Mgs), CaMgSi2O6 + Na2Mg(CO3)2 (Di + Eit), and CaMgSi2O6 + K2Mg(CO3)2 (Di + K2Mg) systems at pressures of 3.0 and 4.5 GPa in the temperature range 850-1300 °C and compared with those established previously at 6.0 GPa. The Di + 2Mgs solidus locates at 1220 °C / 3 GPa and 1400 °C / 6 GPa. Near-solidus melt is carbonatitic with SiO2 < 4 wt% and Ca# 56. The Di + Jd + 2Mgs solidus locates near 1050 °C at 3 GPa, rises to 1200 °C at 4.5 GPa, and 1350 °C at 6 GPa. The solidus is controlled by the reaction: 4NaAlSi2O6.2CaMgSi2O6 (clinopyroxene) + 12MgCO3 (magnesite) = 2MgAl2SiO6.5Mg2Si2O6 (clinopyroxene) + 2[Na2CO3.CaCO3.MgCO3] (liquid) + 6CO2. As pressure increases, the composition of solidus melt evolves from 26Na2CO3?74Ca0.58Mg0.42CO3 at 3 GPa to 10Na2CO3?90Ca0.50Mg0.50CO3 at 6 GPa. Melting in the Di + Eit and Di + K2Mg systems is controlled by the reactions: CaMgSi2O6 (clinopyroxene) + 2(Na or K)2 Mg(CO3)2 (eitelite) = Mg2Si2O6 (orthopyroxene) + 2[(Na or K)2CO3?Ca0.5Mg0.5CO3] (liquid). The Di + Eit solidus locates at 925 °C / 3 GPa and 1100 °C / 6 GPa, whereas the Di + K2Mg solidus is located at 50 °C lower. The resulting melts have alkali-rich carbonate compositions, (Na or K)2CO3?Ca0.4Mg0.6CO3. The obtained results suggest that most carbonates belong to the ultramafic suite would survive during subduction into the deep mantle and experience partial melting involving alkaline carbonates, eitelite or K2Mg(CO3)2, under geothermal conditions of the subcontinental lithospheric mantle (35-40 mW/m2). On the other hand, the jadeite component in clinopyroxene would be an important fluxing agent responsible for the partial melting of carbonated rocks under the rift margin geotherm (60 mW/m2) at a depth of about 100 km, yielding the formation of Na-carbonatite melt.
DS202112-1946
2022
Podborodnikov, I.V.Shatskiy, A., Bekhtenova, A., Arefiev, A.V., Podborodnikov, I.V., Vinogradova, Y.C., Rezvukin, D.I., Litasov, K.D.Solidus and melting of carbonated phlogopite peridotite at 3-6.5 Gpa: implications for mantle metasomatism.Gondwana Research, Vol. 101, 156-174. pdfRussiadeposit - Udachnaya

Abstract: It is well known that water significantly lowers mantle solidi. But it turns out this paradigm is not always true. Here, we studied the interaction of K-rich carbonate melts with the natural garnet lherzolite from the Udachnaya kimberlite (Russia) in the presence of water at 3.0-6.5 GPa, corresponding to depths of 100-200 km. We found that at ? 1100 °C, the metasomatic interaction consumes garnet, orthopyroxene, and melt to produce phlogopite ± K-richterite + magnesite ± dolomite. Besides, primary clinopyroxene is replaced by one with a lower amount of jadeite component. Thus, the addition of water to the K-rich carbonate melt, infiltrating the subcontinental lithospheric mantle, should yield its partial or complete disappearance accompanied by phlogopitization and carbonation. The studied systems have H2O/K2O = 2, like that in phlogopite, and therefore correspond to carbonated phlogopite peridotite under fluid-absent conditions. At 4.0-6.5 GPa, the solidus of carbonated phlogopite peridotite is controlled by the following reaction: phlogopite + clinopyroxene + magnesite = garnet + orthopyroxene + olivine + hydrous K-carbonatite melt, which is bracketed between 1100 and 1200 °C. At 3 GPa, the solidus temperature decreases to about 1050 °C presumably owing to the Ca-Mg exchange reaction, clinopyroxene + magnesite = orthopyroxene + dolomite, which stabilizes dolomite reacting with phlogopite at a lower temperature than magnesite. Our results suggest that the phlogopite- and carbonate-rich metasomatic vein networks, weakening rigid lithosphere and promoting continental rifting, could be formed as a result of infiltration of hydrous K-carbonatite melt at the base of subcontinental lithospheric mantle. Stretching and thinning of the cratonic lithosphere make geotherms warmer and shifts their intersections with the solidus of carbonated phlogopite peridotite to shallower depths. Consequently, the successive erosion of the continental lithosphere and ascent of the lithosphere-asthenosphere boundary during continental rifting should be accompanied by remelting of phlogopite-carbonate metasomes, upward percolation of K-rich melt, and its solidification at the front of the magmatic-metasomatic mantle system.
DS202202-0214
2022
Podborodnikov, I.V.Shatskiy, A., Bekhtenova, A., Podborodnikov, I.V., Arefiev, A.V., Vinogradova, Y.G., Litasov, K.D.Solidus of carbonated phlogopite eclogite at 3- 6 Gpa: implications for mantle metasomatism and ultra high pressure metamorphism.Gondwana Research, Vol. 103, pp. 108-204. pdfMantlemetasomatism

Abstract: The interaction of natural eclogite (Ecl) with synthetic hydrous carbonate melts with Na:K = 0:1 (KH2) and 1:1 (NKH2) was studied in multianvil experiments at 3-6 GPa and 850-1250 °C. The interaction with KH2 consumes garnet and clinopyroxene producing phlogopite and calcite-dolomite solid solution. Besides, the interaction yields a decrease in the jadeite component of clinopyroxene, evolving eclogite toward pyroxenite. This is consistent with a metasomatic alteration of eclogite xenoliths, manifested as Na-poor “spongy” clinopyroxene, replacing primary omphacite, and kelyphitic rims around garnet, containing phlogopite and carbonates. The interaction with NKH2 also produces phlogopite and carbonate, but the latter is more magnesian and represented by magnesite, above the solidus, and magnesite + dolomite below the solidus. The interaction with NKH2 increases the jadeite component in clinopyroxene and grossular component in garnet, evolving eclogite Group A to eclogite Group B. The studied systems have H2O/K2O = 2, like that in phlogopite, and therefore correspond to carbonated phlogopite eclogite under fluid-absent conditions. Based on the obtained results its solidus is situated near 1050 °C at 3 GPa and decreases to 950 °C at 6 GPa. Thus, hydrous K- and Na-K-carbonatite melts can coexist with eclogite in SCLM at depths exceeding 120-170 km, and solidify as temperature decreases below 950-1050 °C according to the following solidus reactions: pyrope + diopside + melt ? phlogopite + dolomite, below 6 GPa, and pyrope + diopside + melt ? phlogopite + magnesite + grossular, at 6 GPa. The melting reaction, involving phlogopite and dolomite, suggests the partial melting at the peak of ultrahigh-pressure metamorphism (UHPM) during continent-continent plate collision. The prograde P-T path of UHPM crosses the solidus of clinopyroxene + garnet + phlogopite + dolomite assemblage at 4.7-5.2 GPa and 970-990 °C and yields the formation of hydrous K-carbonatite melt-fluid in situ. This melt could be responsible for the formation of K-bearing clinopyroxenes and microdiamonds in the UHPM marbles in the Kokchetav massif, Kazakhstan. The retrograde P-T path intersects the solidus that has a negative Clapeyron slope in the diamond stability field. Thus, the hydrous K-carbonatite melt should disappear soon after the peak of metamorphism reacting with garnet to produce Ca-Mg carbonates and phlogopite.
DS202203-0364
2022
Podborodnikov, I.V.Shatskiy, A., Bekhtenova, A., Podborodnikov, I.V., Arefiev, A.V., Litasov, K. S.Towards composition of carbonatite melts in peridotitic mantle.Earth and Planetary Science Letters, Vol. 581, 11p.Mantlemetasomatism

Abstract: It is generally accepted that carbonatite metasomatism in the subcontinental lithospheric mantle (SCLM) inevitably causes wehrlitization of the primary lherzolite substrate. However, the K-rich carbonatite inclusions in kimberlitic diamonds containing orthopyroxene indicate that this is not always the case. In the present study, we equilibrated natural garnet lherzolite with carbonate melts containing 33-38 wt% K2O with various Ca# = 10, 20, 30, and 40 at 6 GPa and 1200-1500 °C, where Ca# = 100?Ca/(Ca+Mg+Fe). The original ratio of peridotite to carbonate was 58 to 42 by weight. In the studied temperature range, the melt retains essentially carbonate composition with silica content increasing from 1 to 11-12 wt%. The melt with Ca# 10 alters lherzolite to harzburgite, replacing clinopyroxene by orthopyroxene and decreasing CaO content in garnet below 4 wt%. The melts with Ca# 20-30 also consume clinopyroxene; although CaO content in garnet remains in the range of lherzolitic compositions. The melt with Ca# 40 yields wehrlitization, consuming orthopyroxene, increasing clinopyroxene fraction, and increasing CaO content in garnet above 6 wt%. After the interaction, the Ca# of the melt changes as follows 10 ? 16-28, 20 ? 20-33, 30 ? 27-34, and 40 ? 30-34. The olivine + orthopyroxene + clinopyroxene + garnet assemblage was found in equilibrium with carbonatite melt with Ca# 34 at 1200 °C and Ca# 30 at 1400 °C. Thus, K-rich (26-35 wt% K2O) carbonatite melts with Ca# = 30-34 can appear in equilibrium with garnet lherzolite, while the melts with Ca# < 30 and > 34 can be in equilibrium with harzburgite and wehrlite, respectively, at 6 GPa and 1200-1400 °C. Considering that Ca-Mg-Fe carbonates do not melt at the geothermal conditions of the SCLM, while sodic, dolomitic melt causes wehrlitization, high-Mg (Ca# < 35) K-rich dolomitic melt is the only possible carbonatite fluids that are thermodynamically stable in equilibrium with garnet harzburgites and lherzolites in the SCLM at a depth of about 200 km. At higher temperatures corresponding to the underlying asthenosphere, the high alkalinity ceases to be a requirement for the stability of the carbonate melt. Nevertheless, the regularities established here for the K-rich melts remain valid for less alkaline (4-15 wt% Na2O+K2O) primary kimberlite (i.e., mantle carbonatite) melts in the sublithospheric mantle.
DS202012-2250
2020
Podbororodnikov, I.V.Shatskiy, A., Bekhtenova, A., Podbororodnikov, I.V., Arefiev, A.V.Carbonate melt interaction with natural eclogite at 6 Gpa and 1100-1200 C Implcations for metasomatic melt composition in subcontinental lithospheric mantle.Chemical Geology, Vol. 558, 119915, 15p. PdfMantlecarbonatite

Abstract: Compositional ranges of carbonate melts stable under P-T conditions corresponding to the base of subcontinental lithospheric mantle (SCLM) are limited by alkali-rich near-eutectic compositions. In the present work, we investigated the interaction of such melts with the natural eclogite of Group A. It was found that the interaction is accompanied by decreasing Ca# in the melt (L) and increasing Ca# in garnet (Grt) according to the reaction: 3CaCO3 (L) + Mg3Al2Si3O12 (Grt) = 3MgCO3 (Mgs and/or L) + Ca3Al2Si3O12 (Grt), where Mgs is magnesite. The interaction with the Na-Ca-Mg-Fe carbonate melt increases amount of jadeite component in clinopyroxene (Cpx) consuming Al2O3 from garnet and Na2O from the melt according to the reaction: Na2CO3 (L) + CaCO3 (L) + 2Mg3Al2Si3O12 (Grt) + 2CaMgSi2O6 (Cpx) = 2NaAlSi2O6 (Cpx) + Ca3Al2Si3O12 (Grt) + 2MgCO3 (Mgs, L) + 3Mg2SiO4 (Ol). As a result, garnet and omphacite compositions evolve from eclogite Group A to eclogite Group B. A byproduct of the reaction is olivine (Ol), which may explain the formation of inclusions of “mixed” eclogite (garnet + omphacite) and peridotite (olivine) paragenesis in lithospheric diamonds. The interaction with the K-Ca-Mg-Fe carbonate melt increases the K2O content in clinopyroxene to 0.5-1.2 wt%, while the Na2O content lowers to 0.3 wt%. The following range of carbonatite melt compositions can be in equilibrium with eclogite at the base of SCLM (1100-1200 °C and 6 GPa): 18(Na0.97K0.03)2CO3?82(Ca0.63Mg0.30Fe0.07)CO2-42(Na0.97K0.03)2CO3?58(Ca0.46Mg0.45Fe0.09)CO2. Our results also suggest that the partial melting of ‘dry’ carbonated eclogite, if any, at 1100 °C and 6 GPa yields the formation of a carbonate melt with the following composition (mol%) 25(Na0.96K0.04)2CO3?75(Ca0.64Mg0.31Fe0.05)CO2, corresponding to 18-27 wt% Na2O in the melt on a volatile-free basis.
DS1992-1213
1992
Podchasov, V.M.Podchasov, V.M.Main industrial and genetic types of diamond placer deposits, methods of prospecting and explorationWalsh, D.E. ed. 13th. Biennial Conference on Placer mining and trade, pp. 18-19. abstractRussiaNo information of any use, Brief overview of placer sized deposits
DS1992-1214
1992
Poddar, B.C.Poddar, B.C.Panna diamond belt in Central India, geological setting and exploration strategy - a profile.International Roundtable Conference on Diamond Exploration and Mining, held, pp. 187-188. abstract only.IndiaGeology, Panna belt
DS1983-0520
1983
Poddar, M.Poddar, M., Rathor, B.S.Vlf Survey of the Weathered Layer in Southern IndiaGeophysical Prospecting, Vol. 31, PP. 524-537.India, Andhra PradeshGeophysics
DS1985-0535
1985
Podgaets, A.V.Podgaets, A.V., Kotelnik, D.D., Voitkovs, I.B., Ilupin, I.P.Genesis and Pecularities of the Transformation of Magnetite from Yakutian Kimberlites. #2Doklady Academy of Sciences AKAD. NAUK SSSR., Vol. 282, No. 5, PP. 1238-1242.RussiaBlank
DS1985-0536
1985
Podgaetskii, A.V.Podgaetskii, A.V., Koteinikov, D.D., Voitkovskii, I.B., Ilupin.Genesis and Pecularities of the Transformation of Magnetite from Yakutian Kimberlites. #1Doklady Academy of Sciences AKAD. NAUK SSSR., Vol. 282, No. 2, PP. 1238-1242.Russia, YakutiaMineralogy
DS1988-0740
1988
Podgaetskii, A.V.Voitkovskii, Yu.B., Kotelnikov, D.D., Podgaetskii, A.V., Ilupin, I.P.Varieties of magnetite from the kimberlites of Yakutia.(Russian)Zap. Vses. Mineral. O-Va, (Russian), Vol. 116, No. 4, pp. 458-465RussiaBlank
DS1986-0903
1986
Podgaetskiy, A.V.Zinchuk, N.N., Kotelnikov, D.D., Podgaetskiy, A.V., Voitkovskiy, Yu.B.Sequence of variation on some iron containing minerals From kimberlites at differemt stage of supergene process.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR (Russian), Vol. 290, No. 6, pp. 1467-1471RussiaMineralogy
DS1987-0583
1987
Podgayetskiy, A.V.Podgayetskiy, A.V., Kotelnikov, D.D., Voytkovskiy, Yu.B., IlupinOrigin and alterations of magnetite from kimberlites of YakutiaDoklady Academy of Sciences Acad. Science USSR Earth Sci. Section, Vol. 282, No. 1-6, pp. 167-172RussiaGeochemistry, Magnetite
DS1988-0782
1988
Podgayetskiy, A.V.Zinchuk, N.N., Kotelnikov, D.D., Podgayetskiy, A.V., VoytkovskiySequence of alteration of some iron bearing kimberlite minerals indifferent stages of the supergene processDoklady Academy of Science USSR, Earth Science Section, Vol. 290, No. 1-6, March pp. 196-199RussiaMagnetics, Geophysics, Yakutia
DS1993-1675
1993
Podgayetskiy, A.V.Viytkovskiy, Yu.B., Podgayetskiy, A.V., Zinchuk, N.N., KotelnikovIlmenite xenoliths and groundmass of kimberlite from the Mir and Sytykanskaya pipes.Doklady Academy of Sciences USSR, Earth Science Section, Vol. 317, pp. 191-195.Russia, YakutiaXenolith mineralogy, Deposits
DS1993-1684
1993
Podgayetskiy, A.V.Voytkovskiy, Yu.B., Podgayetskiy, A.V., Zinchuk, N.N., KotelnikovIlmenite in xenoliths and groundmass of kimberlite from the Mir and Sytykanskaya pipes.Doklady Academy of Sciences USSR, Earth Science Section, Vol. 317, No. 5, pp. 191-195.Russia, Commonwealth of Independent States (CIS), YakutiaXenoliths, Malaya Botuobiya field
DS1975-0871
1978
Podgornikh, N.M.Sobolev, V.S., Panina, L.I., Podgornikh, N.M.Crystallization Temperatures of Several Carbonatite Minerals from Siberia.I Symposio International De Carbonatitos, PP. 215-219.RussiaPetrology, Mineral Chemistry
DS201412-0672
2013
Podgornova, S.T.Perchuk, A.L., Shur, M.Yu., Yapaskurt, V.O., Podgornova, S.T.Experimental modeling of mantle metasomatism coupled with eclogitization of crustal material in a subduction zone.Petrology, Vol. 21, 6, pp. 579-598.MantleSubduction
DS200512-0746
2001
Podgornych, N.M.Morikiyo, T., Miyazaki, T., Kagami, H., Vladykin, N.V., Chernysheva, E.A., Panina, L.I., Podgornych, N.M.Sr Nd C and O isotope characteristics of Siberian carbonatites.Alkaline Magmatism and the problems of mantle sources, pp. 69-84.Russia, SiberiaGeochronology
DS1970-0972
1974
Podgornykh, N.M.Panina, L.I., Podgornykh, N.M.Temperature of Formation of Melilite Rocks of the Turiy Peninsula.Doklady Academy of Science USSR, Earth Science Section., Vol. 217, No. 1-6, PP. 141-144.RussiaGenesis
DS1975-0155
1975
Podgornykh, N.M.Panina, L.I., Podgornykh, N.M.Inclusions of Melt in Minerals from Carbonatite of the Beloziminskiy Pluton.Doklady Academy of Science USSR, Earth Science Section., Vol. 223, No. 1-6, PP. 165-167.RussiaKimberlite
DS1994-1897
1994
Podiadchikov, Y.Weinberg, R.F., Podiadchikov, Y.Diapiric ascent of magmas through power law crust and mantleJournal of Geophysical Research, Vol. 99, No. B5, May 10, pp. 9543-9560.MantleMagmas, Plumes, volcanism
DS201906-1283
2018
Podkamenny, Y.A.Chanturia, V.A., Dvoichenkova, G.P., Morozov, V.V., Kovalchuk, O.E., Podkamenny, Y.A., Yakolev, V.N.Experimental justification of luminophore composition for indication of diamonds in x-ray luminescence separation of kimberlite ore.Journal of Mineral Science, Vol. 54, 3, pp. 458-465.Russialuminescence

Abstract: Organic and inorganic luminophores of similar luminescence parameters as diamonds are selected. Indicators, based on the selected luminophores, are synthesized. Spectral and kinetic characteristics of luminophores are experimentally determined for making a decision on optimal compositions to ensure maximum extraction of diamonds in X-ray luminescence separation owing to extra recovery of non-luminescent diamond crystals. As the components of luminophore-bearing indicators, anthracene and K-35 luminophores are selected as their parameters conform luminescence parameters of diamonds detected using X-ray luminescence separator with standard settings.
DS202111-1761
2020
Podkamennyi, Yu.A.Chanturia, V.A., Dvoichenkova, G.P., Morozov, V.V., Kovalchuk, O.E., Podkamennyi, Yu.A., Yakolev, V.N.Selective attachment of luminophore-bearing emulsion at diamonds - mechanism analysis and mode selection.Journal of Mining Science, Vol. 56, 1, pp. 96-103, 8p. PdfRussialuminescence

Abstract: The authors present an efficient modification method of X-ray fluorescence separation with mineral and organic luminophores used to adjust spectral and kinetic characteristics of anomalously luminescent diamonds. The mechanism of attachment of luminophores at diamonds and hydrophobic minerals is proved, including interaction between the organic component of emulsions and the hydrophobic surface of a treated object and the concentration of insoluble luminophore grains at the organic and water interface. Selective attachment of the luminophore-bearing organic phase of emulsion at the diamond surface is achieved owing to phosphatic dispersing agents. Tri-sodium phosphate and sodium hexametaphosphate added to emulsion reduce attachment of the luminophore-bearing organic phase at the surface of kimberlite minerals. It is shown that phosphate concentration of 1.0-1.5 g/l modifies and stabilizes spectral and kinematic parameters of kimberlite mineral on the level of initial values. This mode maintains the spectral and kinematic characteristics of anomalously luminescent diamonds at the wanted level to ensure extraction of diamonds to concentrate.
DS1994-0437
1994
Podkuiko, Y.A.Dobrzhinetskaya, L.F., Braun, I.V., Sheskel, G.G., Podkuiko, Y.A.Geology and structure of diamond bearing rocks of the Kokchetav Massif, Kazahkstan.Tectonophysics, Vol. 233, No. 3-4, May 30, pp. 293-313.Russia, KazahkstanStructure, Diamondiferous rocks
DS1998-0924
1998
Podkuiko, Y.A.Makhotkin, I.L., Podkuiko, Y.A.Kimberlites of the Polar Ural region: a new geochemical type of kimberlitic rocks depleted in trace elements.Doklady Academy of Sciences, Vol. 361A, No. 6, pp. 993-8.Russia, UralsGeochemistry
DS2001-0719
2001
Podkuiko, Y.A.Mahotkin, I.L., Podkuiko, Y.A., Zhuravlev, D.Z.Early Paleozoic kimberlite melnoite magmatism of the Pri-Polar Urals and thAlkaline Magmatism -problems mantle source, pp. 151-60.GlobalMelnoite, Tectonics
DS200512-0677
2001
Podkuiko, Yu.A.Mahotkin, I.L., Podkuiko, Yu.A., Zhuravlev, D.Z.Early Paleozoic kimberlite melnoite magmatism of the Pre-Polar Urals and the geodynamic formation model.Alkaline Magmatism and the problems of mantle sources, pp. 151-160.Russia, UralsMelnoites
DS1993-1211
1993
Podkuyko, A.Pechnikov, V.A., Bobrov, V.A., Podkuyko, A.Isotopic compositions of diamond and accompanying graphite in north Kazakstan metamorphic rocks.Geochemistry International, Vol. 30, No. 8, pp. 153-157.Russia, KazakhstanGeochronology, Diamond morphology
DS2000-0162
2000
Podlachikov, Yu.Y.Cloetingh, S., Podlachikov, Yu.Y.Perspectives on tectonic modelingTectonophysics, Vol. 320, No. 3-4, May pp. 169-74.GlobalTectonics, Models
DS1994-1390
1994
Podlachikov, Yu.Yu.Podlachikov, Yu.Yu., Poliakov, A.N.B., Yuen, D.A.The effect of lithospheric phase transitions on subsidence of extending continental lithospheres.Earth and Planet. Science Letters, Vol. 124, No. 1-4, June pp. 95-104.MantleSubduction
DS201412-0599
2013
Podladchikov, Y.Moulas, E., Podladchikov, Y., Aranovich, L., Kostopoulos, D.The problem of depth in geology: when pressure does not translate into depth.Petrology, Vol. 21, 6, pp. 527-538.MantleDynamics
DS1995-2044
1995
Podladchikov, Y.Y.Weinberg, R.F., Podladchikov, Y.Y.The rise of solid state diapirsJournal of Structural Geology, Vol. 17, No. 8, pp. 1183-1195.GlobalDiapirs, Magma -crust not specific to kimberlites
DS1998-1511
1998
Podladchikov, Y.Y.Van Balen, R.T., Podladchikov, Y.Y., Cloetingh, S.A.P.L.A new multilayered model for intraplate stress induced differential subsidence of faulted lithosphere..Tectonics, Vol. 17, No. 6, Dec. pp. 938-54.GlobalBasins - rift, Subduction
DS200512-0941
2005
Podladchikov, Y.Y.Schmalholz, S.M., Podladchikov, Y.Y., Jamtveit, B.Structural softening of the lithosphere.Terra Nova, Vol. 17, 1, pp. 66-72.MantleTectonics
DS200812-0450
2008
Podladchikov, Y.Y.Hartz, E.H., Podladchikov, Y.Y.Toasting the jelly sandwich: the effect of shear hearting on lithospheric geotherms and strength.Geology, Vol. 36, 4, pp. 331-4.MantleGeothermometry
DS200812-1070
2008
Podladchikov, Y.Y.Simon, N.S.C., Podladchikov, Y.Y.The effect of mantle composition on density in the extending lithosphere.Earth and Planetary Science Letters, Vol. 272, 1-2, July 30, pp. 148-157.MantleDensity
DS201012-0051
2010
Podladchikov, Y.Y.Beuchert, M.J., Podladchikov, Y.Y.Viscoelastic mantle convection and lithospheric stresses.Geophysical Journal International, in press availableMantleGeotectonics
DS201012-0052
2010
Podladchikov, Y.Y.Beuchert, M.J., Podladchikov, Y.Y., Simon, N.S.C., Rupke, L.H.Modeling of craton stability using a viscoelastic rheology.Journal of Geophysical Research, Vol. 115, B 11, B11413.MantleRheology
DS201012-0682
2010
Podladchikov, Y.Y.Semprich, J., Simon, N.S.C., Podladchikov, Y.Y.Density variations in the thickened crust as a function of pressure, temperature and composition.International Journal of Earth Sciences, Vol. 99, 7, pp. 1487-1510.MantleGeophysics
DS201711-2507
2017
Podladchikov, Y.Y.Chu, X., Ague, J.J., Podladchikov, Y.Y., Tian, M.Ultrafast eclogite formation via melting induced overpressure.Earth and Planetary Science Letters, Vol. 479, pp. 1-17.Mantleeclogite

Abstract: The conventional wisdom holds that metamorphic reactions take place at pressures near-lithostatic so that the thermodynamic pressure, reflected by the mineral assemblage, is directly correlated with depth. On the other hand, recent field-based observations and geodynamic simulations suggest that heterogeneous stress and significant pressure deviations above lithostatic (overpressure) can occur in Earth's crust. Here we show that eclogite, normally interpreted to form at great depths in subduction zones and Earth's mantle, may form at much shallower depths via local overpressure generated in crustal shear zones. The eclogites studied crop out as lenses hosted by felsic paragneiss in a sheared thrust slice and represent a local pressure and temperature anomaly in the Taconic orogenic belt, southern New England. Sharply-defined chemical zones in garnet, which record ?5 kbar pressure rise and fall accompanied by a temperature increase of 150-200?°C, demonstrate extremely short timescales of diffusion. This requires anomalously fast compression (?500 yrs) and decompression. We use coupled phase equilibria and garnet diffusion forward modeling to fit the observed garnet profiles and test the likely paths using a Monte Carlo-type approach, accounting for off-center sectioning of garnet. The simulation shows that a ?5 kbar pressure increase after the temperature peak is necessary to reproduce the garnet zoning. Remarkably, this post-peak-T compression (from 9 kbar to 14 kbar) lasted only ?500 yrs. If the compression was due to burial along a lithostatic pressure gradient, the descent speed would exceed 30 m?yr?1, defying any observed or modeled subduction rates. Local overpressure in response to partial melting in a confined volume (Vrijmoed et al., 2009) caused by transient shear heating can explain the ultra-fast compression without necessitating burial to great depth.
DS1992-1183
1992
Podladchikov, Y.Yu.Perchuk, L.L., Podladchikov, Y.Yu., Polyakov, A.N.Hydrodynamic modelling of some metamorphic processesJournal of Metamorphic Geology, Vol. 10, No. 3, May pp. 311-320GlobalMetamorphic processes, Modelling
DS1993-0917
1993
Podladchikov, Yu.Yu.Litvinovsky, B.A., Podladchikov, Yu.Yu.Crustal anatexis during the influx of mantle volatilesLithos, Vol. 30, pp. 93-107MantleMantle model, Silicic magma
DS1975-0833
1978
Podlesskiy, K.K.Podlesskiy, K.K.Problem of Iron and Magnesium Partition between Coexisting Garnets and Spinels.Doklady Academy of Science USSR, Earth Science Section., Vol. 241, No. 1-6, PP. 156-159.RussiaKimberlite
DS201808-1757
2018
Podmogov, Y.Kertsman, V., Moilanen, J., Podmogov, Y.Special place of airborne electromagnetic survey in detailed exploration of kimberlites in the conditions of the Angolan shield. CatocaAEM2018/7th International Workshop on Airborne electromagnetics, Held June 17-20, 3p.Africa, Angolageophysics - EM
DS1995-0397
1995
Podmore, D.C.Dawes, P.R., Smithies, R.H., Centofanti, J., Podmore, D.C.Sunrise Hill unconformity: a newly discovered regional hiatus between Archean granites and greenstones ..Australian Journal of Earth Sciences, Vol. 42, pp. 635-639AustraliaPilbara Craton, Greenstone belt
DS1982-0498
1982
Podmore, F.Podmore, F.Progress Report: the First Bouguer Anomaly Map of ZimbabweGeological Society of South Africa Transactions, Vol. 85, PP. 127-133.ZimbabweGeophysics, Gravity, Geology
DS1990-1125
1990
Podmore, F.Nyblade, A.A., Pollack, H.N., Jones, D.L., Podmore, F.Terrestrial heat flow in east and southern AfricaJournal of Geophysical Research, Vol. 95, No. B 11, October 10, pp. 17371-17384South AfricaHeat Flow, Mantle
DS200412-1558
2004
Podolefsky, N.S.Podolefsky, N.S., Zhong, S., McNamara, A.K.The anisotropic and rheological structure of the oceanic upper mantle from a simple model of plate shear.Geophysical Journal International, Vol. 158, 1, pp. 287-296.MantleGeodynamics
DS202105-0783
2021
Podolsky, M.Podolsky, M.Primary asset development standard model - deposit to reserve desktop to feasibility governance - example Gahcho Kue mine, Northwest Territories, Canada.Vancouver Kimberlite Cluster recorded,  https://youtu.be/ GMyoKHoQrJECanada, Northwest Territoriesdeposit - Gahcho Kue

Abstract: A primary rock-hosted diamond Deposit to Reserve Asset Development Standard model governed under the 2014 Canadian Institute of Mining, Metallurgy and Petroleum definition standards on Mineral Resources and Reserves and 2016 Toronto Stock Exchange National Instrument 43-101 - Standards of Disclosure for Mineral Projects, is presented and discussed. The Gahcho Kué Mine De Beers Canada - Mountain Province Diamonds joint venture project roadmap from exploration commencing in 1992 to definitive Feasibility Study in 2010 is reviewed under the incorporated 2003 Guidelines for the Reporting of Diamond Exploration Results and 2008 Estimation of Mineral Resources and Mineral Reserves Best Practices Guidelines for Rock Hosted Diamonds. Karowe and Ekati-Sable diamond mines histories are also compared. The Asset Development Standard model utilizes a published De Beers system of kimberlite Deposit to Reserves geo-scientific scorecard classification, that is aligned with reporting of Desktop, Conceptual and Pre-Feasibility to Feasibility Studies.
DS202201-0034
2021
Podolsky, M.Podolsky, M.What is a primary rock hosted diamond deposit, resource and reserve? Desktop to feasibility study governance example under CIM and NI 43-101 guidelines and definition standards and De Beers scorecard classification, Gahcho Kue mine, Northwest Territories.GAC/MAC Meeting UWO, 1p. Abstract p. 245.Canada, Northwest Territoriesdeposit - Gahcho Kue

Abstract: A primary Rock Hosted Diamond Deposit, Resource and Reserve Asset Development Standard (ADS) model governed under the 2014 Canadian Institute of Mining, Metallurgy and Petroleum (CIM) Definition Standards on Mineral Resources and Reserves and 2016 Toronto Stock Exchange National Instrument 43-101 - Standards of Disclosure for Mineral Projects (NI 43-101), is presented. The De Beers Canada - Mountain Province Diamonds joint venture Gahcho Kué Project roadmap from exploration commencing in 1992, reporting of initial Desktop Study in 2000 to definitive Feasibility Study in 2010 and 2014 Study update is reviewed under the incorporated 2003 Guidelines for the Reporting of Diamond Exploration Results and 2008 Estimation of Mineral Resources and Mineral Reserves Best Practices Guidelines for Rock Hosted Diamonds. A published De Beers system of diamond Deposit to Resource geo-scientific scorecard classification is summarized and compared against the CIM and NI 43-101 Definition Standards and reporting guidelines. The ADS governance model utilizes the De Beers classification system, that is aligned with reporting of Desktop, Conceptual and Pre-Feasibility to Feasibility Studies.
DS200812-0903
2008
Podolsky, M.H.Podolsky, M.H., Seller, M.H., Kryvoshlyk, I.N., Seghedi, I., Maicher, D.Whole rock geochemistry investigations of the 5034 and Tuzo kimberlites and potential applications to improving geology and resource models, Gahcho Kue project, NWTNorthwest Territories Geoscience Office, p. 72. abstractCanada, Northwest TerritoriesDeposit - Gahcho Kue
DS1960-0803
1967
Podorina, YE. K.Burkov, V.V., Podorina, YE. K.First Dat a on Rare Earths in KimberliteDoklady Academy of Science USSR, Earth Science Section., Vol. 171, No. 1-6, PP. 215-219.RussiaBlank
DS1988-0076
1988
Podosek, F.A.Bowring, S.A., Arvidson, R.A., Podosek, F.A.The Missouri gravity low: evidence for a cryptic suture?Geological Society of America Abstracts with Program, Vol. 20, No. 2, January p. 91. Sth. Central, LawrenceMissouriBlank
DS1989-0156
1989
Podosek, F.A.Bowring, S.A., King, J.E., Housh, T.B., Isachsen, C.E., Podosek, F.A.Neodymium and lead isotope evidence for enriched early Archean crust in North AmericaNature, Vol. 340, No. 6230, July 20, pp. 222-224North AmericaGeochronology, Archean
DS1989-0157
1989
Podosek, F.A.Bowring, S.A., Podosek, F.A.neodymium isotope evidence from Wopmay Orogen for 2.0-2.4 Gacrust in Western north AmericaEarth and Planetary Science Letters, Vol. 94, pp. 217-230. Database # 18132Northwest TerritoriesOrogeny -Wopmay, Geochronology
DS1960-0523
1965
Podporina, YE. K.Burkov, V.V., Podporina, YE. K.Rare Elements in Kimberlite RocksDoklady Academy of Science USSR, Earth Science Section., Vol. 163, No. 1-6, PP. 169-172.RussiaBlank
DS201212-0380
2012
Podurets, K.M.Kovalenko, E.S., Shiryaev, A.A., Kaloyan, A.A., Podurets, K.M.X-ray tomographic study of spatial distribution of Micro inclusions in natural fibrous diamonds.Diamond and Related Materials, Vol. 30, pp. 31-41.TechnologyDiamond inclusion
DS1996-1605
1996
Podvigina, O.M.Zheligovskiy, V.A., Podvigina, O.M., Sadovskiy, A.M.Some properties of crustal structure in California as indicated by topography and bouguer anomalies...Doklady Academy of Sciences, Vol. 336, pp. 15-20.CaliforniaGeophysics -seismics, Tectonics -faulting
DS201812-2866
2018
Podvysotski, V.Podvysotski, V.Primary diamond placers of Cretaceous age in the Juina area. Mato Grosso State, Brazil7th Symposio Brasileiro de Geologia do Diamante , Title only South America, Brazil, Mato Grossodeposit - Juina
DS1995-1505
1995
Podvysotski, V.T.Podvysotski, V.T.Regularities of allocation and conditions of formation of ancient sedimentary collectors and diamond placers.Proceedings of the Sixth International Kimberlite Conference Almazy Rossii Sakha abstract, p. 32.Russia, YakutiaAlluvials, Placers, Deposit -Siberian Platform
DS201509-0419
2015
Podvysotski, V.T.Podvysotski, V.T., Bashinsli, S.I.A new dat a about Cretaceous Diamondiferous conglomerates in Juin a Province ( Mato Grosso state, Brazil).Vestnik VGU, Seria Geologia, IN RUSSIAN, No. 2, pp. 73-76.South America, Brazil, Mato GrossoDeposit - Juina area
DS1987-0584
1987
Podvysotskii, V.T.Podvysotskii, V.T.Ilmenite and titanomagnetite in the rocks of trapped formation of the Malo-Botuobinsky and Alakit-Markhinsky kimberlitic fields of Yakutian ProvinceDoklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 297, No. 3, pp. 690-695RussiaBlank
DS1987-0585
1987
Podvysotskii, V.T.Podvysotskii, V.T., Belov, E.N., Bessolitsyn, A.E., Lozovik, V.K.On the pre-middle carboniferous collector of kimberlitic minerals in The southwestern part of the Yakutian kimberliticprovinceDoklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 297, No. 1, pp. 170-174RussiaBlank
DS1998-1172
1998
Podvysotskii, V.T.Podvysotskii, V.T.The conditions of formation of sedimentary collectors and diamond placer son the Siberian PlatformDoklady Academy of Sciences, Vol. 361A, No. 6, pp. 790-4.Russia, SiberiaAlluvials, placers
DS200612-1173
2005
Podvysotskii, V.T.Romanko, E.F., Egorov, N.N., Podvysotskii, V.T., Sablukov, S.M., Dyakonov, D.B.A new Diamondiferous kimberlite region in southwestern Angola.Doklady Earth Sciences, Vol. 403A, 6, pp. 817-821.Africa, AngolaDiamond exploration
DS1982-0499
1982
Podvysotskiy, V.T.Podvysotskiy, V.T., Vladimirov, B.M., Ivanov, S.I., Kotelnikov.Serpentinization of KimberliteDoklady Academy of Sciences ACAD. NAUK USSR, EARTH SCI. SECTION., Vol. 256, No. 1-6, PP. 87-90.RussiaAlteration, Petrography
DS1984-0590
1984
Podvysotskiy, V.T.Podvysotskiy, V.T., Yegranova, I.G., Feoktistova, L.P.Magnetite in KimberliteDoklady Academy of Science USSR, Earth Science Section., Vol. 266, No. 1-6, MAY PP. 157-159.RussiaMineralogy, Inclusions, Udachanaya, Malaya Botuobuya, Daldyn
DS1985-0537
1985
Podvysotskiy, V.T.Podvysotskiy, V.T.Serpentine-carbonate Mineralization in KimberlitesInternational Geology Review, Vol. 27, No. 7, July pp. 810-823RussiaCalcite, Udachnaya, Carbonate
DS1985-0538
1985
Podvysotskiy, V.T.Podvysotskiy, V.T.Serpentine Carbonate Mineralization in KimberlitesInternational Geology Review, Vol. 27, No. 7, July pp. 810-823RussiaMineralogy
DS1985-0539
1985
Podvysotskiy, V.T.Podvysotskiy, V.T., Belov, E.N., Bessoliyisyn, A.E., Bialyi, V.I.Age of kimberlites and erosion truncation magnitude of the Malo- Botuoba region southwest Yakutia.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 285, No. 5, pp. 1174-1177RussiaGeochronology
DS1987-0586
1987
Podvysotskiy, V.T.Podvysotskiy, V.T., Belov, Ye.N., Bessolitsyn, A.Ye., et al.Kimberlitic minerals of the reservoir rocks of pre-middle carboniferous Of the southwest of Yakutia Province.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 297, No. 1, pp. 170-174RussiaPetrology, Ultramafics
DS1987-0587
1987
Podvysotskiy, V.T.Podvysotskiy, V.T., Markov, A.S.Ilmenite and titanomagnetite in rocks of the Traprock association in the Malaya Botuobuya and the Alakit-Markha kimberlite fields, YakutiaDoklady Academy of Science USSR, Earth Science Section, Vol. 297, No. 6, Nov-Dec., pp. 144-148RussiaIlmenites, Titanomagnetite
DS1998-1173
1998
Podvysotsky, V.T.Podvysotsky, V.T., Zuev, V.M., Nikulin, LelyoukhConception of formation of magmatogene and terrigenous diamondiferous formations ancient platforms - forecast7th. Kimberlite Conference abstract, pp. 696-8.RussiaCraton, Magmatism
DS2000-0770
2000
Podvysotsky, V.T.Podvysotsky, V.T.Stages of shaping of magmatogene and terrigene Diamondiferous formations of the Siberian PlatformIgc 30th. Brasil, Aug. abstract only 1p.Russia, SiberiaMagmatism, Kimberlites and placers, alluvials
DS200712-0286
2007
Podvysotsky, V.T.Egorov, K.N., Ramnko, E.F., Podvysotsky, V.T., Sabulukov, S.M., Garanin, V.K., Dyakonov, D.B.New dat a on kimberlite magmatism in southwestern Angola.Russian Geology and Geophysics, Vol. 48, 4, pp. 323-336.Africa, AngolaMagmatism - kimberlites
DS1988-0149
1988
Podwysocki, M.Crowley, J., Rowan, M., Podwysocki, M., Meyer, D.Evaluation of airborne visible/infrared imaging spectrometer dat a of the Mountain Pass, California carbonatite complexNational Technical Information Service N89-22169/1, Jet Propulsion Lab. Calif. Institute Tech. Proceedings of, pp. 155-161CaliforniaCarbonatite, Remote Sensing
DS200712-0471
2007
Podyachev, B.Izbekov, E., Podyachev, B., Afanasev, V.Signs of symmetric diamond concentration in the eastern Siberian Platform.Doklady Earth Sciences, Vol. 411, 9, pp. 1339-1340.RussiaDiamond genesis
DS200712-0472
2007
Podyachev, B.Izbekov, E., Podyachev, B., Afanasev, V.Signs of symmetric diamond concentration in the eastern Siberian Platform.Doklady Earth Sciences, Vol. 411, 9, pp. 1339-1340.RussiaDiamond genesis
DS200712-0473
2006
Podyachev, B.P.Izbekov, E.D., Podyachev, B.P., Afanasev, V.P.Signs of symmetric diamond concentration in the eastern Siberian platform.Doklady Earth Sciences, Vol. 411, 9, Nov-Dec. pp. 1339-1340.Russia, SiberiaDiamond genesis
DS201012-0316
2009
Podyachev, B.P.Izbekov, E.D., Podyachev, B.P., Surnin, A.A.Minerageny ( spelling) of the Yakut buried basement uplift in the Siberian platform.Doklady Earth Sciences, Vol. 425, 2, April pp. 378-379.Russia, SiberiaTectonics
DS200612-1174
2006
Poe, B.T.Romano, C., Poe, B.T., Kreidie, N., McCammon, C.A.Electrical conductivities of pyrope almandine garnets up to 19 GPa and 1700 C.American Mineralogist, Vol. 91, 9, pp. 1371-1377.MantleDiscontinuity
DS202004-0534
2020
Poe, B.T.Stagno, V., Stopponi, V., Kono, Y., D'Arco, A., Lupi, S., Romano, C., Poe, B.T., Foustoukos, D.J., Scarlato, P., Manning, C.E.The viscosity and atomic structure of volatile bearing melililititic melts at high pressure and temperature and the transport of deep carbon.Minerals MDPI, Vol. 10, 267 doi: 10.23390/min10030267 14p. PdfMantleMelililite, carbon

Abstract: Understanding the viscosity of mantle-derived magmas is needed to model their migration mechanisms and ascent rate from the source rock to the surface. High pressure-temperature experimental data are now available on the viscosity of synthetic melts, pure carbonatitic to carbonate-silicate compositions, anhydrous basalts, dacites and rhyolites. However, the viscosity of volatile-bearing melilititic melts, among the most plausible carriers of deep carbon, has not been investigated. In this study, we experimentally determined the viscosity of synthetic liquids with ~31 and ~39 wt% SiO2, 1.60 and 1.42 wt% CO2 and 5.7 and 1 wt% H2O, respectively, at pressures from 1 to 4.7 GPa and temperatures between 1265 and 1755 °C, using the falling-sphere technique combined with in situ X-ray radiography. Our results show viscosities between 0.1044 and 2.1221 Pa•s, with a clear dependence on temperature and SiO2 content. The atomic structure of both melt compositions was also determined at high pressure and temperature, using in situ multi-angle energy-dispersive X-ray diffraction supported by ex situ microFTIR and microRaman spectroscopic measurements. Our results yield evidence that the T-T and T-O (T = Si,Al) interatomic distances of ultrabasic melts are higher than those for basaltic melts known from similar recent studies. Based on our experimental data, melilititic melts are expected to migrate at a rate ~from 2 to 57 km•yr?1 in the present-day or the Archaean mantle, respectively.
DS1989-1229
1989
Poelchau, H.S.Poelchau, H.S., Mann, U.Evolution of sedimentary basins- the integrated modeling approach. AnintroductionGeologische Rundschau, Vol. 78, No. 1, pp. 1-6. Database # 18160GlobalBasins, Modeling
DS201312-0937
2013
Poelchau, M.H.Vasconcelos, M.A.R., Crosta, A.P., Reimold, W.U., Goes, A.M., Kenkmann, T., Poelchau, M.H.The Serra da Cangalha impact structure, Brazil: geological, stratigraphic and petrographic aspects of a recently confirmed impact structure.Journal of South American Earth Sciences, Vol. 45, pp. 316-330.South America, BrazilMeteorite
DS201412-0452
2014
Poelchau, M.H.Kenkmann, T., Poelchau, M.H., Wulf, G.Structural geology of impact craters.Journal of Structural Geology, Vol. 62, pp. 156-182.GlobalReview - impact cratering
DS1940-0187
1948
Poese, W.Poese, W.Gem Stone LoreColorado Springs. Mineral Book Co., 54P.United StatesKimberlite
DS200712-0686
2007
Pogge Von Strandemann, P.A.E.Marschall, H.R., Pogge Von Strandemann, P.A.E., Seitz, H-M., Elliott, T., Niu, Y.The lithium isotopic composition of orogenic eclogites and deep subduction zones.Earth and Planetary Science Letters, In press availableMantleSubduction
DS200812-0715
2008
Pogge Von Strandmann, A.E.Marschall, H.R., Pogge Von Strandmann, A.E.Li and Mg exchange between eclogite lenses and their host rocks: evidence from isotope profiles.Goldschmidt Conference 2008, Abstract p.A594.TechnologyEclogite
DS201712-2693
2017
Pogge von Strandmann, A.E.Ionov, D.A., Doucet, L.S., Pogge von Strandmann, A.E., Golovin, A.V., Korsakov, A.V.Links between deformation, chemical enrichment and Li isotope compositions in the lithospheric mantle of the central Siberian craton.Chemical Geology, Vol. 475, pp. 105-121.Russia, Siberiacraton, geochronology

Abstract: We report the concentrations ([Li]) and isotopic compositions of Li in mineral separates and bulk rocks obtained by MC-ICPMS for 14 previously studied garnet and spinel peridotite xenoliths from the Udachnaya kimberlite in the central Siberian craton as well as major and trace element compositions for a new suite of 13 deformed garnet peridotites. The deformed Udachnaya peridotites occur at > 5 GPa; they are metasomatized residues of melt extraction, which as a group experienced greater modal and chemical enrichments than coarse peridotites. We identify two sub-groups of the deformed peridotites: (a) mainly cryptically metasomatized (similar to coarse peridotites) with relatively low modal cpx (< 6%) and garnet (< 7%), low Ca and high Mg#, sinusoidal REE patterns in garnet, and chemically unequilibrated garnet and cpx; (b) modally metasomatized with more cpx and garnet, higher Ca, Fe and Ti, and equilibrated garnet and cpx. The chemical enrichments are not proportional to deformation degrees. The deformation in the lower lithosphere is caused by a combination of localized stress, heating and fluid ingress from the pathways of ascending proto-kimberlite melts, with metasomatic media evolving due to reactions with wall rocks. Mg-rich olivine in spinel and coarse garnet Udachnaya peridotites has 1.2-1.9 ppm Li and ?7Li of 1.2-5.0‰, i.e. close to olivine in equilibrated fertile to depleted off-craton mantle peridotites from literature data, whereas olivine from the deformed peridotites has higher [Li] (2.4-7.5 ppm) and a broader range of ?7Li (1.8-11.6‰), which we attribute to pre-eruption metasomatism. [Li] in opx is higher than in coexisting olivine while ?7LiOl-Opx (?7LiOl ? ?7LiOpx) ranges from ? 6.6 to 7.8‰, indicating disequilibrium inter-mineral [Li] and Li-isotope partitioning. We relate these Li systematics to interaction of lithospheric peridotites with fluids or melts that are either precursors of kimberlite magmatism or products of their fractionation and/or reaction with host mantle. The melts rich in Na and carbonates infiltrated, heated and weakened wall-rock peridotites to facilitate their deformation as well as produce high [Li] and variable, but mainly high, ?7Li in olivine. The carbonate-rich melts preferentially reacted with the opx without achieving inter-mineral equilibrium because opx is consumed by such melts, and because of small volumes and uneven distribution of the metasomatic media, as well as short time spans between the melt infiltration and the capture of the wall-rock fragments by incoming portions of ascending kimberlite magma as xenoliths. Trapped interstitial liquid solidified as cryptic components responsible for high [Li] and the lack of ?7Li balance between olivine and opx, and bulk rocks. Unaltered ?26Mg values (0.20-0.26‰) measured in several olivine separates show no effects of the metasomatism on Mg-isotopes, apparently due to high Mg in the peridotites.
DS200812-0904
2008
Pogge Von Strandmann, P.A.E.Pogge Von Strandmann, P.A.E., Elliott, T., Ionov, D., Niu, Y.Li and Mg isotopes in the mantle: heterogeneity or diffusion?Goldschmidt Conference 2008, Abstract p.A754.MantleSubduction
DS201710-2256
2017
Pogge von Strandmann, P.A.E.Pogge von Strandmann, P.A.E., Desrochers, A., Murphy, M.J., Finlay, A.J., Selby, D., Lenton, T.M.Global climate stabilisation by chemical weathering during the Hirnantian glaciation.Geochemical Perspectives Letters, Vol. 3, pp. 230-237.Canada, Quebec, Anticosti Islandcarbon cycle

Abstract: Chemical weathering of silicate rocks is a primary drawdown mechanism of atmospheric carbon dioxide. The processes that affect weathering are therefore central in controlling global climate. A temperature-controlled “weathering thermostat” has long been proposed in stabilising long-term climate, but without definitive evidence from the geologic record. Here we use lithium isotopes (?7Li) to assess the impact of silicate weathering across a significant climate-cooling period, the end-Ordovician Hirnantian glaciation (~445 Ma). We find a positive ?7Li excursion, suggestive of a silicate weathering decline. Using a coupled lithium-carbon model, we show that initiation of the glaciation was likely caused by declining CO2 degassing, which triggered abrupt global cooling, and much lower weathering rates. This lower CO2 drawdown during the glaciation allowed climatic recovery and deglaciation. Combined, the data and model provide support from the geological record for the operation of the weathering thermostat.
DS201801-0024
2017
Pogge von Strandmann, P.A.E.Ionov, D.A., Doucet, L.S., Pogge von Strandmann, P.A.E., Golovin, A.V., Korsakov, A.V.Links between deformation, chemical enrichments and Li-isotope compositions in the lithospheric mantle of the central Siberian craton.Chemical Geology, Vol. 475, pp. 105-121.Russiadeposit - Udachnaya

Abstract: We report the concentrations ([Li]) and isotopic compositions of Li in mineral separates and bulk rocks obtained by MC-ICPMS for 14 previously studied garnet and spinel peridotite xenoliths from the Udachnaya kimberlite in the central Siberian craton as well as major and trace element compositions for a new suite of 13 deformed garnet peridotites. The deformed Udachnaya peridotites occur at > 5 GPa; they are metasomatized residues of melt extraction, which as a group experienced greater modal and chemical enrichments than coarse peridotites. We identify two sub-groups of the deformed peridotites: (a) mainly cryptically metasomatized (similar to coarse peridotites) with relatively low modal cpx (< 6%) and garnet (< 7%), low Ca and high Mg#, sinusoidal REE patterns in garnet, and chemically unequilibrated garnet and cpx; (b) modally metasomatized with more cpx and garnet, higher Ca, Fe and Ti, and equilibrated garnet and cpx. The chemical enrichments are not proportional to deformation degrees. The deformation in the lower lithosphere is caused by a combination of localized stress, heating and fluid ingress from the pathways of ascending proto-kimberlite melts, with metasomatic media evolving due to reactions with wall rocks. Mg-rich olivine in spinel and coarse garnet Udachnaya peridotites has 1.2-1.9 ppm Li and ?7Li of 1.2-5.0‰, i.e. close to olivine in equilibrated fertile to depleted off-craton mantle peridotites from literature data, whereas olivine from the deformed peridotites has higher [Li] (2.4-7.5 ppm) and a broader range of ?7Li (1.8-11.6‰), which we attribute to pre-eruption metasomatism. [Li] in opx is higher than in coexisting olivine while ?7LiOl-Opx (?7LiOl ? ?7LiOpx) ranges from ? 6.6 to 7.8‰, indicating disequilibrium inter-mineral [Li] and Li-isotope partitioning. We relate these Li systematics to interaction of lithospheric peridotites with fluids or melts that are either precursors of kimberlite magmatism or products of their fractionation and/or reaction with host mantle. The melts rich in Na and carbonates infiltrated, heated and weakened wall-rock peridotites to facilitate their deformation as well as produce high [Li] and variable, but mainly high, ?7Li in olivine. The carbonate-rich melts preferentially reacted with the opx without achieving inter-mineral equilibrium because opx is consumed by such melts, and because of small volumes and uneven distribution of the metasomatic media, as well as short time spans between the melt infiltration and the capture of the wall-rock fragments by incoming portions of ascending kimberlite magma as xenoliths. Trapped interstitial liquid solidified as cryptic components responsible for high [Li] and the lack of ?7Li balance between olivine and opx, and bulk rocks. Unaltered ?26Mg values (0.20-0.26‰) measured in several olivine separates show no effects of the metasomatism on Mg-isotopes, apparently due to high Mg in the peridotites.
DS200712-0687
2007
Pogge von Stranmann, P.A.E.Marschall, H.R., Pogge von Stranmann, P.A.E., Seit, H-M., Elliott, NiuThe lithium isotopic composition of orogenic eclogites and deep subducted slabs.Earth and Planetary Science Letters, Vol. 262, 3-4, Oct. 30, pp. 563-580.MantleSubduction
DS1860-0159
1871
Poggendorff, J.C.Poggendorff, J.C.Bemerkungen Uber den Diamant aus BohmenBeilage Zur Zeitschrift Lotos, 2P.Europe, Czech RepublicDiamond Occurrence
DS1989-1230
1989
Pognante, U.Pognante, U., Sandrone, R.Eclogites in the northern Dora-Maira Nappe, Western Alps, ItalyMineralogy and Petrology, Vol. 40, No. 1, March pp. 57-72ItalyEclogite
DS1991-1359
1991
Pognante, U.Pognante, U.Shoshonitic and ultrapotassic post-collisional dykes from northern Karakorum (Sinkiang China)Lithos, Vol. 26, No. 3/4 January pp. 305-316ChinaShoshonite, Alkaline
DS1970-0405
1971
Pogorelov, B.S.Sarkisyan, S.G., Pogorelov, B.S.Ultramafic Basement Rocks of the West Siberian PlateDoklady Academy of Sciences USSR EARTH SCI., Vol. 200, No. 1-6, PP. 74-76.RussiaKimberlite
DS201012-0314
2010
Pogramoskaya, O.E.Ivanov, K.S., Valizer, P.M., Erokhin, Yu.V., Pogramoskaya, O.E.Genesis of carbonatites of fold belts ( exemplified by the Urals).Doklady Earth Sciences, Vol. 435, 1, pp. 1423-1426.Russia, UralsCarbonatite
DS1960-0346
1963
Pogson, D.J.Gibbons, G.S., Pogson, D.J.Report on the Airly Mountain Diamond ProspectNew South Wales Geological Survey Report., GS 1963/001, (UNPUBL.).AustraliaKimberlite
DS1960-0347
1963
Pogson, D.J.Gibbons, G.S., Pogson, D.J.Diamond Deposits at Mount Rose, Copeton, New South WalesNew South Wales Geological Survey Report., GS 1963/002, (UNPUBL.).AustraliaKimberlite
DS1960-0348
1963
Pogson, D.J.Gibbons, G.S., Webster, S.S., Pogson, D.J.Investigations of Airly Mountains Diamond ProspectNew South Wales Geological Survey Report., GS 1963/064, (UNPUBL.).AustraliaKimberlite
DS1994-1722
1994
Pogson, R.E.Sutherland, F.L., Raynor, L.R., Pogson, R.E.Spinel to garnet lherzolite transition in relation to high temperaturepaleogeotherms, eastern Australia.Australian Journal of Earth Sciences, Vol. 41, No. 3, June pp. 205-220.AustraliaGeothermometry, Lherzolite, xenoliths
DS1998-1428
1998
Pogson, R.E.Sutherland, F.L., Pogson, R.E., Barron, B.J.Paleothermal gradients in Australia: key to 4 D lithospheremapping....reply to O'Reilly, Griffin, GaulAustralian Journal of Earth Sciences, Vol. 45, No. 5, Oct. 1, pp. 817-21.AustraliaGeothermometry, Mantle - mapping
DS200512-1066
2004
Pogson, R.E.Sutherland, F.L., Hollis, J.D., Birch, W.D., Pogson, R.E., Raynor, L.R.Cumulate rich xenolith suite in Late Cenozoic basaltic eruptives, Hepburn Lagoon, Newlyn in relation to western Victorian lithosphere.Australian Journal of Earth Sciences, Vol. 51, 3, pp. 319-337.Australia, VictoriaXenoliths
DS1859-0037
1826
Pogson, W.H.Pogson, W.H.History of BoondelasCalcutta:, PP. 169-IndiaHistory
DS1975-0876
1978
Pogudin, I.A.Sudorov, V.A., Pogudin, I.A., Trusevich, B.B.Testing an Induced Polarization Method in Diamond DepositsRazved. Okhr. Nedr. Sssr., No. 4, PP. 44-46.RussiaKimberlite, Geophysics
DS201705-0890
2017
Pohanka, M.Xu, C., Kynicky, J., Tao, R., Liu, X., Zhang, L., Pohanka, M., Song, W., Fei, Y.Recovery of an oxidized majorite inclusion from Earth's deep asthenosphere.Science Advances, Vol. 3, 4, e1601589MantleEclogite

Abstract: Minerals recovered from the deep mantle provide a rare glimpse into deep Earth processes. We report the first discovery of ferric iron-rich majoritic garnet found as inclusions in a host garnet within an eclogite xenolith originating in the deep mantle. The composition of the host garnet indicates an ultrahigh-pressure metamorphic origin, probably at a depth of ~200 km. More importantly, the ferric iron-rich majoritic garnet inclusions show a much deeper origin, at least at a depth of 380 km. The majoritic nature of the inclusions is confirmed by mineral chemistry, x-ray diffraction, and Raman spectroscopy, and their depth of origin is constrained by a new experimental calibration. The unique relationship between the majoritic inclusions and their host garnet has important implications for mantle dynamics within the deep asthenosphere. The high ferric iron content of the inclusions provides insights into the oxidation state of the deep upper mantle.
DS201610-1888
2016
Pohilenko, N.P.Mikhailenko, D.S., Korsakov, A.V., Golovin, A.V., Zelenovskiy, P.S., Pohilenko, N.P.The first finding of graphite inclusion in diamond from mantle rocks: the result of the study of eclogite xenolith from Udachnaya pipe ( Siberian craton).Doklady Earth Sciences, Vol. 469, 2, pp. 870-873.RussiaDeposit - Udachnaya

Abstract: A xenolith of eclogite from the kimberlite pipe Udachnaya-East, Yakutia Grt+Cpx+Ky + S + Coe/Qtz + Dia + Gr has been studied. Graphite inclusions in diamond have been studied in detail by Confocal Raman (CR) mapping. The graphite inclusion in diamond has a highly ordered structure and is characterized by a substantial shift in the band (about 1580 cm-1) by 7 cm-1, indicating a significant residual strain in the inclusion. According to the results of FTIR spectroscopic studies of diamond crystals, a high degree of nitrogen aggregation has been detected: it is present mainly in form A, which means an "ancient" age of the diamonds. In the xenolith studied, the diamond formation occurred about 1 Byr, long before their transport by the kimberlite melt, and the conditions of the final equilibrium were temperatures of 1020 ± 40°C at 4.7 GPa. Thus, these graphite inclusions found in a diamond are the first evidence of crystallization of metastable graphite in a diamond stability field. They were formed in rocks of the upper mantle significantly below (?20 km) the graphite-diamond equilibrium line.
DS202104-0563
2020
Pohilenko, N.P.Afanasiev, V.P., Pohilenko, N.P., Kuligin, S.S., Samdanov, D.A.On the prospects of diamond content of the southern side of the Vilyui syneclise. ( Lena River)Geology of Ore Deposits, Vol. 62, 6, pp. 535-541.RussiaIndicator minerals

Abstract: The paper describes indicator minerals of kimberlites found on the southern side of the Vilyui syneclise in the Markha River basin, a tributary of the Lena River. It is shown that indicator minerals-pyrope and picroilmenite-derive from Middle Paleozoic kimberlites, very likely diamondiferous. Methods are proposed for further studies on determining the prospects for the diamond content of the southern side of the Vilyui syneclise and the northern slope of the Aldan anteclise.
DS201112-0330
2011
Pohl, F.Fonseca, R.O., Luguet, A., Ballhaus, C., Pohl, F.Experimental constraints on the development of Os isotopic heterogeneity in the Earth's mantle.Goldschmidt Conference 2011, abstract p.858.MantleMelting - tracer
DS1987-0588
1987
Pohl, J.Pohl, J.Research in terrestrial impact structuresBraunschweig Wiesbaden Vieweg, 140pBrazil, Ontario, Texas, GermanyImpact, Tectonics
DS1990-0525
1990
Pohl, R.O.Geballe, T.H., Pohl, R.O., Seitz, R.Cool diamonds. Letters to Science in response to E. Marshall's articleScience, Vol. 250, November 30, pp. 1194-1195GlobalDiamond synthesis, Thermal conductivity
DS1985-0540
1985
Pohl, W.Pohl, W.Probable Kimberlite Indicator Plants in Western KenyaGeological Survey of Kenya, in: Geology for the development of Kenya, Publishing No., p. 66. abstract onlyKenyaProspecting
DS1994-1391
1994
Pohl, W.Pohl, W.Metallogeny of the northeastern Kibara belt, Central Africa- recentperspectivesOre Geology Reviews, Vol. 9, pp. 105-130Zambia, Angola, Zaire, Burundi, Tanzania, RwandaMetallogeny
DS201412-0694
2014
Pohwat, P.W.Pohwat, P.W.Connoisseur's choice: diamond, Dutoitspan mine, Kimberley, Northern Cape Province, South Africa.Rocks and Minerals, Jan-Feb. pp.54-65.Africa, South AfricaDeposit - Dutoitspan
DS1990-0906
1990
Poidebin, J.L.Lavreau, J., Poidebin, J.L., Lendent, D., Liegeois, J.P., Weis, D.Contribution to the geochronology of the basement of the Central AfricanRepublicJournal of African Earth Sciences, Vol. 11, No. 1/2, pp. 69-82Central African RepublicGeochronology, Tectonics
DS1996-1126
1996
Poidevin, J.L.Poidevin, J.L., Alvarez, P.Un segment proximal de rampe carbonatee d'age proterozoique superieur au Nord du Craton d'Afrique..Journal of African Earth Sciences, Vol. 23, No. 2, August pp. 257-266Central African RepublicProterozoic, Craton, stratigraphy
DS1994-1392
1994
Poidevin, J-L.Poidevin, J-L.Boninite like rocks from Paleoproterozoic greenstone belt of Bogain, CAR:geochemistry and petrogenesisPrecambrian Research, Vol. 68, No. 1/2, June pp. 97-114Central African RepublicProterozoic, Geochemistry
DS201412-0101
2014
Poikhilenko, L.N.Carmody, L., Taylor, L.A., Thaisen, K.G., Tychkov, N., Bodnar, R.J., Sobolev, N.V., Poikhilenko, L.N., Poikilenko, N.P.Ilmenite as a diamond indicator mineral in the Siberian craton: a tool to predict diamond potential.Economic Geology, Vol. 109, no. 3, pp. 775-783.RussiaIlmenite, chemistry
DS201412-0373
2014
Poikhilenko, L.N.Howarth, G.H., Barry, P.H., Pernet-Fisher, J.F., Baziotis, I.P., Pokhilenko, N.P., Poikhilenko, L.N., Bodnar, R.L., Taylor, L.A., Agashev, A.M.Superplume metasomatism: evidence from Siberian mantle xenoliths.Lithos, Vol. 184-187, pp. 209-224.RussiaMetasomatism
DS201412-0695
2014
Poikhilenko, L.N.Poikhilenko, N.P., Afanasiev, V.P., Agashev, A.M., Malkovets, V.G., Poikhilenko, L.N.New archean terranes with thick lithosphere of arctic regions of Siberia and North American ancient platforms: are they prospective for Diamondiferous kimberlites?30th. International Conference on Ore Potential of alkaline, kimberlite and carbonatite magmatism. Sept. 29-, Russia, CanadaKimberlite
DS201412-0696
2014
Poikhilenko, L.N.Poikhilenko, N.P., Afanasiev, V.P., Poikhilenko, L.N.Polymict breccia xenolith from Noyabrskaya pipe.30th. International Conference on Ore Potential of alkaline, kimberlite and carbonatite magmatism. Sept. 29-, Russia, SiberiaDeposit - Noyabrskaya
DS201012-0470
2010
Poikhilenko, N.Malkovets, V., Griffin, W., Poikhilenko, N., O'Reilly, S., Mishenin, S.Thickness of diamond bearing metasomatic aureoles in the cratonic SCLM.Goldschmidt 2010 abstracts, PosterMantleDiamond genesis
DS201312-0649
2012
Poikhilenko, N.P.Nikolenko, E.I., Afanasev, V.P., Chepurov, A.I., Sonin, V.M., Poikhilenko, N.P.Experimental study of the interaction between emoilmenite and kimberlite melt at a pressure of 2 Gpa.Doklady Earth Sciences, Vol. 447, 2, pp. 1306-1309.Africa, GuineaDeposit - Massadou
DS201412-0695
2014
Poikhilenko, N.P.Poikhilenko, N.P., Afanasiev, V.P., Agashev, A.M., Malkovets, V.G., Poikhilenko, L.N.New archean terranes with thick lithosphere of arctic regions of Siberia and North American ancient platforms: are they prospective for Diamondiferous kimberlites?30th. International Conference on Ore Potential of alkaline, kimberlite and carbonatite magmatism. Sept. 29-, Russia, CanadaKimberlite
DS201412-0696
2014
Poikhilenko, N.P.Poikhilenko, N.P., Afanasiev, V.P., Poikhilenko, L.N.Polymict breccia xenolith from Noyabrskaya pipe.30th. International Conference on Ore Potential of alkaline, kimberlite and carbonatite magmatism. Sept. 29-, Russia, SiberiaDeposit - Noyabrskaya
DS201810-2325
2018
Poikhilenko. N.P.Gromilov, S.A., Afanasiev, V.P., Poikhilenko. N.P.Moissanites of the Popigai astrobleme.Doklady Earth Sciences, Vol. 481, 2, pp. 997-999.Russiamoissanite

Abstract: Moissanites were found in tagamites of the Popigai meteorite crater along with impact diamonds. We have studied 55 samples including 49 individual polytypes and six intergrowths. The numbers of 6H, 15R, 4H, 6H/15R, and 6H/4H polytypes are 82, 7, 5, 4, and 2%, respectively. By the assemblage of polytypes, the moissanites of the Popigai astrobleme are distinct from kimberlite moissanites, as well as from synthetic SiC, which is characterized by the absence of the 4H polytype and the presence of more diverse inclusions (including Fe-bearing). The Popigai astrobleme is one of few objects with reliable natural moissanite. Technogenic contamination is excluded, since any researcher can find this mineral in tagamites.
DS201606-1095
2016
Poikilanko, N.P.Ilyina, O.V., Tychkov, N.S., Agashev, A.M., Golovin, A.V., Izokh, A.E., Kozmenko, O.A., Poikilanko, N.P.PGE distribution in deformed lherzolites of the Udachnaya kimberlite pipe ( Yakutia).Doklady Earth Sciences, Vol. 467, 2, pp. 408-411.Russia, YakutiaDeposit - Udachnaya

Abstract: The results of the first study of the PGE distribution in deformed lherzolites of the Udachnaya kimberlite pipe (Yakutia) are presented here. The complex character of evolution of the PGE composition in the Deformed lherzolites is assumed to be the result of silicate metasomatism. At the first stage, growth in the amount of clinopyroxene and garnet in the rock is accompanied by a decrease in the concentration of the compatible PGE (Os, Ir). During the final stage, the rock is enriched with incompatible PGE (Pt, Pd) and Re possible due to precipitation of submicron-sized particles of sulfides in the interstitial space of these mantle rocks.
DS201112-1062
2011
Poikilenko, N.Tychkov, N., Agashev, N., Poikilenko, N., Bazhan, I.Estimation of the refertilization grade of lithosphere roots by the chemical composition of garnets from Siberian kimberlites.Doklady Earth Sciences, Vol. 439, 2, pp. 1175-1178.Russia, SiberiaGarnet geochemistry
DS201212-0673
2012
Poikilenko, N.Smith, B., Baziotis, I., Carmody, L., Liu, Y.,Taylor, L.A., Poikilenko, N.The subcontinental lithospheric mantle of the NE Siberian craton: peridotites from Obnazhennaya.GSA Annual Meeting, Paper no. 249-7, abstractRussiaDeposit - Obnazhennaya
DS201412-1007
2014
Poikilenko, N.Yelisseyev, A., Khrenov, A., Afanasiev, V., Pustavarov, V., Gromilov, S., Panchenko, A., Poikilenko, N., Litasov, K.Luminesence of impact diamonds from the Popigai astrobleme.V.S. Sobolev Institute of Geology and Mineralogy Siberian Branch Russian Academy of Sciences International Symposium Advances in high pressure research: breaking scales and horizons ( Courtesy of N. Poikilenko), Held Sept. 22-26, 2p. AbstractRussia, SiberiaDiamond luminescence
DS202112-1951
2021
Poikilenko, N.Sonin, V., Zhimulev, E., Chepurov, A., Gryaznov, I., Chepurov, A., Afanasiev, V., Poikilenko, N.Experimental etching of diamonds: extrapolation to impact diamonds from the Popigai Crater ( Russia)MDPI, Vol. 11, 11p. Pdf Russiadeposit - Popigai

Abstract: Diamond etching in high-temperature ambient-pressure experiments has been performed aimed to assess possible postimpact effects on diamonds in impact craters, for the case of the Popigai crater in Yakutia (Russia). The experiments with different etchants, including various combinations of silicate melts, air, and inert gases, demonstrated the diversity of microstructures on {111} diamond faces: negative or positive trigons, as well as hexagonal, round, or irregularly shaped etch pits and striation. The surface features obtained after etching experiments with kimberlitic diamonds are similar to those observed on natural impact diamonds with some difference due to the origin of the latter as a result of a martensitic transformation of graphite in target rocks. Extrapolated to natural impact diamonds, the experimental results lead to several inferences: (1) Diamond crystals experienced natural oxidation and surface graphitization during the pressure decrease after the impact event, while the molten target rocks remained at high temperatures. (2) Natural etching of diamonds in silicate melts is possible in a large range of oxidation states controlled by O2 diffusion. (3) Impact diamonds near the surface of molten target rocks oxidized at the highest rates, whereas those within the melt were shielded from the oxidizing agents and remained unchanged.
DS201212-0004
2012
Poikilenko, N.P.Afanasiev, V.P., Poikilenko, N.P.Abrasion of diamond: an experimental study and field evidence.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractRussia, YakutiaDiamond morphology
DS201412-0101
2014
Poikilenko, N.P.Carmody, L., Taylor, L.A., Thaisen, K.G., Tychkov, N., Bodnar, R.J., Sobolev, N.V., Poikhilenko, L.N., Poikilenko, N.P.Ilmenite as a diamond indicator mineral in the Siberian craton: a tool to predict diamond potential.Economic Geology, Vol. 109, no. 3, pp. 775-783.RussiaIlmenite, chemistry
DS201412-0308
2014
Poikilenko, N.P.Goryainov, S.V., Likhacheva, A.Y., Rashchenko, S.V., Shubin, A., Afanasev,V.P., Poikilenko, N.P.Raman identification of lonsdalaeite in Popigai impactites.Journal of Raman Spectroscopy, Vol. 45, 4, pp. 305-313.RussiaLonsdaleite
DS201502-0091
2015
Poikilenko, N.P.Poikilenko, N.P., Agashev, A.M., Litasov, K.D., Pokhilenko, L.N.Carbonatite metasomatism of peridotite lithospheric mantle: implications for diamond formation and carbonatite-kimberlite magmatism.Russian Geology and Geophysics, Vol. 56, 1, pp. 280-295.MantleCarbonatite
DS201608-1447
2016
Poikilenko, N.P.Ugapeva, S.S., Pavlushin, A.D., Goryainov, S.V., Afanasiev, V.P., Poikilenko, N.P.Comparative characteristics of diamonds with olivine inclusions from the Ebelyakh placer and kimberlite pipes of the Yakutian Diamondiferous province.Doklady Earth Sciences, Vol. 468, 1, pp. 473-477.RussiaDeposit - Mir, Aykhal, Udachnaya, XXII Congress

Abstract: The results of morphological examination and the character of the structural orientation and estimation of residual pressure calculated from spectra of combination dispersion in olivine inclusions within diamonds of the Ebelyakh placer and kimberlite pipes of the Yakutian Diamondiferous Province are presented. The data analysis aimed at revealing indications of similarity and/or differences between diamonds from the pipes and the placer. Differences in the structural orientation and spectra of combination dispersion of the inclusions of olivine in dodecahedroids of placers of the northeastern part of the Siberian Platform support the assumption of their non-kimberlite nature.
DS1920-0396
1928
Poindexter, O.F.Poindexter, O.F.Constituents of Diamond Bearing Black Sands from Angola, Portuguese West Africa.American Mineralogist., Vol. 13, PP. 236-237.AngolaMineralogy, Alluvial Diamond Placers, Heavy Mineral Concentrate
DS1988-0432
1988
Pointing, A.J.Maguire, P.K.H., Shah, E.R., Pointing, A.J., Cooke, P.A.V., KhanThe seismicity of KenyaJournal of African Earth Sciences, Vol. 7, No. 7-8, pp. 915-924KenyaGeophysics
DS201808-1779
2018
Pointon, M.Pointon, M.De Beers's diamond mine in 1880's: Robert Harris and the Kimberley Searching System.History of Photography, Vol. 42, 1, pp. 4-24.Africa, South Africahistory

Abstract: In the mid 1880s a little-known photographer named Robert Harris produced a series of albumen prints showing the stages of body searching that black labourers in De Beers diamond mines were obliged to undergo by state ordinance enacted in 1883. The original photographs surfaced briefly in the sale-room in 2007 but have since disappeared. Two sets of copies survive. Bearing in mind the history of documentary photography in South Africa, this essay examines the historical and textual significance of this series of photographs in the context of the history of mining and discusses the imperatives and ethics of locating, researching and publishing controversial imagery in the internet age.
DS201810-2368
2018
Pointon, M.Pointon, M.De Beer's diamond mine in the 1880's: Robert Harris and the Kimberley searching system.History of Photography, Vol. 42, 1, pp. 4-24. doi.org/10.1080/ 03087298.2018. 1429095Africa, South Africadeposit - Kimberley

Abstract: In the mid 1880s a little-known photographer named Robert Harris produced a series of albumen prints showing the stages of body searching that black labourers in De Beers diamond mines were obliged to undergo by state ordinance enacted in 1883. The original photographs surfaced briefly in the saleroom in 2007 but have since disappeared. Two sets of copies survive. Bearing in mind the history of documentary photography in South Africa, this article examines the historical and textual significance of this series of photographs in the context of the history of mining and discusses the imperatives and ethics of locating, researching, and publishing controversial imagery in the Internet age.
DS2001-0824
2001
PoirierNarteau, C., Le Mouel, Poirier, Sepulveda, ShnirmanOn a small scale roughness of the core mantle boundaryEarth and Planetary Science Letters, Vol. 191, No. 1-2, Aug. 30, pp. 49-60.MantleCore - boundary
DS201910-2295
2019
Poirier, A.Rizo, H., Abdrault, D., Bennett, N.R., Humayun, M., Brandon, A., Vlastelic, I., Moine, B., Poirier, A., Bouhifd, M.A., Murphy, D.T.182W evidence for core-mantle interaction in the source of mantle plumes.Geochemical Perspectives Letters, Vol. 11, pp. 6-11.Mantlemantle plumes, hotspots

Abstract: Tungsten isotopes are the ideal tracers of core-mantle chemical interaction. Given that W is moderately siderophile, it preferentially partitioned into the Earth’s core during its segregation, leaving the mantle depleted in this element. In contrast, Hf is lithophile, and its short-lived radioactive isotope 182Hf decayed entirely to 182W in the mantle after metal-silicate segregation. Therefore, the 182W isotopic composition of the Earth’s mantle and its core are expected to differ by about 200 ppm. Here, we report new high precision W isotope data for mantle-derived rock samples from the Paleoarchean Pilbara Craton, and the Réunion Island and the Kerguelen Archipelago hotspots. Together with other available data, they reveal a temporal shift in the 182W isotopic composition of the mantle that is best explained by core-mantle chemical interaction. Core-mantle exchange might be facilitated by diffusive isotope exchange at the core-mantle boundary, or the exsolution of W-rich, Si-Mg-Fe oxides from the core into the mantle. Tungsten-182 isotope compositions of mantle-derived magmas are similar from 4.3 to 2.7 Ga and decrease afterwards. This change could be related to the onset of the crystallisation of the inner core or to the initiation of post-Archean deep slab subduction that more efficiently mixed the mantle.
DS2003-0260
2003
Poirier, G.Clements, B., Lucas, R., Birkett, T., Poirier, G., Bertrand, P.The Diamondiferous Renard cluster, Otish Mountains region, Quebec: an explorationCordilleran Exploration Roundup, p. 82-3, abstract.Quebec, Otish MountainsNews item, Ashton, Soquem
DS2003-1087
2003
Poirier, G.Poirier, G., et al.Diamond potential of the Renard cluster, Foxtrot property, Monts Otish, Qu?becQuebec Exploration 2003, diamond session, 1 page, extended abstractQuebecRenard pipes - diamond potential
DS2003-1088
2003
Poirier, G.Poirier, G., Bertrand, P., Birkett, T., Clements, B., Lucas, R.T.Diamond potential of the Renard cluster, Foxtrot property, Monte Otish QuebecQuebec Exploration Conference, Nov. 25-27, 1p. abstractQuebec, Otish MountainsGeology - Renard, Ashton, Soquem
DS200412-0195
2003
Poirier, G.Boyd, R., Clement, B., Lucas, R.,Birkett, T., Poirier, G., Bertrand, P.The Diamondiferous Renard cluster, Otish Mountains region, Quebec.Geological Association of Canada Annual Meeting, Abstract onlyCanada, QuebecGeology
DS200412-1559
2003
Poirier, G.Poirier, G., Bertrand, P., Birkett, T., Clements, B., Lucas, R.T.Diamond potential of the Renard cluster, Foxtrot property, Monte Otish Quebec.Quebec Exploration Conference, Nov. 25-27, 1p. abstractCanada, Quebec, Otish MountainsGeology - Renard, Ashton, Soquem
DS201503-0169
2015
Poirier, G.Poirier, G.Renard: Quebec's first diamond mine.PDAC 2015, Abstract, 1p.Canada, QuebecDeposit - Renard
DS202011-2043
2019
Poirier, G.Horvath, L., Gault, R.A., Pfenninger-Horvath, Poirier, G.Mont Saint-Hilaire: history, geology, mineralogy.The Canadian Mineralogist, Special Publication 14, 634p. Canada, QuebecBook

Abstract: This paper introduces a special section of the Canadian Journal of Development Studies, "The Africa Mining Vision: A Manifesto for More Inclusive Extractive Industry-Led Development?" Conceived by African ministers "in charge of mineral resources" with inputs and guidance from African Union Heads of State, the Africa Mining Vision (AMV) was officially launched in February 2009. The papers presented in this special section reflect critically on progress that has since been made with operationalising the AMV at the country level across Africa; the general shortcomings of the manifesto; and the challenges that must be overcome if the continent is to derive g Taking over 20 years of meticulous preparation, László and Elsa Horváth, a duo of dedicated and dynamic amateur mineralogists, along with two researchers, Robert Gault, a mineralogist, and Glenn Poirier, a geologist, have produced the ultimate book "Mont Saint-Hilaire: History, Geology, Mineralogy". The photography captures the colors of Vásárely, the symmetry of Escher, the form of Bartók and the intricate patterns of Mandelbrot, all found here, in this miracle of nature. One cannot but marvel at how this single, small quarry contains such mineral diversity. At last count, over 434 mineral species have been found at Mont Saint-Hilaire, representing 9% of all known mineral species. The 66 type minerals first described from this locality represent 1.3 % of all mineral species, placing the Poudrette quarry in an extremely rarified class for worldwide mineral localities. Almost half, 47, of all known chemical elements are included in this mineral mix. Beginning some 124 million years ago, several million years and a variety of geological processes were needed to accomplish this assemblage. Be captivated, learn and, most of all, enjoy!reater economic benefit from its abundant mineral wealth.
DS1989-0869
1989
Poirier, G.G.Leclair, A.D., Poirier, G.G.The Kapuskasing uplift in the Kapuskasing area, OntarioGeological Survey of Canada Current Research, Paper No. 89-lC, pp. 225-234Ontario, MidcontinentStructure, Tectonics
DS1992-1235
1992
Poirier, J.P.Price, G.D., Poirier, J.P.Dislocation melting of mantle mineralsEos, Transactions, Annual Fall Meeting Abstracts, Vol. 73, No. 43, October 27, abstracts p. 599.MantleMineralogy, Enstatite melting point
DS1995-0021
1995
Poirier, J.P.Allegre, C.J., Poirier, J.P., Hofmann, A.W.The chemical composition of the earthEarth and Planetary Science Letters, Vol. 134, No. 3-4, Sept. 1, pp. 515-526.GlobalGeochemistry, Composition -chemical
DS2001-0647
2001
Poirier, J.P.Labroose, S., Poirier, J.P., Lemouel, J.L.The age of the inner coreEarth and Planetary Science Letters, Vol. 190, No. 3-4, pp. 111-123.MantleCore - boundary, Geochronology
DS2002-0914
2002
Poirier, J.P.Langenhorst, F., Poirier, J.P.Transmission electron microscopy of coesite inclusions in the Dora Maira high pressure metamorphic pyrope quartzite.Earth and Planetary Science Letters, Vol. 203, 3-4, pp. 793-803.EuropeCoesite - inclusions, UHP, ultra high pressure
DS1993-1433
1993
Poirier, J-P.Shankland, T.J., Peyronneau, J., Poirier, J-P.Electrical conductivity of the earth's lower mantleNature, Vol. 366, No. 6454, December 2, pp. 453-455.MantleGeophysics- seismics
DS1995-1151
1995
Poirier, J-P.Malavergne, V., Guyot, F., Peyronneau, J., Poirier, J-P.Distribution du fer, cobalt, nickel, entre mineraux du manteau inferieurterrestre haute pressure/temperatureCompte Rendus Sci. Paris., (in French), Vol. 320, II a, pp. 455-462.MantlePerovskite, Microscopy
DS1988-0547
1988
Poirier, M.Poirier, M.Diamond tools- evolution or revolution?Dimensional Stone, April/May, pp. 38-39GlobalBlank
DS2003-0147
2003
Poirier G.Boyd, R., Clement, B., Lucas, R., Birkett, T., Poirier G., Bertrand, P.The Diamondiferous Renard cluster, Otish Mountains region, QuebecGeological Association of Canada Annual Meeting, Abstract onlyQuebecGeology
DS1983-0402
1983
Poirot, J.P.Leung, C.S., Merigoux, H., Poirot, J.P., Zecchini, P.Identification of precious stones and synthesis by infraredspectroscopy.(in French)Revue de Gemmologie, (in French), Vol. 75, pp. 14-15GlobalSpectroscopy
DS1910-0558
1918
Poitevin, E.Poitevin, E., Graham, R.P.D.Contribution to the Mineralogy of Black Lake Area, QuebecGeological Survey of Canada (GSC) MUSEUM Bulletin., No. 27; ( GEOL. SERIES No. 35) 103P.Canada, QuebecBlank
DS201604-0622
2016
Poitras, S.Poitras, S., Pearson, D.G., Stachel, T., Cairns, S., Day, S.A geochemical study of diamond indicator minerals from the NWT Interior Platform.GAC MAC Meeting Special Session SS11: Cratons, kimberlites and diamonds., abstract 1/4p.Canada, Northwest TerritoriesDiamond indicators

Abstract: The Central Mackenzie Valley (CMV) area of the Northwest Territories (NWT) comprises a Phanerozoic sedimentary basin that lies between the western margin of the Slave craton and the Cordillera. Although the region is considerably outside the bounds of the exposed Slave craton, both LITHOPROBE and more recent regional-scale surface wave studies (e.g., Priestley and McKenzie, 2006) indicate the likely presence of lithospheric mantle extending into the diamond stability field. Recent work conducted by Olivut Resources Ltd. led to the discovery of 29 kimberlites in the CMV. However, the indicator mineral chemistry of discovered kimberlites does not appear to be a good match (www.olivut.ca) with those during regional till and stream sediment sampling by the Geologic Survey of Canada (GSC) and Northwest Territories Geologic Survey (NTGS) in August 2003 and July 2005. We present new geochemical data on the regional indicator minerals with the aim of obtaining geotherm and depth of mantle sampling constraints on those indicator minerals discovered to date. A statistical evaluation of the data will compare the similarities to indicator mineral chemistry with parts of the Slave craton to evaluate whether the CMV indicators may ultimately be derived from that region. In total 3600 kimberlite indicator mineral grains were picked from the 0.25-2.0 mm size fractions. Peridotitic garnet grains dominate (46%), followed by magnesium ilmenite (26%), with decreasing individual proportions >15% of chromite, low-chrome diopside, olivine, chrome-diopside and eclogitic garnet. A sub-sample of these grains (3143) were analysed by EPMA. Garnet grains classify (after Grütter et al., 2004) as 1015 (62.1%) G9, 270 (16.5%) G11, 113 (6.9%) G10, 103 (6.3%) G12, 57 (3.5%) G1, 46 (2.8%) G10D, and the remaining 31 (1.9%) as G0, G3, G3D, G4, and G5. A sub-set of garnet grains (~700) were selected for LA-ICP-MS trace element analysis. Of the grains selected 74% G9, 14% G10 (and G10D), and 8% G11, with only 4% G12 and G0 (Grütter et al., 2004). Nickel concentrations from these grains range from 2.6-168.2 ppm, with the majority (>80%) between 20-100 ppm, yielding TNi (Canil, 1999) values ranging from 643-1348°C, with the majority between ~1000-1200°C. Using a central Slave craton geothermal gradient (Hasterok and Chapman, 2011), equilibration pressures for these garnet grains range from 20-80 kbars with the majority between 40-60 kbars (120-185 km). Preliminary analysis has 581 (81%) of the erupted peridotitic mantle garnet grains plotting within the diamond stability field (Kennedy and Kennedy, 1976). Of the 128 clinopyroxene grains analysed, only a few represent garnet peridotite (lherzolite) facies KIM clinopyroxene grains following compositional screening. Thermobarometry of these grains (Nimis and Taylor, 2000), assuming they were all derived from the same lithospheric section, yields P-T arrays identical to the central Slave geotherm that was 220 km thick at the time of eruption. These results are encouraging for diamond exploration. We thank Overburden Drilling Management Ltd. for grain picking and recovery of the small diamond, SGS Lakefield Research for mounting grains, and the GSC for probing of the grains.
DS201605-0884
2016
Poitras, S.Poitras, S.Indicator mineral chemistry of the Horn Plateau, NWT.DCO Edmonton Diamond Workshop, June 8-10Canada, Northwest TerritoriesGeochemistry - KIMS
DS201708-1737
2017
Poitras, S.Poitras, S.Evidence for a >200 km thick diamond -bearing root beneath the Central Mackenzie Valley, Northwest Territories, Canada: diamond indicator mineral geochemistry from the Horn Plateau and Trout Lakes regions.11th. International Kimberlite Conference, OralCanada, Northwest Territoriesindicator minerals
DS201709-1968
2017
Poitras, S.Bussweiler, Y., Poitras, S., Borovinskaya, O., Tanner, M., Pearson, G.Rapid multielemental analysis of garnet with LA-ICP-TOF-MS implications for diamond exploration studies.Goldschmidt Conference, abstract 1p.Canada, Northwest Territoriesdiamond potential

Abstract: Garnet arguably constitutes the most important mineral in diamond exploration studies; not only can the presence of mantle garnet in exploration samples point to kimberlite occurrences, but its minor and trace element composition can further be used to assess the “diamond potential” of a kimberlite. The content of Cr and Ca, especially, has been found to be a reliable tool to test whether garnets originate from within the diamond stability field in the mantle [1]. Trace element patterns can further indicate the mantle host rock of the garnets, for example, whether they originate from a depleted or ultra-depleted mantle section [2]. Routinely, two separate analytical methods are necessary to fully characterize the composition of garnet; major and minor elements are usually determined by electron probe micro-analysis (EPMA), whereas determination of trace elements requires the more sensitive method of laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Here, we demonstrate rapid measurement of the entire suite of elements in garnet employing a new, commercially available timeof-flight (TOF) mass spectrometer, the icpTOF (TOFWERK AG, Thun, Switzerland), coupled to a fast wash-out laser ablation system (Teledyne Cetac Technologies Inc., Omaha, NE, USA). Using garnets from exploration samples taken from the Horn Plateau, Northwest Territories, Canada [3], we directly compare the icpTOF results to EPMA and LA-ICP-MS data. We examine whether the icpTOF can reliably characterize the garnets in Cr versus Ca space and at the same time reproduce their trace element patterns, thereby offering a cost effective method of analysis. The method of LA-ICP-TOF-MS, with its high speed of data acquisition and its ability to record the entire mass spectrum simultaneously, may have great benefits for (diamond) exploration studies. Moreover, the method can be used for fast, highresolution imaging, which is applicable to a wide range of geological materials and settings [4].
DS201902-0308
2018
Poitras, S.Poitras, S.Kimberlite indicator minerals from the Central Mackenzie Valley, Northwest Territories, Canada: a reconnaissance geochemical survey.University of Alberta, Msc thesis https://doi.org/ 10.7939/R3C53FH3P availableCanada, Northwest Territoriesmineral chemistry

Abstract: The Central Mackenzie Valley (CMV) area of Northwest Territories is underlain by Precambrian basement belonging to the North American Craton. The potential of this area to host kimberlitic diamond deposits is relatively high judging from the seismologically-defined lithospheric thickness, the age of basement rocks (2.2-1.7 Ga) and presence of kimberlite indicator minerals (KIMs) in Quaternary sediments. This study presents new major, minor and trace element chemistry data for kimberlite indicator mineral (KIM) grains collected from two regions within the Central Mackenzie Valley, Northwest Territories. The data, along with new kimberlite-related rutile U-Pb ages and ilmenite Hf isotopic compositions are used to constrain the composition and thickness of the lithospheric mantle sampled by the source kimberlite(s) and age of these kimberlites for these two regions. In the processed samples, peridotitic garnets dominate (> 25 % at each location) while eclogitic garnet is almost absent in both regions (< 1 % each). KIM chemistry for the Horn Plateau indicates significant diamond potential, with a strong similarity to KIM systematics from the Central and Western Slave Craton. The most significant issue to resolve in assessing the local diamond potential is the degree to which KIM chemistry reflects local and/or distal kimberlite bodies. Radiogenic isotope analysis of detrital kimberlite-related CMV oxide grains requires at least two broad age groups for eroded source kimberlites. Statistical analysis of the data suggests that it is probable that some of these KIMs were derived from primary and/or secondary sources within the CMV area, while others may have been transported to the area from the east-northeast by Pleistocene glacial and/or glaciofluvial systems. At this stage, KIM chemistry does not allow the exact location of the kimberlitic source(s) to be constrained.
DS201512-1958
2015
Poitras, S.P.Poitras, S.P.A geochemical study of diamond indicator minerals from the NWT interior platform.43rd Annual Yellowknife Geoscience Forum Abstracts, abstract p. 86.Canada, Northwest TerritoriesGeochemistry

Abstract: The Central Mackenzie Valley (CMV) area of the Northwest Territories (NWT) comprises a Phanerozoic sedimentary basin that lies between the western margin of the Slave craton and the Cordillera. Although the region is considerably outside the bounds of the exposed Slave craton, both LITHOPROBE and more recent regional-scale surface wave studies (e.g., Priestley and McKenzie, 2006) indicate the likely presence of lithospheric mantle extending into the diamond stability field. Recent work conducted by Olivut Resources Ltd. led to the discovery of 29 kimberlites in the CMV. However, the indicator mineral chemistry of discovered kimberlites does not appear to be a good match (www.olivut.ca) with those during regional till and stream sediment sampling by the Geologic Survey of Canada (GSC) and Northwest Territories Geologic Survey (NTGS) in August 2003 and July 2005. We present new geochemical data on the regional indicator minerals with the aim of obtaining geotherm and depth of mantle sampling constraints on those indicator minerals discovered to date. A statistical evaluation of the data will compare the similarities to indicator mineral chemistry with parts of the Slave craton to evaluate whether the CMV indicators may ultimately be derived from that region. In total 3600 kimberlite indicator mineral grains were picked from the 0.25-2.0 mm size fractions. Peridotitic garnet grains dominate (46%), followed by magnesium ilmenite (26%), with decreasing individual proportions >15% of chromite, low-chrome diopside, olivine, chrome-diopside and eclogitic garnet. A sub-sample of these grains (3143) were analysed by EPMA. Garnet grains classify (after Grütter et al., 2004) as 1015 (62.1%) G9, 270 (16.5%) G11, 113 (6.9%) G10, 103 (6.3%) G12, 57 (3.5%) G1, 46 (2.8%) G10D, and the remaining 31 (1.9%) as G0, G3, G3D, G4, and G5. A sub-set of garnet grains (~700) were selected for LA-ICP-MS trace element analysis. Of the grains selected 74% G9, 14% G10 (and G10D), and 8% G11, with only 4% G12 and G0 (Grütter et al., 2004). Nickel concentrations from these grains range from 2.6-168.2 ppm, with the majority (>80%) between 20-100 ppm, yielding TNi (Canil, 1999) values ranging from 643-1348°C, with the majority between ~1000-1200°C. Using a central Slave craton geothermal gradient (Hasterok and Chapman, 2011), equilibration pressures for these garnet grains range from 20-80 kbars with the majority between 40-60 kbars (120-185 km). Preliminary analysis has 581 (81%) of the erupted peridotitic mantle garnet grains plotting within the diamond stability field (Kennedy and Kennedy, 1976). Of the 128 clinopyroxene grains analysed, only a few represent garnet peridotite (lherzolite) facies KIM clinopyroxene grains following compositional screening. Thermobarometry of these grains (Nimis and Taylor, 2000), assuming they were all derived from the same lithospheric section, yields P-T arrays identical to the central Slave geotherm that was 220 km thick at the time of eruption. These results are encouraging for diamond exploration. We thank Overburden Drilling Management Ltd. for grain picking and recovery of the small diamond, SGS Lakefield Research for mounting grains, and the GSC for probing of the grains.
DS201812-2867
2018
Poitras, S.P.Poitras, S.P., Pearson, D.G., Hardman, M.F., Stachel, T., Nowell, G.M.Evidence for a 200 km thick diamond bearing root beneath the Central Mackenzie Valley, Northwest Territories, Canada? Diamond indicator mineral geochemistry from the Horn Plateau and Trout Lake regions.Mineralogy and Petrology, doi.org/10.1007/ s00710-018-0641-4 18p.Canada, Northwest Territoriesindicator minerals, geocthermobarometry

Abstract: The Central Mackenzie Valley (CMV) area of Northwest Territories is underlain by Precambrian basement belonging to the North American Craton. The potential of this area to host kimberlitic diamond deposits is relatively high judging from the seismologically-defined lithospheric thickness, age of basement rocks (2.2-1.7 Ga) and presence of kimberlite indicator minerals (KIMs) in Quaternary sediments. This study presents data for a large collection of KIMs recovered from stream sediments and till samples from two study areas in the CMV, the Horn Plateau and Trout Lake. In the processed samples, peridotitic garnets dominate the KIM grain count for both regions (> 25% each) while eclogitic garnet is almost absent in both regions (< 1% each). KIM chemistry for the Horn Plateau indicates significant diamond potential, with a strong similarity to KIM systematics from the Central and Western Slave Craton. The most significant issue to resolve in assessing the local diamond potential is the degree to which KIM chemistry reflects local and/or distal kimberlite bodies. Radiogenic isotope analysis of detrital kimberlite-related CMV ilmenite and rutile grains requires at least two broad age groups for eroded source kimberlites. Statistical analysis of the data suggests that it is probable that some of these KIMs were derived from primary and/or secondary sources within the CMV area, while others may have been transported to the area from the east-northeast by Pleistocene glacial and/or glaciofluvial systems. At this stage, KIM chemistry does not allow the exact location of the kimberlitic source(s) to be constrained.
DS200612-1097
2006
Poitrasson, F.Poitrasson, F.On the iron isotope homogeneity level of the continental crust.Chemical Geology, In press, availableMantleGeochemistry, igneous rocks
DS200712-0849
2007
Poitrasson, F.Poitrasson, F., Delpech, G., Grgeoire, M., Moine, B.N.Significance of the mantle Fe isotope variations.Plates, Plumes, and Paradigms, 1p. abstract p. A799.Africa, South AfricaXenoliths
DS200812-0255
2009
Poitrasson, F.Dalou, C., Koga, K.T., Hammouuda, T., Poitrasson, F.Trace element partitioning between carbonatitic melts and mantle transition zone minerals: implications for the source of carbonatites.Geochimica et Cosmochimica Acta, Vol. 73, 1, pp. 239-255.MantleCarbonatite
DS200912-0146
2009
Poitrasson, F.Dalou, C., Koga, K.T., Hammouda, T., Poitrasson, F.Trace element partitioning between carbonatitic melts and mantle transition zone minerals: implications for the source of carbonatites.Geochimica et Cosmochimica Acta, Vol. 73, 1, Jan. pp. 239-255.MantleCarbonatite
DS201312-0713
2013
Poitrasson, F.Poitrasson, F., Delpech, G., Gregoire, M.On the iron isotope heterogeneity of lithospheric mantle xenoliths: implications for mantle metasomatism, the origin of basalts and the iron isotope composition of the Earth.Contributions to Mineralogy and Petrology, Vol. 165, 6, pp. 1243-1258.Africa, Cameroon, South AfricaMelting
DS201012-0017
2010
Pokhienko, L.I.Ashchepkov, I., Pokhienko, N., Afansiev, V., Logvinova, A., Pokhienko, L.I., Ntaflos, Ionov, Kuligin, MityukhinMonomineral thermobarometry for the diamond inclusions from Siberia: genetic links.International Mineralogical Association meeting August Budapest, abstract p. 184.RussiaThermobarometry - Mir, Alakite
DS201012-0017
2010
Pokhienko, N.Ashchepkov, I., Pokhienko, N., Afansiev, V., Logvinova, A., Pokhienko, L.I., Ntaflos, Ionov, Kuligin, MityukhinMonomineral thermobarometry for the diamond inclusions from Siberia: genetic links.International Mineralogical Association meeting August Budapest, abstract p. 184.RussiaThermobarometry - Mir, Alakite
DS200412-0725
2004
PokhilenkGriffin, W.L., O'Reilly, S.Y., Doyle, B.J., Pearson, N.J., Coopersmith, H., Kivi, K., Melkovets, V., PokhilenkLithosphere mapping beneath the North American plate.Lithos, Vol. 77, 1-4, Sept. pp. 873-922.Canada, Northwest Territories, Europe, GreenlandArchon, Proton, Tecton, Slave Craton, Kapuskasing Struc
DS1995-1799
1995
PokhilenkoSobolev, V.N., Taylore, L.A., Snyder, G.A., PokhilenkoA unique metasomatised peridotite xenolith from the Mir kimberlite, Siberian PlatformProceedings of the Sixth International Kimberlite Conference Abstracts, pp. 555-557.Russia, SiberiaXenolith -peridotite, Deposit -Mir
DS1998-0011
1998
PokhilenkoAgashev, A.M., Watanabe, T., Kuligin, S.S., PokhilenkoStrontium neodymium isotopes in the garnet pyroxenite xenoliths from Siberian kimberlites: a new insight into lithospheric..7th International Kimberlite Conference Abstract, pp. 11-13.Russia, SiberiaGarnet pyroxenite, mantle, Geochemistry
DS1998-1228
1998
PokhilenkoReimers, L.F., Pokhilenko, Yefimova, SobolevUltramafic mantle assemblages from Sytykanskaya kimberlite pipe, Yakutia7th. Kimberlite Conference abstract, pp. 730-32.Russia, YakutiaXenoliths, mineral chemistry, Deposit - Sytykanskaya
DS2000-0006
2000
PokhilenkoAfanasev, V.P., Pokhilenko, Loginova, Zinchuk, EfimovaProblem of false kimberlite indicators: a new morphogenetic type Cr spinellide Diamondiferous areas.Russian Geology and Geophysics, Vol.41,12,pp.1676-89., Vol.41,12,pp.1676-89.RussiaGeochemistry - indicators, Chrome spinellide
DS2000-0007
2000
PokhilenkoAfanasev, V.P., Pokhilenko, Loginova, Zinchuk, EfimovaProblem of false kimberlite indicators: a new morphogenetic type Cr spinellide Diamondiferous areas.Russian Geology and Geophysics, Vol.41,12,pp.1676-89., Vol.41,12,pp.1676-89.RussiaGeochemistry - indicators, Chrome spinellide
DS2000-0916
2000
PokhilenkoSonin, V.M., Federov, I.I., Pokhilenko, L., PokhilenkoDiamond oxidation rate as related to oxygen fugacityGeol. Ore Dep., Vol. 42, No. 6, pp. 496-503.RussiaDiamond - geochemistry
DS2001-0006
2001
PokhilenkoAgashev, A.M., Pokhilenko, McDonald, Takazawa, VavilovA unique kimberlite carbonatite primary association in the Snap lake dyke system: evidence from geochemical..Slave-Kaapvaal Workshop, Sept. Ottawa, 2p. abstractNorthwest TerritoriesGeochemistry, geochronology, Slave Craton, Deposit - Snap Lake
DS2001-0007
2001
PokhilenkoAgashev, A.M., Watanabe, Bydaev, Pokhilenko, FominGeochemistry of kimberlites from the Nakyn field, Siberia: evidence for unique source composition.Geology, Vol. 29, No. 3, Mar. pp. 267-70.Russia, SiberiaGeochronology, geochemistry
DS2001-0008
2001
PokhilenkoAgashev, A.M., Watanabe, T., Kuligin, S.S., PokhilenkoRubidium-Strontium and Samarium-neodymium isotopes in garnet pyroxenite xenoliths from Siberian kimberlites: an insight into lith. mantleJournal of Mineralogy and Petrology. Sciences, Vol. 96, No. 1, pp. 7-18.Russia, SiberiaGeochronology, Lithospheric - xenoliths
DS2003-0869
2003
PokhilenkoMalkovets, V.G., Taylor, L.A., Griffin, W., O'Reilly, S., Pearson, N., PokhilenkoCratonic considitons beneath Arkhangelsk, Russia: garnet peridotites form the Grib8ikc, Www.venuewest.com/8ikc/program.htm, Session 4, POSTER abstractRussia, Kola PeninsulaMantle geochemistry, Deposit - Grib
DS200612-0047
2006
PokhilenkoAshchepkov, I.V., Vladykin, Sobolev, Pokhilenko, Rotman, Logvinova, Afanasiev, Pokhilenko, KarpenkoReconstruction of the mantle sequences and the structure of the feeding and vein magmatic systems beneath the kimberlite fields of Siberian platform.Vladykin: VI International Workshop, held Mirny, Deep seated magmatism, its sources and plumes, pp. 79-103.Russia, SiberiaDyke systems
DS200612-0047
2006
PokhilenkoAshchepkov, I.V., Vladykin, Sobolev, Pokhilenko, Rotman, Logvinova, Afanasiev, Pokhilenko, KarpenkoReconstruction of the mantle sequences and the structure of the feeding and vein magmatic systems beneath the kimberlite fields of Siberian platform.Vladykin: VI International Workshop, held Mirny, Deep seated magmatism, its sources and plumes, pp. 79-103.Russia, SiberiaDyke systems
DS200612-0048
2006
PokhilenkoAshchepkov, I.V., Vladykin, Sobolev, Pokhilenko, Rotman, Logvinova, Afanasiev, Pokhilenko, KarpenkoVariations of the oxygen conditions in mantle column beneath Siberian kimberlite pipes and it's application to lithospheric structure of feeding systems.Vladykin: VI International Workshop, held Mirny, Deep seated magmatism, its sources and plumes, pp. 125-144.Russia, SiberiaRedox
DS200612-0048
2006
PokhilenkoAshchepkov, I.V., Vladykin, Sobolev, Pokhilenko, Rotman, Logvinova, Afanasiev, Pokhilenko, KarpenkoVariations of the oxygen conditions in mantle column beneath Siberian kimberlite pipes and it's application to lithospheric structure of feeding systems.Vladykin: VI International Workshop, held Mirny, Deep seated magmatism, its sources and plumes, pp. 125-144.Russia, SiberiaRedox
DS200812-0051
2008
PokhilenkoAshchepkov, I.V., Pokhilenko, Vladykin, Rotam, Afansiev, Logvinova, Kostrovitsky, Karpenko, KuliginReconstruction of mantle sections beneath Yakutian kimberlite pipes using monomineral thermobaraometry.Geological Society of London, Special Publication, SP 293, pp. 335-352.RussiaGeothermometry
DS200812-0053
2008
PokhilenkoAshchepkov, Pokhilenko, Vladykon, Loginova, Rotman, Afansiev, Kuligin, Malygina, Alymova, Stegnitsky, KhmetnikovaPlume interaction and evolution of the continental mantle lithosphere.Deep Seated Magmatism, its sources and plumes, Ed. Vladykin, N.V., 2008 pp. 104-121.MantlePlume
DS200912-0016
2009
PokhilenkoAschepokov, L., Logvinova, A., Kuligin, Pokhilenko, Vladykin, Mityukhin, Alymova, Malygina, VishnyakovaClinopyroxene eclogite peridotite thermobarometry of the large Yakutian kimberlite pipes.Goldschmidt Conference 2009, p. A58 Abstract.Russia, YakutiaThermobarometry
DS201012-0016
2010
PokhilenkoAshchepkov, I., Afanasiev, Vladykin, Pokhilenko, Ntaflos, Travin, Ionov, Palessky, Logvinova, Kuligin, MityukhinReasons of variations of the mineral compositions of the mantle rocks beneath the Yakutian kimberlite province.International Mineralogical Association meeting August Budapest, abstract p. 141.Russia, YakutiaGeothermometry
DS201012-0018
2010
PokhilenkoAshchepkov, I.V., Pokhilenko, Vladykin, Logvinova, Afansiev, Kuligin, Malygina, Alymova, KostrovitskyStructure and evolution of the lithospheric mantle beneath Siberian Craton, theromobarometric study.Tectonophysics, Vol. 485, pp. 17-41.RussiaGeothermometry
DS201012-0020
2009
PokhilenkoAshchepkov, Vladykin, Pokhilenko, Logvinova, Kuligin, Pokhilenko, Malgina, Alymova, Mityukhin, KopylovaApplication of the monomineral thermobarometers for the reconstruction of the mantle lithosphere structure.Deep Seated Magmatism, its sources and plumes, Ed. Vladykin, N.V., p. 98-116.MantleGeothermometry
DS201012-0020
2009
PokhilenkoAshchepkov, Vladykin, Pokhilenko, Logvinova, Kuligin, Pokhilenko, Malgina, Alymova, Mityukhin, KopylovaApplication of the monomineral thermobarometers for the reconstruction of the mantle lithosphere structure.Deep Seated Magmatism, its sources and plumes, Ed. Vladykin, N.V., p. 98-116.MantleGeothermometry
DS201012-0247
2010
PokhilenkoGrakhanov, S.A., Malanin, Yu.A., Pavlov, Afanasev, Pokhilenko, Gerasimchuk, LipashovaRhaetian diamond placers in Siberia.Russian Geology and Geophysics, Vol. 51, pp. 127-135.Russia, Yakutia, SakhaAlluvials
DS201112-0037
2010
PokhilenkoAshchepkov, Ntaflos, Vladykin, Ionov, Kuligin, Malygina, Pokhilenko, Logvinova, Mityukhin, Palessky, Khmelnikova, RotmasDeep seated xenoliths from the phlogopite bearing brown breccia of the Udachnaya pipe.Vladykin, N.V., Deep Seated Magmatism: its sources and plumes, pp. 164-186.RussiaMetasomatism
DS201112-0639
2011
PokhilenkoMalkovets, V.G., Griffin, Pearson, Rezvukhin, O'Reilly, Pokhilenko, Garanin, Spetsius, LitasovLate metasomatic addition of garnet to the SCLM: Os-isotope evidence.Goldschmidt Conference 2011, abstract p.1395.RussiaUdachnaya, Daldyn
DS201112-0640
2011
PokhilenkoMalkovets, V.G., Zedgenizov, Sobolev, Kuzmin, Gibsher, Shchukina, Golovin, Verichev, PokhilenkoContents of trace elements in olivines from diamonds and peridotite xenoliths of the V.Grib kimberlite pipe ( Arkhangel'sk Diamondiferous province, Russia).Doklady Earth Sciences, Vol. 436, 2, pp. 301-307.RussiaDeposit - Grib
DS2000-0916
2000
Pokhilenko, L.Sonin, V.M., Federov, I.I., Pokhilenko, L., PokhilenkoDiamond oxidation rate as related to oxygen fugacityGeol. Ore Dep., Vol. 42, No. 6, pp. 496-503.RussiaDiamond - geochemistry
DS201312-0839
2012
Pokhilenko, L.Smith, B., Baziotis, I., Carmody, L., Liu, Y., Taylor, L.A., Pokhilenko, N., Pokhilenko, L.The subcontinental lithospheric mantle of the NE Siberian craton: peridotites from Obnazhennaya.Geological Society of America Annual Meeting abstract, Paper 249-7, 1/2p. AbstractRussiaDeposit - Obnazhennaya
DS201412-0697
2014
Pokhilenko, L.Pokhilenko, L.Classification pecularities of mantle eclogites from Udachnaya-East pipe ( Yakutia).ima2014.co.za, AbstractRussia, YakutiaDeposit - Udachnaya-East
DS201909-2077
2019
Pokhilenko, L.Pokhilenko, N., Agashev, A., Pokhilenko, L.Features of metasomatic treatment of the lithosphere mantle depleted peridotites in relation with scale and diamond grade of kimberlite magmatism.Goldschmidt2019, 1p. Poster abstractSouth America, Brazildeposit - RosaRio-6

Abstract: Three main cycle of kimberlite magmatism are known for the Siberian Platform (SP) to date: Middle Paleozoic (D3), and two Mesozoic (T2-3 and J3). All economic highgrade kimberlites are of Middle Paleozoic (MP) age, and this feature is related with influence of melts/fluids of Permian-Triassic Siberian Super Plume produced huge changes in structure and composition of the SP Lithospheric Mantle (LM) including its enrichment by basaltic components, thinning, increase of fo2 and resorption of diamonds. Nevertheless, there are incredible differences in amounts of kimberlite bodies and their average diamond grade between different kimberlite fields of MP age, and these features are connected with intensity of carbonatite and silicate types of metasomatic treatment of the most deep-seated SP LM depleted peridotites especially of Lithosphere-Asthenosphere (LA) interaction zone. U-type lithospheric diamond formation is related with initial stage of carbonatite metasomatism, and its increase produce wehrlitezation and then carbonation of initial Cr-pyrope harzburgites and dunites but not related with diamond formation. Minor scale of silicate metasomatism of these modified LM peridotites produced conditions for generation of insignificant amount of kimberlite melts which form kimberlite fields with few bodies, but significant part of them are presented by high-grade kimberlite. And in case of significant scale of both carbonatite and silicate metasomatism of the LM peridotites produce large volume of kimberlite melt and hundreds of kimberlite bodies in fields with minor amonts of high grade ones.
DS202107-1123
2021
Pokhilenko, L.Pokhilenko, L.Kelphite rims on garnets of contrast parageneses in mantle xenoliths from the Udachnaya-East kimberlite pipe ( Yakutia).Minerals MDPI, Vol. 11, 615 29p. PdfRussia, Yakutiadeposit - Udachnaya-East

Abstract: A new classification of kelyphitic rims on garnets from xenoliths of peridotitic and eclogitic parageneses of the mantle section under the Udachnaya-East kimberlite pipe (Yakutia) is presented. Five types of rims are identified: Rim1 develops between garnet and olivine/pyroxene (or rim2) and is composed of high-alumina pyroxenes, spinel, phlogopite; rim2, the coarse grain part of rim1, is located between rim1 and olivine/pyroxene, and mainly consists of phlogopite and less aluminous larger pyroxenes and spinel; rim3 develops between garnet and kimberlite, and presents with phlogopite and Fe-Ti spinel; rim4 sometimes presents instead of rim1/rim2 and consists of zoned high-Cr phlogopite with rare fine grains of chromium spinel; rim5, a “pocket” between garnet and rim1, is represented by microcrystalline aggregates of clinopyroxene, mica, spinel, calcite, and feldspar in different variations. Rims 1, 2, and 3 are typical for garnets of all studied parageneses. Rims 4 and 5 develop on high-Cr subcalcic garnets of the most depleted peridotites. Reactions of the formation of all types of rims are given in the article. Each type of kelyphite demonstrates a clear enrichment with a certain component: Rim1—MgO and alkalis; rim2—TiO2; rim3—FeO and TiO2; rim4—Cr2O3; and rim5—CaO, suggesting the multistage injection of different components by mantle fluid.
DS1994-1393
1994
Pokhilenko, L.N.Pokhilenko, L.N., Federov, I.I., Pokhilenko, N.P., et al.Fluid regime of formation of mantle rocks according to dat a of chromatographic analysis and thermodynamic cal.Russian Geology and Geophysics, Vol. 35, No. 4, pp. 60-64.RussiaMantle, Kimberlites
DS2003-1089
2003
Pokhilenko, L.N.Pokhilenko, L.N., Tomilenko, A.A., Kuligin, S.S., Khlestov, V.V.The upper mantle heterogeneity: thermodynamic calculations and methods of8 Ikc Www.venuewest.com/8ikc/program.htm, Session 6, POSTER abstractRussia, YakutiaBlank
DS200412-1560
2003
Pokhilenko, L.N.Pokhilenko, L.N., Tomilenko, A.A., Kuligin, S.S., Khlestov, V.V.The upper mantle heterogeneity: thermodynamic calculations and methods of mathematical statistics.8 IKC Program, Session 6, POSTER abstractRussia, YakutiaMantle petrology
DS200412-1563
2003
Pokhilenko, L.N.Pokhilenko, N.P., Griffin, W.L., Shimizu, N., McLean, R.C., Malkovets, V.G., Pokhilenko, L.N., Malygina, E.V.Pyropes and chromites of the Snap Lake King Lake kimberlite dyke system in relation to the problem of the southern Slave Craton8 IKC Program, Session 6, POSTER abstractCanada, Northwest TerritoriesMantle petrology Deposit - Snap Lake King Lake
DS200812-0905
2008
Pokhilenko, L.N.Pokhilenko, L.N., Pokhilenko, N.P., Fedorov, L.I., Tomilenko, A.A., Usova, L.V., Fomina, L.N., Sobolev, V.S.Fluid regime pecularities of the lithosphere mantle of the Siberian Platform.Deep Seated Magmatism, its sources and plumes, Ed. Vladykin, N.V., 2008 pp. 122-136.Russia, SiberiaMantle chemistry
DS200912-0766
2009
Pokhilenko, L.N.Tomilenko, A.A., Kovyazin, S.V., Pokhilenko, L.N., Sobolev, N.V.Primary hydrocarbon inclusions in garnet of Diamondiferous eclogite from the Udachnaya kimberlite pipe, Yakutia.Doklady Earth Sciences, Vol. 427, 4, pp. 695-8.Russia, YakutiaDeposit - Udachnaya
DS201112-0806
2011
Pokhilenko, L.N.Pokhilenko, L.N., Aliforova, T.A.Plagioclase and apatite from exsolution structures in minerals from mantle xenoliths.Doklady Earth Sciences, Vol. 437, 2, pp. 483-485.MantleMineralogy
DS201112-0807
2010
Pokhilenko, L.N.Pokhilenko, L.N., Pokhilenko, N.P., Vladykin, N.V.Garnet orthopyroxenites from the Udachnaya kimberlite pipe ( Yakutia): features of their composition and orogin.Vladykin, N.V., Deep Seated Magmatism: its sources and plumes, pp. 128-144.Russia, YakutiaMineralogy - genesis
DS201112-1050
2011
Pokhilenko, L.N.Tomilenko, A.A., Kovyazin, S.V., Pokhilenko, L.N., Sobolev, N.V.Silicate globules in kyanite from grospydites of the Zagadochnaya kimberlite pipe, Yakutia: the problem of origin.Doklady Earth Sciences, Vol. 436, 1, pp. 98-101.Russia, YakutiaPetrology
DS201212-0009
2012
Pokhilenko, L.N.Alifirova, T.A., Pokhilenko, L.N., Ovchinnikov, Y.I., Riches, A.J.V., Taylor, L.A.Petrologic origin of exsolution textures in mantle minerals: evidence in pyroxenitic xenoliths from Yakutia kimberlites.International Geology Review, in press availableRussia, YakutiaPetrology
DS201212-0010
2012
Pokhilenko, L.N.Alifirova, T.A., Pokhilenko, L.N., Malkovets, V.G., Griffin, W.L.Petrological inferences for the role of exsolution in upper mantle: evidence from the Yakutian kimberlite xenoliths.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractRussia, YakutiaPetrology
DS201212-0011
2012
Pokhilenko, L.N.Aliforova, T.A., Pokhilenko, L.N., Ovchinnikov, Y.I., Donnelly, C.L., Riches, A.J.V., Taylor, L.A.Petrologic origin of exsolution textures in mantle minerals: evidence in pyroxenite xenoliths from Yakutia kimberlites.International Geology Review, Vol. 54, 9, pp. 1071-1092.RussiaDeposit - Yakutia
DS201212-0037
2012
Pokhilenko, L.N.Ashchepkov, IV., Nntalfos, T., Pokhilenko, L.N., Ionov, D.A., Vladykin, N.V., Kuligin, S.S., Mityukhin, S.I., Palessky, S.V.Mantle structure beneath Udachnaya pipe reconstructed by fresh mantle xenoliths from brown breccia.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractRussia, YakutiaDeposit - Udachnaya
DS201212-0257
2012
Pokhilenko, L.N.Goncharov, A.G., Ionov, D.A., Doucet, L.S., Pokhilenko, L.N.Thermal stress, oxygen fugacity and C O H fluid appreciation in cratonic lithospheric mantle: new dat a on peridotite xenoliths from the Udachnaya kimberlite, Siberia.Earth and Planetary Science Letters, Vol. 357-358, pp. 99-110.RussiaDeposit - Udachnaya
DS201212-0559
2012
Pokhilenko, L.N.Pokhilenko, L.N., Alifirova, T.A., Yudin, D.S.40Ar/39Ar dating of phlogopite of mantle xenoliths from kimberlite pipes of Yakutia: evidence for deep ancient metasomatism of the Siberian platform.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractRussia, YakutiaGeochronology
DS201212-0560
2012
Pokhilenko, L.N.Pokhilenko, L.N., Aliflrova, T.A., Yudin, D.S.40Ar/39Ar dating of phlogopite of mantle xenoliths from kimberlite pipes of Yakutia: evidence for deep ancient metasomatism of the Siberian platform.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractRussia, SiberiaGeochronology
DS201212-0562
2012
Pokhilenko, L.N.Pokhilenko, N.P., Afanasev, V.P., McDonald, J.A., Vavilov, M.A., Kulgin, S.S., Pokhilenko, L.N., Golovin, A.V., Agashev, A.M.Kimberlite indicator minerals in terrigene sediments of lower part of Mackenzie River Basin, NWT, Canada: evidence of new craton with thick lithosphere.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractCanada, Northwest TerritoriesGeochemistry - KIMS
DS201312-0014
2013
Pokhilenko, L.N.Alifirova, T.A., Pokhilenko, L.N.Apatite exsolution as an indicator of Udachnaya grospydite UHP history.Goldschmidt 2013, AbstractRussiaUHP
DS201312-0401
2014
Pokhilenko, L.N.Howarth, G.H., Barry, P.H., Pernet-Fisher, J.F., Baziotis, I.P., Pokhilenko, N.P., Pokhilenko, L.N., Bodnar, R.J., Taylor, L.A.Superplume metasomatism: evidence from Siberian mantle xenoliths.Lithos, Vol. 184-187, pp. 209-224.Russia, SiberiaMetasomatism
DS201412-0698
2014
Pokhilenko, L.N.Pokhilenko, L.N., Malkovets, V.G., Kuzmin, D.V., Pokhilenko, N.P.New dat a on the mineralogy of megacrystalline pyrope peridotite from the Udachnaya kimberlite pipe, Siberian Craton, Yakutian Diamondiferous province.Doklady Earth Sciences, Vol. 454. no. 2, pp. 179-184.Russia, YakutiaDeposit - Udachnaya
DS201502-0091
2015
Pokhilenko, L.N.Poikilenko, N.P., Agashev, A.M., Litasov, K.D., Pokhilenko, L.N.Carbonatite metasomatism of peridotite lithospheric mantle: implications for diamond formation and carbonatite-kimberlite magmatism.Russian Geology and Geophysics, Vol. 56, 1, pp. 280-295.MantleCarbonatite
DS201503-0131
2015
Pokhilenko, L.N.Alifirova, T.A., Pokhilenko, L.N., Korsakov, A.V.Apatite, SiO2, rutile and orthopyroxene precipitates in minerals of eclogite xenoliths from Yakutian kimberlites, Russia.Lithos, Vol. 226, pp. 31-49.Russia, YakutiaDeposit - Udachnaya, Zarnitsa, Obnazhennaya

Abstract: Eclogite mantle xenoliths from the central part of Siberian craton (Udachnaya and Zarnitsa kimberlite pipes) as well as from the northeastern edge of the craton (Obnazhennaya kimberlite) were studied in detail. Garnet and clinopyroxene show evident exsolution textures. Garnet comprises rutile, ilmenite, apatite, and quartz/coesite oriented inclusions. Clinopyroxene contains rutile (± ilmenite) and apatite precipitates. Granular inclusions of quartz in kyanite and garnet usually retain features of their high-pressure origin. According to thermobarometric calculations, studied eclogitic suite was equilibrated within lithospheric mantle at 3.2–4.9 GPa and 813–1080 °C. The precursor composition of garnets from Udachnaya and Zarnitsa eclogites suggests their stability at depths 210–260 km. Apatite precipitation in clinopyroxenes of Udachnaya and Zarnitsa allows us to declare that original pyroxenes could have been indicative of their high P–T stability. Raman spectroscopic study of quartz and coesite precipitates in garnet porphyroblasts confirms our hypothesis on the origin of the exsolution textures during pressure-temperature decrease. With respect to mineralogical data, we suppose the rocks to be subjected to stepwise decompression and cooling within mantle reservoir.
DS201504-0202
2015
Pokhilenko, L.N.Howarth, G.H., Sobolev, N.V., Pernet-Fisher, J.F., Ketcham, R.A., Maisano, J.A., Pokhilenko, L.N., Taylor, D.3-D X-ray tomography of Diamondiferous mantle eclogite xenoliths, Siberia: a review.Journal of Asian Earth Sciences, Vol. 101, 1, pp. 39-67.RussiaDeposit - Udachnaya
DS201709-1950
2017
Pokhilenko, L.N.Alifirova, T.A., Pokhilenko, L.N., Taylor, L.A.Evolution of garnet clinopyroxenites from a margin of Siberian craton in major and rare element viewpoint.Goldschmidt Conference, abstract 1p.Russia, Siberiadeposit - Obnazhennaya

Abstract: Clinopyroxenite mantle xenoliths from Obnazhënnaya kimberlite pipe, NE part of Siberian craton (Russia), preserve porphyroclastic clinopyroxene with no less than two generations of garnet and orthopyroxene lamellae, sometimes together with rutile. Their crystallographic relationships are consistent with an origin by solid-state exsolution. According to reintegrated major-element chemistry and datasets for natural systems the homogeneous high-Al clinopyroxenes were previously in equilibrium within a T range of ~1400– 1500 şC at a minimum P of 2 GPa. Ca and Al variations in a clinopyroxene assume exsolution to take place during a cooling accompanied by a compression. According to Al contents the growth of orthopyroxene lamellae in the rocks is continued down to ~850 şC and 2.7 GPa. The xenoliths matrix assemblage of Cpx+Grt±Opx marks strain-induced recrystallization where the exsolution features in recrystallized minerals are absent. Later re-equilibration of the mineral assemblage occurred at 790–810 şC and 3.0–3.2 GPa in the cratonic mantle prior to the removal of rocks by kimberlite melts; the reactions were controlled by the diffusion of Ca and Al in a pyroxene structure. It was noted that Sr in clinopyroxenes (284–556 ppm) increases from core to rim together with V (149–226 ppm) and Ca, opposite to Al content higher in the center of Cpx porphyroclasts. A positive Eu anomaly is significant both in clinopyroxenes and garnets (Eu/Eu* = 1.5–1.8 and 1.3–2.0, respectively). Substitution of Al for Si in the pyroxene tetrahedral sites has allowed charging balance for the substitution of additional trivalent REE into the pyroxene M2 site [1]. The process has affected to the Sr2+, Sm3+ and V3+ contents and Eu2+/Eu3+ relations responsible for the presence of Eu anomaly in a pyroxene. The work was supported by the grant of the President of the Russian Federation MK-2231.2017.5. The study with LAT was funded by NSF grant EAR-1144337.
DS201709-2000
2017
Pokhilenko, L.N.Ilyina, O.V., Pokhilenko, L.N., Agashev, A.M.Characteristics of platinum group elements ( PGE) distribution in mantle xenoliths from kimberlite Udachnaya pipe ( Yakutia).Goldschmidt Conference, abstract 1p.Russia, Yakutiadeposit - Udachnaya

Abstract: We report PGE data in xenoliths of the deformed and granular peridotites. The deformed peridotites are the most deep-seated rocks and represent a narrow range of depth (180-220 km) while granular peridotites are located throughout the section of the lithospheric mantle. PGE distribution in the deformed peridotites [1] generally corresponds to that in our granular peridotites and xenoliths from Lesotho [2]. But in contrast with broad range of PGE concentrations in granular peridotites, the deformed peridotites show nearly flat pattern from Os to Pt, except of Pd (Fig.1). Granular peridotites show good positive correlation between PGE and Fe2O3. We suppose that they enriched in PGE by iron phase during its evolution. As for deformed peridotites we propose that they were depleted in Ir and Os followed by the increase of Ga and Cpx on the first stage of mantle metasomatism. On the last stage the enrichment of Pt, Pd and Re was probably a result of submicron sulphide phase’s presipitation in the interstices of mantle rocks.
DS201709-2044
2017
Pokhilenko, L.N.Pokhilenko, L.N.Exotic olivine glimmerites of Yakutia - the related polymict breccias.Goldschmidt Conference, abstract 1p.Russiaglimmerite

Abstract: The rocks, which are totally comprised of olivine and mica, have been found among the xenoliths of the Udachnaya-East pipe (Yakutia). The essential amount (first percents) of ilmenite of different morphology has been found in two rocks. These exotic olivine glimmerites appeared to be similar to the polymict breccia in the wide variations of olivine (LUV709/11 and LUV659/11 - Mg#(%): 86-93 and 83-91, respectively), phlogopite ((wt.%), LUV659/11: SiO2 38.5-40.6, TiO2 2.5-6, Al2O3 11.3-14, Cr2O3 0.4-1, MgO 19.8-23.1, FeO 6.1-7.9, Na2O 0.5-1.3, K2O 8.6-9.9), ilmenite (LUV709/11: Mg#(%) 23.6-47.8; Cr2O3 (wt.%): 0.63-1.01) compositions and also in the abundance of accessory minerals (chromite, rutile, sulphides, calcite, dolomite, siderite, barite). The compositions of rock-forming minerals of the glimmerites do not fall within the compositional fields of similar minerals from the peridotites of kimberlite xenoliths but strongly overlap with that from the polymict breccias. Moreover, the compositions of phlogopite from the glimmerites have demonstrated similar in Al, Fe and Ti composition kimberlite trend typical of phlogopites from the polymict breccia of the South Africa. Unusual olivine glimmerites LUV659/11 and LUV709/11 were probably formed from the ancient protokimberlite melts like polymict breccias. Initially they have been strongly depleted and hence olivine is the main rock-forming mineral. Therefore, two main stages of metasomatic retreatment before the capture by kimberlite can be recognized. One is related with Ti and Fe introduction (ilmenite formation), another, more strong, with abundant introduction of Al and alkalis (mainly K) with a consequent formation of abundant phlogopite. These stages probably had several phases as evidenced by the compositional variations of the formed minerals.
DS201807-1477
2018
Pokhilenko, L.N.Agashev, A.M., Pokhilenko, L.N., Pokhilenko, N.P., Shchukina, E.V.Geochemistry of eclogite xenoliths from the Udachnaya kimberlite pipe: section of ancient oceanic crust sampled.Lithos, DOI:10.1016 /j.lithos.2018 .05.027 available 52p.Russiadeposit - Udachnaya

Abstract: A suite of seventeen unique, large, and fresh eclogite xenoliths from the Udachnaya pipe have been studied for their whole-rock and mineral major- and trace-element compositions. Based on their major-element compositions, the Udachnaya eclogites can be subdivided in two groups: high magnesian (Mg# 68.8-81.9) and low magnesian (Mg# 56.8-59). The two eclogite groups are clearly different in the style of correlation between major elements. Positive correlations of FeO and CaO with MgO are observed in the low-magnesian group, whereas these correlations are negative in the high-magnesian group. In terms of trace element composition, the Udachnaya eclogites are enriched over Primitive Mantle, but comparable to mid-ocean-ridge basalt composition, except for significant enrichment in large-ion lithophile elements (LILE; Rb, Ba, K, Sr). Most of the samples show a positive Eu anomaly, irrespective of group. Reconstructed whole-rock composition from clinopyroxene and garnet modal abundances contains much less incompatible elements (LILE, light rare earth elements, high field strength elements) than measured composition. Approximately 60 to 100% of the middle rare earth elements, Zr, and Hf, and nearly 100% of the heavy rare earth elements, Co, V, and Sc of the whole-rock budget are concentrated in Gar and Cpx. Variations in major element compositions cover a full section of the modern and Archaean oceanic crust, from troctolite, through gabbroic rocks, to basalts. The low-Mg# eclogites could have formed from upper oceanic crust protoliths, being a mixture of basalts and gabbro, whereas the high-Mg# eclogites are originated from gabbro-troctolite section of the lower oceanic crust. Concordant variations of Eu anomaly with the Lu/Sr ratio and the V and Ni contents in the eclogite compositions are in agreement with the fractionation of plagioclase, clinopyroxene, and olivine in their low-pressure precursor rocks. Negative correlations of SiO2 and MgO, and a low Nd/YbNMORB ratio, in the low-Mg# eclogites are in agreement with partial melt loss, but the presence of accessory quartz limits the degree of melting to 13%. Major and trace element compositions suggest that the high-Mg# eclogites, and, consequently, the lower oceanic crust, could not have experienced significant melt loss, and subduction in the Archaean may have been essentially dry, compared to the present day.
DS201810-2369
2018
Pokhilenko, L.N.Pokhilenko, L.N.Exotic olivine mica rocks from the Udachnaya -East pipe ( Yakutia): features of the chemical composition and origin.Doklady Earth Sciences, Vol. 481, 2, pp. 1050-1055.Russia, Yakutiadeposit - Udachnaya -East
DS201909-2074
2019
Pokhilenko, L.N.Pernet-Fisher, J.F., Barry, P.H., Day, J.M.D., Pearson, D.G., Woodland, S., Agashev, A.M., Pokhilenko, L.N., Pokhilenko, N.P.Heterogeneous kimberlite metasomatism revealed from a combined He-Os isotope study of Siberian megacrustalline dunite xenoliths.Geochimica et Cosmochimica Acta, in press available 45p. PdfRussia, Siberiadeposit - Udachnaya East
DS1994-1654
1994
Pokhilenko, N.Sobolev, N.V., Afanasyev, V.P., Pokhilenko, N., Kaminsky, F.Pyropes and diamonds from the Algerian SaharaDoklady Academy of Sciences USSR, Vol. 326, Oct. pp. 151-157.AlgeriaAlluvials, Geochemistry -garnets
DS1997-0890
1997
Pokhilenko, N.Patchen, A.D., Taylor, L.A., Pokhilenko, N.Ferrous freudenbergite in ilmenite megacrysts: a unique paragenesis From the Dalnaya kimberlite, Yakutia.American Mineralogist, Vol. 82, No. 9-10, Sept-Oct. pp. 991-1000.Russia, YakutiaMineralogy, Deposit - Dalnaya
DS1998-0010
1998
Pokhilenko, N.Agashev, A.M., Fomin, A.S., Watanabe, T., Pokhilenko, N.Preliminary age determination of recently discovered kimberlites of the Siberian kimberlite province.7th International Kimberlite Conference Abstract, pp. 9-10.Russia, SiberiaGeochronology, Deposit - Sredne-Marxz, Botuobinskaya, Nurbinskaya
DS1998-0977
1998
Pokhilenko, N.McDonald, J.A., Pokhilenko, N., Melnyk, W., Hall, A.Camsell Lake kimberlites, Slave Province, northwest TerritoriesGeological Society of America (GSA) Annual Meeting, abstract. only, p.A245.Northwest TerritoriesExploration - history outline, Deposit - Camsell Lake, Snap Lake, dike
DS2002-1032
2002
Pokhilenko, N.McDonald, J.A., Pokhilenko, N., Melnyk, W., Hall, A.Camsell Lake kimberlites, Slave Province, Northwest TerritoriesCanadian Institute of Mining and Metallurgy, Vol. 53, Industrial Minerals of Canada, pp. 361-2.Northwest TerritoriesHistory - exploration
DS201312-0006
2013
Pokhilenko, N.Afanasiev, V., Agashev, A., Pokhilenko, N.Dispersion haloes of kimberlite indicator minerals in the Siberian Platform: history and formation conditions.Geology of Ore Deposits, Vol. 55, 4, pp. 256-264.RussiaMineral chemistry
DS201312-0839
2012
Pokhilenko, N.Smith, B., Baziotis, I., Carmody, L., Liu, Y., Taylor, L.A., Pokhilenko, N., Pokhilenko, L.The subcontinental lithospheric mantle of the NE Siberian craton: peridotites from Obnazhennaya.Geological Society of America Annual Meeting abstract, Paper 249-7, 1/2p. AbstractRussiaDeposit - Obnazhennaya
DS201312-0995
2013
Pokhilenko, N.Yelisseyev, A., Meng, G.S., Afanasyev, V., Pokhilenko, N., Pustovarov, V., Isakova, A., Lin, Z.S, Lin, H.Q.Optical properties of impact diamonds from the Popigai astroblemes.Diamond and Related Materials, Vol. 37, pp. 8-16.Russia, SiberiaMeteortic diamonds
DS201412-0699
2014
Pokhilenko, N.Pokhilenko, N.Kimberlite indicator minerals in terrigine sediments of Arctic regions of Siberian and North American ancient platforms: evidence of new cratons with thick lithosphere.ima2014.co.za, PosterRussia, CanadaGeochemistry
DS201412-0700
2014
Pokhilenko, N.Pokhilenko, N.Peridotites of the diamond stability field of the ancient craton lithospheric mantle: relationship with evolution of lithosphere roots and kimberlite melts generation.ima2014.co.za, AbstractMantleMelting
DS201412-0795
2014
Pokhilenko, N.Sharygin, I., Litasov, K., Shatskiy, A., Golovin, A., Ohtani, E., Pokhilenko, N.Is kimberlite magma ascent fuelled by CO2 degassing via orthopyroxene assimilation?V.S. Sobolev Institute of Geology and Mineralogy Siberian Branch Russian Academy of Sciences International Symposium Advances in high pressure research: breaking scales and horizons ( Courtesy of N. Poikilenko), Held Sept. 22-26, 2p. AbstractTechnologyModel
DS201412-0796
2014
Pokhilenko, N.Sharygin, I., Litasov, K., Shatskiy, A., Golovin, A., Ohtani, E., Pokhilenko, N.Melting phase relations of the Udachnaya East Group 1 kimberlite at 3.0-6.5 GPA: experimental evidence for alkali-carbonatite composition of primary kimberlite melt.V.S. Sobolev Institute of Geology and Mineralogy Siberian Branch Russian Academy of Sciences International Symposium Advances in high pressure research: breaking scales and horizons ( Courtesy of N. Poikilenko), Held Sept. 22-26, 2p. AbstractRussia, YakutiaDeposit - Udachnaya-East
DS201502-0100
2015
Pokhilenko, N.Shchukina, E., Agashev, A., Pokhilenko, N.Multistage metasomatism in lithospheric mantle beneath V. Grib pipe ( Arkhangelsk Diamondiferous province, Russia): evidence from REE patterns in garnet xenocrysts.Economic Geology Research Institute 2015, Vol. 17,, # 1940, 1p. AbstractRussia, Kola Peninsula, ArchangelDeposit - Grib
DS201509-0439
2015
Pokhilenko, N.Yelisseyev, A., Khrenov, A., Afanasiev, V., Pustovarov, V., Gromilov, S., Panchenko, A., Pokhilenko, N., Litasov, K.Luminescence of natural carbon nanomaterial: impact diamonds from the Popigai crater.Diamond and Related Materials, Vol. 58, pp. 69-77.RussiaDeposit - Popigai

Abstract: Impact diamonds (IDs) from the Popigai crater are aggregates of nanoparticulate graphite and cubic and hexagonal diamonds. IDs demonstrate broad-band emissions at 3.05, 2.8, 2.3 and 2.0 eV, which are associated with structural defects and are similar to those in detonation ultra-dispersed diamonds and CVD diamond films. A doublet with components at 1.7856 and 1.7892 eV in some ID samples is related to R1,2 lines of Cr3 + ions in corundum inclusions. The presence of N3, H3, NV0 and NV? vibronic systems in some of the ID samples shows that (i) there is nitrogen impurity and (ii) samples underwent high temperature annealing that promoted vacancies and nitrogen diffusion and defect aggregation. The luminescence decay fits with a sum of two exponential components: lifetime of the fast one is in the 5 to 9 ns range. Parameters of the traps responsible for broad thermoluminescence peaks at 148, 180, 276 and 383 K were estimated.
DS201909-2077
2019
Pokhilenko, N.Pokhilenko, N., Agashev, A., Pokhilenko, L.Features of metasomatic treatment of the lithosphere mantle depleted peridotites in relation with scale and diamond grade of kimberlite magmatism.Goldschmidt2019, 1p. Poster abstractSouth America, Brazildeposit - RosaRio-6

Abstract: Three main cycle of kimberlite magmatism are known for the Siberian Platform (SP) to date: Middle Paleozoic (D3), and two Mesozoic (T2-3 and J3). All economic highgrade kimberlites are of Middle Paleozoic (MP) age, and this feature is related with influence of melts/fluids of Permian-Triassic Siberian Super Plume produced huge changes in structure and composition of the SP Lithospheric Mantle (LM) including its enrichment by basaltic components, thinning, increase of fo2 and resorption of diamonds. Nevertheless, there are incredible differences in amounts of kimberlite bodies and their average diamond grade between different kimberlite fields of MP age, and these features are connected with intensity of carbonatite and silicate types of metasomatic treatment of the most deep-seated SP LM depleted peridotites especially of Lithosphere-Asthenosphere (LA) interaction zone. U-type lithospheric diamond formation is related with initial stage of carbonatite metasomatism, and its increase produce wehrlitezation and then carbonation of initial Cr-pyrope harzburgites and dunites but not related with diamond formation. Minor scale of silicate metasomatism of these modified LM peridotites produced conditions for generation of insignificant amount of kimberlite melts which form kimberlite fields with few bodies, but significant part of them are presented by high-grade kimberlite. And in case of significant scale of both carbonatite and silicate metasomatism of the LM peridotites produce large volume of kimberlite melt and hundreds of kimberlite bodies in fields with minor amonts of high grade ones.
DS1982-0500
1982
Pokhilenko, N.P.Pokhilenko, N.P., Sobolev, N.V., Efimova, E.S.Xenolith of Cataclazed Diamond Bearing Disthenic Eclogite from the Pipe 'udachnaia' Yakutia.Doklady Academy of Sciences AKAD. NAUK SSSR., Vol. 266, No. 1, PP. 212-216.RussiaBlank
DS1983-0010
1983
Pokhilenko, N.P.Amshinskii, A.N., Pokhilenko, N.P.Some Distinctive Features of the Composition of Picrolimenites from the Zarnitsa Kimerlite Pipe (yakutia).Soviet Geology and GEOPHYSICS, Vol. 24, No. 11, PP. 106-110.RussiaMineralogy
DS1983-0354
1983
Pokhilenko, N.P.Kharkiv, A.D., Pokhilenko, N.P., Sobolev, N.V.Large Xenoliths of Cataclased Lherzolites from the Udachnaya Kimberlite Pipe of Yakutia.Soviet Geology And Geophysics, Vol. 24, No. 1, PP. 67-72.RussiaMineralogy
DS1984-0591
1984
Pokhilenko, N.P.Pokhilenko, N.P., Sobolev, N.V., Yefimova, YE.S.Xenolith of Broken Down Diamond Bearing Kyanite Eclogite From the Udachnaya Pipe, Yakutia.Doklady Academy of Science USSR, Earth Science Section., Vol. 266, No. 1-6, MAY PP. 90-94.Russia, YakutiaLherzolite, Geothermometry, Genesis, Diamond Morphology
DS1984-0613
1984
Pokhilenko, N.P.Rodionov, A.S., Pokhilenko, N.P., Sobolev, N.V.Comparative Description of Major Minerals of the Concentrate of the Two Varieties of Kimberlite of the Dalnyi Pipe of Yakutia.Soviet Geology And Geophysics, Vol. 25, No. 5, PP. 33-44.Russia, YakutiaMineralogy
DS1984-0693
1984
Pokhilenko, N.P.Sobolev, N.V., Pokhilenko, N.P., Efimova, E.S.Diamond Bearing Peridotite Xenoliths in Kimberlites and The problem of the Origin of Diamonds.Soviet Geology And Geophysics, Vol. 25, No. 12, PP. 62-76.RussiaGenesis
DS1984-0694
1984
Pokhilenko, N.P.Sobolev, N.V., Pokhilenko, N.P., Efimova, E.S.Xenoliths of Diamond Bearing Peridotites in Kimberlites And the Problem of Diamonds Origin.Geologii i Geofiziki, No. 12, (300) DECEMBER PP. 63-RussiaGenesis, Petrography
DS1986-0647
1986
Pokhilenko, N.P.Pokhilenko, N.P., Sobolev, N.V.Xenoliths of Diamondiferous peridotites from Udachnaya kimberlite pipe, YakutiaProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, pp. 309-310RussiaBlank
DS1986-0766
1986
Pokhilenko, N.P.Sobolev, N.V., Kharkiv, A.D., Pokhilenko, N.P.Kimberlites, lamproites and the composition of the upper mantleSoviet Geology and Geophysics, Vol. 27, No. 7, pp. 10-18RussiaKimberlite, Lamproite
DS1986-0767
1986
Pokhilenko, N.P.Sobolev, N.V., Pokhilenko, N.P., Carswell, D.A., Rodionov, A.S.Sheared lherzolites from kimberlites of YakutiaProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, pp. 338-339RussiaBlank
DS1988-0582
1988
Pokhilenko, N.P.Rodionov, A.S., Amshinskiy, A.N., Pokhilenko, N.P.Ilmenite-pyrope wehrlites: a new type of paragenesis in xenoliths fromkimberliteSoviet Geology and Geophysics, Vol. 29, No. 7, pp. 48-51RussiaXenoliths, Wehrlites
DS1989-0696
1989
Pokhilenko, N.P.Jagoutz, E., Shatsky, V.S., Sobolev, N.V., Pokhilenko, N.P.lead-neodymium-Sr isotope study of the Kokchetav Massif;the outcrop of the lowerlithosphereDiamond Workshop, International Geological Congress, July 15-16th. editors, pp. 32-35. AbstractRussiaMantle, Geochronology
DS1989-0739
1989
Pokhilenko, N.P.Kadik, A.A., Sobolev, N.V., Zharkova, E.V., Pokhilenko, N.P.Redox conditions of formation of diamond bearing peridotite xenoliths from Udachnaya kimberlite pipe,Yakutia.(Russian)Geochemistry International (Geokhimiya), (Russian), No. 8, August pp. 1120-1135RussiaGeochemistry, Xenoliths - peridotite
DS1989-1426
1989
Pokhilenko, N.P.Sobolev, N.V., Sobolev, A.V., Pokhilenko, N.P., Yefimova, E.S.Chrome spinels coexisting with Yakutian diamondsDiamond Workshop, International Geological Congress, July 15-16th. editors, pp. 105-108. AbstractRussiaMineral chemistry, Chrome spinels
DS1990-0793
1990
Pokhilenko, N.P.Kadik, A.A., Sobolev, N.V., Zharkova, Ye.V., Pokhilenko, N.P.Redox conditions of formation of diamond bearing peridotite xenoliths In the Udachnaya kimberlite pipe, YakutiaGeochemistry Int, Vol. 27, No. 4, pp. 41-54RussiaRedox Udachnaya, Peridotite
DS1990-1191
1990
Pokhilenko, N.P.Pokhilenko, N.P.Clinopyroxenes and their composition products in xenoliths of mantle Rocks in kimberlites of YakutiaInternational Mineralogical Association Meeting Held June, 1990 Beijing China, Vol. 2, extended abstract p. 819-821RussiaClinopyroxenes, Kimberlites
DS1991-0003
1991
Pokhilenko, N.P.Afanasev, V.P., Sobolev, N.V., Pokhilenko, N.P.Exogenous changes of the indicator minerals at the formation of mineralogical halos of kimberlite bodiesProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 1-2RussiaAlluvial, Diamonds -mineralogy
DS1991-1360
1991
Pokhilenko, N.P.Pokhilenko, N.P., Pearson, D.G., Boyd, F.R., Sobolev, N.V.Megacrystalline dunites and peridotites: hosts for Siberian diamondsCarnegie Institute Annual Report of the Director Geophysical Laboratory, No. 2250, pp. 11-18Russia, SiberiaDunites, Peridotites
DS1991-1446
1991
Pokhilenko, N.P.Rodionov, A.S., Sobolev, N.V., Pokhilenko, N.P., Suddaby, P.Ilmenite-bearing peridotites and megacrysts from Dalnaya kimberlite pipe, YakutiaProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 339-341RussiaMineral chemistry, ilmenite-pyrope lherzolite, Ilmenite-pyrope wehrlites, Metasomatism
DS1991-1623
1991
Pokhilenko, N.P.Sobolev, N.V., Bakumenko, I.T., Yefimova, E.S., Pokhilenko, N.P.Morphological features of microdiamonds, sodium in garnet and potassium inpyroxenes content of two eclogite xenoliths from Udachnaya pipe(Yakutia).(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 321, No. 3, pp. 585-592Russia, Commonwealth of Independent States (CIS), YakutiaMicrodiamonds, Udachanya pipe
DS1991-1624
1991
Pokhilenko, N.P.Sobolev, N.V., Bakumenko, I.T., Yefimova, E.S., Pokhilenko, N.P.Pecularities of microdiamond morphology, sodium content in garnets andDoklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 321, No. 3, pp. 585-592. #hh968RussiaMicro-diamonds, Geochemistry
DS1992-1446
1992
Pokhilenko, N.P.Sobolev, N.V., Afanasev, V.P., Pokhilenko, N.P., Kaminsky, F.V.Pyropes and diamonds of the Algerian Sahara.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 325, No. 2, pp. 367-373.AlgeriaIndicator minerals, Pyropes, diamonds
DS1992-1449
1992
Pokhilenko, N.P.Sobolev, N.V., Pokhilenko, N.P., Grib, V.P., Skripnichenko, V.A.Specific composition and conditions of formation of deep seated mineralsRussian Geology and Geophysics, Vol. 33, No. 10, pp. 71-78.Russia, Commonwealth of Independent States (CIS), Arkangelsk, RussiaZolotisa Field, Tectonics, Explosion pipes, Kimberlites
DS1993-0151
1993
Pokhilenko, N.P.Boyd, F.R., Pearson, D.G., Pokhilenko, N.P., Mertzman, S.A.Cratonic mantle composition: evidence from Siberian xenolithsEos, Transactions, American Geophysical Union, Vol. 74, No. 16, April 20, supplement abstract p. 321Russia, SiberiaBulk composition, Mineral chemistry
DS1993-0585
1993
Pokhilenko, N.P.Griffin, W.L., Sobolev, N.V., Ryan, C.G., Pokhilenko, N.P., WinTrace elements in garnets and chromites: diamond formation in the SiberianlithosphereLithos, Vol. 29, pp. 235-256Russia, Commonwealth of Independent States (CIS), Siberia, YakutiaGeochemistry, Diamond genesis
DS1993-1247
1993
Pokhilenko, N.P.Pokhilenko, N.P., Sobolev N.V., Boyd, F.R., Pearson, D.G., Shimizum N.Megacrystalline pyrope peridotites in the lithosphere of the Siberianplatform: mineralogy, geochemical pecularities and the problem of their origin.Russian Geology and Geophysics, Vol. 34, No. 1, pp. 1-12.Russia, Commonwealth of Independent States (CIS), SiberiaPyrope peridotites, Siberian Platform, Geochemistry
DS1993-1454
1993
Pokhilenko, N.P.Shimizu, N., Pokhilenko, N.P.Trace element zoning patterns of mantle garnetsGeological Society of America Annual Abstract Volume, Vol. 25, No. 6, p. A36 abstract onlySouth Africa, Russia, YakutiaGarnet dunite, Deposit -Jagersfontein, Udachnaya
DS1993-1499
1993
Pokhilenko, N.P.Sobolev, N.V., Pokhilenko, N.P., Afanasev, V.P.Kimberlite pyropes and chromites morphology and chemistry as indicators of diamond grade in Yakutian and Arkangelsk Provinces.Mid-continent diamonds Geological Association of Canada (GAC)-Mineralogical Association of Canada (MAC) Symposium ABSTRACT volume, held Edmonton May, pp. 63-70.Russia, Commonwealth of Independent States (CIS), YakutiaMineral chemistry, Diamond morphology
DS1994-1393
1994
Pokhilenko, N.P.Pokhilenko, L.N., Federov, I.I., Pokhilenko, N.P., et al.Fluid regime of formation of mantle rocks according to dat a of chromatographic analysis and thermodynamic cal.Russian Geology and Geophysics, Vol. 35, No. 4, pp. 60-64.RussiaMantle, Kimberlites
DS1994-1591
1994
Pokhilenko, N.P.Shimizu, N., Boyd, F.R., Sobolev, N.V., Pokhilenko, N.P.Chemical zoning of garnets in peridotites and diamondsMineralogical Magazine, Vol. 58A, pp. 831-832. AbstractSouth Africa, Russia, YakutiaGeochemistry, mineral inclusions, Diamond inclusions
DS1995-0192
1995
Pokhilenko, N.P.Boyd, F.R., Pokhilenko, N.P., Pearson, D.G., Sobolev, N.V.Peridotite xenoliths from the Udachnaya kimberlite pipeProceedings of the Sixth International Kimberlite Conference Extended Abstracts, p. 57-59.Russia, YakutiaXenoliths, Deposit -Udachnaya
DS1995-1033
1995
Pokhilenko, N.P.Kryuchkov, A.I., Kharkiv, A.D., Pokhilenko, N.P.Identification of kimberlite bodies subjected to dynamic effect oftraps.... Yubileinaya pipe.Russian Geology and Geophysics, Vol. 36, No. 5, pp. 61-71.Russia, YakutiaSill, Trap rocks, Deposit -Jubillee, Ozernaya
DS1995-1458
1995
Pokhilenko, N.P.Pearson, D.G., Kelley, S.P., Pokhilenko, N.P., Boyd, F.R.Laser 40 Ar-39 Ar analyses of phlogopites from kimberlites and theirxenoliths: constraints eruptionProceedings of the Sixth International Kimberlite Conference Abstracts, pp. 424-426.Russia, Yakutia, South AfricaGeochronology -eruption ages, Argon, Deposit -Mir, Udachnaya, Leningrad, Letseng, Kampfersda
DS1995-1506
1995
Pokhilenko, N.P.Pokhilenko, N.P., McDonald, J.A., Melnyk, W., McCorquodaleIndicator minerals of CL 25 kimberlite pipe, Slave Craton, northwest TerritoriesProceedings of the Sixth International Kimberlite Conference Abstracts, pp. 444-445.Northwest TerritoriesGeochemistry -indicator minerals, Deposit -CL-25 pipe
DS1995-1507
1995
Pokhilenko, N.P.Pokhilenko, N.P., Sobolev, N.V.Mineralogical mapping of the southeast section of the Yakutian kimberlite province and its main results.Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 446-448.Russia, YakutiaMineralogy, Deposit -Olenek River Basin area
DS1995-1736
1995
Pokhilenko, N.P.Shimizu, N., Pokhilenko, N.P., Biyd, F.R., Pearson, D.G.Geochemical characteristics of mantle xenoliths from the Udachnaya kimberlite pipe.Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 524-525.Russia, YakutiaGeochemistry, Deposit -Udachnaya
DS1997-0120
1997
Pokhilenko, N.P.Boyd, F.R., Pokhilenko, N.P., Finger, L.W.Composition of the Siberian Cratonic mantle: evidence from Udachnaya peridotite xenoliths.Contributions to Mineralogy and Petrology, Vol. 128, No. 2-3, pp. 228-246.RussiaSiberian Craton, Deposit - Udachnaya
DS1997-0917
1997
Pokhilenko, N.P.Pokhilenko, N.P., McDonald, J., Melnik, U., McCorquodaleIndicator minerals of CL-25 kimberlite pipe Slave Craton, NorthwestTerritories, Canada.Russian Geology and Geophysics, Vol. 38, No. 2, pp. 550-558.Northwest TerritoriesGeochemistry, Deposit - CL-25
DS1998-0009
1998
Pokhilenko, N.P.Afanasiev, V.P., Pokhilenko, N.P., Logvinova, A.M.Problem of false indicators for kimberlites and lamproites ( on the exampleof chromites).7th International Kimberlite Conference Abstract, pp. 7-8.Russia, Yakutia, ArkangelskMineralogy - chromium spinels
DS1998-1174
1998
Pokhilenko, N.P.Pokhilenko, N.P., McDonald, J.A., Melnyk, Hall, ShimizuKimberlites of Camsell Lake field and some features of construction and composition of lithosphere roots...7th. Kimberlite Conference abstract, pp. 699-701.Northwest TerritoriesCraton - Slave, Deposit - Camsell Lake
DS1998-1175
1998
Pokhilenko, N.P.Pokhilenko, N.P., Sobolev, N.V., Kuligin, ShimizuPeculiarities of pyroxenite paragenesis garnets distribution in Yakutian kimberlites .. craton mantle7th. Kimberlite Conference abstract, pp. 702-4.Russia, Siberia, YakutiaCraton - lithospheric mantle evolution, Magmatism
DS1998-1340
1998
Pokhilenko, N.P.Shimizu, N., Pokhilenko, N.P., Boyd, F.R., Pearson, D.Trace element characteristics of garnet dunites/harzburgites, host rocks for peridotite diamond7th International Kimberlite Conference Abstract, pp. 803-4.Russia, SiberiaMineral chemistry, Peridotite diamonds
DS1998-1341
1998
Pokhilenko, N.P.Shimizu, N., Pokhilenko, N.P., McDonald, J.A.Geochemical characteristics of the Slave Craton lithosphere: a view heavy mineral concentrate garnets7th International Kimberlite Conference Abstract, pp. 805-6.Northwest TerritoriesGeochemistry, Peridotite diamonds
DS1999-0561
1999
Pokhilenko, N.P.Pokhilenko, N.P., Sobolev, N.V., Kuligin, S.S., ShimizuPeculiarities of distribution of pyroxenite paragenesis garnets in Yakutian kimberlites and some aspects of...7th International Kimberlite Conference Nixon, Vol. 2, pp. 689-98.Russia, Yakutia, KharamaiCraton - evolution of Siberian craton, petrography, Udachnaya, Obnazhennaya
DS1999-0664
1999
Pokhilenko, N.P.Shimizu, N., Pokhilenko, N.P., Boyd, F.R., Pearson, D.Trace element characteristics of garnet dunites /harzburgites. Host rocks for Siberian peridotitic ..7th International Kimberlite Conference Nixon, Vol. 2, pp. 773-82.Russia, Siberia, YakutiaPeridotite - diamond, geochemistry, Deposit - Udachnaya
DS2000-0771
2000
Pokhilenko, N.P.Pokhilenko, N.P., Sobolev, N.V., Chernyi, S.D., YanginPyropes and chromites from kimberlites in the Nakyn Field, and Snipe Lake (Slave River region) Evidence...Doklady Academy of Sciences, Vol. 372, No. 4, May-June pp. 638-42.Northwest Territories, Russia, YakutiaLithosphere - structure, Deposit - Nakyn, Snipe Lake
DS2001-0934
2001
Pokhilenko, N.P.Pokhilenko, N.P., McDonald, Hall, SobolevAbnormally thick Cambrian lithosphere of the southeast Slave Craton evidence from crystalline inclusions ..Slave-Kaapvaal Workshop, Sept. Ottawa, 3p. abstractNorthwest TerritoriesDiamonds and pyrope compositions - kimberlites, Deposit - Snap Lake
DS2001-0935
2001
Pokhilenko, N.P.Pokhilenko, N.P., Sobolev, McDonald, Hall, YefimovaCrystalline inclusions in diamonds from kimberlites of the Snap lake area: new evidence anomalous lithosphereDoklady Academy of Sciences, Vol. 381, No. 7, Sept/Oct. pp. 806-11.Northwest TerritoriesDiamond - inclusions, Deposit - Snap Lake
DS2001-0936
2001
Pokhilenko, N.P.Pokhilenko, N.P., Sobolev, N.V., McDonald, Hall et alCrystalline inclusions in diamonds from kimberlites of the Snap lake: new evidence anomalous lithosphericDoklady Academy of Sciences, Vol. 380, No. 7, Sept-Oct. pp.806-12.Northwest TerritoriesDiamond - inclusions, Deposit - Snap lake
DS2002-0591
2002
Pokhilenko, N.P.Golovin, A.V., Sharygin, V.V., Pokhilenko, N.P., Malkovets, V.G., KoelsovSecondary melt inclusions in olivine from unaltered kimberlites of the Udachnaya East pipe, Yakutia.Doklady Earth Sciences, Vol. 388,1,pp. 93-96.Russia, YakutiaPetrology, deposit - Udachnaya
DS2002-1328
2002
Pokhilenko, N.P.Reutskii, V.N., Pokhilenko, N.P., Hall, A.E., Sobolev, N.V.Polygenous character of diamonds from kimberlites of the Snap lake region ( SlaveDoklady Earth Sciences, Vol. 386, 7, Sept-Oct.pp. 791-4.Northwest TerritoriesDiamond - morphology, Deposit - Snap Lake
DS2002-1772
2002
Pokhilenko, N.P.Zedgenizov, D.A., Pokhilenko, N.P., Rylov, G.M., Milledge, J.H., Jones, A.P.Assorted diamond population from Snap lake mine ( Canada)18th. International Mineralogical Association Sept. 1-6, Edinburgh, abstract p.116Northwest TerritoriesDiamond - morphology
DS2003-0043
2003
Pokhilenko, N.P.Ashchepkov, I.V., Vladykin, N.V., Pokhilenko, N.P., et al.Clinopyroxene geotherms for the mantle columns beneath kimberlite pipes from8 Ikc Www.venuewest.com/8ikc/program.htm, Session 6, POSTER abstractRussia, SiberiaGeothermometry
DS2003-0479
2003
Pokhilenko, N.P.Golovin, A.V., Sharygin, V.V., Pokhilenko, N.P., Malkovets, V.G., KolesavSecondary melt inclusions in olivine from unaltered kimberlites of the Udachnaya EastDoklady Earth Sciences, Vol. 388,1, pp. 93-96.Russia, YakutiaInclusions, Deposit - Udachnaya
DS2003-0480
2003
Pokhilenko, N.P.Golovin, A.V., Sharygin, V.V., Pokhilenko, N.P., Malkovets, V.G., Sobolev, N.V.Secondary melt inclusions in olivine from unaltered kimberlites of the Udachnaya8 Ikc Www.venuewest.com/8ikc/program.htm, Session 7, POSTER abstractRussia, YakutiaDeposit - Udachnaya
DS2003-0870
2003
Pokhilenko, N.P.Malkovets, V.G., Taylor, L.A., Griffin, W.L., O'Reilly, S., Pokhilenko, N.P.Eclogites from the Grib kimberlite pipe, Arkangelsk, Russia8ikc, Www.venuewest.com/8ikc/program.htm, Session 2, POSTER abstractRussia, ArkangelskEclogites and Diamonds, Deposit - Grib
DS2003-0871
2003
Pokhilenko, N.P.Malygina, E.V., Pokhilenko, N.P., Sobolev, N.V.Coarse peridotite xenoliths of Udachnaya kimberlite pipe, Yakutia: garnetization of8 Ikc Www.venuewest.com/8ikc/program.htm, Session 6, POSTER abstractRussia, Siberia, YakutiaDeposit - Udachnaya
DS2003-1090
2003
Pokhilenko, N.P.Pokhilenko, N.P., Agashev, A.M., McDonald, J.A., Sobolev, N.V., MityukhinKimberlites of the Nakyn field, Siberia and the Snap Lake King Lake dyke system8 Ikc Www.venuewest.com/8ikc/program.htm, Session 7, POSTER abstractNorthwest TerritoriesDeposit - Snap Lake, King Lake
DS2003-1091
2003
Pokhilenko, N.P.Pokhilenko, N.P., Agashev, A.M., McDonald, J.A., Vavilov, M.A., Clark, D.B..Kimberlites and carbonatites of the Snap Lake King Lake dyke system: structural8 Ikc Www.venuewest.com/8ikc/program.htm, Session 7, POSTER abstractNorthwest TerritoriesDeposit - Snap Lake, King Lake
DS2003-1092
2003
Pokhilenko, N.P.Pokhilenko, N.P., Griffin, W.L., Shimizu, N., McLean, R.C., Malkovets, V.G.Pyropes and chromites of the Snap Lake King Lake kimberlite dyke system in relation8 Ikc Www.venuewest.com/8ikc/program.htm, Session 6, POSTER abstractNorthwest TerritoriesDeposit - Snap Lake King Lake
DS2003-1093
2003
Pokhilenko, N.P.Pokhilenko, N.P., McDonald, J.A., Sobolev, N.V., Reutsky, V.N., Hall, A.E.Crystalline inclusions and C isotope composition of diamonds from the Snap lake/King8 Ikc Www.venuewest.com/8ikc/program.htm, Session 3, AbstractNorthwest TerritoriesDiamonds - geochronology, Deposit - Snap Lake
DS2003-1094
2003
Pokhilenko, N.P.Pokhilenko, N.P., McDonald, J.A., Turner, R.C.Snap Lake kimberlite dyke system - history and methods of a new type of largeGeological Association of Canada Annual Meeting, Abstract onlyNorthwest TerritoriesTechniques
DS2003-1258
2003
Pokhilenko, N.P.Sharygin, V.V., Golovin, A.V., Pokhilenko, N.P.Djerfisherite from unaltered kimberlites of the Udachnaya eastern pipe, Yakutia8 Ikc Www.venuewest.com/8ikc/program.htm, Session 7, POSTER abstractRussia, YakutiaDeposit - Udachnaya
DS2003-1259
2003
Pokhilenko, N.P.Sharygin, V.V., Golovin, A.V., Pokhilenko, N.P., Sobolev, N.V.Djerfisherite in unaltered kimberlites of the Udachnaya East pipe, YakutiaDoklay Earth Sciences, Vol. 390, 4, May-June pp. 554-8.RussiaMineralogy, Deposit - Udachnaya
DS200412-0064
2003
Pokhilenko, N.P.Ashchepkov, I.V., Vladykin, N.V., Pokhilenko, N.P., et al.Clinopyroxene geotherms for the mantle columns beneath kimberlite pipes from Siberian Craton.8 IKC Program, Session 6, POSTER abstractRussia, SiberiaMantle petrology Geothermometry
DS200412-0686
2003
Pokhilenko, N.P.Golovin, A.V., Sharygin, V.V., Pokhilenko, N.P., Malkovets, V.G., Sobolev, N.V.Secondary melt inclusions in olivine from unaltered kimberlites of the Udachnaya eastern pipe, Yakutia.8 IKC Program, Session 7, POSTER abstractRussia, YakutiaKimberlite petrogenesis Deposit - Udachnaya
DS200412-1213
2003
Pokhilenko, N.P.Malygina, E.V., Pokhilenko, N.P., Sobolev, N.V.Coarse peridotite xenoliths of Udachnaya kimberlite pipe, Yakutia: garnetization of peridotites of the central Siberian platform8 IKC Program, Session 6, POSTER abstractRussia, Siberia, YakutiaMantle petrology Deposit - Udachnaya
DS200412-1561
2003
Pokhilenko, N.P.Pokhilenko, N.P., Agashev, A.M., McDonald, J.A., Sobolev, N.V., Mityukhin, S.I., Vavilov, M.A., Yanygin, Y.T.Kimberlites of the Nakyn field, Siberia and the Snap Lake King Lake dyke system, Slave Craton, Canada: a new variety of kimberli8 IKC Program, Session 7, POSTER abstractCanada, Northwest TerritoriesKimberlite petrogenesis Deposit - Snap Lake, King Lake
DS200412-1562
2003
Pokhilenko, N.P.Pokhilenko, N.P., Agashev, A.M., McDonald, J.A., Vavilov, M.A., Clark, D.B., Wright, K.J.Kimberlites and carbonatites of the Snap Lake King Lake dyke system: structural setting, petrochemistry and petrology of a uniqu8 IKC Program, Session 7, POSTER abstractCanada, Northwest TerritoriesKimberlite petrogenesis Deposit - Snap Lake, King Lake
DS200412-1563
2003
Pokhilenko, N.P.Pokhilenko, N.P., Griffin, W.L., Shimizu, N., McLean, R.C., Malkovets, V.G., Pokhilenko, L.N., Malygina, E.V.Pyropes and chromites of the Snap Lake King Lake kimberlite dyke system in relation to the problem of the southern Slave Craton8 IKC Program, Session 6, POSTER abstractCanada, Northwest TerritoriesMantle petrology Deposit - Snap Lake King Lake
DS200412-1564
2003
Pokhilenko, N.P.Pokhilenko, N.P., McDonald, J.A., Sobolev, N.V., Reutsky, V.N., Hall, A.E., Logvinova, A.M., Reimers, L.F.Crystalline inclusions and C isotope composition of diamonds from the Snap lake/King Lake kimberlite dyke system: evidence for a8 IKC Program, Session 3, AbstractCanada, Northwest TerritoriesDiamonds - geochronology Deposit - Snap Lake
DS200412-1565
2003
Pokhilenko, N.P.Pokhilenko, N.P., McDonald, J.A., Turner, R.C.Snap Lake kimberlite dyke system - history and methods of a new type of large primary diamond deposit discovery.Geological Association of Canada Annual Meeting, Abstract onlyCanada, Northwest TerritoriesTechniques
DS200412-1566
2004
Pokhilenko, N.P.Pokhilenko, N.P., Sobolev, N.V., Reutsky, V.N., Hall, A.E., Taylor, L.A.Crystalline inclusions and C isotope ratios in diamonds from the Snap Lake/King Lake kimberlite dyke system: evidence of ultradeLithos, Vol. 77, 1-4, Sept. pp. 57-67.Canada, Northwest TerritoriesDiamond inclusions, Carbon isotopes
DS200412-1592
2004
Pokhilenko, N.P.Promprated, P., Taylor, L.A., Anand, M., Floss, C., Sobolev, N.V., Pokhilenko, N.P.Multiple mineral inclusions in diamonds from the Snap Lake/King Lake kimberlite dike, Slave Craton: a trace element perspective.Lithos, Vol. 77, 1-4, Sept. pp. 69-81.Canada, Northwest TerritoriesDiamond inclusions, trace element, REE, in situ analysi
DS200412-1797
2003
Pokhilenko, N.P.Sharygin, V.V., Golovin, A.V., Pokhilenko, N.P.Djerfisherite from unaltered kimberlites of the Udachnaya eastern pipe, Yakutia.8 IKC Program, Session 7, POSTER abstractRussia, YakutiaKimberlite petrogenesis Deposit - Udachnaya
DS200412-1798
2003
Pokhilenko, N.P.Sharygin, V.V., Golovin, A.V., Pokhilenko, N.P., Sobolev, N.V.Djerfisherite in unaltered kimberlites of the Udachnaya East pipe, Yakutia.Doklady Earth Sciences, Vol. 390, 4, May-June pp. 554-8.RussiaMineralogy Deposit - Udachnaya
DS200412-2181
2004
Pokhilenko, N.P.Yelisseyev, A.P., Pokhilenko, N.P., Steeds, J.W., Zedgenizov, D.A., Afanasiev, V.P.Features of coated diamonds from the Snap Lake/King Lake kimberlite dyke, Slave Craton, Canada, as revealed by optical topographLithos, Vol. 77, 1-4, Sept. pp. 83-97.Canada, Northwest TerritoriesCoated diamonds, absorption, luminescence, nickel, nitr
DS200512-0007
2004
Pokhilenko, N.P.Agashev, A.M., Pokhilenko, N.P., Tolstov, A.V., Polyanichko, Malkovets, SobolevNew age dat a on kimberlites from the Yakutian Diamondiferous Province.Doklady Earth Sciences, Vol. 399, 8, pp.1142-1145.Russia, YakutiaGeochronology
DS200512-0495
2004
Pokhilenko, N.P.Kamenetsky, M.B., Sobolev, A.V., Kamenetsky, V.S., Maas, R., Danyushevsky, L.V., Thomas, R., Pokhilenko, N.P., Sobolev, N.V.Kimberlite melts rich in alkali chlorides and carbonates: a potent metasomatic agent in the mantle.Geology, Vol. 32, 10, Oct. pp. 845-848.Russia, Siberia, YakutiaUdachnaya, Group I, volatiles, metasomatism, inclusions
DS200512-0760
2004
Pokhilenko, N.P.Nadolinnyi, V.A., Yreva, O.P., Yelisseyev, A.P., Pokhilenko, N.P., Chepurov, A.A.Disruption of B1 nitrogen defects in 1aB natural diamonds.Doklady Earth Sciences, Vol. 399A, Nov-Dec. pp. 1228-1272.Diamond morphology
DS200512-0966
2004
Pokhilenko, N.P.Sharygin, V.V., Golovin, A.V., Pokhilenko, N.P.Genesis of djerfisherite from kimberlites and xenoliths of the Udachnaya diatreme, Yakutia Russia.Deep seated magmatism, its sources and their relation to plume processes., pp. 236-256.RussiaMineralogy
DS200612-0004
2006
Pokhilenko, N.P.Agashev, A.M., Pokhilenko, N.P., Malkovets, V.G., Sobolev, N.V.Sm Nd isotopic system in garnet megacrysts from the Udachnaya kimberlite pipe (Yakutia) and petrogenesis of kimberlites.Doklady Earth Sciences, Vol. 407A, 3, pp. 491-494.Russia, YakutiaGeochronology - Udachnaya
DS200612-0045
2005
Pokhilenko, N.P.Ashchepkov, I.V., Vladykin, N.V., Pokhilenko, N.P., Rotman, A.Y., Afansiev, V.P., Logvinova, A.M.Using the monomineral thermobarometry for the reconstruction of the mantle sections.Problems of Sources of Deep Magmatism and Plumes., pp. 210-228.MantleGeothermometry
DS200712-0032
2007
Pokhilenko, N.P.Ashchepkov, I.V., Pokhilenko, N.P., Logvinova, A.M., Vladykin, N.P., Rotman, Palessky, Alymova, VishnyakovaEvolution of kimberlite magmatic sources beneath Siberia.Plates, Plumes, and Paradigms, 1p. abstract p. A39.RussiaMir
DS200712-0922
2007
Pokhilenko, N.P.Rylov, G.M., Fedorova, E.N., Logvinova, A.M., Pokhilenko, N.P., Kulipanov, G.N., Sobolev, N.V.The peculiarities of natural plastically deformed diamond crystals from Internationalnaya pipe, Yakutia.Nuclear Instruments and Methods in Physics Research Section A., Vol. 575, 1-2, pp. 152-154.RussiaDiamond morphology
DS200712-0970
2007
Pokhilenko, N.P.Sharygin, V.V., Kamenetsky, V.S., Kamenetskaya, M.B., Seretkin, Yu.V., Pokhilenko, N.P.Rasvumite from the Udachnaya East pipe: the first finding in kimberlites.Doklady Earth Sciences, Vol. 445, 6, pp. DOI:10.1134/S1028334 X07060232Russia, YakutiaMineralogy
DS200812-0003
2008
Pokhilenko, N.P.Agashev, A.M., Kuligan, S.S., Orihashi, Y., Pokhilenko, N.P., Vavilov, M.A., Clarke, D.Ages of zircons from Jurassic sediments of Bluefish River slope, NWT and the possible age of kimberlite activity in the Lena West property.Doklady Earth Sciences, Vol. 421, 1, pp. 751-754.Canada, Northwest TerritoriesDeposit - Lena West, geochronology
DS200812-0004
2008
Pokhilenko, N.P.Agashev, A.M., Pokhilenko, N.P., Takazawa, E., McDonald, J.A., Vavilov, M.A., Watanabe, T., Sobolev, N.V.Primary melting sequence of a deep ( >250 km) lithospheric mantle as recorded in the geochemistry of kimberlite carbonatite assemblages, Snap Lake dyke system, Canada.Chemical Geology, Vol. 255, 3-4, pp. 317-328.Canada, Northwest TerritoriesDeposit - Snap Lake
DS200812-0050
2008
Pokhilenko, N.P.Ashcheperov, I.V., Pokhilenko, N.P., Vladykin, N.P., Logovina, A.M., Nikoleva,I., Palessky, RotmanMelts in mantle columns beneath Siberian kimberlites.Goldschmidt Conference 2008, Abstract p.A35.Russia, SiberiaDeposit - Alkite
DS200812-0423
2008
Pokhilenko, N.P.Golovin, A.V., Kamenetsky, M.B., Kamenetsky, V.S., Sharygin, V.V., Pokhilenko, N.P.Groundmass of unaltered kimberlites of the Udachnaya East pipe (Yakutia Russia): a sample of the kimberlite melt.9IKC.com, 3p. extended abstractRussiaDeposit - Udachnaya
DS200812-0539
2008
Pokhilenko, N.P.Kamenetsky, V.S., Kamenetsky, M.B., Golovin, A.V., Maas, R., Sharygin, V.V., Pokhilenko, N.P.Salty kimberlite of the Udachnaya East pipe ( Yakutia, Russia): a petrological oddity, victim of contamination or a new magma type?9IKC.com, 3p. extended abstractRussiaDeposit - Udachnaya - taste!
DS200812-0798
2008
Pokhilenko, N.P.Nikolenko, E.I., Afanasev, V.P., Pokhilenko, N.P.Garnets of crustal parageneses in alluvial deposits of the eastern Siberian platform: genesis and search significance.Russian Geology and Geophysics, Vol. 49, pp. 655-666.Russia, YakutiaMuna Markha drainage
DS200812-0905
2008
Pokhilenko, N.P.Pokhilenko, L.N., Pokhilenko, N.P., Fedorov, L.I., Tomilenko, A.A., Usova, L.V., Fomina, L.N., Sobolev, V.S.Fluid regime pecularities of the lithosphere mantle of the Siberian Platform.Deep Seated Magmatism, its sources and plumes, Ed. Vladykin, N.V., 2008 pp. 122-136.Russia, SiberiaMantle chemistry
DS200812-0906
2008
Pokhilenko, N.P.Pokhilenko, N.P.Permo-Triassic superplume and its influence to the Siberian lithospheric mantle.Deep Seated Magmatism, its sources and plumes, Ed. Vladykin, N.V., 2008 pp. 41-53.Russia, SiberiaPlume, hot spots
DS200812-0987
2007
Pokhilenko, N.P.Rylov, G.M., Fedorova, E.N., Logvinova, A.M., Pokhilenko, N.P.The pecularities of natural plastically deformed diamond crystals from International pipe.Nuclear Instruments and Methods in Physics Research Section A., Vol. 575, no. 1/2, pp. 152-154.TechnologyDeposit - International
DS200812-1092
2008
Pokhilenko, N.P.Sobolev, N.V., Logvinova, A.M., Zedgenizov, D.A., Pokhilenko, N.P., Kuzmin, D.V., Sobolev, A.V.Olivine inclusions in Siberian diamonds: high precision approach to minor elements.European Journal of Mineralogy, Vol. 20, no. 3, pp. 305-315.Russia, SiberiaDiamond inclusions
DS200812-1190
2008
Pokhilenko, N.P.Tychkov, N.S., Pokhilenko, N.P., Kuligin, S.S., Malygina, E.V.Composition and origin of peculiar pyropes from lherzolites: evidence for the evolution of the lithospheric mantle of the Siberian Platform.Russian Geology and Geophysics, Vol. 49, 4, pp. 225-239.RussiaMineralogy - garnets
DS200912-0003
2009
Pokhilenko, N.P.Afanasyev, V.P., Agashev, A.M., Orihashi, Y., Pokhilenko, N.P., Sobolev, N.V.Paleozoic U Pb age of rutile inclusions in diamonds of the V-VII variety from placers of the northeast Siberian platform.Doklady Earth Sciences, Vol. 428, 1, pp. 1151-1155.RussiaDiamond inclusions
DS200912-0112
2009
Pokhilenko, N.P.Chepurov, A.I., Zhimulev, E.I., Sonin, V.M., Chepurov, A.A., Pokhilenko, N.P.Crystallization of diamond in metal sulfide melts.Doklady Earth Sciences, Vol. 428, 1, pp. 1139-1141.MantleDiamond morphology, geochemistry
DS200912-0470
2009
Pokhilenko, N.P.Malkovets, V.G., Belousova, E.A., Griffin, W.L., Buzlukova, L.V., Shatsky, V.S., O'Reilly, S.Y., Pokhilenko, N.P.U/Pb dating of zircons from the lower crustal xenoliths from Siberian kimberlites.Goldschmidt Conference 2009, p. A823 Abstract.Russia, SiberiaDeposit - Udachnaya
DS200912-0529
2009
Pokhilenko, N.P.Nadolinny, V.A., Yurjeva, O.P., Pokhilenko, N.P.EPR and luminescence dat a on the nitrogen aggregation in diamonds from Snap Lake dyke system.Lithos, In press - available 19p.Canada, Northwest TerritoriesDeposit - Snap Lake
DS200912-0589
2009
Pokhilenko, N.P.Pokhilenko, N.P.Polymict breccia xenoliths: evidence for the complex character of kimberlite formation.Lithos, In press - available 29p.Russia, Africa, South AfricaDeposit - Premier, Sytykanskaya
DS200912-0707
2008
Pokhilenko, N.P.Sobolev, N., Wirth, R., Logvinova, A.M., Pokhilenko, N.P., Kuzmin, D.V.Retrograde phase transitions of majorite garnets included in diamonds: a case study of subcalcic Cr rich majorite pyrope from a Snap Lake diamond, Canada.American Geological Union, Fall meeting Dec. 15-19, Eos Trans. Vol. 89, no. 53, meeting supplement, 1p. abstractCanada, Northwest TerritoriesDeposit - Snap lake
DS200912-0708
2009
Pokhilenko, N.P.Sobolev, N.V., Logvinova, A.M., Zedgenizov, D.A., Pokhilenko, N.P., Malygina, E.V., Kuzmin, D.V., Sobolev, A.V.Petrogenetic significance of minor elements in olivines from diamonds and peridotite xenoliths from kimberlites of Yakutia.Lithos, In press - available 38p.Russia, YakutiaDiamond inclusions
DS201012-0005
2010
Pokhilenko, N.P.Agashev, A.M., Pokhilenko, N.P., Cherepanova, Yu.V., Golovin, A.V.Geochemical evolution of rocks at the base of the lithospheric mantle: evidence from study of xenoliths of deformed peridotites from kimberlite of UdachnayaDoklady Earth Sciences, Vol. 432, 2, pp. 746-749.RussiaDeposit - Udachnaya
DS201012-0335
2009
Pokhilenko, N.P.Kamenetsky, V.S., Kamenetsky, M.B., Sobolev, A.V., Golovin, A.V., Sharyginb, V.V., Pokhilenko, N.P., Sobolev, N.V.Can pyroxenes be liquidus minerals in the kimberlite magma?Lithos, Vol. 112 S pp. 213-235.MantleChemistry
DS201012-0541
2010
Pokhilenko, N.P.Nikolenko, E.I., Afanasev, V.P., Pokhilenko, N.P.Pecularities of the composition of zoned picroilmenites from the Massadou field, (Guinea) and Dachanya pipe ( Yakutia) kimberlites.Doklady Earth Sciences, Vol. 434, 2, pp.1386-1389.Africa, Guinea, RussiaGeochemistry - Massadou, Dachanaya
DS201012-0590
2010
Pokhilenko, N.P.Pokhilenko, N.P., Afanasev, V.P., Vavilov, M.A.Behaviour of kimberlite indicator minerals during the formation of mechanical dispersion halos in glacial settings.Lithology and Mineral Resources, Vol. 45, 4, pp. 324-329.Canada, Northwest TerritoriesDeposit - CL 25
DS201012-0741
2010
Pokhilenko, N.P.Sonin, V.M., Zhimulev, E.I., Chepurov, A.I., Afanasev, V.P., Pokhilenko, N.P.High pressure etching of diamond in chloride melt in the presence of aqueous fluid.Doklady Earth Sciences, Vol. 434, 2, pp. 1359-1361.TechnologyUHP
DS201112-0005
2011
Pokhilenko, N.P.Afanasev, V.P., Lobanov, S.S., Pokhilenko, N.P., Koptil, Mityukhin, Gerasimchuk, Pomazanski, GorevPolygenesis of diamonds in Siberian Platform. Five groups of diamonds have been distinquished.Russian Geology and Geophysics, Vol.l 52, pp. 259-274.Russia, SiberiaDiamond placers, alluvials
DS201112-0006
2010
Pokhilenko, N.P.Afanasiev, V.P., Tychkov, N.S., Pokhilenko, N.P., Ovchinnikov, Yu.I.About kimberlite indicator minerals in the Triassic tuffs of the Tunguska sineclise.Doklady Earth Sciences, Vol. 435, 2, pp. 1555-1559.RussiaDiamond exploration
DS201112-0465
2011
Pokhilenko, N.P.Ionov, D.A., Doucet, L.S., Carlson, R.W., Pokhilenko, N.P., Golovin, A.V., Ashchepkov, I.V.Peridotite xenolith inferences on the formation and evolution of the central Siberian cratonic mantle.Goldschmidt Conference 2011, abstract p.1085.Russia, SiberiaUdachnaya
DS201112-0606
2010
Pokhilenko, N.P.Litasov, K.D., Sharygin, I.S., Shatskiy, A.F., Ohtani, E., Pokhilenko, N.P.Experimental constraints on the role of chloride in the origin and evolution of kimberlitic magma.Doklady Earth Sciences, Vol. 435, 2, pp. 1641-1646.MantleMineralogy
DS201112-0608
2011
Pokhilenko, N.P.Litasov, K.D., Shatskiy, A.F., Pokhilenko, N.P.Phase relations and melting in the systems of peridotite H2O CO2 and eclogite H2OCO2 at pressures up to 27 GPa.Doklady Earth Sciences, Vol. 437, 2, pp. 498-502.MantleUHP
DS201112-0807
2010
Pokhilenko, N.P.Pokhilenko, L.N., Pokhilenko, N.P., Vladykin, N.V.Garnet orthopyroxenites from the Udachnaya kimberlite pipe ( Yakutia): features of their composition and orogin.Vladykin, N.V., Deep Seated Magmatism: its sources and plumes, pp. 128-144.Russia, YakutiaMineralogy - genesis
DS201112-0808
2011
Pokhilenko, N.P.Pokilanko, L.N., Golovin, A.V., Shrygin, I.S., Pokhilenko, N.P.Accessory minerals of mantle xenoliths: first finds of Cl-free K-Fe sulphides.Doklady Earth Sciences, Vol. 440, 2, pp. 1404-1409.MantleXenolith petrology
DS201112-0942
2011
Pokhilenko, N.P.Sharygin, I.S., Golovin, A.V., Pokhilenko, N.P.Djerfisherite in kimberlites of the Kuoikskoe field as an indicator of enrichment of kimberlite melts in chlorine.Doklady Earth Sciences, Vol. 436, 2, pp. 219-223.RussiaPetrology
DS201112-1063
2011
Pokhilenko, N.P.Tychkov, N.S., Agashev, A.M., Pokhilenko, N.P., Bzhan, I.S.Estimation of the refertilization grade of lithosphere roots by the chemical composition of garnets from Siberian kimberlites.Doklady Earth Sciences, Vol. 439, 2, pp.1175-1178.Russia, SiberiaGeochemistry - garnets
DS201212-0005
2012
Pokhilenko, N.P.Agashev, A.M., Ionov, D.A., Pokhilenko, N.P., Golovin, A.V., Surgutonova, E.A., Sharygin, I.S.Metasomatism in cratonic mantle root: insight from geochemistry of deformed peridotite xenoliths of Udachnaya pipe.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractRussia, YakutiaDeposit - Udachnaya
DS201212-0006
2012
Pokhilenko, N.P.Agashev, A.M., Orihashi, Y., Rotman, A.Ua., Pokhilenko, N.P., erov, I.V., Tolstov, A.V.Rutile and titanite as the minerals for dating kimberlite emplacement age: an example of Amakinskaya and Taezhnaya pipes of Mirny field, Siberia10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractRussia, YakutiaDeposit - Mirny field
DS201212-0252
2012
Pokhilenko, N.P.Golovin, A.V., Sherygin, I.S., Korsakov, A.V., Pokhilenko, N.P.Can be parental kimberlite melts alkali-carbonate liquids: results investigations composition melt inclusions in mantle xenoliths from kimberlites.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractMantleMelting
DS201212-0412
2012
Pokhilenko, N.P.Litasov, K.D., Shatskiy, A., Ohtani, E., Pokhilenko, N.P.Melting phase relations in the systems peridotite-H2O-CO2 and eclogite-H2O-CO2 at pressures up to 27 Gpa.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractMantleMelting
DS201212-0438
2012
Pokhilenko, N.P.Malkovets, V.G., Griffin, W.L., Pearson, N.J., Rezvukhin, D.I., Oreilly, S.Y., Pokhilenko, N.P., Garanin, V.K., Spetsius, Z.V., Litasov, K.D.Late metasomatic addition of garnet to the SCLM: Os-itope evidence.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractMantleMetasomatism
DS201212-0439
2012
Pokhilenko, N.P.Malkovets, V.G., Griffin, W.L., Pokhilenko, N.P., O'Reilly, S.Y., Dak, A.I., Tolstov, A.V., Serov, I.V., Bazhan, I.S., Kuzmin, D.V.Lithosphere mantle structure beneath the Nakyn kimberlite field, Yakutia.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractRussia, YakutiaDeposit - Nakyn
DS201212-0440
2012
Pokhilenko, N.P.Malygina, E.V., Pokhilenko, N.P.Pecurlarities of composition of coarse peridotite xenoliths of some kimberlite pipes of South Africa.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractAfrica, South AfricaDeposit - Bells Bank, Roberts Victor, Wesselton, Bostoff Road
DS201212-0561
2012
Pokhilenko, N.P.Pokhilenko, N.P.Mineralogical and petrological evidences of lithosphere thickness variations inside ancient cratons.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractRussia, Canada, Northwest TerritoriesCraton
DS201212-0562
2012
Pokhilenko, N.P.Pokhilenko, N.P., Afanasev, V.P., McDonald, J.A., Vavilov, M.A., Kulgin, S.S., Pokhilenko, L.N., Golovin, A.V., Agashev, A.M.Kimberlite indicator minerals in terrigene sediments of lower part of Mackenzie River Basin, NWT, Canada: evidence of new craton with thick lithosphere.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractCanada, Northwest TerritoriesGeochemistry - KIMS
DS201212-0583
2012
Pokhilenko, N.P.Rezvukhin, D.I., Malkovets, V.G., Gibsher, A.A., Kuzmin, D.V., Griffin, W.L., Pokhilenko, N.P., O'Reilly, S.Y.Mineral inclusions in pyropes from some kimberlite pipes of Yakutia.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractRussia, YakutiaDeposit - Internationskaya
DS201212-0636
2012
Pokhilenko, N.P.Sharygin, I.S., Golovin, A.V., Pokhilenko, N.P.Djerfisherite in xenoliths of sheared peridotite in the Udachanaya East pipe ( Yakutia): origin and relationship with kimberlitic magmatism.Russian Geology and Geophysics, Vol. 53, 3, pp. 247-261.Russia, YakutiaDeposit - Udachnaya
DS201212-0637
2012
Pokhilenko, N.P.Sharygin, I.S., Golovin, A.V., Pokhilenko, N.P.Djerfisherite in kimberlite - hosted mantle xenoliths: textural features, composition and origin.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractRussiaDeposit - Udachnaya East
DS201212-0638
2012
Pokhilenko, N.P.Sharygin, I.S., Litasov, K.D., Shatskiy, A., Golovin, A.V., Ohtani, E., Pokhilenko, N.P.Melting phase relations of chlorine bearing kimberlite at 2.1-6.5 GPA and 900-1500 ON10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractMantleMelting
DS201212-0642
2012
Pokhilenko, N.P.Shchukina, E.V., Malkovets, V.G., Golovin, N.N., Pokhilenko, N.P.Peridotitic mantle section beneath V Grib kimberlite pipe ( Arkhangelsk region, Russia): mineralogical composition P-T conditions, metasomatism.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractRussia, Archangel, Kola PeninsulaDeposit - Grib
DS201212-0643
2012
Pokhilenko, N.P.Shchulina, E.V., Golovin, N.N., Malkovets, V.G., Pokhilenko, N.P.Mineralogy and equilibrium P-T estimates for peridotite assemblages from the V Grib kimberlite pipe (Arkangelsk kimberlite province).Doklady Earth Sciences, Vol. 444, 2, pp. 776-781.Russia, Kola Peninsula, ArchangelDeposit - Grib
DS201212-0739
2012
Pokhilenko, N.P.Tychkov, N.S., Agashev, A.M., Pokhilenko, N.P.Refertilisation grade estimations of lithosphere roots by the chemical composition of garnets from Siberian kimberlites.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractRussia, SiberiaGarnet
DS201312-0008
2013
Pokhilenko, N.P.Afanasiev, V.P., Snegirev, O.V., Tychkov, N.S., Pokhilenko, N.P.Stability of kimberlite garnets exposed to chemical weathering: relationship with Cr contents.Doklady Earth Sciences, Vol. 448, 1, pp. 103-105.TechnologyGarnet mineralogy
DS201312-0401
2014
Pokhilenko, N.P.Howarth, G.H., Barry, P.H., Pernet-Fisher, J.F., Baziotis, I.P., Pokhilenko, N.P., Pokhilenko, L.N., Bodnar, R.J., Taylor, L.A.Superplume metasomatism: evidence from Siberian mantle xenoliths.Lithos, Vol. 184-187, pp. 209-224.Russia, SiberiaMetasomatism
DS201312-0534
2013
Pokhilenko, N.P.Letnikova, E.F., Lobanov, S.S., Pokhilenko, N.P., Izokh, A.E., Nikolenko, E.I.Sources of clastic material in the Carnian diamond bearing horizon of the northeastern part of the Siberian Platform.Doklady Earth Sciences, Vol. 451, 1, pp. 702-705.Russia, SiberiaCarnion
DS201312-0714
2013
Pokhilenko, N.P.Pokhilenko, N.P., Afanasiev, V.P.New prospective for diamond deposits in Siberia.PDAC 2013, March 4, 1/2p. Abstract only as conflict in his scheduleRussiaOverview - Siberia
DS201312-0803
2013
Pokhilenko, N.P.Sharygin, I.S., Litasov, K.D., Shatskiy, A., Golovin, A.V., Ohtani, E., Pokhilenko, N.P.Melting phase relations in Udachnaya-East kimberlite and search for parental melt composition. Group IGoldschmidt 2013, AbstractRussiaDeposit - Udachnaya
DS201312-1016
2013
Pokhilenko, N.P.Zhimulev, E.I., Shein, M.A., Pokhilenko, N.P.Diamond crystallization in the Fe-S-C system.Doklady Earth Sciences, Vol. 451, 1, pp. 729-731.TechnologyDiamond morphology
DS201412-0373
2014
Pokhilenko, N.P.Howarth, G.H., Barry, P.H., Pernet-Fisher, J.F., Baziotis, I.P., Pokhilenko, N.P., Poikhilenko, L.N., Bodnar, R.L., Taylor, L.A., Agashev, A.M.Superplume metasomatism: evidence from Siberian mantle xenoliths.Lithos, Vol. 184-187, pp. 209-224.RussiaMetasomatism
DS201412-0698
2014
Pokhilenko, N.P.Pokhilenko, L.N., Malkovets, V.G., Kuzmin, D.V., Pokhilenko, N.P.New dat a on the mineralogy of megacrystalline pyrope peridotite from the Udachnaya kimberlite pipe, Siberian Craton, Yakutian Diamondiferous province.Doklady Earth Sciences, Vol. 454. no. 2, pp. 179-184.Russia, YakutiaDeposit - Udachnaya
DS201412-0721
2014
Pokhilenko, N.P.Rakhmanova, M.I., Nadolinny, V.A., Yuryeva, O.P., Pokhilenko, N.P.Pecularities of nitrogen impurity aggregation in diamonds from the Sytykanskaya pipe, Yakutia.European Journal of Mineralogy, Vol. 27, 1, pp. 51-56.Russia, YakutiaDeposit - Sytykanskaya
DS201412-0797
2013
Pokhilenko, N.P.Sharygin, I.S., Golovin, A.V., Korsakov, A.V., Pokhilenko, N.P.Eitelite in sheared peridotite xenoliths from Udachnaya-East kimberlite pipe ( Russia) - a new locality and host rock type.European Journal of Mineralogy, Vol. 25, pp. 825-834.Russia, YakutiaDeposit - Udachnaya
DS201412-0798
2014
Pokhilenko, N.P.Sharygin, I.S., Litasov, K.D., Shatskiy, A., Golovin, A.V., Ohtani, E., Pokhilenko, N.P.Melting phase relations of the Udachnaya-East Group 1 kimberlite at 3.0-6.5GPa: experimental evidence for alkali-carbonatite composition of primary kimberlite melts and implications for mantle plumes.Gondwana Research, in press availableRussiaDeposit - Udachnaya-East
DS201412-0937
2014
Pokhilenko, N.P.Tychkov, N.S., Agashev, A.M., Malygina, E.V., Nikolenko, E.I., Pokhilenko, N.P.Thermal pertubations in the lithospheric mantle as evidenced from P-T equilibrium conditions of xenoliths from the Udachnaya kimberlite pipe.Doklady Earth Sciences, Vol. 454, 1, pp. 84-88.Russia, YakutiaDeposit - Udachnaya
DS201412-0952
2014
Pokhilenko, N.P.Vladykin, N.V., Kotov, A.B., Borisenko, A.S., Yarmolyuk, V.V., Pokhilenko, N.P., Salnikova, E.B., Travin, A.V., Yakovleva, S.Z.Age boundaries of formation of the Tomtor alkaline ultramafic pluton: U Pb and 40 Ar 39 Ar geochronological studies.Doklady Earth Sciences, Vol. 454, 1, pp. 7-11.RussiaGeochronology
DS201412-1013
2014
Pokhilenko, N.P.Yudin, D.S., Tomilenko, A.A., Travin, A.V., Agashev, A.M., Pokhilenko, N.P., Orihashi, yu.The age of the Udachnaya-East kimberlite: U/Pb and 40 Ar/39Ar data.Doklady Earth Sciences, Vol. 455, 1, pp. 288-290.RussiaDeposit - Udachnaya
DS201503-0170
2015
Pokhilenko, N.P.Rakhmanova, M.I., Nadolinny, V.A., Yuryeva, O.P., Pokhilenko, N.P., Logvinova, A.M.Pecularities of nitrogen impurity aggregation in diamonds from the Sytykanskaya pipe, Yakutia.European Journal of Mineralogy, Vol. 27, pp. 51-56.Russia, YakutiaDeposit - Sytykanskaya
DS201504-0183
2015
Pokhilenko, N.P.Barry, P.H., Hilton, D.R., Day, J.M.D., Pernet-Fisher, J.F., Howarth, G.H., Magna, T., Agashev, A.M., Pokhilenko, N.P., Opkhilenko, L.N., Taylor, L.A.Helium isotope evidence for modification of the cratonic lithosphere during the Permo-Triassic Siberian flood basalt event.Lithos, Vol. 216-217, pp. 73-80.Russia, SiberiaDeposit - Udachnaya, Obnazhennaya

Abstract: Major flood basalt emplacement events can dramatically alter the composition of the sub-continental lithospheric mantle (SCLM). The Siberian craton experienced one of the largest flood basalt events preserved in the geologic record — eruption of the Permo-Triassic Siberian flood basalts (SFB) at ~250 Myr in response to upwelling of a deep-rooted mantle plume beneath the Siberian SCLM. Here, we present helium isotope (3 He/ 4 He) and concentra-tion data for petrologically-distinct suites of peridotitic xenoliths recovered from two temporally-separated kim-berlites: the 360 Ma Udachnaya and 160 Ma Obnazhennaya pipes, which erupted through the Siberian SCLM and bracket the eruption of the SFB. Measured 3 He/ 4 He ratios span a range from 0.1 to 9.8 R A (where R A = air 3 He/ 4 He) and fall into two distinct groups: 1) predominantly radiogenic pre-plume Udachnaya samples (mean clinopyroxene 3 He/ 4 He = 0.41 ± 0.30 R A (1?); n = 7 excluding 1 outlier), and 2) 'mantle-like' post plume Obnazhennaya samples (mean clinopyroxene 3 He/ 4 He = 4.20 ± 0.90 R A (1?); n = 5 excluding 1 outlier). Olivine separates from both kimberlite pipes tend to have higher 3 He/ 4 He than clinopyroxenes (or garnet). Helium con-tents in Udachnaya samples ([He] = 0.13–1.35 ?cm 3 STP/g; n = 6) overlap with those of Obnazhennaya ([He] = 0.05–1.58 ?cm 3 STP/g; n = 10), but extend to significantly higher values in some instances ([He] = 49– 349 ?cm 3 STP/g; n = 4). Uranium and thorium contents are also reported for the crushed material from which He was extracted in order to evaluate the potential for He migration from the mineral matrix to fluid inclusions. The wide range in He content, together with consistently radiogenic He-isotope values in Udachnaya peridotites suggests that crustal-derived fluids have incongruently metasomatized segments of the Siberian SCLM, whereas high 3 He/ 4 He values in Obnazhennaya peridotites show that this section of the SCLM has been overprinted by Permo-Triassic (plume-derived) basaltic fluids. Indeed, the stark contrast between pre-and post-plume 3 He/ 4 He ra-tios in peridotite xenoliths highlights the potentially powerful utility of He-isotopes for differentiating between various types of metasomatism (i.e., crustal versus basaltic fluids).
DS201506-0301
2015
Pokhilenko, N.P.Zedgenizov, D.A., Pokhilenko, N.P., Griffin, W.L.Carbonate- silicate composition of diamond forming media of fibrous diamonds from Snap Lake area, Canada.Doklady Earth Sciences, Vol. 461, 1, pp. 297-300.Canada, Northwest TerritoriesMicro-inclusions
DS201507-0336
2015
Pokhilenko, N.P.Shchukina, E.V., Agashev, A.M., Golovin, N.N., Pokhilenko, N.P.Equigranualr eclogites from the V. Grib kimberlite pipe: evidence for Paleoproterozoic subduction on the territory of the Arkangelsk Diamondiferous province.Doklady Earth Sciences, Vol. 462, 1, pp. 497-501.Russia, Archangel, Kola PeninsulaDeposit - Grib
DS201508-0347
2015
Pokhilenko, N.P.Chepurov, A.A., Pokhilenko, N.P.Experimental estimation of the kimberlite melt velosity. ( Nyurbinskaya mentioned)Doklady Earth Sciences, Vol. 462, 2, pp. 592-595.TechnologyPetrology - geodynamic model
DS201602-0237
2015
Pokhilenko, N.P.Shchukina, E.V., Agashev, A.M., Kostrovitsky, S.I., Pokhilenko, N.P.Metasomatic processes in the lithospheric mantle beneath the V. Grib kimberlite pipe ( Arkangelsk Diamondiferous province, Russia).Russian Geology and Geophysics, Vol. 56, pp. 1701-1716.RussiaDeposit - Grib

Abstract: New data on metasomatic processes in the lithospheric mantle in the central part of the Arkhangelsk diamondiferous province (ADP) are presented. We studied the major- and trace-element compositions of minerals of 26 garnet peridotite xenoliths from the V. Grib kimberlite pipe; 17 xenoliths contained phlogopite. Detailed mineralogical, petrographic, and geochemical studies of peridotite minerals (garnet, clinopyroxene, and phlogopite) have revealed two types of modal metasomatic enrichment of the lithospheric-mantle rocks: high temperature (melt) and low-temperature (phlogopite). Both types of modal metasomatism significantly changed the chemical composition of the peridotites. Low-temperature modal metasomatism manifests itself as coarse tabular and shapeless phlogopite grains. Two textural varieties of phlogopite show significant differences in chemical composition, primarily in the contents of TiO2, Cr2O3, FeO, Ba, Rb, and Cs. The rock-forming minerals of phlogopite-bearing peridotites differ in chemical composition from phlogopite-free peridotites, mainly in higher FeO content. Most garnets and clinopyroxenes in peridotites are the products of high-temperature mantle metasomatism, as indicated by the high contents of incompatible elements and REE pattern in these minerals. Fractional-crystallization modeling gives an insight into the nature of melts (metasomatic agents). They are close in composition to picrites of the Izhmozero field, basalts of the Tur’ino field, and carbonatites of the Mela field of the ADP. The REE patterns of the peridotite minerals make it possible to determine the sequence of metasomatic enrichment of the lithospheric mantle beneath the V. Grib kimberlite pipe.
DS201604-0625
2015
Pokhilenko, N.P.Sharygin, I.S., Litasov, K.D., Shatskiy, A., Golovin, A.V., Ohtani, E., Pokhilenko, N.P.Melting phase relations of the Udachnaya-East group 1 kimberlite at 3.0-6.5 Gpa: experimental evidence for alkali- carbonatite composition of primary kimberlite melts and implications for mantle plumes.Gondwana Research, Vol. 28, pp. 1391-1414.RussiaDeposit - Udachnaya -East

Abstract: Experiments on the origin of the Udachnaya-East kimberlite (UEK) have been performed using a Kawai-type multianvil apparatus at 3-6.5GPa and 900-1500°C. The studied composition represents exceptionally fresh Group-I kimberlite containing (wt.%): SiO2=25.9, TiO2=1.8, Al2O3=2.8, FeO=9.0, MgO=30.1, CaO=12.7, Na2O=3.4, K2O=1.3, P2O5=1.0, Cl=0.9, CO2=9.9, and H2O=0.5. The super-solidus assemblage consists of melt, olivine (Ol), Ca-rich (26.0-30.2wt.% CaO) garnet (Gt), Al-spinel (Sp), perovskite (Pv), a CaCO3 phase (calcite or aragonite), and apatite. The low pressure assemblage (3-4GPa) also includes clinopyroxene. The apparent solidus was established between 900 and 1000°C at 6.5GPa. At 6.5GPa and 900°C Na-Ca carbonate with molar ratio of (Na+K)/Ca?0.44 was observed. The UEK did not achieve complete melting even at 1500°C and 6.5GPa, due to excess xenogenic Ol in the starting material. In the studied P-T range, the melt has a Ca-carbonatite composition (Ca#=molar Ca/(Ca+Mg) ratio=0.62-0.84) with high alkali and Cl contents (7.3-11.4wt.% Na2O, 2.8-6.7wt.% K2O, 1.6-3.4wt.% Cl). The K, Na and Cl contents and Ca# decrease with temperature. It is argued that the primary kimberlite melt at depths>200km was an essentially carbonatitic (<5wt.% SiO2), but evolved toward a carbonate-silicate composition (up to 15-20wt.% SiO2) during ascent. The absence of orthopyroxene among the run products indicates that xenogenic orthopyroxene was preferentially dissolved into the kimberlite melt. The obtained subliquidus phase assemblage (Ol+Sp+Pv+Ca-rich Gt) at P-T conditions of the UEK source region, i.e. where melt was in the last equilibrium with source rock before magma ascent, differs from the Opx-bearing peridotitic mineral assemblage of the UEK source region. This difference can be ascribed to the loss of substantial amounts of CO2 from the kimberlite magma at shallow depths, as indicated by both petrological and experimental data. Our study implies that alkali-carbonatite melt would be a liquid phase within mantle plumes generated at the core-mantle boundary or shallower levels of the mantle, enhancing the ascent velocity of the plumes. We conclude that the long-term activity of a rising hot mantle plume and associated carbonatite melt (i.e. kimberlite melt) causes thermo-mechanical erosion of the subcontinental lithosphere mantle (SCLM) roots and creates hot and deformed metasomatic regions in the lower parts of the SCLM, which corresponds to depths constrained by P-T estimates of sheared Gt-peridotite xenoliths. The sheared Gt-peridotites undoubtedly represent samples of these regions.
DS201605-0887
2016
Pokhilenko, N.P.Rezvukhin, D.I., Malkovets, V.G., Sharygin, I.S., Kuzmin, D.V., Litasov, K.D., Gibsher, A.A., Pokhilenko, N.P., Sobolev, N.V.Inclusions of Cr- and Cr-Nb-Rutile in pyropes from the Internationalnaya kimberlite pipe, Yakutia.Doklady Earth Sciences, Vol. 466, 2, Feb. pp. 173-176.Russia, YakutiaDeposit - International

Abstract: The results of study of rutile inclusions in pyrope from the Internatsionalnaya kimberlite pipe are presented. Rutile is characterized by unusually high contents of impurities (up to 25 wt %). The presence of Cr2O3 (up to 9.75 wt %) and Nb2O5 (up to 15.57 wt %) are most typical. Rutile inclusions often occur in assemblage with Ti-rich oxides: picroilmenite and crichtonite group minerals. The Cr-pyropes with inclusions of rutile, picroilmenite, and crichtonite group minerals were formed in the lithospheric mantle beneath the Mirnyi field during their joint crystallization from melts enriched in Fe, Ti, and other incompatible elements as a result of metasomatic enrichment of the depleted lithospheric mantle.
DS201605-0888
2016
Pokhilenko, N.P.Rezvukhin, D.I., Malkovets, V.G., Sharygin, I.S., Kuzmin, D.V., Litasov, K.D., Gibsher, A.A., Pokhilenko, N.P., Sobolev, N.V.Inclusions of crichonite group minerals in pyropes from the Internatsionalnaya kimberlite pipe, Yakutia.Doklady Earth Sciences, Vol. 466, 2, Feb. pp. 206-209.Russia, YakutiaDeposit - International
DS201606-1111
2016
Pokhilenko, N.P.Samdanov, D.A., Afanasiev, V.P., Tychkov, N.S., Pokhilenko, N.P.Mineralogical zoning of the Diamondiferous areas: application experience of paragenetic analysis of garnets from kimberlites.Doklady Earth Sciences, Vol. 467, 1, pp. 228-231.Russia, YakutiaDeposit area - Muna-Markha

Abstract: Paragenetic analysis of pyropes from alluvial deposits of the Muna—Markha interfluve (Sakha-Yakutia Republic) made it possible to distinguish relatively uniform areas that are promising for the discovery of kimberlite bodies.
DS201606-1115
2016
Pokhilenko, N.P.Sharygin, I.S., Golovin, A.V., Korsakov, A.V., Pokhilenko, N.P.Tychite in mantle xenoliths from kimberlites: the first find of a new genetic type.Doklady Earth Sciences, Vol. 467, 1, pp. 270-274.Russia, YakutiaDeposit -Udachnaya East

Abstract: Tychite Na6Mg2(CO3)4(SO3) is a rare natural Na and Mg sulfatocarbonate. It is found only as minor mineral in deposits of saline lakes in the United States, Canada, Uganda, and China. In these continental evaporites tychite has sedimentary genesis. In this study, we report the first occurrence of tychite as a crystal phase in the melt inclusions in olivine from mantle xenoliths of the Udachnaya-East kimberlite pipe. This find provides an evidence for the probability of tychite crystallization from melts; i.e., this rare sulfatocarbonate may have a magmatic origin as well.
DS201608-1452
2016
Pokhilenko, N.P.Yudin, D.S., Tomilanko, A.A., Alifirova, T.A., Travin, A.V., Murzintsev, N.G., Pokhilenko, N.P.Results of 40 Ar/39 Ar dating of phlogopites from kelphyphitic rims around garnet grains ( Udachnaya- Vostochnaya pipe).Doklady Earth Sciences, Vol. 469, 1, pp. 728-731.RussiaDeposit - Udachnaya - Vostochnaya
DS201610-1886
2016
Pokhilenko, N.P.Melkovets, V.G., Rezvukhin, D.I., Belousova, E.A., Griffin, W.L., Sharygin, I.S., Tretiakova, I.G., Pokhilenko, N.P., Sobolev, N.V.Cr-rich rutile: a powerful tool for diamond exploration.Lithos, in press available 8p.Russia, SiberiaDeposit - Internationalnaya

Abstract: Mineralogical studies and U-Pb dating have been carried out on rutile included in peridotitic and eclogitic garnets from the Internatsionalnaya pipe, Mirny field, Siberian craton. We also describe a unique peridotitic paragenesis (rutile + forsterite + enstatite + Cr-diopside + Cr-pyrope) preserved in diamond from the Mir pipe, Mirny field. Compositions of rutile from the heavy mineral concentrates of the Internatsionalnaya pipe and rutile inclusions in crustal almandine-rich garnets from the Mayskaya pipe (Nakyn field), as well as from a range of different lithologies, are presented for comparison. Rutile from cratonic mantle peridotites shows characteristic enrichment in Cr, in contrast to lower-Cr rutile from crustal rocks and off-craton mantle. Rutile with Cr2O3 > 1.7 wt% is commonly derived from cratonic mantle, while rutiles with lower Cr2O3 may be both of cratonic and off-cratonic origin. New analytical developments and availability of standards have made rutile accessible to in situ U-Pb dating by laser ablation ICP-MS. A U-Pb age of 369 ± 10 Ma for 9 rutile grains in 7 garnets from the Internatsionalnaya pipe is consistent with the accepted eruption age of the pipe (360 Ma). The equilibrium temperatures of pyropes with rutile inclusions calculated using Ni-in-Gar thermometer range between ~ 725 and 1030 °C, corresponding to a depth range of ca ~ 100-165 km. At the time of entrainment in the kimberlite, garnets with Cr-rich rutile inclusions resided at temperatures well above the closure temperature for Pb in rutile, and thus U-Pb ages on mantle-derived rutile most likely record the emplacement age of the kimberlites. The synthesis of distinctive rutile compositions and U-Pb dating opens new perspectives for using rutile in diamond exploration in cratonic areas.
DS201611-2139
2016
Pokhilenko, N.P.Sharygin, I.S., Litasov, K.D., Shatskiy, A., Safonov, O.G., Golovin, A.V., Ohtani, E., Pokhilenko, N.P.Experimental constraints on orthopyroxene dissolution in alkali carbonate melts in the lithospheric mantle: implications for kimberlite melt composition and magma ascent.Chemical Geology, in press available 42p.TechnologyMagma melting

Abstract: Although kimberlite magma carries large amounts of mantle-derived xenocrysts and xenoliths (with sizes up to meters), this magma ascends from the Earth's mantle (> 150-250 km) to the surface in a matter of hours or days, which enables diamonds to survive. The recently proposed assimilation-fuelled buoyancy model for kimberlite magma ascent emphasizes the importance of fluid CO2 that is produced via the reactive dissolution of mantle-derived orthopyroxene xenocrysts into kimberlite melt, which initially has carbonatitic composition. Here, we use a series of high-pressure experiments to test this model by studying the interaction of orthopyroxene (Opx) with an alkali-dolomitic melt (simplified to 0.7Na2CO3 + 0.3K2CO3 + 2CaMg(CO3)2), which is close to the melt that is produced by the partial melting of a kimberlite source, at P = 3.1-6.5 GPa and T = 1200-1600 °C, i.e., up to pressures that correspond to depths (~ 200 km) from where the ascent of kimberlite magma would start. During the first set of experiments, we study the reaction between powdered Opx and model carbonate melt in a homogeneous mixture. During the second set of experiments, we investigate the mechanism and kinetics of the dissolution of Opx crystals in alkali-dolomitic melt. Depending on the P-T conditions, Opx dissolves in the alkali-dolomitic melt (CL) either congruently or incongruently via the following reactions: Mg2Si2O6 (Opx) + CaMg(CO3)2 (CL) = CaMgSi2O6 (clinopyroxene) + 2MgCO3 (CL) and Mg2Si2O6 (Opx) = Mg2SiO4 (olivine) + SiO2 (CL). The experiments confirm that the dissolution of Opx causes gradual SiO2 enrichment in the initial carbonate melt, as previously suggested. However, the assimilation of Opx by carbonate melt does not produce fluid CO2 in the experiments because the CO2 is totally dissolved in the evolved melt. Thus, our results clearly demonstrate the absence of exsolved CO2 fluid at 3.1-6.5 GPa in ascending kimberlite magma and disprove the assimilation-fuelled buoyancy model for kimberlite magma ascent in the lithospheric mantle. We alternatively suggest that the extreme buoyancy of kimberlite magma at depths of 100-250 km is an exclusive consequence of the unique physical properties (i.e., low density, ultra-low viscosity and, thus, high mobility) of the kimberlite melt, which are dictated by its carbonatitic composition.
DS201612-2297
2016
Pokhilenko, N.P.Egorova, E.O., Afanasev, V.P., Pokhilenko, N.P.Middle Paleozoic kimberlite magmatism in the northeastern Siberia.Doklady Earth Sciences, Vol. 470, 2, pp. 1023-1026.Russia, SiberiaDeposit - Billyakh River placers

Abstract: The mineral chemistry and crystal morphology of kimberlite pyropes from the Billyakh River placer in the northeastern Siberian craton are characterised in terms of the placer history. The pyropes bear signatures of chemical weathering (dissolution), presumably in a Middle Paleozoic laterite profile, and therefore were originally hosted by Middle Paleozoic kimberlites. The broad occurrence of placer pyropes with lateritic dissolution signatures points to the presence of Middle Paleozoic diamond-bearing kimberlites in the study area.
DS201612-2320
2016
Pokhilenko, N.P.Malkovets, V.G., Rezvukhin, D.I., Belousova, E.A., Griffin, W.L., Sharygin, I.S., Tretiakov, I.G., Gibsher, A.A., O'Reilly, S.Y., Kuzmin, D.V., Litasov, K.D., Logvinova, A.M., Pokhilenko, N.P., Sobolev, N.V.Cr-rich rutile: a powerful tool for diamond exploration.Lithos, Vol. 265, pp. 304-311.Russia, SiberiaDeposit - Internationalskaya

Abstract: Mineralogical studies and U-Pb dating have been carried out on rutile included in peridotitic and eclogitic garnets from the Internatsionalnaya pipe, Mirny field, Siberian craton. We also describe a unique peridotitic paragenesis (rutile + forsterite + enstatite + Cr-diopside + Cr-pyrope) preserved in diamond from the Mir pipe, Mirny field. Compositions of rutile from the heavy mineral concentrates of the Internatsionalnaya pipe and rutile inclusions in crustal almandine-rich garnets from the Mayskaya pipe (Nakyn field), as well as from a range of different lithologies, are presented for comparison. Rutile from cratonic mantle peridotites shows characteristic enrichment in Cr, in contrast to lower-Cr rutile from crustal rocks and off-craton mantle. Rutile with Cr2O3 > 1.7 wt% is commonly derived from cratonic mantle, while rutiles with lower Cr2O3 may be both of cratonic and off-cratonic origin. New analytical developments and availability of standards have made rutile accessible to in situ U-Pb dating by laser ablation ICP-MS. A U-Pb age of 369 ± 10 Ma for 9 rutile grains in 6 garnets from the Internatsionalnaya pipe is consistent with the accepted eruption age of the pipe (360 Ma). The equilibrium temperatures of pyropes with rutile inclusions calculated using Ni-in-Gar thermometer range between ~ 725 and 1030 °C, corresponding to a depth range of ca ~ 100-165 km. At the time of entrainment in the kimberlite, garnets with Cr-rich rutile inclusions resided at temperatures well above the closure temperature for Pb in rutile, and thus U-Pb ages on mantle-derived rutile most likely record the emplacement age of the kimberlites. The synthesis of distinctive rutile compositions and U-Pb dating opens new perspectives for using rutile in diamond exploration in cratonic areas.
DS201612-2336
2016
Pokhilenko, N.P.Shchukina, E.V., Agashev, A.M., Pokhilenko, N.P.Metasomatic origin of garnet xenocrysts from the V. Grib kimberlite pipe, Arkhangelsk region, NW Russia.Geoscience Frontiers, in press availableRussia, Archangel, Kola PeninsulaDeposit - Grib

Abstract: This paper presents new major and trace element data from 150 garnet xenocrysts from the V. Grib kimberlite pipe located in the central part of the Arkhangelsk diamondiferous province (ADP). Based on the concentrations of Cr2O3, CaO, TiO2 and rare earth elements (REE) the garnets were divided into seven groups: (1) lherzolitic “depleted” garnets (“Lz 1”), (2) lherzolitic garnets with normal REE patterns (“Lz 2”), (3) lherzolitic garnets with weakly sinusoidal REE patterns (“Lz 3”), (4) lherzolitic garnets with strongly sinusoidal REE patterns (“Lz 4”), (5) harzburgitic garnets with sinusoidal REE patterns (“Hz”), (6) wehrlitic garnets with weakly sinusoidal REE patterns (“W”), (7) garnets of megacryst paragenesis with normal REE patterns (“Meg”). Detailed mineralogical and geochemical garnet studies and modeling results suggest several stages of mantle metasomatism influenced by carbonatite and silicate melts. Carbonatitic metasomatism at the first stage resulted in refertilization of the lithospheric mantle, which is evidenced by a nearly vertical CaO-Cr2O3 trend from harzburgitic (“Hz”) to lherzolitic (“Lz 4”) garnet composition. Harzburgitic garnets (“Hz”) have probably been formed by interactions between carbonatite melts and exsolved garnets in high-degree melt extraction residues. At the second stage of metasomatism, garnets with weakly sinusoidal REE patterns (“Lz 3”, “W”) were affected by a silicate melt possessing a REE composition similar to that of ADP alkaline mica-poor picrites. At the last stage, the garnets interacted with basaltic melts, which resulted in the decrease CaO-Cr2O3 trend of “Lz 2” garnet composition. Cr-poor garnets of megacryst paragenesis (“Meg”) could crystallize directly from the silicate melt which has a REE composition close to that of ADP alkaline mica-poor picrites. P-T estimates of the garnet xenocrysts indicate that the interval of ?60-110 km of the lithospheric mantle beneath the V. Grib pipe was predominantly affected by the silicate melts, whereas the lithospheric mantle deeper than 150 km was influenced by the carbonatite melts.
DS201701-0034
2016
Pokhilenko, N.P.Surgutanova, E.A., Agashev, A.M., Demonterova, E.I., Golovin, A.V., Pokhilenko, N.P.Sr and Nd isotope composition of deformed peridotite xenoliths from Udachnaya kimberlite pipe.Doklady Earth Sciences, Vol. 471, 1, pp. 1104-1207.RussiaDeposit - Udachnaya

Abstract: New results of Rb-Sr and Sm-Nd isotope analyses have been obtained on samples of deformed peridotite xenoliths collected from the Udachnaya kimberlite pipe (Yakutia). The data obtained imply two main stages of metasomatic alteration of the lithospheric mantle base matter in the central part of the Siberian Craton. Elevated ratios of Sr isotopes may be considered as evidence of an ancient stage of metasomatic enrichment by a carbonatite melt. The acquired Nd isotope composition together with the geochemistry of the deformed peridotite xenoliths suggests that the second stage of metasomatic alteration took place shortly before formation of the kimberlite melt. The metasomatic agent of this stage had a silicate character and arrived from an asthenosphere source, common for the normal OIB type (PREMA) and the Group-I kimberlite.
DS201702-0258
2016
Pokhilenko, N.P.Zhimulev, E.I., Sonin, V.M., Afanasiev, V.P., Chepuov, A.I., Pokhilenko, N.P.Fe-S melt as a likely solvent of diamond under mantle conditions.Doklady Earth Sciences, Vol. 471, 2, pp. 1277-1279.MantleDiamond morphology

Abstract: The first results of experimental study of diamond dissolution in a S-bearing Fe melt at high P-T parameters are reported and the morphology of partially dissolved crystals is compared with that of natural diamonds. Our results show that under the experimental conditions (4 GPa, 1400°C), flat-faced octahedral diamond crystals are transformed into curve-faced octahedroids with morphological features similar to those of natural diamonds.
DS201705-0892
2017
Pokhilenko, N.P.Zhimulev, E.I., Sonin, V.M., Afanasiev, V.P., Chepurov, A.I., Pokhilenko, N.P.Fe-S melt as a likely solvent of diamond under mantle conditions.Doklady Earth Sciences, Vol. 471, 2, pp. 1277-1279.MantleDiamond morphology

Abstract: The first results of experimental study of diamond dissolution in a S-bearing Fe melt at high P-T parameters are reported and the morphology of partially dissolved crystals is compared with that of natural diamonds. Our results show that under the experimental conditions (4 GPa, 1400°C), flat-faced octahedral diamond crystals are transformed into curve-faced octahedroids with morphological features similar to those of natural diamonds.
DS201707-1336
2017
Pokhilenko, N.P.Ivanova, O.A., Logvinova, A.M., Pokhilenko, N.P.Inclusions in diamonds from Snap Lake kimberlites ( Slave craton, Canada): geochemical features of crystallization.Doklady Earth Sciences, Vol. 474, 1, pp. 490-493.Canada, Northwest Territoriesdeposit - Snap Lake

Abstract: The results of integrated studies of inclusion-containing diamonds from kimberlites of the Snap Lake dike complex (Canada) are presented. Features of the morphology, defect–impurity composition, and internal structure of the diamonds were determined by optic and scanning microscopy. The chemical composition of crystalline inclusions (olivine, garnet, and pyroxene) in diamonds was studied using a microanalyzer with an electronic probe. The inclusions of ultramafic paragenesis in the diamond (87%) are predominant. Carbonates, sulfide and hydrated silicate phases were found only in multiphase microinclusions. The large phlogopite inclusion studied was similar in composition to earlier studied nanosize inclusions of high-silica mica in diamonds from Snap Lake kimberlites. Revealed features of studied diamonds and presence of high-silica mica suggest that diamonds from Snap Lake have formed as the result of interaction between enriched in volatile and titanium high-potassium carbonate–silicate melts and peridotitic substrate at the base of thick lithospheric mantle.
DS201707-1364
2017
Pokhilenko, N.P.Sharygin, I.S., Litasov, K.D., Shatskiy, A., Safonov, O.G., Golovin, A.V., Ohtani, E., Pokhilenko, N.P.Experimental constraints on orthopyroxene dissolution in alkali-carbonate melts in the lithospheric mantle: implications for kimberlite melt composition and magma ascent.Chemical Geology, Vol. 455, pp. 44-56.Mantlekimberlite, carbonatite

Abstract: Although kimberlite magma carries large amounts of mantle-derived xenocrysts and xenoliths (with sizes up to meters), this magma ascends from the Earth's mantle (> 150–250 km) to the surface in a matter of hours or days, which enables diamonds to survive. The recently proposed assimilation-fuelled buoyancy model for kimberlite magma ascent emphasizes the importance of fluid CO2 that is produced via the reactive dissolution of mantle-derived orthopyroxene xenocrysts into kimberlite melt, which initially has carbonatitic composition. Here, we use a series of high-pressure experiments to test this model by studying the interaction of orthopyroxene (Opx) with an alkali-dolomitic melt (simplified to 0.7Na2CO3 + 0.3K2CO3 + 2CaMg(CO3)2), which is close to the melt that is produced by the partial melting of a kimberlite source, at P = 3.1–6.5 GPa and T = 1200–1600 °C, i.e., up to pressures that correspond to depths (~ 200 km) from where the ascent of kimberlite magma would start. During the first set of experiments, we study the reaction between powdered Opx and model carbonate melt in a homogeneous mixture. During the second set of experiments, we investigate the mechanism and kinetics of the dissolution of Opx crystals in alkali-dolomitic melt. Depending on the P-T conditions, Opx dissolves in the alkali-dolomitic melt (CL) either congruently or incongruently via the following reactions: Mg2Si2O6 (Opx) + CaMg(CO3)2 (CL) = CaMgSi2O6 (clinopyroxene) + 2MgCO3 (CL) and Mg2Si2O6 (Opx) = Mg2SiO4 (olivine) + SiO2 (CL). The experiments confirm that the dissolution of Opx causes gradual SiO2 enrichment in the initial carbonate melt, as previously suggested. However, the assimilation of Opx by carbonate melt does not produce fluid CO2 in the experiments because the CO2 is totally dissolved in the evolved melt. Thus, our results clearly demonstrate the absence of exsolved CO2 fluid at 3.1–6.5 GPa in ascending kimberlite magma and disprove the assimilation-fuelled buoyancy model for kimberlite magma ascent in the lithospheric mantle. We alternatively suggest that the extreme buoyancy of kimberlite magma at depths of 100–250 km is an exclusive consequence of the unique physical properties (i.e., low density, ultra-low viscosity and, thus, high mobility) of the kimberlite melt, which are dictated by its carbonatitic composition.
DS201709-2001
2017
Pokhilenko, N.P.Ivanov, O.A., Logvinova, A.M., Pokhilenko, N.P.Characteristics of nitrogen impurity in octahedral diamonds from Snap Lake ( Slave craton, Canada).Goldschmidt Conference, abstract 1p.Canada, Northwest Territoriesdeposit - Snap Lake

Abstract: The nitrogen concentration and aggregation form reflect the conditions of diamond formation and diamond evolution in primary source [1]. FTIR measurements were made on 40 colorless or slightly greenish octahedral diamonds from Snap Lake kimberlite dyke system. Studied diamonds differ in nitrogen content, distribution and aggregation degree. The total nitrogen content in different diamond zones is up to 1600 ppm. Diamonds have been classified into two groups on the basis of nitrogen aggregation degree in them. Group 1 includes poorly-aggregated-nitrogen diamonds. We suggest that such diamonds belong to the same generation such as cubic diamonds from Snap Lake [2]. The low degree of nitrogen aggregation in diamonds is indicative of short mantle residence and suggests that they crystallized shortly before kimberlite eruption. Diamonds of Group 2 are characterized by high nitrogen aggregation degree (up to 98.6%). Group 2 includes diamonds either with uniform nitrogen distribution throughout the crystal volume or with a predominance of Bdefect in the center. Inhomogeneity in nitrogen distribution from the center to the edge of the octahedral crystals indicates, at least, about the two, or even more growth stages of a part of the studied diamonds. High nitrogen aggregation degree according to “annealing” model is evidence of diamond staying in the high temperature region or of their residence in the mantle conditions. Results obtained support that significant part of octahedral diamonds from Snap Lake may have formed at the base of a thick lithospheric mantle at depth below 300 km [3].
DS201802-0269
2017
Pokhilenko, N.P.Tomshin, M.D., Pokhilenko, N.P., Tarskikh, E.V.Morphology of the Nyurba kimberlite pipe and its relationship with the dolerite dike.Doklady Earth Sciences, Vol. 477, 2, pp. 1458-1460.Russiadeposit - Nyturba

Abstract: Study of the magmatics in the Nakyn kimberlite field, with consideration of the isotope dating results, allowed us to establish a sequence of their formation. First, 368.5-374.4 Ma ago intrusions of the Vilyui-Markha dike belt formed. Then (363-364 Ma) intrusion of kimberlites took place. In the Early Carboniferous (338.2-345.6 Ma), alkaline basaltic magma intruded through faults controlling the kimberlites. The magmatic activity finished 331-324.9 Ma ago with the formation of explosive breccias. It has been found that the Nyurba kimberlite pipe consists of two bodies: their kimberlite melts have successively intruded through independent channels.
DS201804-0734
2018
Pokhilenko, N.P.Sharygin, I.S., Shatskiy, A., Litasov, K.D., Golovin, A.V., Ohtani, E., Pokhilenko, N.P.Interaction of peridotite with Ca-rich carbonatite melt at 3.1 and 6.5 Gpa: implications for merwinite formation in upper mantle, and for metasomatic origin of sublithospheric diamonds with Ca rich suite of inclusions.Contribution to Mineralogy and Petrology, Vol. 173, 22p.Mantlecarbonatite

Abstract: We performed an experimental study, designed to reproduce the formation of an unusual merwinite?+?olivine-bearing mantle assemblage recently described as a part of a Ca-rich suite of inclusions in sublithospheric diamonds, through the interaction of peridotite with an alkali-rich Ca-carbonatite melt, derived from deeply subducted oceanic crust. In the first set of experiments, we studied the reaction between powdered Mg-silicates, olivine and orthopyroxene, and a model Ca-carbonate melt (molar Na:K:Ca?=?1:1:2), in a homogeneous mixture, at 3.1 and 6.5 GPa. In these equilibration experiments, we observed the formation of a merwinite?+?olivine-bearing assemblage at 3.1 GPa and 1200 °C and at 6.5 GPa and 1300-1400 °C. The melts coexisting with this assemblage have a low Si and high Ca content (Ca#?=?molar 100?×?Ca/(Ca?+?Mg)?>?0.57). In the second set of experiments, we investigated reaction rims produced by interaction of the same Ca-carbonate melt (molar Na:K:Ca?=?1:1:2) with Mg-silicate, olivine and orthopyroxene, single crystals at 3.1 GPa and 1300 °C and at 6.5 GPa and 1400 °C. The interaction of the Ca-carbonate melt with olivine leads to merwinite formation through the expected reaction: 2Mg2SiO4 (olivine)?+?6CaCO3 (liquid)?=?Ca3MgSi2O8 (merwinite)?+?3CaMg(CO3)2 (liquid). Thus, our experiments confirm the idea that merwinite in the upper mantle may originate via interaction of peridotite with Ca-rich carbonatite melt, and that diamonds hosting merwinite may have a metasomatic origin. It is remarkable that the interaction of the Ca-carbonate melt with orthopyroxene crystals does not produce merwinite both at 3.1 and 6.5 GPa. This indicates that olivine grain boundaries are preferable for merwinite formation in the upper mantle.
DS201807-1477
2018
Pokhilenko, N.P.Agashev, A.M., Pokhilenko, L.N., Pokhilenko, N.P., Shchukina, E.V.Geochemistry of eclogite xenoliths from the Udachnaya kimberlite pipe: section of ancient oceanic crust sampled.Lithos, DOI:10.1016 /j.lithos.2018 .05.027 available 52p.Russiadeposit - Udachnaya

Abstract: A suite of seventeen unique, large, and fresh eclogite xenoliths from the Udachnaya pipe have been studied for their whole-rock and mineral major- and trace-element compositions. Based on their major-element compositions, the Udachnaya eclogites can be subdivided in two groups: high magnesian (Mg# 68.8-81.9) and low magnesian (Mg# 56.8-59). The two eclogite groups are clearly different in the style of correlation between major elements. Positive correlations of FeO and CaO with MgO are observed in the low-magnesian group, whereas these correlations are negative in the high-magnesian group. In terms of trace element composition, the Udachnaya eclogites are enriched over Primitive Mantle, but comparable to mid-ocean-ridge basalt composition, except for significant enrichment in large-ion lithophile elements (LILE; Rb, Ba, K, Sr). Most of the samples show a positive Eu anomaly, irrespective of group. Reconstructed whole-rock composition from clinopyroxene and garnet modal abundances contains much less incompatible elements (LILE, light rare earth elements, high field strength elements) than measured composition. Approximately 60 to 100% of the middle rare earth elements, Zr, and Hf, and nearly 100% of the heavy rare earth elements, Co, V, and Sc of the whole-rock budget are concentrated in Gar and Cpx. Variations in major element compositions cover a full section of the modern and Archaean oceanic crust, from troctolite, through gabbroic rocks, to basalts. The low-Mg# eclogites could have formed from upper oceanic crust protoliths, being a mixture of basalts and gabbro, whereas the high-Mg# eclogites are originated from gabbro-troctolite section of the lower oceanic crust. Concordant variations of Eu anomaly with the Lu/Sr ratio and the V and Ni contents in the eclogite compositions are in agreement with the fractionation of plagioclase, clinopyroxene, and olivine in their low-pressure precursor rocks. Negative correlations of SiO2 and MgO, and a low Nd/YbNMORB ratio, in the low-Mg# eclogites are in agreement with partial melt loss, but the presence of accessory quartz limits the degree of melting to 13%. Major and trace element compositions suggest that the high-Mg# eclogites, and, consequently, the lower oceanic crust, could not have experienced significant melt loss, and subduction in the Archaean may have been essentially dry, compared to the present day.
DS201809-2094
2018
Pokhilenko, N.P.Sonin, V.M., Zhimulev, E.I., Chepurov, A.A., Chepurov, A.I., Pokhilenko, N.P.Influence of the sulfur concentration in the Fe-S melt on diamond preservation under P-T conditions of the Earth's mantle.Doklady Earth Sciences, Vol. 481, 1, pp. 922-924.Mantlegeochemistry

Abstract: The results of experiments on dissolution of diamond in a Fe melt with variable concentrations of S at high P-T parameters are presented. It is established that the maximal degree of diamond dissolution occurs at a sulfur concentration of 15 wt %. With decreasing or increasing S content, dissolution of diamond slows down and almost does not occur during the period of the experiment (60 min), when the "eutectic" composition is gained. In contrast to a pure Fe melt, the presence of S decreases the carbon solubility and, therefore, reduces the aggressiveness of metal melt in relation to diamonds, thus, stimulating their preservation in the Earth’s mantle, especially if the concentration of S exceeds that in the "eutectic" composition.
DS201811-2613
2018
Pokhilenko, N.P.Tomilenko, A.A., Zhimulev, E.I., Bulbak, T.A., Sonin, V.M., Chepurov, A.I., Pokhilenko, N.P.Peculiarities of the composition of volatiles of diamonds synthesized in the Fe-S-C system: data on gas chromatography - mass spectrometry.Doklady Earth Sciences, Vol. 482, 1, pp. 1207-1211.Russiaspectrometry

Abstract: The first chromatography-mass spectroscopy data on volatiles in diamonds synthesized in the Fe-S-C system with 5 wt % S at 1400-1450°C and 5.0-5.5 GPa indicate the evolution of volatile composition during the diamond growth and, correspondingly, the variation in redox conditions of the reaction cell. A significant role is played by various hydrocarbons (HCs) and their derivatives, the content of which can reach 87%. Our data on possible abiogenic synthesis of HCs (components of natural gas and oil) can result in global recalculations (including climate) related to the global C cycle.
DS201906-1315
2019
Pokhilenko, N.P.Litasov, K.D., Kagi, H., Voropaev, S.A., Hirata, T., Ohfuji, H., Ishibashi., Makino, Y., Bekker, T.B., Sevastyanov, V.S., Afanasiev,V.P., Pokhilenko, N.P.Comparison of enigmatic diamonds from the Tolbachik arc volcano ( Kamchatka) and Tibetan ophiolites: assessing the role of contamination by synthetic materials. Gondwana Research, in press available 38p.Russia, Asia, Tibetdeposit - Tolbachik

Abstract: The enigmatic appearance of cuboctahedral diamonds in ophiolitic and arc volcanic rocks with morphology and infrared characteristics similar to synthetic diamonds that were grown from metal solvent requires a critical reappraisal. We have studied 15 diamond crystals and fragments from Tolbachik volcano lava flows, using Fourier transform infrared spectrometry (FTIR), transmission electron microscopy (TEM), synchrotron X-ray fluorescence (SRXRF) and laser ablation inductively coupled plasma mass-spectrometry (LA-ICP-MS). FTIR spectra of Tolbachik diamonds correspond to typical type Ib patterns of synthetic diamonds. In TEM films prepared using focused ion beam technique, we find Mn-Ni and Mn-Si inclusions in Tolbachik diamonds. SRXRF spectra indicate the presence of Fe-Ni and Fe-Ni-Mn inclusions with Cr, Ti, Cu, and Zn impurities. LA-ICP-MS data show variable but significantly elevated concentrations of Mn, Fe, Ni, and Cu reaching up to 70?ppm. These transition metal concentration levels are comparable with those determined by LA-ICP-MS for similar diamonds from Tibetan ophiolites. Mn-Ni (+Fe) solvent was widely used to produce industrial synthetic diamonds in the former USSR and Russia with very similar proportions of these metals. Hence, it appears highly probable that the cuboctahedral diamonds recovered from Kamchatka arc volcanic rocks represent contamination and are likely derived from drilling tools or other hard instruments. Kinetic data on diamond dissolution in basaltic magma or in fluid phase demonstrate that diamond does not form under the pressures and temperature conditions prevalent within the magmatic system beneath the modern-day Klyuchevskoy group of arc volcanoes. We also considered reference data for inclusions in ophiolitic diamonds and compared them with the composition of solvent used in industrial diamond synthesis in China. The similar inclusion chemistry close to Ni70Mn25Co5 for ophiolitic and synthetic Chinese diamonds scrutinized here suggests that most diamonds recovered from Tibetan and other ophiolites are not natural but instead have a synthetic origin. In order to mitigate further dubious reports of diamonds from unconventional tectonic settings and source rocks, we propose a set of discrimination criteria to better distinguish natural cuboctahedral diamonds from those produced synthetically in industrial environments and found as contaminants in mantle- and crust-derived rocks.
DS201909-2074
2019
Pokhilenko, N.P.Pernet-Fisher, J.F., Barry, P.H., Day, J.M.D., Pearson, D.G., Woodland, S., Agashev, A.M., Pokhilenko, L.N., Pokhilenko, N.P.Heterogeneous kimberlite metasomatism revealed from a combined He-Os isotope study of Siberian megacrustalline dunite xenoliths.Geochimica et Cosmochimica Acta, in press available 45p. PdfRussia, Siberiadeposit - Udachnaya East
DS202005-0718
2020
Pokhilenko, N.P.Afanasiev, V.P., Pokhilenko, N.P., Egorova, E.O., Lindenblot, E.S.The most ancient diamond crystals of the Siberian platform. Lamproites Morgogor Creek .. Ebelyakh River.Doklady Earth Sciences, Vol. 489, 2, pp. 1409-1412. pdf Russia, Siberiadiamond alluvials

Abstract: Based on a study of diamond grains from placers of the northeastern Siberian Platform, it is shown that certain types of diamonds (rounded dodecahedroids, diamonds of the II and V?VII varieties, according to the classification by Yu.L. Orlov) could have originated from Precambrian sources. “Ancient” diamonds also differ in terms of their sedimentological history: those of varieties V?VII, despite the maximum abrasion resistance, have the maximum degree of rounding, reflecting their more long-term sedimentological history, and, therefore, their ore bodies were likely the most ancient.
DS202006-0908
2020
Pokhilenko, N.P.Afanasiev, V.P., Pokhilenko, N.P., Grinenko, V.S., Kostin, A.V., Malkovets, V.G., Oleinikov, O.B.Kimberlitic magmatism in the south western flank of the Vilui basin. ( pyrope from Kenkeme River catchment) Jurassic-Cretaceous barren kimberlites.Doklady Earth Science, Vol. 490, 2, pp. 51-54.Russiageochronology

Abstract: We have analyzed 141 grains of pyrope from Neogene sediments in a quarry of construction materials, in the Kenkeme River catchment, along its left-side tributary (Chakiya River), about 60 km northwest of Yakutsk city. The mineral chemistry patterns of pyropes are typical of Jurassic-Cretaceous barren kimberlites, like the pipes of Obnazhennaya or Muza, but are uncommon to diamondiferous Middle Paleozoic kimberlites. The results allow identifying the magmatic event and placing time constraints on kimberlite magmatism in the southeastern flank of the Vilui basin, which was part of the Late Jurassic-Early Cretaceous tectonic-magmatic event in northeastern Asia.
DS202010-1880
2020
Pokhilenko, N.P.Sonin, V.M., Tomilenko, A.A., Zhimulev, E.I., Bulbak, T.A., Timina, T.Y., Chepurov, A.I., Pokhilenko, N.P.Diamond crystallization at high pressure: the relative efficiency of metal graphite and metal carbonate systems.Doklady Earth Sciences, Vol. 493, 1, pp. 508-512.RussiaUHP

Abstract: Data on the interaction of the Fe-Ni melt with CaCO3 and graphite at 5 GPa and 1400°? under the thermogradient conditions used in experiments on the growth of diamond on the BARS high-pressure apparatus are presented. The phase composition and component composition of the fluid captured by diamonds in the form of inclusions were studied by gas chromatography-mass spectrometry (GC-MS). Diamonds were synthesized from graphite. During the interaction of the Fe-Ni melt with CaCO3, Ca-Fe oxides and (Fe, Ni)3C carbide were formed. The stability of heavy hydrocarbons under the experimental conditions was confirmed. It was established that the composition of the fluid in synthesized diamonds is close to the composition of the fluid from inclusions in some natural diamonds. Nevertheless, it was concluded that crystallization of large diamonds under natural conditions is hardly possible due to the filling of the main crystallization volume with refractory oxide phases.
DS202011-2029
2001
Pokhilenko, N.P.Ashchepkov, I.V., Afanasiev, V.P., Pokhilenko, N.P., Sobolev, N.V., Vladykin, N.V., Saprykin, A.I., Khmelnikova, O.S., Anoshin, G.N.Small note on the composition of Brazilian mantle. *** NOTE DATERevista Brasileira de Geociencas*** ENG, Vol. 31, 4, pp. 653-660. pdfSouth America, Brazilkimberlites

Abstract: Garne ts from couc eru ratc from the vargcm l kimberl ite pipe show a long compos itional range and reveallong lincar tre nds within the lherzolite field in a Cr~Ol - CaO% dia gram (Sobolcv et til. 1974) (lip (0 11% MgO). fon ned by grains of different dimensions with fcw deviations to harzburg itcs . Larger grains (fraction +3) arc higher in CaO with less Cr~01 (to 5.5%). TIle Cr20 1 freq uen cy reduc es in hyperbo lic function for each fraction . IImenites reve;1142-56% Ti0 2l..'Olllpositionai range with linear FeO - MgO correhuions but 3(4) separate groups for A I ~01 suggest different proport ion of co-prccipimted gimlet , probably due to polybn ric Irncnonanon. lncreasing Cr~O l nnd r"t..-Q% conte nt (fractionation uegn:e ) with red ucing TiO~ is in accord with Ar c mod el.. Ganict xenolith fnnnldnin II pipe with large Ga r- Cpxgrains and fine Mica-Curb bearing mat rix refer to 60 kbcr and 35 mv/m2 gcothcrm . 11displays enr iched trace c lement pat ter ns but not completely equilibrated compositions for Ga r anti Cpx. sugges ting low degree me lting of rela tively fertile mantle. St udied uuuc rinlmay s uggcsrmcrasomu tized, relat ively fertile and irre gularly heated mantle bene ath Sombcrn Bra zil as found by (Carvalho & Lccnnrdos 1997).
DS202011-2071
2020
Pokhilenko, N.P.Zhimulev, E.I., Babich, Yu.V., Karpovich, Z.A., Chepurov, A.I., Pokhilenko, N.P.Low nitrogen diamond growth in Fe-C-S system.Doklady Earth Sciences, Vol. 494, 1, pp. 696-698.Russiadiamond genesis

Abstract: The first results on diamond growth in the Fe-?-S system with 1 wt % S (relative to Fe) at 6 GPa and 1450°C have been reported. The diamonds obtained contain about 30 ppm N, on average, and belong to the low-N transition diamond group Ib-IIa. It has been suggested that the reduction conditions formed by certain active elements such as S can play an important role in the formation of natural low-N diamonds.
DS202105-0779
2021
Pokhilenko, N.P.Nikolenko, E.I., Sharygin, I.S., Rezvukhin, D.I., Malkovets, v.G., Tychkov, N.S., Pokhilenko, N.P.Sulfide-bearing polymineralic inclusions in mantle-derived garnets from lamprophyres of the Chompolo field, (Central Aldan, Siberian Craton).Doklady Earth Sciences, Vol. 497, pp. 300-304.Russia, Siberiadeposit - Chompolo

Abstract: Sulfide-bearing polymineralic inclusions in mantle-derived chromium pyrope garnets of lherzolite paragenesis from lamprophyres of the Chompolo field (Aldan shield, southern Siberian craton) have been studied. The inclusions are composed of either only sulfides or sulfides in association with other minerals (carbonates, silicates, oxides, etc.). The sulfide part of the inclusions is represented by up to four minerals. Among the sulfides, minerals rich in Cu and Ni have been found, whereas Fe sulfides (pyrrhotite, troilite) are absent. This distinguishes the inclusions studied from the majority of sulfide inclusions in mantle minerals and diamonds, as well as in mantle xenoliths from kimberlites. The formation of polymineralic inclusions in chromium garnets of the Chompolo field is attributed to the effect of a carbonate-silicate metasomatic melt/fluid on mantle peridotites, as evidenced by the mineral suite associated with the sulfides. The research results indicate significant differences in the nature of metasomatic processes that occurred in the lithospheric mantle of the southern and central parts of the Siberian craton.
DS202107-1135
2021
Pokhilenko, N.P.Sonin, V.M., Gryaznov, I.A., Chepurov, A. I., Pokhilenko, N.P.H2O as a possible initiator of surface graphitization of impact diamonds.Doklady Earth Sciences, Vol. 498, 1, pp. 388-391.Russiadiamond crystallography
DS202110-1637
2021
Pokhilenko, N.P.Solovev, K.A., Golovin, A.V., Sharygin, I.S., Pokhilenko, N.P.Origin of epigenetic iron-rich olivine in lherzolite xenolith from the Udachnaya kimberlite pipe ( Siberian craton).Doklady Earth Sciences, Vol. 499, 2, pp. 619-622.Russiadeposit - Udachnaya

Abstract: Olivine is the most common rock-forming mineral of the majority of the lithospheric mantle rocks beneath ancient cratons. This study provides the information about an epigenetic olivine in a lherzolite xenolith from the Udachnaya kimberlite pipe (Siberian craton), which is characterized by lower Mg# compared to the rock-forming one (Mg# = 87.4). The iron-rich olivine has been observed in the epigenetic mineral assemblage that forms a kelyphite shell around the rock-forming garnet. Olivine from the kelyphite shell occurs as both homogeneous grains (Mg# = 84.3-85.9) and zoned grains (Mg# = 85.1-87.5). The major and minor elements asymmetric zoning patterns have been found in the rock-forming olivine grains at the contact with the kelyphite shell. These olivine grains have an outer low Mg# (up to 85.9) zone at the contact with the kelyphite shell as the epigenetic olivine grains in the kelyphite shell. We suggest that the iron-rich epigenetic olivine was produced as the result of a reaction between the rock-forming garnet and the primitive kimberlite melt. During this reaction, a hybrid melt was formed in the interstitial space. The hybrid melt was iron-enriched relative to the kimberlite melt. The source of iron for the micro-portions of the interstitial hybrid melt was the rock-forming garnet.
DS202110-1642
2021
Pokhilenko, N.P.Tychkov, N.S., Agashev, A.M., Pokhilenko, N.P.Lithospheric refertilization trends in xenoliths and xenocrysts from the Udachnaya kimberlite ( Siberian craton).Doklady Earth Sciences, Vol. 499, 2, pp. 634-638.Russiadeposit - Udachnaya

Abstract: Comprehensive studies of peridotitic xenoliths from the Udachnaya kimberlite (Yakutian diamond province, Siberian craton) confirm that garnet shows inverse correlation of its volumetric percentage with its Cr2O3 contents in refertilizated peridotites, but no such correlation is observed in depleted peridotites. The correlation relationship plots as an isosceles hyperbola, which is consistent with the existing knowledge of origin of refertilized peridotite. The bulk content of aluminum is proportional to the garnet percentage both in depleted and refertilized peridotites, but Al2O3 in the rock correlates with Cr2O3 in garnet only in the refertilized varieties, while the two parameters are independent in depleted mantle rocks. According to the modeling of refertilization-related composition changes in the Udachnaya peridotites, garnet percentages are directly proportional to the amount of clinopyroxene (Gnt = 0.879*Cpx + 0.022, R2 = 0.78) and inversely proportional to that of olivine (Gnt = 0.026/Ol3.141, R2 = 0.79). As the shares of Gnt and Cpx increase from minimum values, orthopyroxene first increases (to 0.16) and then decreases since 0.65 Ol, 0.09 Cpx, and 0.10 Gnt. This model can constrain the place of the parent rock in the refertilization series knowing Cr2O3 contents in separate garnet grains. The average refertilization degree of lithospheric mantle in the region estimated from the compositions of more than 800 garnet xenocrysts in the Udachnaya kimberlite is expressed in the rock modal composition as: Ol = 0.72, Opx = 0.15, Gnt = 0.07, and Cpx = 0.06 (median values).
DS202112-1945
2021
Pokhilenko, N.P.Sharygin, I.S., Golovin, A.V., Dymshits, A.M., Kalugina, A.D., Solovev, K.A., Malkovets, V.G., Pokhilenko, N.P.Relics of deep alkali-carbonate melt in the mantle xenolith from the Komosomolskaya-Magnitnaya kimberlite pipe ( Upper Muna field, Yakutia).Doklady Earth Sciences, Vol. 500, 2, pp. 842-847.Russia, Yakutiadeposit - Komosomolskaya-Magnitnaya

Abstract: The results of study secondary crystallized melt inclusions in olivine of a sheared peridotite xenolith from the Komsomolskaya-Magnitnaya kimberlite pipe (Upper Muna field, Yakutia) are reported. Monticellite, phlogopite, tetraferriphlogopite KMg3(Fe3+)Si3O10(F,Cl,OH), apatite, aphthitalite K3Na(SO4)2, burkeite Na6CO3(SO4)2, and carbonates, namely calcite, nyerereite (Na,K)2Ca(CO3)2, shortite Na2Ca2(CO3)3, and eitelite Na2Mg(CO3)2, were detected among the daughter minerals of the melt inclusions by the method of confocal Raman spectroscopy. The abundance of alkali carbonates in the inclusions indicates the alkali-carbonate composition of the melt. Previously, identical inclusions of alkali-carbonate melt were reported in olivine of sheared peridotites from the Udachnaya pipe (Daldyn field). Melt inclusions in sheared peridotites are the relics of a crystallized kimberlite melt that penetrated into peridotites either during the transport of xenoliths to the surface or directly in the mantle shortly prior to the entrapment of xenoliths by the kimberlite magma. If the second scenario took place, the finds of alkali-carbonate melt inclusions in sheared peridotites carried from different mantle depths in the Udachnaya and Komsomolskaya-Magnitnaya kimberlite pipes indicate a large-scale metasomatic alteration of the lithospheric mantle of the Siberian Craton by alkaline-carbonate melts, which preceded the kimberlite magmatism. However, regardless of which of the two models proposed above is correct, the results reported here support the alkali-carbonate composition of primary kimberlite melts.
DS1970-0829
1973
Pokhilenko, N.P. USOVA.Sobolev, N.V., Lavrentev, Y.G., Pokhilenko, N.P. USOVA.Chrome Rich Garnets from Kimberlites of Yakutia and their ParagenesesContributions to Mineralogy and Petrology, Vol. 40, pp. 39-52.Russia, YakutiaMineralogy - Garnets
DS1998-0816
1998
Pokhilenlo, N.P.Kuligin, S.S., Pokhilenlo, N.P.Mineralogy of xenoliths of garnet pyroxenites from kimberlite pipes of Siberian Platform7th International Kimberlite Conference Abstract, pp. 480-2.Russia, SiberiaPyroxenite paragenesis, Deposit - Udachnaya, Mir, Obnazhennaya
DS1988-0009
1988
Pokhvisneva, E.A.Altukov, E.N., Pokhvisneva, E.A.On the regularities of carbonatite distribution. (Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 298, No. 3, pp. 684-688RussiaCarbonatite
DS1988-0007
1988
Pokhvisneva, Ye.A.Altukhov, Ye.N., Pokhvisneva, Ye.A.Laws of carbonatite location.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 298, No. 3, pp. 684-687RussiaCarbonatite, Distribution
DS1989-0022
1989
Pokhvisneva, Ye.A.Altukhov, Ye.N., Pokhvisneva, Ye.A.Patterns of distribution of carbonatitesDoklady Academy of Science USSR, Earth Science Section, Vol. 298, No. 1-6, April pp. 60-63RussiaCarbonatite, Distribution
DS201112-0808
2011
Pokilanko, L.N.Pokilanko, L.N., Golovin, A.V., Shrygin, I.S., Pokhilenko, N.P.Accessory minerals of mantle xenoliths: first finds of Cl-free K-Fe sulphides.Doklady Earth Sciences, Vol. 440, 2, pp. 1404-1409.MantleXenolith petrology
DS201112-0182
2011
Pokilenko, N.P.Chepurov, A.I., Zhimulev, E.I., Sonin, V.M., Chepurov, A.A., Tomilenko, A.A., Pokilenko, N.P.Experimental estimation of the rate of gravitiation fractioning of xenocrysts in kimberlite magma at high P-T parameters.Doklady Earth Sciences, Vol. 440, 2, pp. 1427-1430.MantleDiamond genesis
DS201112-0809
2011
Pokrovskaya, N.E.Pokrovskaya, N.E., Litvin, Yu.A.Experimental modeling of syngenesis of diamond and minerals of peridotite and eclogite parageneses.Vestnik ONZ RAN *** in english, 4p. IN ENGLISHTechnologyMantle melting - genesis of diamond
DS201709-1962
2017
Pokrovski, G.S.Borisova, A.Y., Zagrtdenov, N.R., Toplis, M.J., Bohrson, W.A., Nedelec, A., Safonov, O.G., Pokrovski, G.S., Ceileneer, G., Melnik, O.E., Bychkov, A.Y., Gurenko, A.A., Shscheka, S., Terehin, A., Polukeev, V.M., Varlamov, D.A., Gouy, S., De Parseval, P.Making Earth's continental crust from serpentinite and basalt. Goldschmidt Conference, abstract 1p.Mantleperidotites

Abstract: How the Earth's continental crust was formed in the Hadean eon is a subject of considerable debates [1-4]. For example, shallow hydrous peridotites [2,5], in particular the Hadean Earth's serpentinites [6], are potentially important ingredients in the creation of the continental ptoto-crust, but the mechanisms of this formation remain elusive. In this work, experiments to explore serpentinite-basalt interaction under conditions of the Hadean Earth were conducted. Kinetic runs lasting 0.5 to 48 hours at 0.2 to 1.0 GPa and 1250 to 1300°C reveal dehydration of serpentinite and release of a Si-Al-Na-K-rich aqueous fluid. For the first time, generation of heterogeneous hydrous silicic melts (56 to 67 wt% SiO2) in response to the fluid-assisted fertilisation and the subsequent partial melting of the dehydrated serpentinite has been discovered. The melts produced at 0.2 GPa have compositions similar to those of the bulk continental crust [2,3]. These new findings imply that the Earth's sialic proto-crust may be generated via fluid-assisted melting of serpentinized peridotite at shallow depths (?7 km) that do not require plate subduction during the Hadean eon. Shallow serpentinite dehydration and melting may be the principal physico-chemical processes affecting the earliest lithosphere. Making Earth's continental crust from serpentinite and basalt.
DS1998-1176
1998
Pokrovskii, B.G.Pokrovskii, B.G., Andreeva, Vrublevskii, GrinevContamination mechanisms of alkaline gabbroid intrusions in the southern framing of Siberian PlatformPetrology, Vol. 6, No. 3, June, pp. 230-236.Russia, SiberiaGeochronology, Alkaline rocks
DS1998-1177
1998
Pokrovskii, B.G.Pokrovskii, B.G., Seliverstov, V.A.Carbon and oxygen isotope composition of carbonatites from easternKamchatka.Geochemistry International, Vol. 36, No. 1, Jan. pp. 34-39.Russia, KamchatkaCarbonatite, Geochronology
DS2001-0937
2001
Pokrovskii, B.G.Pokrovskii, B.G., et al.Oxygen and carbon isotopic compositions of carbonatite like rocks in the Tunguska synclise.Petrology, Vol. 9, No. 4, pp. 376-RussiaCarbonatite, Geochronology
DS2001-0938
2001
Pokrovskii, B.G.Pokrovskii, B.G., Kravchenko, S.M.Stable isotopes in the Khibiny and Lovozero Massifs: magma sources and conditions postmagmatic alterationsGeochem, International, Vol. 39, No. S1 S88-98.RussiaGeochronology
DS2003-1435
2003
Pokrovskii, B.G.Vrublevskii, V.V., Pokrovskii, B.G., Zhuravlev, D.Z., Anoshin, G.N.Composition and age of the Penchenga linear carbonatite complex, Yenesei RangePetrology, Vol. 11, 2, pp. 130-146.RussiaCarbonatite, Geochronology
DS2003-1526
2003
Pokrovskii, B.G.Yarmolyuk, V.V., Ivanov, V.G., Kovalenko, V.I., Pokrovskii, B.G.Magmatism and geodynamics of the southern Baikal volcanic region ( mantle hot spot):Petrology, Vol. 11, No. 1, pp. 1-30.RussiaGeochronology, Geochemistry
DS1987-0589
1987
Pokrovskiy, B.G.Pokrovskiy, B.G., Vinogradov, V.I.Isotope composition of some elements in ultrabasic Alkaline rocks of the Meimecha-Kotui province.(USSR).(Russian)Soviet Geology, (Russian), No. 5, pp. 81-91RussiaBlank
DS1991-1361
1991
Pokrovskiy, B.G.Pokrovskiy, B.G., Andreyeva, Ye.D.Petrography and isotope geochemistry of melilite rocks associated with the Patyn pluton #1International Geology Review, Vol. 33, No. 7, July, pp. 689-703RussiaMelilite, Patyn pluton
DS1991-1362
1991
Pokrovskiy, B.G.Pokrovskiy, B.G., Belyakov, A.Yu., Kravchenko, S.M., GryaznovaIsotope dat a on the origin of carbonatites and mineralized strat a in the Tomtor intrusion, northwest YakutiaGeochemistry International, Vol. 28, No. 4, pp. 93-101RussiaCarbonatite, Geochronology
DS1991-1363
1991
Pokrovskiy, B.G.Pokrovskiy, B.G., Vinogradov, V.I.Isotope investigations on alkalic rocks of central and western SiberiaInternational Geology Review, Vol. 33, No. 2, February pp. 122-134RussiaGeochronology, Alkaline rocks
DS1993-0853
1993
Pokrovskiy, B.G.Kravchenko, S.M., Belyakov, A.Yu., Pokrovskiy, B.G.Geochemistry and origin of the Tomtor massif in the North SiberianPlatformGeochemistry International, Vol. 30, No. 3, pp. 20-36.RussiaAlkali ultrabasic complex, Rare earth
DS1994-0950
1994
Pokrovskiy, B.G.Kravchenko, S.M., Belyakov, A.Yu., Pokrovskiy, B.G.Geochemistry and origin of the Tomtor Massif (North Siberian Platform)Doklady Academy of Sciences Acad. Science, Vol. 322, pp. 170-176.Russia, SiberiaCarbonatite, Tomtor Massif
DS200612-0979
2006
Pokrovsky, B.G.Nikiforov, A.V., Bolonin, A.V., Pokrovsky, B.G., Sugorokova, A.M., Chugaev, A.V., Lykhin, D.A.Isotope geochemistry ( O, C, S. Sr) and Rb-Sr age of carbonatites in Central Tuva.Geology of Ore Deposits, Vol. 48, 4, pp. 256-276.RussiaCarbonatite
DS201805-0953
2018
Pokrovsky, B.G.Ivanov, A.V., Mukasa, S.B., Kamenetsky, V.S., Ackerman, M., Demonterova, E.I., Pokrovsky, B.G., Vladykin, N.V., Kolesnichenko, M.V., Litasov, K.D., Zedgenizov, D.A.Origin of high-Mg melts by volatile fluxing without significant excess of temperature.Chemical Geology, https://doi.org/ 10.1016/j .chemgeo. 2018.03.11Russiameimechites
DS1900-0683
1908
Polak, H.Levitcus, F., Polak, H.Geillustreerde Encyclopaedie der DiamantnizverheidHaarlem: Erven F Bohn., 526P.GlobalDictionary, History, Kimberley
DS201801-0048
2017
Polak, L.Polak, L., Ackerman, L., Rapprich, V., Magna, T.Platinum group element and rhenium osmium geochemistry of selected carbonatites from India, USA and East africa.Carbonatite-alkaline rocks and associated mineral deposits , Dec. 8-11, abstract p. 22-23.India, United States, Africa, East Africacarbonatites

Abstract: Carbonatites and associated alkaline silicate rocks might have potential economic impact for a large variety of metals such as Cu, Ni, Fe and platinum-group elements (PGE - Os, Ir, Ru, Pd, Pt) as it is demonstrated in South Africa (Phalaborwa; Taylor et al. 2009) or Brazil (Ipanema; Fontana 2006). In addition, determined PGE contents along with Re-Os isotopic compositions may also provide important information about PGE fractionation during the genesis of upper mantle-derived carbonatitic melts and nature of their sources. Nevertheless, the existing PGE data for carbonatites are extremely rare, limited mostly to Chinese localities and they are not paralleled by Re-Os isotopic data (Xu et al. 2008). Therefore, in this study, we present the first complete PGE datasets together with Re-Os determinations for a suite of selected carbonatite bodies worldwide. We have chosen eight carbonatite sites with different alkaline rock association, age and geotectonic position. Among these, the youngest samples are from East African rift system and include Oldoinyo Dili, Tanzania with an age spanning from ~0 to 45 Ma; same as Tororo and Sukulu in Uganda (Woolley and Kjarsgaard 2008). These carbonatites are in association with pyroxenites and nepheline syenites. Another young carbonatitic complex is Amba Dongar in west India with Cretaceous age of ~65 Ma associated with alkaline volcanic rocks such as trachybasalts within Deccan Traps (Sukheswala and Udas 1963). Proterozoic bodies are represented by Iron Hill, USA carbonatites associated with pyroxenite, melitolite and ijolite with age ranging from ~520 to 580 Ma (Nash 1972). These carbonatites are famous for their intensive and varied fenitization. Last and the oldest carbonatites in this study comes from Samalpatti and Sevattur, South India having the age of ~800 Ma (Schleicher et al. 1997) and outcropping as small bodies within alkaline rocks such as pyroxenite, syenite and gabbro. The PGE concentrations and Re-Os isotopic ratios were determined by standard methods consisting of decarbonatization using HCl, decomposition of samples in Carius Tubes in the presence of reverse aqua regia and spikes (isotopic dilution), separation of Os by CHCl3 followed by N-TIMS measurements and Ir, Ru, Pd, Pt, Re isolation by anion exchange chromatography followed by ICP-MS measurements. All analysed carbonatites exhibit extremely low PGE contents (? PGE up to 1 ppb), even in the samples with high S contents (up to 1.5 wt. %). Such values are much lower than other determined so far for upper mantle-derived melts such as basalts, komatiites, etc. (Day et al. 2016). Such signatures indicate very low partitioning of PGE into carbonatitic melts and/or early separation of PGE-bearing fraction. Elements from iridium-group I-PGE; Os, Ir and Ru; mostly < 0.1 ppb) are distinctly lower compared to palladiumgroup elements and Re (PPGE; Pt, Pd, Re; mostly > 0.1 ppb) with some rocks being largely enriched in Re (up to ~6 ppb). Most of the analysed carbonatites exhibit progressive enrichment from Os to Re and consequently, PdN/ReN < 0.1 except south India carbonatites and associated alkaline rocks (> 0.30). Rocks analysed so far for Os have OsN/IrN up to 6.2 that might suggest that the carbonatites might concentrate Os over Ir. The highest HSEtot contents have been found in Mg-Cr-rich silicocarbonatites from South India (up to 40 ppb) and taking into account their only slightly radiogenic 187Os/188Os ratios (0.14-0.57), these rocks represents mixture of CO2-rich alkaline mantle melts and country rocks. Very high concentrations of HSE have been also found in magnetite separated from Fe-carbonatite from Amba Dongar, India (0.2-0.5 ppb of I-PGE and 0.9-9 ppb of P-PGE). The 187Os/188Os ratios determined so far for carbonatites from South India vary from 0.24 to 6.5 and calculated ?Os values range from +100 up to +5000. Such wide range of values suggest extremely heterogenous source of the melts and/or possible contamination by 187Os-rich crustal materials.
DS201910-2241
2019
Polak, L.Ackerman, L., Polak, L., Magna, T., Rapprich, V., Jana, D., Upadhyay, D.Highly siderophile element geochemistry and Re-Os isotopic systematics of carbonatites: insights from Tamil Nadu, India.Earth and Planetary Science letters, Vol. 520, pp. 175-187.Indiacarbonatites

Abstract: Carbonatite metasomatism has been widely implicated for worldwide mafic mantle suites but so far, no combined data have been available for highly siderophile element systematics (HSE - Os, Ir, Ru, Pt, Pd, Re) and Re-Os isotopic compositions in carbonatites themselves. We present the first systematic survey of the HSE and Re-Os isotopic compositions in a suite of well-characterized Neoproterozoic carbonatites, silicocarbonatites and associated silicate rocks (pyroxenites, monzogabbros, syenites) from south India in order to place constraints on the HSE systematics in carbonatite magmas, anchoring possible mantle sources of carbonatites and relationship to the ambient crustal lithologies as well as preliminary constraints on carbonatite metasomatism in Earth's mantle. The most plausible explanation for generally low HSE contents in calciocarbonatites from Tamil Nadu (?HSE < 1.22 ppb) involves a low-degree (<1%) partial melting of the mantle source producing sulfur-saturated carbonatitic magmas leaving behind sulfide phases retaining HSE. The new data also indicate a strong FeO control on the distribution of Os and Pt during segregation of carbonatite melt from its enriched mantle source and/or melt differentiation. The combined 187Re/188Os values (from 0.10 to 217), 187Os/188Os ratios (0.186-10.4) and initial ?Os values back-calculated to 800 Ma (from +0.1 to +6052) predict that most Tamil Nadu calciocarbonatites were plausibly derived from a carbonated peridotite source with <10% recycled component. This model would thus provide significant constraints on the origin/source of carbonatites, irrespective of their post-emplacement history. The unusual, volumetrically rare, Mg-Cr-rich silicocarbonatites (?HSE = 14-41 ppb) display almost identical HSE patterns with those of host pyroxenites and predominantly high Pt (up to 38 ppb), the origin of which remains unknown. Positive co-variations between Pt, Pd and Re, and the well-developed positive correlation between Pt and MgO in these Mg-Cr-rich silicocarbonatites argue for a source coming predominantly from the upper mantle. The Re-Os isotopic systematics agree with direct incorporation of enriched mantle-derived material into parental melts but variable incorporation of potassium-rich crustal materials is evidenced by highly positive ?Os800 Ma values for a sub-suite of Mg-Cr-rich silicocarbonatites, indicating intense fenitization. The highly radiogenic Os isotopic compositions of monzogabbros and a syenite argue for their derivation from crustal lithologies with no or only negligible contribution of mantle material. Collectively, low Ir, Ru, Pt and Pd contents found in the Tamil Nadu carbonatites appear to indicate the incapability to significantly modify the total budget of these elements in the Earth's mantle during carbonatite metasomatism. In contrast, very high Re/Os ratios found in some of the analyzed carbonatites, paralleled by extremely radiogenic 187Os/188Os signature, can produce large modification of the Re-Os isotopic composition of mantle peridotites during carbonatite melt percolation when high melt/rock ratios are achieved.
DS1994-0480
1994
Poland, L.J.Eby, G.N., Maher, S.G., Poland, L.J.Petrology and geochemistry of the Beemerville nepheline syenite complex, northern New Jersey, USAGeological Association of Canada (GAC) Abstract Volume, Vol. 19, p. posterGlobalAlkaline rocks, Beemerville
DS201710-2210
2017
Poland, M.P.Anderson, K.R., Poland, M.P.Abundant carbon in the mantle beneath Hawaii.Nature Geoscience, Vol. 10, 9, pp. 704-708.United States, Hawaiicarbon

Abstract: Estimates of carbon concentrations in Earth’s mantle vary over more than an order of magnitude, hindering our ability to understand mantle structure and mineralogy, partial melting, and the carbon cycle. CO2 concentrations in mantle-derived magmas supplying hotspot ocean island volcanoes yield our most direct constraints on mantle carbon, but are extensively modified by degassing during ascent. Here we show that undegassed magmatic and mantle carbon concentrations may be estimated in a Bayesian framework using diverse geologic information at an ocean island volcano. Our CO2 concentration estimates do not rely upon complex degassing models, geochemical tracer elements, assumed magma supply rates, or rare undegassed rock samples. Rather, we couple volcanic CO2 emission rates with probabilistic magma supply rates, which are obtained indirectly from magma storage and eruption rates. We estimate that the CO2 content of mantle-derived magma supplying Hawai‘i’s active volcanoes is 0.97?0.19+0.25 wt% -roughly 40% higher than previously believed-and is supplied from a mantle source region with a carbon concentration of 263?62+81?ppm. Our results suggest that mantle plumes and ocean island basalts are carbon-rich. Our data also shed light on helium isotope abundances, CO2/Nb ratios, and may imply higher CO2 emission rates from ocean island volcanoes.
DS201212-0563
2012
Polansky, O.P.Polansky, O.P., Korobeynikov, S.N., Babichev, A.V., Reverdatto, V.V.Formation and upwelling of mantle diapirs through the cratonic lithosphere: numerical thermomechanical modeling.Petrology, Vol. 20, 2, pp. 120-137.Russia, SiberiaMagmatism
DS1999-0386
1999
Polat, A.Kusky, T.M., Polat, A.Growth of granite greenstone terranes at convergent margins, and stabilization of Archean Cratons.Tectonophysics, Vol. 305, No. 1-3, May 10, pp. 43-74.GlobalCraton
DS2000-0487
2000
Polat, A.Kerrich, R., Polat, A.The mechanism and timing of growth and recycling of Archean continental crust: incompatible trace elementsGeological Association of Canada (GAC)/Mineralogical Association of Canada (MAC) 2000 Conference, 3p. abstract.Ontario, ManitobaSuperior Province - model, Subduction
DS2001-0939
2001
Polat, A.Polat, A., Kerrich, R.Geodynamic processes, continental growth, and mantle evolution recorded in late Archean greenstone belts...Precambrian Research, Vol. 112, No. 1-2, pp. 5-25.OntarioSuperior Province - southern, Tectonics
DS2002-1271
2002
Polat, A.Polat, A., Hofmann, A.W., Rosing, M.T.Boninite like volcanic rocks in the 3.7-3.8 Ga Isua greenstone belt: geochemical evidence for intra oceanicChemical Geology, Vol. 184, No.3-4, pp.231-54.GreenlandSubduction zone - Early Earth
DS2002-1272
2002
Polat, A.Polat, A., Kerrich, R.Nd isotope systematics of 2.7 Ga adakites, magnesian andesites and arc basalts, Superior Province: evidence for shallow crustal recycling at Archean subduction zonesEarth and Planetary Science Letters, Vol. 202, 2, pp. 345-60.Manitoba, Saskatchewan, Alberta, Northwest TerritoriesSubduction, Geochronology
DS2002-1744
2002
Polat, A.Wyman, D.A., Kerrich, R., Polat, A.Assembly of Archean cratonic mantle lithosphere and crust: plume arc interaction in the Abitibi Wawa subduction accretion complex.Precambrian Research, Vol.115,No.1-4, pp.37-62.Ontario, QuebecCraton - hot spot, Tectonics
DS200412-0580
2004
Polat, A.Frei, R., Polat, A., Meibom, A.The Hadean upper mantle conundrum: evidence for source depletion and enrichment from Sm-Nd Re-Os and Pb isotopic compositions inGeochimica et Cosmochimica Acta, Vol. 68, 7, April 1, pp. 1645-1660.Europe, GreenlandGeochronology, boninites
DS200612-0690
2006
Polat, A.Kerrich, R., Polat, A.Archean greenstone tonalite duality: thermochemical mantle convection models or plate tectonics in the early Earth global dynamics?Tectonophysics, Vol. 415, 1-4, pp. 141-165.MantleGeothermometry, convection, plumes, arc volcanism
DS200612-1098
2006
Polat, A.Polat, A., Herxberg, C., Munker, C., Rodgers, R., Kusky, T., Li, J., Fryer, B.Geochemical and petrological evidence for a supra subduction zone origin of Neoarchean (ca 2.5 Ga) peridotites, central orogenic belt, North Chin a craton.Geological Society of America Bulletin, Vol. 118, 7, July pp. 771-784.ChinaPeridotite, picrites
DS200612-1099
2005
Polat, A.Polat, A., Kerrich, R.Reading the geochemical fingerprints of Archean hot subduction volcanic rocks: evidence for accretion and crustal recycling in a mobile tectonic regime.Benn, K., Mareschal, J-C., Condie, K.C. Archean Geodynamics and Environments, AGU Geophysical Monograph, No. 164, pp. 189-214.Canada, Ontario, Superior ProvinceTectonics - subduction
DS200712-0445
2007
Polat, A.Hoffmann, J.E., Munker, C., Polat, A., Mezger, K.Evidence for Hadean mantle depletion in the sources of ~ 3.75 Ga subduction related rocks, Isua, SW Greenland.Plates, Plumes, and Paradigms, 1p. abstract p. A410.Europe, GreenlandSubduction - boninites
DS200812-0286
2008
Polat, A.Dilek, Y., Polat, A.Supra subduction zone ophiolites and Archean tectonics.Geology, Vol. 36., 5, pp. 431-432.GlobalOphiolites
DS200912-0590
2009
Polat, A.Polat, A., Kerrich, R., Windley, R.Archean crustal growth processes in southern West Greenland and the southern Superior Province, geodynamic and magmatic constraints.Geological Society of London, Special Publication Earth Accretionary systems in Space and Time, No. 318, pp. 155-191.Canada, Ontario, Europe, GreenlandGeodynamics
DS201012-0350
2010
Polat, A.Kerrich, R., Wyman, D., Polat, A.Archean lithospheric mantle: plume arc interaction.Goldschmidt 2010 abstracts, AbstractMantleReview paper
DS201112-0810
2011
Polat, A.Polat, A., Appel, P.W.U., Fryer, B.J.An overview of the geochemistry of Eoarchean to Mesoarchean ultramafic to mafic volcanic rocks, SW Greenland: implications for mantle depletionGondwana Research, Vol. 20, 2-3, pp. 255-273.MantlePetrogenetic processes at subduction zones Early Earth
DS201603-0377
2015
Polat, A.Friedman, E., Polat, A., Thorkelson, D.J., Frei, R.Lithospheric mantle xenoliths sampled by melts from upwelling asthenosphere: the Quaternary Tasse alkaline basalts of southeastern British Columbia, Canada.Gondwana Research, In press available 22p.Canada, British ColumbiaAlkaline rocks, basalts

Abstract: The Quaternary Tasse basalts are exposed near the north shore of Quesnel Lake in southeastern British Columbia. They host a variety of mantle xenoliths consisting predominantly of spinel lherzolite with minor dunite and pyroxenite. Mineralogically, the xenoliths are composed of olivine, orthopyroxene, clinopyroxene and spinel characterized by forsterite (Fo87-93), enstatite (En90-92), diopside (En45-50-Wo40-45-Fs5), and Cr-spinel (6 ? 11 wt.% Cr), respectively. All of the mantle xenoliths are coarse-grained and show granoblastic textures. Clinopyroxene and spinel display textural evidence for chemical reactions with percolating melts. The mantle xenoliths are characterized by restricted Mg-numbers (89 ? 92) and low abundances of incompatible elements (Ba = 2 ? 11 ppm; Sr = 3 ? 31 ppm) and Yttrium (1 ? 3 ppm). On the basis of REE patterns, the xenoliths are divided into three groups reflecting the various degrees of mantle metasomatism: (1) Group 1 consists of concave-up LREE patterns (La/Smcn = 0.48 ? 1.16; Gd/Ybcn = 0.71 ? 0.92); (2) Group 2 possesses flat to moderately LREE-enriched patterns (La/Smcn = 1.14 ? 1.92; Gd/Ybcn = 0.87 ? 1.09); and (3) Group 3 is characterized by strongly LREE-enriched patterns (La/Smcn = 1.53 ? 2.45; Gd/Ybcn = 1.00 ? 1.32). On MORB-normalized trace element diagrams, the majority of the xenolith samples share the enrichment of LILE (Rb, Ba, K), U, Th, Pb, Sr and the depletion of HFSE (Nb, Ta, Ti, Y) relative to REE. These geochemical characteristics are consistent with a compositionally heterogeneous subcontinental lithospheric mantle source that originated as subarc mantle wedge peridotite at a convergent plate margin. The Tasse basalts have alkaline compositions characterized by low SiO2 (44 ? 46 wt.%) and high alkali (Na2O + K2O = 5.1 ? 6.6 wt.%) contents. They are strongly enriched in incompatible elements (TiO2 = 2.4 ? 3.1 wt.%; Ba = 580 ? 797 ppm; Sr = 872 ? 993 ppm) and, display OIB-like trace element patterns (La/Smn = 3.15 ? 3.85; Gd/Ybn = 3.42 ? 4.61). They have positive ?Nd (+ 3.8 to + 5.5) values, with 338 ? 426 Ma depleted mantle model ages, and display uniform OIB-like Sr (87Sr/86Sr = 0.703346 ? 0.703591) and Pb (206Pb/204Pb = 19.40 ? 19.58; 207Pb/204Pb = 15.57 ? 15.60; 208Pb/204Pb = 38.99 ? 39.14) isotopic compositions. The basalts erupted discontinuously along a > 1000 km long SE-NW-trending linear belt with minimal compositional variation indicative of a homogenous mantle source. The Sr ? Nd ? Pb isotope and trace element systematics of the alkaline basalts suggests that they originated from partial melting of an upwelling asthenospheric mantle source. Melting of the asthenospheric mantle might have stemmed from extension of the overlying lithosphere in response to the early stages of back-arc basin opening in the Omineca and Intermontane belts. Ridge subduction beneath the Canadian Cordillera might have played an important role in the weakening of the lithospheric mantle prior to its extension. Alternatively, melting of the upwelling asthenosphere in response to the delamination of the lithospheric mantle beneath the Rocky Mountain Trench might have generated the alkaline lavas.
DS202012-2255
2020
Polat, A.Windley, B.F., Kusky, T., Polat, A.Onset of plate tectonics by the Eoarchean. ( accretionary and collisional)Precambrian Research, in press available, 43p. PdfMantleplate tectonics

Abstract: One of the most contentious areas of Earth Science today is when, or whether or not modern-style plate tectonics was in operation in the Archean Eon. In this review we present evidence that the onset of plate tectonics was not at 3.2 Ga, as popularly conceived, but was in operation during the Eoarchean by at least ca. 4.0 Ga. Following a review of the main Eoarchean supracrustal belts of the world, constrained by relevant geochemical/isotopic data, we present evidence that suggests that from at least ca. 4.0 Ga Earth produced considerable juvenile mafic crust and consequent island arcs by Accretionary Cycle Plate Tectonics. From ~3.2 Ga there was a gradual transition in geodynamics to more abundant active continental margin magmatism in the form of voluminous TTGs and sanukitoids. From 3.2 Ga to 2.5 Ga juvenile oceanic crust and arcs continued to form, accompanied by more active continental margin magmatism until ~2.7-2.5 Ga, by which time there were sufficient crustal rocks to amalgamate into incipient large continents, the fragmentation of which started the first complete classical Wilson Cycle Plate Tectonics of breaking apart and re-assembling large continental masses. In other words, there were two types of plate tectonics in operation in the early Earth, Accretionary Cycle Plate Tectonics and Wilson Cycle Plate Tectonics, but Wilson Cycle type plate interactions only became more common after contiguous continental landmass became voluminous and extensive enough around 2.7-2.5 Ga. Failure to realize this dual mechanism of continental growth may lead to erroneous ideas such as "plate tectonics started at 3.2 Ga", or "mantle plumes generated early Archean magmatic rocks." We present new geochemical data that together with lithological and structural relationships, negate the various plume-type speculations including stagnant lids, heat pipes, and mushy-lid tectonics. It is interesting to consider that the way Earth’s crust developed in the first Gigayear of the geological record continued later, albeit in more advanced forms, into the Phanerozoic, where we can still recognize Accretionary Cycle Plate Tectonics and orogens still with short boundaries in examples including the Altaids of Central Asia, the Arabian-Nubian Shield, the Japanese Islands, and in incipient form in Indonesia, as well as Wilson Cycle Plate Tectonics that leads inexorably to continental collisions as in the Alpine-Himalayan orogen with its long plate boundaries. We recommend this holistic view of crustal growth and the evolution of continents that leads to a robust, viable, and testable model of Earth evolution.
DS202102-0235
2021
Polat, A.Windley, B.F., Kusky, T., Polat, A.Onset of plate tectonics by the Eoarchean.Precambrian Research, doi.org/1-.1016/ j.precamres.2020 .105980, 43p. PdfMantleplate tectonics

Abstract: One of the most contentious areas of Earth Science today is when, or whether or not modern-style plate tectonics was in operation in the Archean Eon. In this review we present evidence that the onset of plate tectonics was not at 3.2 Ga, as popularly conceived, but was in operation during the Eoarchean by at least ca. 4.0 Ga. Following a review of the main Eoarchean supracrustal belts of the world, constrained by relevant geochemical/isotopic data, we present evidence that suggests that from at least ca. 4.0 Ga Earth produced considerable juvenile mafic crust and consequent island arcs by Accretionary Cycle Plate Tectonics. From ~3.2 Ga there was a gradual transition in geodynamics to more abundant active continental margin magmatism in the form of voluminous TTGs and sanukitoids. From 3.2 Ga to 2.5 Ga juvenile oceanic crust and arcs continued to form, accompanied by more active continental margin magmatism until ~2.7-2.5 Ga, by which time there were sufficient crustal rocks to amalgamate into incipient large continents, the fragmentation of which started the first complete classical Wilson Cycle Plate Tectonics of breaking apart and re-assembling large continental masses. In other words, there were two types of plate tectonics in operation in the early Earth, Accretionary Cycle Plate Tectonics and Wilson Cycle Plate Tectonics, but Wilson Cycle type plate interactions only became more common after contiguous continental landmass became voluminous and extensive enough around 2.7-2.5 Ga. Failure to realize this dual mechanism of continental growth may lead to erroneous ideas such as "plate tectonics started at 3.2 Ga", or "mantle plumes generated early Archean magmatic rocks." We present new geochemical data that together with lithological and structural relationships, negate the various plume-type speculations including stagnant lids, heat pipes, and mushy-lid tectonics. It is interesting to consider that the way Earth’s crust developed in the first Gigayear of the geological record continued later, albeit in more advanced forms, into the Phanerozoic, where we can still recognize Accretionary Cycle Plate Tectonics and orogens still with short boundaries in examples including the Altaids of Central Asia, the Arabian-Nubian Shield, the Japanese Islands, and in incipient form in Indonesia, as well as Wilson Cycle Plate Tectonics that leads inexorably to continental collisions as in the Alpine-Himalayan orogen with its long plate boundaries. We recommend this holistic view of crustal growth and the evolution of continents that leads to a robust, viable, and testable model of Earth evolution.
DS200612-0747
2006
Polazchenko, O.Kudrayvtseva, G.P., Posukhova, T.V., Polazchenko, O.Diamonds from the V Grib pipe: internal structure and origin.International Mineralogical Association 19th. General Meeting, held Kobe, Japan July 23-28 2006, Abstract p. 140.RussiaGrip - diamond morphology
DS201212-0419
2012
Polekhovsky, I.N.Lokhov, K., Lukyanova, L., Antonev, A.V., Polekhovsky, I.N., Antonov, A.V., Afanasev, Z.L., Bogomolov, E.S., Sergeev, S.A.U Pb and Lu-Hf isotopic systems in zircons and Hf-Nd isotopic systemization of the Kimozero kimberlites, Karelia.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractRussia, Archangel, Kola PeninsulaDeposit - Kimozero
DS200812-0299
2008
Polekhovsky, Yu.Dubopvikova, Z., Polekhovsky, Yu.Some special features of Kimozero kimberlites of Onega Flexure (Karelia, Russia).9IKC.com, 3p. extended abstractRussiaDeposit - Kimozero
DS1995-1508
1995
Polet, J.Polet, J., Anderson, D.L.Depth extent of cratons as inferred from tomographic studiesGeology, Vol. 23, No. 3, March pp. 205-208.Canada, South AfricaCraton, Tomography
DS1997-0339
1997
Poletaev, A.I.Fedorenko, V.S., Kalinin, E.V., Poletaev, A.I.Construction of geodynamic models of the endogenic and exogenic activity Of the earth's crustMoscow University of Bulletin, Vol. 51, No. 5, pp. 40-43RussiaGeodynamic, tectonic
DS201611-2132
2016
Poletti, J.E.Poletti, J.E., Cottle, J.M., Hagen-Peter, G.A., Lackey, J.S.Petrochronological constraints on the origin of the Mountain Pass ultrapotassic and carbonatite intrusive suite, California.Journal of Petrology, In press available, 44p.United States, CaliforniaCarbonatite

Abstract: Rare earth element (REE) ore-bearing carbonatite dikes and a stock at Mountain Pass, California, are spatially associated with a suite of ultrapotassic plutonic rocks, and it has been proposed that the two are genetically related. This hypothesis is problematic, given that existing geochronological constraints indicate that the carbonatite is ?15-25 Myr younger than the ultrapotassic rocks, requiring alternative models for the formation of the REE ore-bearing carbonatite during a separate event and/or via a different mechanism. New laser ablation split-stream inductively coupled plasma mass spectrometry (LASS-ICP-MS) petrochronological data from ultrapotassic intrusive rocks from Mountain Pass yield titanite and zircon U-Pb dates from 1429?±?10 to 1385?±?18?Ma, expanding the age range of the ultrapotassic rocks in the complex by ?20 Myr. The ages of the youngest ultrapotassic rocks overlap monazite Th-Pb ages from a carbonatite dike and the main carbonatite ore body (1396?±?16 and 1371?±?10?Ma, respectively). The Hf isotope compositions of zircon in the ultrapotassic rocks are uniform, both within and between samples, with a weighted mean ?Hfi of 1•9?±?0•2 (MSWD?=?0•9), indicating derivation from a common, isotopically homogeneous source. In contrast, in situ Nd isotopic data for titanite in the ultrapotassic rocks are variable (?Ndi?=?-3•5 to -12), suggesting variable contamination by an isotopically enriched source. The most primitive ?Ndi isotopic signatures, however, do overlap ?Ndi from monazite (?Ndi?=?-2•8?±?0•2) and bastnäsite (?Ndi?=?-3•2?±?0•3) in the ore-bearing carbonatite, suggesting derivation from a common source. The data presented here indicate that ultrapotassic magmatism occurred in up to three phases at Mountain Pass (?1425, ?1405, and ?1380?Ma). The latter two stages were coeval with carbonatite magmatism, revealing previously unrecognized synchronicity in ultrapotassic and carbonatite magmatism at Mountain Pass. Despite this temporal overlap, major and trace element geochemical data are inconsistent with derivation of the carbonatite and ultrapotassic rocks by liquid immiscibility or fractional crystallization from common parental magma. Instead, we propose that the carbonatite was generated as a primary melt from the same source as the ultrapotassic rocks, and that although it is unique, the Mountain Pass ultrapotassic and carbonatite suite is broadly similar to other alkaline silicate-carbonatite occurrences in which the two rock types were generated as separate mantle melts.
DS1987-0221
1987
Poli, G.Francalanci, L., Peccerillo, A., Poli, G.Partition coefficients for minerals in potassium alkaline rocks: dat a from Roman province (Central Italy)Geochemical Journal, Vol. 21, No. 1, pp. 1-10ItalyAlkaline rocks, Analyses
DS1988-0537
1988
Poli, G.Peccerillo, A., Poli, G., Serri, G.Petrogenesis of oreniditic and kamafugitic rocks from central ItalyCanadian Mineralogist, Vol. 26, No. 1, March pp. 23-44ItalyBlank
DS2002-1273
2002
Poli, G.Poli, G., Perugini, D.Strange attractors in magmas: evidence from lava flowsLithos, Vol. 65, 3-4, Dec. pp. 287-97.GlobalMagmatism
DS200512-0850
2005
Poli, G.Petrilli, M., Poli, G., Perugini, D., Peccerillo, A.PetroGraph: a new software to visualize, model, and present geochemical dat a in igneous petrology.Geochemistry, Geophysics, Geosystems: G3, Vol. 6, doi. 10.1029/2005 GC000932TechnologyComputer - program, PetroGraph, major, trace elements
DS201312-0172
2013
Poli, G.Contincelli, S., Avanzinelli, R., Poli, G., Braschi, E., Giordano, G.Shift from lamproite-like to leucitic rocks: Sr-Nd-Pb isotope dat a from the Monte Cimino volcanic complex vs the Vico stratovolcano, central Italy.Chemical Geology, Vol. 353, pp. 246-266.Europe, ItalyLeucites
DS201312-0194
2013
Poli, G.Conticelli, S., Avanzinelli, R., Poli, G., Braschi, E., Giordano, G.Shift from lamproite-like to leucitic rocks: Sr-Nd-Pb isotope dat a from the Monte Cimino volcanic complex vs the Vico stratovolcano, central Italy.Chemical Geology, Vol. 353, pp. 246-266.Europe, ItalyLamproite
DS2001-0940
2001
Poli, L.C.Poli, L.C., Oliver, G.J.H.Constrictional deformation in the central zone of the Damara Orogen, NamibiaJournal of African Earth Sciences, Vol.33,2,Aug.pp.303-321.NamibiaTectonics
DS2001-0941
2001
Poli, L.C.Poli, L.C., Oliver, G.J.H.Constrictional deformation in the Central Zone of the Damara Orogen, NamibiaJournal of African Earth Sciences, Vol.33,2,Aug.pp.303-22.NamibiaTectonics - structure, Orogeny
DS201312-0088
2013
Poli, P.Bou, P., Poli, P., Campillo, M., Pedersen, H., Briand, X., Roux, P.Teleseismic correlations of ambient seismic noise for deep global imaging of the Earth.Geophysical Journal International, Vol. 194, 2, pp. 844-848.MantleGeophysics - seismics
DS1998-1296
1998
Poli, S.Schmidt, M.W., Poli, S.Experimentally based water budgets for dehydrating slabs and sequences for arc magmas generation.Earth and Planetary Science Letters, Vol. 163, No. 1-4, Nov. pp. 361-379.MantleMagmas, Slabs
DS2002-1274
2002
Poli, S.Poli, S., Schmidt, M.W.Petrology of subducted slabsAnnual of Review Earth Planetary Science, Vol.30,pp. 207-235.MantleSubduction
DS2002-1275
2002
Poli, S.Poli, S., Schmidt, M.W.Petrology of subducted slabsAnnual Review of Earth and Planetary Sciences, Vol.30,pp. 207-235.MantleSubduction
DS2003-1095
2003
Poli, S.Poli, S., Schmidt, M.W.Petrology of subducted slabsAnnual Review of Earth and Planetary Sciences, Vol. 30, 29p.GlobalSubduction
DS200412-1350
2004
Poli, S.Molina, J.F., Poli, S., Austrheim, J., Glodny, J., Rusin, A.Eclogite facies vein systems in the Marun-Keu complex ( Polar Urals, Russia): textural, chemical, thermal constraints for patterContributions to Mineralogy and Petrology, Vol. 147, 4, pp. 484-504.Russia, UralsEclogite
DS200612-1100
2006
Poli, S.Poli, S., Molina, J-F., Franzolin, E.Fe Mg Ca partitioning between carbonates, garnet and clinopyroxene at high pressure: experimental constraints in mafic systems up to 6 GPa.International Mineralogical Association 19th. General Meeting, held Kobe, Japan July 23-28 2006, Abstract p.TechnologyEclogite, carbonatite
DS200912-0469
2009
Poli, S.Malaspina, N., Poli, S., Fumagalli, P.The oxidation state of metasomatized mantle wedge: insights from COH-bearing garnet peridotite.Journal of Petrology, Vol. 50, 8, pp. 1533-1552.MantleMetasomatism
DS200912-0779
2009
Poli, S.Tumiati, S., Fumagalli, P., Poli, S.Carbonate silicate equilibration temperatures in upper mantle peridotites saturated with C O H fluids.Goldschmidt Conference 2009, p. A1352 Abstract.MantleSubduction
DS201112-0635
2010
Poli, S.Malaspina, N., Scambelluri, M., Poli, S., Van Roermund, H.L.M., Langenhorst, F.The oxidation state of mantle wedge majoritic garnet websterites metasomatised by C-bearing subduction fluids.Earth and Planetary Science Letters, Vol. 298, 3-4, pp. 417-426.MantleMetasomatism
DS201212-0433
2012
Poli, S.Malaspina, N., Langenhorst, F., Fumagalli, P., Tumiati, S., Poli, S.Fe 3+ distribution between garnet and pyroxenes in mantle wedge carbonate bearing garnet peridotites ( Sulu, China) and implications for their oxidation state.Lithos, Vol. 146-147, pp. 11-17.ChinaUHP
DS201212-0434
2012
Poli, S.Malaspina, N., Langenhorst, F., Fumagalli, P., Tumiati, S., Poli, S.Fe 3 + distribution between garnet and pyroxenes in mantle wedge carbonate bearing garnet peridotites ( Sulu China) and implications for their oxidation state.Lithos, Vol. 146-147, pp. 11-17.ChinaUHP
DS201212-0435
2012
Poli, S.Malaspina, N., Langenhorst, F., Poli, S.C-O-H metasomatism and redox processes in the mantle at subduction zones.emc2012 @ uni-frankfurt.de, 1p. AbstractChinaSulu area
DS201212-0564
2012
Poli, S.Poli, S.Carbonatites out of a subducted altered oceanic crust? New experimental evidences for "low temperature" carbonatitic melts in COH bearing gabbros at 3.8-4.2 Gpa.emc2012 @ uni-frankfurt.de, 1p. AbstractTechnologyCarbonatite, subduction
DS201312-0715
2013
Poli, S.Poli, S.Carbonatites out of a subducted altered oceanic crust? Experimental evidences for epidote-dolomite eclogite melting at 3.8-4.2 Gpa.Goldschmidt 2013, AbstractMantleCarbonatite
DS201509-0420
2015
Poli, S.Poli, S.Carbon mobilized at shallow depths in subduction zones by carbonatitic liquids.Nature Geoscience, Vol. 8, pp. 633-636.MantleCarbonatite

Abstract: More than half a gigaton of CO2 is subducted into Earth’s interior each year1. At least 40% of this CO2 is returned to the atmosphere by arc volcanism2, 3, 4. Processes that are known to release carbon from subducting slabs—decarbonation or carbonate dissolution in fluids—can account for only a portion of the CO2 released at arc volcanoes5. Carbonatitic liquids may form from the subducting crust, but are thought to form only at very high temperatures. Melting of carbonated rocks could restrict the subduction of carbon into the deeper Earth. However, the behaviour of such rock types in subduction zones is unclear. Here I use laboratory experiments to show that calcium-rich hydrous carbonatitic liquids can form at temperatures as low as 870 to 900 °C, which corresponds to shallow depths of just 120 km beneath subduction zone arcs, in warm thermal regimes. I find that water strongly depresses the solidus for hydrous carbonate gabbro and limestone rocks, creating carbonatitic liquids that efficiently scavenge volatile elements, calcium and silicon, from the slab. These extremely mobile and reactive liquids are expected to percolate into the mantle wedge, and create a CO2 source for subduction zone magmatism. Carbonatitic liquids thus provide a potentially significant pathway for carbon recycling at shallow depths beneath arcs.
DS201610-1899
2016
Poli, S.Poli, S.Melting carbonated epidote eclogites: carbonatites from subducting slabs.Progress in Earth and Planetary Science, Vol. 3, 18p.MantleCarbonatite

Abstract: Current knowledge on the solidus temperature for carbonated eclogites suggests that carbonatitic liquids should not form from a subducted oceanic lithosphere at sub-arc depth. However, the oceanic crust includes a range of gabbroic rocks, altered on rifts and transforms, with large amounts of anorthite-rich plagioclase forming epidote on metamorphism. Epidote disappearance with pressure depends on the normative anorthite content of the bulk composition; we therefore expect that altered gabbros might display a much wider pressure range where epidote persists, potentially affecting the solidus relationships. A set of experimental data up to 4.6 GPa, and 1000 °C, including new syntheses on mafic eclogites with 36.8 % normative anorthite, is discussed to unravel the effect of variable bulk and volatile compositions in model eclogites, enriched in the normative anorthite component (An 37 and An 45). Experiments are performed in piston cylinder and multianvil machines. Garnet, clinopyroxene, and coesite form in all syntheses. Lawsonite was found to persist at 3.7 GPa, 750 °C, with both dolomite and magnesite; at 3.8 GPa, 775-800 °C, fluid-saturated conditions, epidote coexists with kyanite, dolomite, and magnesite. The anhydrous assemblage garnet, omphacite, aragonite, and kyanite is found at 4.2 GPa, 850 °C. At 900 °C, a silicate glass of granitoid composition, a carbonatitic precipitate, and Na-carbonate are observed. Precipitates are interpreted as evidence of hydrous carbonatitic liquids at run conditions; these liquids produced are richer in Ca compared to experimental carbonatites from anhydrous experiments, consistently with the dramatic role of H2O in depressing the solidus temperature for CaCO3. The fluid-absent melting of the assemblage epidote + dolomite, enlarged in its pressure stability for An-rich gabbros, is expected to promote the generation of carbonatitic liquids. The subsolidus breakdown of epidote in the presence of carbonates at depths exceeding 120 km provides a major source of C-O-H volatiles at sub-arc depth. In warm subduction zones, the possibility of extracting carbonatitic liquids from a variety of gabbroic rocks and epidosites offers new scenarios on the metasomatic processes in the lithospheric wedge of subduction zones and a new mechanism for recycling carbon.
DS201812-2902
2018
Poli, S.Zhao, S., Schettino, E., Merlini, M., Poli, S.The stability and melting of aragonite: an experimental and thermodynamic model for carbonated eclogites in the mantle.Lithos, doi.org/10.1016/ j.lithos.2018.11.005 38p.Mantleeclogite

Abstract: Subduction of calcium carbonate, sequestered in the oceanic crust by hydrothermal metamorphism and biogenic action, accounts for a significant flux of carbon into the mantle, where it contributes to the genesis of carbonatitic and silica-undersaturated melts. However, the reported phase relations in the system CaCO3, notably the transition boundary from disordered calcite (calcite V, here ccv) to aragonite (ara), vary considerably among different studies. Moreover, the thermodynamic properties of ccv and of liquid CaCO3 (CaCO3L) remain to be determined. In order to address the dearth of experimental data on phase relations, and to determine a set of internally consistent thermodynamic properties for ara, ccv and CaCO3L, multi-anvil experiments were performed at 3-6?GPa and 1300-1750?°C. By re-evaluating all experimental data, the transformation of ccv-ara fits the equation Tccv-ara?=?397.6?+?320.17?×?P and the melting curve Tm?=?1578.9?+?139.65?×?P???11.646?×?P2, where pressure is in GPa and temperature in K. Thermodynamic properties retrieved for calcite V and liquid CaCO3 are used to compute phase diagrams of relevance for chemical compositions representative of eclogite heterogeneities of the astenospheric mantle, and compared with experimentally derived phase relationships. Aragonite represents a carbonate of major abundance in carbonated eclogites at high temperature, close to the solidus; its ability to fractionate REE and Ba-Sr contributes to the peculiar geochemical signatures of silica undersaturated magmas. The relatively refractory nature of aragonite impacts on our understanding of the deep carbon cycle.
DS201902-0335
2019
Poli, S.Zhao, S., Schettino, E., Merlini, M., Poli, S.The stability and melting of aragonite: an experimental and thermodynamic model for carbonated eclogites in the mantle.Lithos, Vo.. 324, 1, pp. 105-114.Mantleeclogites

Abstract: Subduction of calcium carbonate, sequestered in the oceanic crust by hydrothermal metamorphism and biogenic action, accounts for a significant flux of carbon into the mantle, where it contributes to the genesis of carbonatitic and silica-undersaturated melts. However, the reported phase relations in the system CaCO3, notably the transition boundary from disordered calcite (calcite V, here ccv) to aragonite (ara), vary considerably among different studies. Moreover, the thermodynamic properties of ccv and of liquid CaCO3 (CaCO3L) remain to be determined. In order to address the dearth of experimental data on phase relations, and to determine a set of internally consistent thermodynamic properties for ara, ccv and CaCO3L, multi-anvil experiments were performed at 3-6?GPa and 1300-1750?°C. By re-evaluating all experimental data, the transformation of ccv-ara fits the equation Tccv-ara?=?397.6?+?320.17?×?P and the melting curve Tm?=?1578.9?+?139.65?×?P???11.646?×?P2, where pressure is in GPa and temperature in K. Thermodynamic properties retrieved for calcite V and liquid CaCO3 are used to compute phase diagrams of relevance for chemical compositions representative of eclogite heterogeneities of the astenospheric mantle, and compared with experimentally derived phase relationships. Aragonite represents a carbonate of major abundance in carbonated eclogites at high temperature, close to the solidus; its ability to fractionate REE and Ba-Sr contributes to the peculiar geochemical signatures of silica undersaturated magmas. The relatively refractory nature of aragonite impacts on our understanding of the deep carbon cycle.
DS2001-0151
2001
Poliakov, A.Burov, E., Jolivet, L., LePourhiet, L., Poliakov, A.A thermomechanical model of exhumation of high pressure HP and ultra high pressure UHP metamorphic rocks...Tectonophysics, Vol. 342, No. 2, pp. 113-36.GlobalAlpine type collision belts, UHP
DS2001-0833
2001
Poliakov, A.Nicolas, A., Poliakov, A.Melt migration and mechanical state in the lower crust of oceanic ridgesTerra Nova, Vol. 13, pp. 64-9.MantleMelt migration
DS1994-1390
1994
Poliakov, A.N.B.Podlachikov, Yu.Yu., Poliakov, A.N.B., Yuen, D.A.The effect of lithospheric phase transitions on subsidence of extending continental lithospheres.Earth and Planet. Science Letters, Vol. 124, No. 1-4, June pp. 95-104.MantleSubduction
DS1984-0257
1984
Poliakov, V.P.Eliutin, V.P., Poliakov, V.P., et al.Investigation of the Process of Polycrystalline Diamond Formation.Doklady Academy of Sciences AKAD. NAUK SSSR., Vol. 275, No. 1, PP. 135-139.RussiaMineralogy
DS1990-1192
1990
Poliakov, V.P.Poliakov, V.P., Eliutin, V.P., et al.Effect of the growth system geometry on the morphology of diamondcrystal.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 311, No. 4, pp. 870-873RussiaCrystallography, Diamond morphology
DS201807-1478
2018
Polianichko, V.Bournas, N., Prikhodko, A., Plastow, G., Legault, J., Polianichko, V., Treshchev, S.Exploring for kimberlite pipes in the Cuango area, Angola using helicopter-borne EM survey.AEM2018/7th International Workshop on Airborne electromagnetics, Held June 17-20, 4p.Africa, Angolageophysics - TEM
DS201212-0565
2012
Poliannikov, O.V.Poliannikov, O.V., Rondenay, S., Chen, L.Interfeometric imaging of the underside of a subduction crust.Geophysical Journal International, in press availableMantleSubduction
DS1995-0170
1995
Polikashina, N.S.Boriskenko, L.F., Polikashina, N.S.Titanium in weathering crusts and related alluvial placersLithology and Mineral resources, No. 1, pp. 46-54Russia, UkraineAlluvials, Laterites
DS1920-0462
1929
Polinard, E.Polinard, E.Les Diamants Translucides et Opaques des Gisements de la Bushimaie.Soc. Geol. (belge) Annual, Vol. 52, PP. 197-218.Democratic Republic of Congo, Central AfricaDiamonds, Translucent, Opaque, Bushmanland
DS1930-0037
1930
Polinard, E.Polinard, E.Les Gisements Diamantiferes des Collines de Bakwanga Divindji sur la Bushimaie.International CONGRESS Mines 6TH., Vol. 1, PP. 25-42.Democratic Republic of Congo, Central AfricaDiamond Occurrences
DS1930-0038
1930
Polinard, E.Polinard, E.Les Diamants Transparents des Gisements de la BushimaieSoc. Geol. Belge Annual, Vol. 53, No. 1, PP. C1-C33.Democratic Republic of Congo, Central AfricaDiamonds
DS1930-0039
1930
Polinard, E.Polinard, E.Le Diamant dans Les Roches Genetiques et dans Les Gisementssecondaires.International CONGRESS Mines 6TH., Vol. 1, PP. 5-12.Democratic Republic of Congo, Central AfricaMineralogy, Genesis
DS1930-0075
1931
Polinard, E.Polinard, E.Les Deformations Exterieures, Les Proprietes Internes et Les Modalities de la Cristallisation des Diamants de la Bushimaie.Acad. Roy. Belge Bulletin. De la Classe Des Sciences, SER. 5, Vol. 17, No. 1, PP. 137-162.Democratic Republic of Congo, Central AfricaCrystallography, Genesis, Diamonds
DS1930-0076
1931
Polinard, E.Polinard, E.Les Diamants En Agglomeration de Cristaux et Les Diamants Acristallisation Confuse de Gisements de la Bushimaie.Soc. Geol. Belge Annual Bulletin., Vol. 54, PP. C 1-C22.Democratic Republic of Congo, Central AfricaCystallography
DS1930-0119
1932
Polinard, E.Polinard, E.Les Formes Cristallines des Diamants de L'oubangui-chariSoc. Min. (france) Bulletin., Vol. 55, No. 7-8, PP. 213-235.West Africa, French Equatorial Africa, Central African RepublicCrystallography, Diamond
DS1930-0148
1933
Polinard, E.Polinard, E.Les Gisements Diamantiferous et Accessoirement Auriferes Dela Region de Bria En Oubangui-chari.Soc. Geol. (belge) Annual, Vol. 57, PP. C65-85.West Africa, French Equatorial Africa, Central African RepublicDiamond Deposits, Gold
DS1930-0174
1934
Polinard, E.Polinard, E.Les Champs Diamantiferes du CongoAssociation POUR LE PERFECT DU MATERIEL COL. Bulletin., No. 4, PP. 3-32.Democratic Republic of Congo, Central AfricaDiamond Fields
DS1950-0038
1950
Polinard, E.Polinard, E.Sur Une Forme Tetraedrique du DiamantGeological Society BELGE Annual, Vol. 74, PT. B, No. 1-3, PP. 59-63.Democratic Republic of Congo, Central AfricaCrystallography, Diamond
DS1992-1215
1992
Poling, G.Poling, G.Bulk samplingNorthwest Territories Geoscience Forum held November 25, 26th. 1992, Poster, AbstractNorthwest TerritoriesSampling, Bulk sampling, laboratory
DS1990-1529
1990
Poling, G.W.Waldman, M.A., Poling, G.W.North America's only large capacity diamond recovery plantDia Met Handout, Prospectors and Developers Association of Canada (PDAC) Meeting, Held March, 6pColoradoDiamond recovery plant, Overview
DS1991-1364
1991
Poling, G.W.Poling, G.W., Waldman, M.A.Dia Met's diamond recovery pilot plant in ColoradoThe Canadian Mining and Metallurgical Bulletin (CIM Bulletin) ., Session on Diamonds at The Canadian Institute of Mining, Metallurgy and Petroleum (CIM) Annual Meeting April, Vol. 84, No. 947, March p. 99. AbstractColoradoDiamond recovery, Mining applications-processing
DS1992-1216
1992
Poling, G.W.Poling, G.W., Waldman, M.A.Dia Met Minerals' diamond recovery pilot plant in ColoradoThe Canadian Mining and Metallurgical Bulletin (CIM Bulletin), Vol. 85, No. 956, January pp. 72-83ColoradoDiamond processing, Diamond recovery - example
DS1993-1248
1993
Poling, G.W.Poling, G.W.Diamond recovery processesThe Canadian Mining and Metallurgical Bulletin (CIM Bulletin) , Annual Meeting Abstracts LESS than approximately 10, Vol. 86, No. 968, March ABSTRACT p. 75.Northwest TerritoriesMineral processing, Evaluation, economics
DS1997-0990
1997
Poling, G.W.Rylatt, M.G., Poling, G.W., Popplewell, G.The northwest Territories diamonds project - diamond processing in the Canadian arcticThe Canadian Mining and Metallurgical Bulletin (CIM Bulletin) ., Vol. 90, No. 1015, Nov-Dec. p. 33.(paper 24p.)Northwest TerritoriesMineral processing, Deposit - Ektaki
DS2003-1096
2003
Poling, G.W.Poling, G.W., Ashley, R.M.The discovery of EKATI, roles of the Dia Met BHP joint ventureGeological Association of Canada Annual Meeting, Abstract onlyNorthwest TerritoriesHistory - Dia Met
DS200412-1567
2003
Poling, G.W.Poling, G.W., Ashley, R.M.The discovery of EKATI, roles of the Dia Met BHP joint venture.Geological Association of Canada Annual Meeting, Abstract onlyCanada, Northwest TerritoriesHistory - Dia Met
DS1991-0140
1991
Politiuk, V.I.Bogdanov, E.I., Politiuk, V.I.Alluvial mining in the USSRAlluvial Mining, Institute of Mining and Metallurgy (IMM) Special Volume, pp. 1-18RussiaAlluvial mining, Placers - not specific to diamonds
DS200612-1585
2006
Politov, A.A.Zegrenizov, D.A., Harte, B., Shatsky, V.S., Politov, A.A., Rylov, G.M., Sobolev, N.V.Directional chemical variations in diamonds showing octahedral following cuboid growth.Contributions to Mineralogy and Petrology, Vol. 151, 1, Jan. pp. 45-57.Russia, YakutiaMineral chemistry, subduction
DS1991-1365
1991
Politz, F.F.Politz, F.F.Two stage model of African absolute motion during the last 30 millionyearsTectonophysics, Vol. 194, No. 1-2, pp. 91-106AfricaTectonics, Geochronology
DS200812-1163
2008
Politz, F.F.Thatcher, W., Politz, F.F.Temporal evolution of continental lithospheric strength in actively deforming regions.GSA Today, Vol. 18, 4, April pp. 4-11.United StatesTectonics
DS202203-0343
2022
Polivchuk, M.J.Desbarats, A.J., Percival, J.B., Bilot, I., Polivchuk, M.J., Venance, K.E.Drainage geochemistry of mine tailings from a carbonatite-hosted Nb-REE deposit, Oka Quebec, Canada.Applied Geochemistry, Vol. 138, 14p. PdfCanada, Quebecdeposit - Oka

Abstract: Potential environmental issues associated with the mining of carbonatites are receiving increased attention due to the importance of critical metals for green technologies. This study investigates the chemistry of tailings seepage at the former Saint Lawrence Columbium mine near Oka, Québec, Canada, which produced pyrochlore concentrate and ferroniobium from a carbonatite-hosted Nb-REE deposit. Detailed field sampling and laboratory methods were used to characterize the hydraulic properties of the tailings, their bulk chemistry, mineralogy, pore water and effluent chemistries. The tailings are composed of REE-enriched calcite (64-89 wt %) and fluorapatite (2-22 wt %), as well as biotite (6-17 wt %) and chlorite (0-7 wt %). Minor minerals include ankerite, pyrite, sphalerite, molybdenite, magnetite and unrecovered pyrochlore. Secondary minerals include gypsum, barite, strontianite and rhodochrosite. Geochemical mass balance modeling, constrained by speciation modeling, was used to identify dissolution, precipitation and exchange reactions controlling the chemical evolution of pore water along its flow path through the tailings impoundment. In the unsaturated zone, these reactions include sulfide oxidation and calcite dissolution with acid neutralization. Below the water table, gypsum dissolution is followed by sulfate reduction and FeS precipitation driven by the oxidation of organic carbon in the tailings. Incongruent dissolution of biotite and chlorite releases K, Mg, Fe, Mn, Ba and F and forms kaolinite and Ca-smectite. Cation exchange reactions further remove Ca from solution, increasing concentrations of Na and K. Fluoride concentrations reach 23 mg/L and 8 mg/L in tailings pore water and effluent, respectively. These values exceed Canadian guidelines for the protection of aquatic life. In the mildly alkaline (pH 8.3) pore waters, Mo is highly mobile and reaches an average concentration of 83 ?g/L in tailings effluent, which slightly exceeds environmental guidelines. Concentrations (unfiltered) of Zn reach 1702 ?g/L in tailings pore water although values in effluent are usually less than 20 ?g/L. At the ambient pH, Zn is strongly adsorbed by Fe-Mn oxyhydroxides. Although U forms mobile complexes in tailings pore water, concentrations do not exceed 16 ?g/L due to the low solubility of its pyrochlore host. Adsorption and the low solubility of pyrochlore limit concentrations of Nb to less than 49 ?g/L. Cerium, from calcite dissolution, is strongly adsorbed although it reaches concentrations (unfiltered) in excess of 1 mg/L and 100 ?g/L in pore water and effluent, respectively. Results of this study show that mine tailings from carbonatite deposits are enriched in a wide variety of incompatible elements with multiple mineral hosts of varying solubility. Some of these elements, such as F and Mo, may represent contaminants of concern because of their mobility in alkaline tailings waters.
DS1960-1232
1969
Polkanov, YU.A.Yeremenko, G.K., Polkanov, YU.A.Luminescence of Small Diamonds from Sandy Sediments of the Ukraine.Doklady Academy of Science USSR, Earth Science Section., Vol. 188, No. 4, PP. 149-151.RussiaKimberlite, Photoluminescence, Colour
DS1970-0175
1970
Polkanov, YU.A.Polkanov, YU.A., Yeremenko, G.K.Diamond Potential of the Southwest Margin of the Russian Platform.Kiev:, RussiaKimberlite, Kimberley
DS1970-0858
1973
Polkanov, YU.A.York, YU.YU., Kashkarov, I.F., Polkanov, YU.A., Eremenko, G.K.Small (sand Size) Diamonds of the UkraineKiev: Izdat Naikova Dumka., 167P.Russia, UkraineKimberlite, Diamond, Kimberley
DS1980-0059
1980
Polkanov, YU.A.Belimenko, L.D., Polkanov, YU.A., Samoylovich, M.I.Electron Microscopic Research on Diamonds from Titaniferous placers on the Russian PlatformTsnigri, No. 153, PP. 36-43.RussiaBlank
DS1980-0189
1980
Polkanov, YU.A.Kirikilitsa, S.I., Polkanov, YU.A., Khrenov, A.YA.The Morphology and Luminescent Properties of Small Diamonds from Placers in Kazakhstan and Western Siberia.Tsnigri, No. 153, PP. 29-31.RussiaBlank
DS1986-0443
1986
Polkanov, Yu.A.Kirikilitsa, S.I., Polkanov, Yu.A.Crystal morphology and structural characteristics of diamonds of different genetic type.(Russian)Mineral. Kristallogr. I EE Prim. V. Prakt. Geol. Kiev (Russian), Vol. 1986 pp. 122-132RussiaBlank
DS1986-0444
1986
Polkanov, Yu.A.Kirikiltsa, S.I., Polkanov, Yu.A.Crystal structure of genetically different diamonds.(Russian)In: Mineralogical crystallography and its application mineral, pp. 122-132RussiaDiamond morphology
DS1994-1394
1994
Polkanov, Yu.A.Polkanov, Yu.A.Fine grained placers:the problem of diamondiferousness and the key to discovery of new genetic types -diamond.Russian Acad. of Sciences, Placers and weathered rock, Nov. 2p.RussiaDiamonds, Placers, alluvials
DS1960-0589
1965
Pollack, D.W.Pollack, D.W.The Potash Sulfur Springs Alkali Complex, Garland County, ArkansasMining Engineering, Vol. 17, PP. 45-46. (abstract.).United States, Gulf Coast, Arkansas, Garland CountyBlank
DS1975-0485
1977
Pollack, H.N.Cowan, I.M., Pollack, H.N.Gravity in ZambiaNature., Vol. 266, PP. 615-617.GlobalGeophysics, Regional Tectonics
DS1987-0026
1987
Pollack, H.N.Ballard, S., Pollack, H.N.Diversion of heat by Archean cratons: a model for southern AfricaEarth and Planetary Science Letters, Vol. 85, No. 1-3, September pp. 253-264South AfricaCraton, Heat flow
DS1987-0027
1987
Pollack, H.N.Ballard, S., Pollack, H.N., Skinner, N.J.Terrestrial heat flow in Botswana and NamibiaJournal of Geophysical Research, Vol. 92, No. B7, June 10, pp. 6291-6300.GlobalLithosphere, Archean, Heat flow data
DS1988-0036
1988
Pollack, H.N.Ballard, S., Pollack, H.N.Modern and ancient geotherms beneath Southern AfricaEarth and Planetary Science Letters, Vol. 88, No. 1-2, April pp. 132-142AfricaBlank
DS1990-1125
1990
Pollack, H.N.Nyblade, A.A., Pollack, H.N., Jones, D.L., Podmore, F.Terrestrial heat flow in east and southern AfricaJournal of Geophysical Research, Vol. 95, No. B 11, October 10, pp. 17371-17384South AfricaHeat Flow, Mantle
DS1993-1148
1993
Pollack, H.N.Nyblade, A.A., Pollack, H.N.Can differences in heat flow between east and southern Africa be easilyinterpreted? Implications for understanding regional variability in continentalheatTectonophysics, Vol. 219, pp. 257-272South AfricaHeat Flow, Craton, Archean, Tanzanian, Mozambique Belt
DS1993-1149
1993
Pollack, H.N.Nyblade, A.A., Pollack, H.N.A comparative study of parameterized and full thermal convection models In the interpretation of heat flow from cratons and mobile belts.Geophysical Journal International, Vol. 113, pp. 747-751.South AfricaKalahari Craton, Lithosphere
DS1993-1249
1993
Pollack, H.N.Pollack, H.N., Hurter, S.J., Johnson, J.R.Heat flow from the earth's interior: analysis of the global dat a setReviews of Geophysics, Vol. 31, No. 3, August pp. 267-280.MantleGeophsyics, Lithosphere
DS1993-1250
1993
Pollack, H.N.Pollack, H.N., Hurterm S.J., Johnson, J.R.Heat flow from the earth's interior: analysis of the global dat a setReviews of Geophysics, Vol. 31, No. 3, August pp. 267-280GlobalGeophysics, Mantle, Heat Flow
DS200412-1568
1977
Pollack, H.N.Pollack, H.N.On the regional variation of heat flow, geotherms and lithospheric thickness.Tectonophysics, Vol. 38, pp. 279-296.MantleGeothermometry
DS1975-0164
1975
Pollak, I.Pollak, I.The World of the DiamondHicksville, N.y.: Exposition Press, 127P.GlobalKimberlite, Kimberley
DS200512-0863
2005
Pollard, D.Pollard, D., Keating, J.F.Snowball Earth: a thin ice solution with flowing sea glaciers.Journal of Geophysical Research, Bol. 110, C7, C7010Geomorphology
DS1981-0135
1981
Pollard, D.D.Delaney, P.T., Pollard, D.D.Deformation of Host Rocks and Flow of Magma During Growth Of Minette Dikes and Breccia- Bearing Intrusions Near Ship Rock, New Mexico.United States Geological Survey (USGS) PROF. PAPER., No. 1202, 61P.United States, New Mexico, Colorado PlateauKimberlite, Diatreme, Colorado Plateau, Rocky Mountains
DS1950-0150
1953
Pollard, E.R.Pollard, E.R.The Diamond and Gold Deposits of the Mekuru District Cuyuni RiverBritish Guiana Geological Survey, Bulletin. 24, 25p.GlobalDiamond Occurrences
DS1950-0348
1957
Pollard, E.R.Pollard, E.R., Dixon, C.G., Dujardin, R.A.Diamond Resources of British GuianaBritish Guiana Geological Survey, Bulletin. 28, 43p.GlobalDiamond Occurrences
DS1986-0049
1986
Pollard, H.N.Ballard, S.III., Pollard, H.N.Present day heat flow and thermobarometry of ancient diamonds:implications for diversion of heat by archean cratonsEos, Vol. 67, No. 44, Nov. 4, p. 1183. (abstract.)GlobalMantle, Thermobarometry
DS1996-1407
1996
Pollard, P.J.Taylor, R.P., Pollard, P.J.Rare earth mineralization in peralkaline systems: the T zone rare earth elements (REE) Yttrium, Berylium deposit, Thor Lake, northwest Territories.Mineralogical Soc. Series, No. 7, pp. 167-192.Northwest TerritoriesRare earth minerals, Yttrium, Berylium, Deposit -Thor Lake
DS200512-0864
2005
Poller, U.Poller, U., Gladkochub, D., Donskaya, T., Mazukabzov, A., Sklyarov, E., Todt, W.Multistage magmatic and metamorphic evolution in the southern Siberian craton: Archean and paleoproterozoic zircon ages revealed by SHRIMP and TIMS.Precambrian Research, Vol. 136, 3-4, pp. 353-368.Russia, SiberiaGeochronology
DS200512-0865
2005
Poller, U.Poller, U., Gladkochub, D.P., Donskaya, T.V., Mazukabzov, A.M., Sklyarov, E.V., Todt, W.Timing of Early Proterozoic magmatism along the southern margin of the Siberian Craton ( Kitoy area).Geological Society of America Special Paper, No. 389, pp. 215-226.RussiaMagmatism ( not specific to diamonds)
DS200912-0182
2009
Poller, U.Donskaya, T.V., Gladkochub, D.P., Pisarevsky, S.A., Poller, U., Mazukabov, A.M., Bayanova, T.B.Discovery of Archean crust within the Akitkan orogenic belt of the Siberian craton: new insight into its architecture and history.Precambrian Research, Vol. 170, 1-2, pp. 61-72.Russia, SiberiaTectonics
DS1930-0260
1937
Pollett, J.D.Pollett, J.D.The Diamond Deposits of Sierra LeoneImp. Institute Bulletin., Vol. 35, No. 3, PP. 333-348.Sierra Leone, West Africa, Kono, Nimini, GoriGeology, Kimberlite History, Prospecting, Diamond Mining Recovery
DS1950-0080
1951
Pollett, J.D.Pollett, J.D.The Geology and Mineral Resources of Sierra Leone (1951)Colon. Geol. Min. Res., Vol. 2, No. 1, PP. 3-28.Sierra Leone, West AfricaGeology, Diamonds
DS1950-0233
1955
Pollett, J.D.Pollett, J.D.The Geology and Mineral Resources of Sierra Leone (1955)Geological Survey SIERRA LEONE Annual Report, FOR 1953Sierra Leone, West AfricaDiamonds, Geology
DS201012-0591
2010
Pollington, A.D.Pollington, A.D., Baxter, E.F.High resolution Sm Nd garnet geochronology reveals the uneven pace of tectonomorphic processes.Earth and Planetary Science Letters, Vol. 293, 1-2, pp. 63-71.MantleGeochronology
DS201312-0716
2014
Pollitiz, F.F.Pollitiz, F.F., Mooney, W.D.Seismic structure of the central US crust and shallow upper mantle: uniqueness of the Reelfoot Rift.Earth and Planetary Science Letters, Vol. 402, pp. 157-166.United StatesGeophysics - seismics
DS2003-1421
2003
Pollitz, F.Vergnolle, M., Pollitz, F., Calais, E.Constraints on the viscosity of the continental crust and mantle from GPS measurementsJournal of Geophysical Research, Vol. 108, B10, 2502 DOI. 1029/2002JB002374Mongolia, AsiaGeophysics - siesmics, GPS
DS2003-1422
2003
Pollitz, F.Vergnolle, M., Pollitz, F., Calasi, E.Constraints on the viscosity of the continental crust and mantle from GPS measurementsJournal of Geophysical Research, Vol. 108, 10, ETG 15 10.1029/2002JB002374MongoliaGeophysics - seismics
DS200412-2053
2003
Pollitz, F.Vergnolle, M., Pollitz, F., Calasi, E.Constraints on the viscosity of the continental crust and mantle from GPS measurements and postseismic deformation models in wesJournal of Geophysical Research, Vol. 108, 10, ETG 15 10.1029/2002 JB002374Asia, MongoliaGeophysics - seismics
DS201112-0750
2011
Pollitz, F.Obrebski, M., Allen, R.M., Pollitz, F., Hung, S-H.Lithosphere asthenosphere interaction beneath the western United States from the joint inversion of body-wave traveltimes and surface wave phase veolocities.Geophysical Journal International, March 25, In press availableUnited StatesGeophysics - seismics
DS1999-0562
1999
Pollitz, F.F.Pollitz, F.F.Earth sciences: from rifting to driftingNature, Vol. 398, No. 6722, Mar. 4, p. 21.GlobalTectonics, Continental Drift
DS201412-0701
2014
Pollitz, F.F.Pollitz, F.F., Mooney, W.D.Seismic structure of the central US crust and shallow upper mantle: uniqueness of the Reelfoot Rift.Earth and Planetary Science Letters, Vol. 402, pp. 157-166.United StatesGeophysics - seismics
DS201603-0412
2016
Pollitz, F.F.Pollitz, F.F., Mooney, W.D.Seismic velocity structure of the crust and shallow mantle of the central and eastern United States by seismic surface wave imaging.Geophysical Research Letters, Vol. 43, 1, pp. 118-126.United StatesGeophysics - seismics
DS201810-2357
2018
Pollock, K.Moss, S.W., Kobussen, A., Powell, W., Pollock, K.Kimberlite emplacement and mantle sampling through time at A154N kimberlite volcano, Diavik Diamond mine: lessons from the deep.Mineralogy and Petrology, doi.org/10.1007/ s00710-018-0630-7 14p.Canada, Northwest Territoriesdeposit - Diavik

Abstract: The Diavik Diamond Mine in the NWT of Canada has produced in excess of 100 million carats from 3 kimberlite pipes since mining commenced in 2002. Here, we present new findings from deep (>400 m below surface) mining, sampling and drilling work in the A154N kimberlite volcano that require a revision of previous geological and emplacement models and provide a window into how the sub-continental lithospheric mantle (SCLM) below Diavik was sampled by kimberlite magmas through time. Updated internal geological models feature two volcanic packages interpreted to represent two successive cycles of explosive eruption followed by active and passive sedimentation from a presumed crater-rim, both preceded and followed by intrusions of coherent kimberlite. Contact relationships apparent among the geological units allow for a sequential organization of as many as five temporally-discrete emplacement events. Representative populations of mantle minerals extracted from geological units corresponding to four of the emplacement events at A154N are analyzed for major and trace elements, and provide insights into the whether or not kimberlites randomly sample from the mantle. Two independent geothermometers using clinopyroxene and garnet data indicate similar source depths for clinopyroxenes and G9 garnets (130-160 km), and suggest deeper sampling with time for both clinopyroxene and garnets. Harzburgite is limited to 110-160 km, and appears more prevalent in early, low-volume events. Variable ratios of garnet parageneses from the same depth horizons suggest random sampling by passing magmas, but deeper garnet sampling through time suggests early preferential sampling of shallow/depleted SCLM. Evaluations of Ti, Zr, Y and Ga over the range of estimated depths support models of the SCLM underlying the central Slave terrane.
DS201812-2852
2018
Pollock, K.Moss, S., Porritt, L., Pollock, K., Fomradas, G., Stubley, M., Eichenberg, D., Cutts, J.Diavik deposit: Geology, mineral chemistry, and structure of the kimberlites at Diavik diamond mine: indicators of cluster-scale cross-fertilization, mantle provenance, and pipe morphology.Society of Economic Geology Geoscience and Exploration of the Argyle, Bunder, Diavik, and Murowa Diamond Deposits, Special Publication no. 20, pp. 287-318.Canada, Northwest Territoriesdeposit - Diavik
DS201812-2868
2018
Pollock, K.Pollock, K., Davy, A.T., Moss, S.Diavik deposit: Evaluation of the Diavik diamond deposit.Society of Economic Geology Geoscience and Exploration of the Argyle, Bunder, Diavik, and Murowa Diamond Deposits, Special Publication no. 20, pp. 267-286.Canada, Northwest Territoriesdeposit - Diavik
DS1996-1127
1996
Pollock, S.H.Pollock, S.H., Henry, J.J.Mineral extraction and United Kingdom policies for sustainabledevelopmentMinerals Industry International, January pp. 13-16GlobalEconomics, Sustainability
DS1987-0590
1987
Pollock, S.J.Pollock, S.J.The isotopic geochemistry of the Prairies Lake carbonatite complexMsc. Thesis Carleton University, 71p. QE 438 P777 Ontario Geological Survey (OGS)OntarioCarbonatite
DS1987-0591
1987
Pollock, S.P.Pollock, S.P.The isotopic geochemistry of the Prairies Lake carbonatite complex, OntarioMsc. Thesis Carleton University, No pages givenOntarioCarbonatite, Prairie Lake
DS1990-0482
1990
PolloniFolger, D.W., Irwin, B.J., McCullough, J.R., Rowland, R.W., PolloniMap showing free-air gravity anomalies off the southern coast of west-central Africa; Liberia to GhanaUnited States Geological Survey (USGS) Map, MF 2098-E, 1: 500, 000 $ 1.50GlobalGeophysics -gravity, Coast
DS1990-0483
1990
PolloniFolger, D.W., Irwin, B.J., McCullough, J.R., Rowland, R.W., PolloniMap showing free air gravity anomalies off the southern coast of west central Africa: Liberia to GhanaUnited States Geological Survey (USGS) Map, No. MF-2098-E 1: 500, 000 $ 1.50West AfricaGravity, Map, Geophysics
DS201903-0541
2019
Polo, L.Roverato, M., Giordano, D., Giovanardi, T., Juliani, C., Polo, L.The 2.0-1.88 Ga Paleoproterozoic evolution of the southern Amazonian Craton ( Brazil): an interpretation inferred by lithofaciological, geochemical and geochronological data.Gondwana Research, Vol. 70, pp. 1-24. doi:10.1016/ j.gr.2018.12.005South America, Brazilcraton

Abstract: The study of Paleoproterozoic rocks is crucial for understanding Earth's tectonic evolution during the time when most of the modern crust and ore deposits were formed. The rocks of the Brazilian Amazonian Craton record some of the most-complete and best-preserved Paleoproterozoic magmatic and volcanic episodes on Earth. Following previous investigations, we present new lithofaciological and stratigraphic records of the felsic rocks of the Tapajós Mineral Province (TMP) (~2-1.88?Ga) and the Săo Felix do Xingú region (SFX) (~1.88?Ga) which, combined with new petrological and geochronological data, help providing a more complete understanding of the tectonic, magmatic and volcanological evolution of the Amazonian Craton. This magmatism/volcanism is thought to be formed in a late-/post-orogenic to extentional regime confirmed by the new geochemical data presented here. The transition from late-convergent to extensional tectonic setting could register the beginning of the taphrogenesis that marked the Amazonian Craton throughout the Mesoproterozoic. The volcanological approach of this contribution can serve as a strategy for the modelling of the evolution of Precambrian volcano-sedimentary basins around the world. The large amount of rocks analyzed are divided into primary and secondary volcaniclastic products depending on if they resulted from a direct volcanic activity (pyroclastic) or processes that reworked pyroclastic fragments. Furthermore, the deposits are subdivided into massive and stratified, depending on their primary mechanisms of transport and emplacement. By confirming the results from previous studies, our study permits to depict a more precise paleo-environmental picture of the processes that occurred in the Amazonian Craton during the Late-Paleoproterozoic. In particular, the presence of large regional-scale fissural systems and caldera collapses produced large silicic explosive volcanic eruptions, also accompanied by the emission of large volume effusive products. Although studies on the Amazonian Craton are still scarce and controversial, the present study provides new evidence that this volcanism may have formed one of the largest Silicic Large Igneous Provinces (SLIP) on earth. Our data also confirm that at least two major Paleoproterozoic periods of formation of volcanic rocks exist in the Amazonian craton. This point is of great relevance for any future interpretation of the geological evolution of this craton.
DS201905-1074
2019
Polo, L.Roverato, M., Giordano, D., Giovanardi, T., Juliani, C., Polo, L.The 2.0-1.88 Ga Paleoproterozoic evolution of the southern Amazonian Craton ( Brazil): an interpretation inferred by lithofaciological, geochemical and geochronological data.Gondwana Research, Vol. 70, pp. 1-24.South America, Brazilcraton

Abstract: The study of Paleoproterozoic rocks is crucial for understanding Earth's tectonic evolution during the time when most of the modern crust and ore deposits were formed. The rocks of the Brazilian Amazonian Craton record some of the most-complete and best-preserved Paleoproterozoic magmatic and volcanic episodes on Earth. Following previous investigations, we present new lithofaciological and stratigraphic records of the felsic rocks of the Tapajós Mineral Province (TMP) (~2-1.88?Ga) and the Săo Felix do Xingú region (SFX) (~1.88?Ga) which, combined with new petrological and geochronological data, help providing a more complete understanding of the tectonic, magmatic and volcanological evolution of the Amazonian Craton. This magmatism/volcanism is thought to be formed in a late-/post-orogenic to extentional regime confirmed by the new geochemical data presented here. The transition from late-convergent to extensional tectonic setting could register the beginning of the taphrogenesis that marked the Amazonian Craton throughout the Mesoproterozoic. The volcanological approach of this contribution can serve as a strategy for the modelling of the evolution of Precambrian volcano-sedimentary basins around the world. The large amount of rocks analyzed are divided into primary and secondary volcaniclastic products depending on if they resulted from a direct volcanic activity (pyroclastic) or processes that reworked pyroclastic fragments. Furthermore, the deposits are subdivided into massive and stratified, depending on their primary mechanisms of transport and emplacement. By confirming the results from previous studies, our study permits to depict a more precise paleo-environmental picture of the processes that occurred in the Amazonian Craton during the Late-Paleoproterozoic. In particular, the presence of large regional-scale fissural systems and caldera collapses produced large silicic explosive volcanic eruptions, also accompanied by the emission of large volume effusive products. Although studies on the Amazonian Craton are still scarce and controversial, the present study provides new evidence that this volcanism may have formed one of the largest Silicic Large Igneous Provinces (SLIP) on earth. Our data also confirm that at least two major Paleoproterozoic periods of formation of volcanic rocks exist in the Amazonian craton. This point is of great relevance for any future interpretation of the geological evolution of this craton.
DS201908-1808
2019
Polo, L.Roverato, M., Giordano, D., Giovanardi, T., Juliani, C., Polo, L.The 2.0-1.88 Ga Paleoproterozoic evolution of the southern Amazonian craton ( Brazil): an interpretation inferred by lithofaciological, geochemical and geochronological data.Gondwana Research, Vol. 70, pp. 1-24.South America, Braziltectonics

Abstract: The study of Paleoproterozoic rocks is crucial for understanding Earth's tectonic evolution during the time when most of the modern crust and ore deposits were formed. The rocks of the Brazilian Amazonian Craton record some of the most-complete and best-preserved Paleoproterozoic magmatic and volcanic episodes on Earth. Following previous investigations, we present new lithofaciological and stratigraphic records of the felsic rocks of the Tapajós Mineral Province (TMP) (~2-1.88?Ga) and the Săo Felix do Xingú region (SFX) (~1.88?Ga) which, combined with new petrological and geochronological data, help providing a more complete understanding of the tectonic, magmatic and volcanological evolution of the Amazonian Craton. This magmatism/volcanism is thought to be formed in a late-/post-orogenic to extentional regime confirmed by the new geochemical data presented here. The transition from late-convergent to extensional tectonic setting could register the beginning of the taphrogenesis that marked the Amazonian Craton throughout the Mesoproterozoic. The volcanological approach of this contribution can serve as a strategy for the modelling of the evolution of Precambrian volcano-sedimentary basins around the world. The large amount of rocks analyzed are divided into primary and secondary volcaniclastic products depending on if they resulted from a direct volcanic activity (pyroclastic) or processes that reworked pyroclastic fragments. Furthermore, the deposits are subdivided into massive and stratified, depending on their primary mechanisms of transport and emplacement. By confirming the results from previous studies, our study permits to depict a more precise paleo-environmental picture of the processes that occurred in the Amazonian Craton during the Late-Paleoproterozoic. In particular, the presence of large regional-scale fissural systems and caldera collapses produced large silicic explosive volcanic eruptions, also accompanied by the emission of large volume effusive products. Although studies on the Amazonian Craton are still scarce and controversial, the present study provides new evidence that this volcanism may have formed one of the largest Silicic Large Igneous Provinces (SLIP) on earth. Our data also confirm that at least two major Paleoproterozoic periods of formation of volcanic rocks exist in the Amazonian craton. This point is of great relevance for any future interpretation of the geological evolution of this craton.
DS202101-0037
2020
Polonia, A.Vannucchi, P., Morgan, J.P., Polonia, A., Molli, G.The life cycle of subcontinental peridotites: from rifted continental margins to mountains via subduction processes.Geology, Vol. 48, pp. 1154-1158. pdfMantlesubduction

Abstract: Serpentinization greatly affects the physical and chemical properties of lithospheric mantle. Here we address the fate of serpentinized peridotites and their influence over an entire Wilson cycle. We document the near-surface journey of serpentinized subcontinental peridotites exhumed during rifting and continental breakup, reactivated as buoyant material during subduction, and ultimately emplaced as "ophiolite-like" fragments within orogenic belts. This life cycle is particularly well documented in former Tethys margins, where recent studies describe the ongoing incorporation of Mesozoic serpentinized subcontinental peridotites that diapirically rise from a subducting lower plate’s mantle to be emplaced into the accretionary prism in front of a continental arc. This newly recognized mode of subduction-linked serpentine diapirism from the downgoing lithospheric slab is consistent with the origin of some exhumed serpentinized subcontinental peridotites in the Apennines (Italy), these assemblages reaching their present locations during Alpine orogenesis. Transfer of serpentinized subcontinental peridotites from the downgoing to the overriding plate motivates the concept of a potentially "leaky" subduction channel. Weak serpentine bodies may in fact rise into, preferentially migrate within, and eventually leave the intraplate shear zone, leading to strong lateral heterogeneities in its composition and mechanical strength.
DS201012-0403
2010
Polozov, A.Kopylova, M., Polozov, A.Petrography of kimberlites and mantle xenoliths: solid foundation or slippery ground?38th. Geoscience Forum Northwest Territories, Abstract pp. 58-59.Canada, Northwest TerritoriesDeposit - Gahcho Kue 5034
DS200812-0432
2008
Polozov, A.C.Grishina, S.N., Polozov, A.C., Mazurov, M.P., Titov, A.T.Origin of chloride xenoliths of Udachnaya East kimberlite pipe, Siberia: evidence from fluid and saline melt inclusions.9IKC.com, 3p. extended abstractRussia, SiberiaDeposit - Udcahnaya inclusions
DS200812-0907
2008
Polozov, A.C.Polozov, A.C., Sukhov, S.S., Gornova, M.A., Grishina, S.N.Salts from Udachnaya East kimberlite pipe ( Yakutia, Russia): occurrences and mineral composition.9IKC.com, 3p. extended abstractRussiaDeposit - Udachnaya
DS200812-0908
2008
Polozov, A.C.Polozov, A.C., Sveneen, H., Planke, S.Chlorine isotopes of salts xenoliths from Udachnaya East kimberlite pipe, Russia.9IKC.com, 3p. extended abstractRussiaDeposit - Udachnaya
DS1990-1525
1990
Polozov, A.G.Vorontosov, A.E., Polozov, A.G., Kostrovitskii, S.I., Bobrov, I.D.On the geochemistry of nickel and Co in post magmatic magnetites fromkimberlites.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 311, No. 1, pp. 179-182RussiaGeochemistry, Magnetites-kimberlites
DS1991-0773
1991
Polozov, A.G.Ivanitskiy, V.P., Kharkiv, A.D., Matyash, I.V., Polozov, A.G.NMR spectra of magnetite from kimberlite and iron ore deposits of the Siberian Platform*(in Russian)Mineral. Zhurn., (Russian), Vol. 13, No. 2, April pp. 45-54RussiaUdachnaya pipe, Geochemistry
DS200712-0375
2007
Polozov, A.G.Gornova, M.A., Polozov, A.G., Ignatev, A.V., Velivetskaya, T.A.Peridotite nodules from the Udachnaya kimberlite pipe, nonmantle oxygen isotope ratios in garnets.Doklady Earth Sciences, Vol. 415, 5, pp. 777-781.RussiaDeposit - Udachnaya
DS201412-0316
2014
Polozov, A.G.Grishina, S.N., Polozov, A.G., Mazurov, M.P., Goryinov, S.V.Genesis of chloride-carbonate segregations of the Udachnaya-East pipe.Doklady Earth Sciences, Vol. 458, 1, pp. 1129-1131.Russia, YakutiaDeposit - Udachnaya-East
DS201609-1726
2016
Polozov, A.G.Kopylova, M.G., Gaudet, M., Kostrovitsky, S.I., Polozov, A.G., Yakovlev, D.A.Origin of salts and alkali carbonates in the Udachnaya East kimberlite: insights from petrography of kimberlite phases and their carbonate and evaporite xenoliths.Journal of Volcanology and Geothermal Research, in press available 19p.RussiaDeposit - Udachnaya East

Abstract: The Udachnaya East kimberlite is characterized by the presence of chlorides, sulfates and alkali carbonates. This highly atypical mineralogy underpinned a model for an anhydrous alkali-rich primary kimberlite melt, despite the absence of petrographic studies providing textural context to the exotic minerals. The present work documents the petrography of the Udachnaya East kimberlite in order to address this problem. The pipe comprises two varieties of Fort-a-la-Corne type pyroclastic kimberlite, olivine-rich and magmaclast-rich, and coherent kimberlite. These kimberlites entrain xenoliths of limestones, altered shales and siltstones, halite-dominated rocks, dolomites, and coarse calcite rocks. The distinct varieties of the Udachnaya East kimberlite carry different populations of crustal xenoliths, which partially control the mineralogy of the host kimberlite. In magmaclast-rich pyroclastic kimberlite, where halite is absent from the crustal xenoliths, it is not observed in the interclast matrix, or within the magmaclasts. Halite occurs in the interclast matrix of olivine-rich pyroclastic kimberlite, where halite xenoliths are common. Large, ~ 30 cm halite xenoliths are uniquely restricted to the coherent kimberlite and show a strong reaction with it. The halite xenoliths are sourced from depths of ? 1500 to ? 630 m, where carbonate beds host multiple karst cavities filled with halite and gypsum and occasional sedimentary evaporites. The style of secondary mineralization at Udachnaya depends on whether the kimberlite is coherent or pyroclastic. Shortite, pirssonite and other alkali carbonates replacing calcite and possibly serpentine are abundant only in porous pyroclastic kimberlites of both types and in their shale/siltstone xenoliths. The lower porosity of the coherent kimberlite prevented the interaction of kimberlite with Na brines. Serpentinization localized around halite xenoliths started at temperatures above 500 °C, as indicated by its association with high-temperature iowaite. The model of the “dry” Na and Cl-rich primary kimberlite melt is invalidated on the basis of 1) the restriction of exotic salt minerals to certain kimberlite types and xenoliths; and 2) the absence of halite-rich melt inclusions in olivine of coherent kimberlite.
DS1986-0777
1986
Poltaeatskii, V.G.Sozin, Yu.I., Nikitin, Yu.I., Poltaeatskii, V.G.Substructure and phase composition of natural diamonds containing lonsdaleite #2Sverkhtverd Material (Russian), No. 4, pp. 12-15RussiaDiamond, Morphology
DS1998-1024
1998
PoltaratskayaMitioukhine, S.I., Manakov, Poltaratskaya, RomanovNew dat a about the structure of the Earth's crust according to regional geophysical investigations.7th International Kimberlite Conference Abstract, pp. 606-8.Russia, YakutiaGeophysics - magnetotellurics, Geodynamics
DS1993-1251
1993
Poltaratskaya, O.L.Poltaratskaya, O.L.The prediction of the kimberlite fields according to deep geoelectrics -1.Diamonds of Yakutia, pp. 129-130.Russia, YakutiaGeophysics
DS1993-1252
1993
Poltaratskaya, O.L.Poltaratskaya, O.L.The prediction of the kimberlite fields on the base of deep geoelectricsPreprint handout at PDA Conference March 30, 1993, 2p.Russia, Siberia, Commonwealth of Independent States (CIS)Geophysics, Historical background
DS1993-1253
1993
Poltaratskaya, O.L.Poltaratskaya, O.L., Makhorin, A.M.The prediction of the kimberlite fields according to deep geoelectrics -1Diamonds of Yakutia, pp. 127-128.Russia, YakutiaGeophysics, Geoelectrics
DS1995-1509
1995
Poltoratskaya, O.L.Poltoratskaya, O.L.Lithosphere structure within the kimberlite fields of Yakutian diamondiferous Province: Magneto-telluric..Proceedings of the Sixth International Kimberlite Conference Almazy Rossii Sakha abstract, p. 19.Russia, YakutiaGeophysics -magnetics, Tellurics, Tectonics, structure
DS1986-0778
1986
Poltoratskii, V.G.Sozin, Yu.I., Nikitin, Yu.I., Poltoratskii, V.G.Substructure and phase composition of natural diamonds containing lonzdaleite #1Soviet Journal of Superhard. Mater, Vol. 8, No. 4, pp. 14-18RussiaNatural diamond
DS1987-0706
1987
Poltoratskiy, V.G.Sozin, Yu.I., Nikitin, Yu.I., Poltoratskiy, V.G.Natural mosaic diamond single crystals containing lonsdaleite.(Russian)Izmenie Svoistv. Mater. Pod. Deist. Vys. Davl. Kiev., (Russian), pp. 44-8. Khim. Zhur. abstract No. 4E293 1987RussiaBlank
DS201709-1962
2017
Polukeev, V.M.Borisova, A.Y., Zagrtdenov, N.R., Toplis, M.J., Bohrson, W.A., Nedelec, A., Safonov, O.G., Pokrovski, G.S., Ceileneer, G., Melnik, O.E., Bychkov, A.Y., Gurenko, A.A., Shscheka, S., Terehin, A., Polukeev, V.M., Varlamov, D.A., Gouy, S., De Parseval, P.Making Earth's continental crust from serpentinite and basalt. Goldschmidt Conference, abstract 1p.Mantleperidotites

Abstract: How the Earth's continental crust was formed in the Hadean eon is a subject of considerable debates [1-4]. For example, shallow hydrous peridotites [2,5], in particular the Hadean Earth's serpentinites [6], are potentially important ingredients in the creation of the continental ptoto-crust, but the mechanisms of this formation remain elusive. In this work, experiments to explore serpentinite-basalt interaction under conditions of the Hadean Earth were conducted. Kinetic runs lasting 0.5 to 48 hours at 0.2 to 1.0 GPa and 1250 to 1300°C reveal dehydration of serpentinite and release of a Si-Al-Na-K-rich aqueous fluid. For the first time, generation of heterogeneous hydrous silicic melts (56 to 67 wt% SiO2) in response to the fluid-assisted fertilisation and the subsequent partial melting of the dehydrated serpentinite has been discovered. The melts produced at 0.2 GPa have compositions similar to those of the bulk continental crust [2,3]. These new findings imply that the Earth's sialic proto-crust may be generated via fluid-assisted melting of serpentinized peridotite at shallow depths (?7 km) that do not require plate subduction during the Hadean eon. Shallow serpentinite dehydration and melting may be the principal physico-chemical processes affecting the earliest lithosphere. Making Earth's continental crust from serpentinite and basalt.
DS202004-0504
2020
Polushin, N.I.Chernykh, S.V., Chernykh, A.V., Tarelkin, S., Didenko, S. ,Kondakov, M.N., Shcherbachev, K.D., Trifonova, E.V., Drozdova, T.E., Troschiev, S.Y., Prikhodko, D.D., Glybin, Y.N., Chubenko, A.P., Britvich, G.I., Kiselev, D.A., Polushin, N.I., Rabinovich, O.IHPHT single crystal diamond type IIa characterization for particle detectors.Physicsa Status Solidi , doi:10.1002/pssa.201900888GlobalHPHT

Abstract: Various samples of multisectoral high?pressure high?temperature (HPHT) single?crystal diamond plate (IIa type) (4?×?4?×?0.53?mm) are tested for particle detection applications. The samples are investigated by X?ray diffractometry, photoluminescence spectroscopy, Raman spectroscopy, Fourier?transform infrared, and visible/ultraviolet (UV) absorption spectroscopy. High crystalline perfection and low impurity concentration (in the {100} growth sector) are observed. To investigate detector parameters, circular 1.0 and 1.5?mm diameter Pt Schottky barrier contacts are created on {111} and {100} growth sectors. On the backside, a Pt contact (3.5?×?3.5?mm) is produced. The {100} growth sector is proved to be a high?quality detector: the full width at half maximum energy resolution is 0.94% for the 5.489?MeV 226Ra ??line at an operational bias of +500?V. Therefore, it is concluded that the HPHT material {100} growth sector is used for radiation detector production, whose quality is not worse than the chemical vapor deposition method or specially selected natural diamond detectors.
DS1993-1616
1993
Polve, M.Trull, T., Nadeau, S., Pineau, F., Polve, M., Javoy, M.C-He systematics in hotspot xenoliths: implications for mantle carbon contents and carbon recycling.Earth and Planetary Science Letters, Vol. 118, No. 1-4, July, pp. 43-64.Mantle, Hawaii, Kerguelen Islands, IndiaXenoliths -Carbon and helium, Hotspots
DS2001-0003
2001
Polve, M.Abraham, A.C., Francis, D., Polve, M.Recent alkaline basalts as probes of the lithospheric mantle roots of the Northern Canadian Cordillera.Chemical Geology, Vol. 175, pp. 361-86.Yukon, British Columbia, CordilleraTectonics, Geochronology
DS201112-0223
2011
Polyak, V.Crow, R., Karlstrom, K., Asmerom, Y., Schmandt, B., Polyak, V., DuFrane, S.A.Shrinking of the Colorado Plateau via lithospheric mantle erosion: evidence from Nd and Sr isotopes and geochronology of Neogene basalts.Geology, Vol. 39, 1, pp. 27-30.United States, Colorado PlateauGeochronology
DS201201-0861
2011
PolyakaZaitsev, A.N., Chakmouradian, A.R., Sidra, O.I., Spratt, J., Williams, Stanley, Petrov, Britvin, PolyakaFlourine , yttrium and lanthaide rich cerianite (Ce) from carbonatitic rocks of the Kerimasi volcano and surrounding explosive craters Gregory Rift Tanzania.Mineralogical Magazine, Vol. 75, 6, pp. 2813-2822.Africa, TanzaniaCarbonatite
DS200512-1155
2004
PolyakovVrublevskii, V.V., Gertner, I.F., Polyakov, Izokh, Krupchatnikov, Travin, VoitenkoAr Ar isotopic age of lamproite dikes of the Chua Complex, Gornyi Altai.Doklady Earth Sciences, Vol. 399A, 9, Nov-Dec. pp. 1252-55.RussiaLamproite
DS1985-0328
1985
Polyakov, A.I.Kapustin, YE.L., Polyakov, A.I.Carbonatite Volcanoes of Eastern Africa and the Genesis of CarbonatitesIzves. Akad. Nauk, Sssr., No. 3, MARCH PP. 30-43.East AfricaBlank
DS1985-0329
1985
Polyakov, A.I.Kapustin, YU.L., Polyakov, A.I.Carbonatite Volcanoes of East Africa and the Genesis of Carbon- AtitesInternational Geology Review, Vol. 27, No. 4, pp. 434-448East Africa, Kenya, Uganda, TanzaniaCarbonatite
DS1989-1075
1989
Polyakov, A.I.Muravyeva, N.S., Polyakov, A.I., Kolesov, G.M., Shubina, N.A., SerinComposition of upper mantle and evidence of mantle metasomatism in the Baykal rift zoneGeochemistry International, Vol. 26, No. 9, pp. 24-38RussiaMantle -Lherzolites, Petrology
DS1992-1183
1992
Polyakov, A.N.Perchuk, L.L., Podladchikov, Y.Yu., Polyakov, A.N.Hydrodynamic modelling of some metamorphic processesJournal of Metamorphic Geology, Vol. 10, No. 3, May pp. 311-320GlobalMetamorphic processes, Modelling
DS1995-1510
1995
Polyakov, G.V.Polyakov, G.V., Trong Yem, N., et al.Geology and substance composition of the cocites of North VietnamProceedings of the Sixth International Kimberlite Conference Abstracts, pp. 449-451.GlobalUltrapotassic, alkaline, Coesites
DS1996-0151
1996
Polyakov, G.V.Bognikov, V.I., Pavlov, A.L., Polyakov, G.V.The platinum group elements in the Atalyk ultrabasite basite intrusion, Gornyy AltayDoklady Academy of Sciences USSR, Vol. 336, pp. 92-97Russiaplatinum group elements (PGE), Layered intrusion, Deposit -Atalyk
DS1996-1128
1996
Polyakov, G.V.Polyakov, G.V., et al.Ultrapotassic basic rocks of Northern Vietnam -cocites in relation to The problem of lamproitic magmatismInternational Geological Congress 30th Session Beijing, Abstracts, Vol. 2, p. 390.GlobalLamproites, Coesites
DS200612-1496
2006
Polyakov, G.V.Vrublevskii, V.V., Voitenko, N.N., Romanov, A.P., Polyakov, G.V., Izokh, A.E., Gertner, I.F., Krupchatnikov, V.I.Magma sources of Triassic lamproites of Gornyi Altai and Taimyr: Sr and Nd isotope evidence for plume lithosphere interaction.Doklady Earth Sciences, Vol. 405A 9, pp. 1365-1367.RussiaLamproite
DS1993-0769
1993
Polyakov, I.V.Kalinkin, M.M., Arzamastsev, A.A., Polyakov, I.V.Kimberlites and related rocks of the Kola Peninsula.(Russian)Petrologiya, (Russian), Vol. 1, No. 2, April, pp. 205-214.RussiaKimberlites, Geochronology
DS1993-1254
1993
Polyakov, I.V.Polyakov, I.V., Kalinkin, M.M.Diamonds and associated minerals in kimberlites and loose sediments of Tersky shore (Kola Peninsula).(Russian)Proceedings of the Russian Mineralogical Society, (Russian), No. 1, pp. 96-101.Russia, Kola PeninsulaDiamonds, Geomorphology
DS201112-0811
2011
Polyakov, S.N.Polyakov, S.N., Denisov, V.N., Kuzmin, N.V., Kuznetsov, M.S., Martyushov, S.Yu., Nosukhin, Terentiev, BlankCharacterization of top quality type IIa synthetic diamonds for new x-ray optics.Diamond and Related Materials, Vol. 20, no. 5-6m pp. 726-728.TechnologyDiamond - synthesis applications
DS1996-1129
1996
Polyakov, V.B.Polyakov, V.B., Kharlashina, N.N.Direct calculation of B factors for graphite and diamond from measured specific heat capacities.Geochemistry International, Vol. 33, No. 8, pp. 16-30.GlobalGeothermometry, Petrology -Graphite and diamond
DS201212-0566
2012
Polyakov, V.B.Polyakov, V.B., Horita, J.Theoretical carbon isotope fractionation under deep earth conditions.Goldschmidt Conference 2012, abstract 1p.MantleCarbon
DS1987-0423
1987
Polyakov, V.P.Loladze, N.T., Polyakov, V.P., Fedorseev, D.F.Dependence of diamond formation on the crystallite size Of the starting carbonaceous material.(Russian)Kolloidn. Zh.(Russian), Vol. 49, No. 2, pp. 352-353GlobalCrystallography
DS1987-0424
1987
Polyakov, V.P.Loladze, N.T., Polyakov, V.P., Fedoseev, D.F.Dependence of the diamond formation process on the size of the crystallites of the starting carbonaceous material (technicalnote)Colloid. Journal, Vol. 9, No.2, Mar-Apr. pp. 307-308GlobalBlank
DS1991-1911
1991
Polyakov, V.P.Yelutin, A.V., Polyakov, V.P., Chernykh, R.O.Solubility of graphite and diamond in NIMN melt under the high pressure.(Russian)Doklady Academy of Sciences Nauk SSR, (Russian), Vol. 320, No. 4, pp. 864-867RussiaExperimental petrology, Graphite
DS200812-0909
2007
Polyakova, E.Polyakova, E., Journel, A.G.The Nu expression for probablistic dat a integration.Mathematical Geology, Vol. 39, pp. 715-733.TechnologyStatistical probability - not specific to diamonds
DS201112-0812
2011
Polyakova, E.A.Polyakova, E.A., Chakhmouradian, A.R., Siidra ,Britvin, Petrov, Spratt, Williams, Stanley, ZaitsevFluorine, yttrium and lanthanide rich cerianite from carbonatitic rocks of the Kerimasi volcano and surrounding explosion craters, Gregory Rift.Peralk-Carb 2011, workshop held Tubingen Germany June 16-18, PosterAfrica, TanzaniaCarbonatite
DS200512-0007
2004
PolyanichkoAgashev, A.M., Pokhilenko, N.P., Tolstov, A.V., Polyanichko, Malkovets, SobolevNew age dat a on kimberlites from the Yakutian Diamondiferous Province.Doklady Earth Sciences, Vol. 399, 8, pp.1142-1145.Russia, YakutiaGeochronology
DS201412-0877
2014
Polyanichko, V.V.Spetsius, Z.V., Polyanichko, V.V., Xarlamova, E.I.,Tarskix, O.V., Ivanov, A.S.Geology, petrography and mineralogy of the Zarya pipe kimberlites.Deep Seated Magmatism, its sources and plumes, Ed. Vladykin, N.V., pp. 160-177.RussiaDeposit - Zarya
DS201510-1807
2014
Polyanichko, V.V.Spetsius, Z.V., Polyanichko, V.V., Xarlamova, E.I., Tarskix, O.V., Ivanov, A.S.Geology, petrography and mineralogy of the Zarya pipe kimberlites.Deep-seated magmatism, its sources and plumes, Proceedings of XIII International Workshop held 2014., Vol. 2014, pp. 160-177.RussiaDeposit - Zarya
DS2000-0772
2000
Polyanov, Yu.N.Polyanov, Yu.N., Sokol, A.G., Khokhryakov et al.Diamond and graphite crystallization in COH fluid at Pt parameters of the natural diamond formation. #1Doklady Academy of Sciences, Vol. 375A, No. 9, pp. 1395-8.GlobalDiamond - morphology
DS1995-1567
1995
Polyanskii, O.P.Reverdatto, V.V., Sheplev, V.S., Polyanskii, O.P.Burial metamorphism and evolution of rift troughs: a model approachPetrology, (QE 420 P4), Vol. 3, No. 1, Jan-Feb. pp. 31-37RussiaTectonics, Rifting
DS201112-0278
2010
Polyansky, O.P.Dobretsov, N.L., Polyansky, O.P.On formation mechanisms of deep sedimentary basins: is there enough evidence for eclogitization?Russian Geology and Geophysics, Vol. 51, pp. 1314-1321.MantleGeodynamics, rifting
DS200812-0594
2008
Polyansky, V.G.Korobeyniko, S.N., Polyansky, V.G., Babichev, A.V., Reverdatto, V.V.Computer modeling of underthrusting and subduction under conditions of gabbro eclogite transition in the mantle.Doklady Earth Sciences, Vol. 421, 1, pp. 724-728.MantleSubduction
DS1983-0107
1983
Polykanov, Y.V.A.Argunov, K.P., Gafiyllina, D.S., Kirikitsa, S.I., Polykanov, Y.V.A.Trace Elements in Small Natural Diamonds.(russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 270, No. 3, pp. 693-695RussiaDiamond Morphology
DS1996-1582
1996
Polykovskiy, V.S.Yusupov, R.G., Polykovskiy, V.S., Mustafin, S.K.Native metals and nonmetals, carbides and silicides and the gas composition of their fluid inclusions...Doklady Academy of Sciences, Vol. 336, pp. 96-100.China, Tien ShanDiamond, Granulite ecologite
DS1989-0060
1989
Polzar, B.D.Bailey, R.C., Craven, J.A., Macnae, J.C., Polzar, B.D.Deep UTEM controlled source electromagnetic sounding across the Ivanhoe Lake cataclastic zoneGeological Association of Canada (GAC) Annual Meeting Program Abstracts, Vol. 14, p. A124. (abstract.)OntarioTectonics, Kapuskasing Zone
DS1989-0061
1989
Polzer, B.D.Bailey, R.C., Craven, J.A., Macnae, J.C., Polzer, B.D.Imaging of deep fluids in Archean crustNature, Vol. 340, No. 6229, July 13, pp. 136-8 Database #18038OntarioGeophysics, Midcontinent- Ivanhoe Lake
DS1994-1975
1994
Polzhaeva, L.Zaitsev, A., Polzhaeva, L.Dolomite calcite textures in carbonatites of the Kovdor ore deposit, KolaPeninsula: their genesis and application for calcite-dolomite geotherm.Contr. Mineralogy and Petrology, Vol. 116, No. 3, pp. 339-344.Russia, Kola PeninsulaCarbonatite, Deposit -Kovdor
DS1998-1178
1998
Pomares, J.S.Pomares, J.S.Assessment report on the drilling campaign over exploration permit 0001295Wemindji area, Quebec.Quebec Department of Mines, GM 56048, 43p.QuebecExploration - assessment, Monopros Limited
DS201112-0005
2011
PomazanskiAfanasev, V.P., Lobanov, S.S., Pokhilenko, N.P., Koptil, Mityukhin, Gerasimchuk, Pomazanski, GorevPolygenesis of diamonds in Siberian Platform. Five groups of diamonds have been distinquished.Russian Geology and Geophysics, Vol.l 52, pp. 259-274.Russia, SiberiaDiamond placers, alluvials
DS201112-1049
2011
Pomazanskii, B.S.Titkov, S.V., Ryabchikov, I.D., Pomazanskii, B.S., Magazina, L.O.Chloride Micro inclusions in diamonds of the Siberian Platform.Doklady Earth Sciences, Vol. 437, 2, pp. 503-506.Russia, SiberiaDiamond inclusions
DS202104-0609
2020
Pomazanskii, B.S.Sonin, V.M., Zhimulev, E.I., Chepurov, A.A., Lindenblot, E.S., Loginova, A.M., Shcheglov, D.V., Pomazanskii, B.S., Afanasiev, V.P., Chepurov, A.I.Dissolution of natural octahedral diamonds in an Fe-S melt at high pressure.Geology of Ore Deposits, Vol. 62, 6, pp. 497-507. pdfRussia, Yakutiadeposit Yubileinaya

Abstract: An experimental study was carried out on the dissolution of natural octahedral diamonds from the Internatsionalnaya and Yubileinaya kimberlite pipes (Yakutia) in an Fe-S melt at 4 GPa and 1450-1500°C with different sulfur contents (10-25 wt %). It was found that with an increase in sulfur content in the iron melt, the degree of diamond dissolution sharply decreases. The stationary (final) shape of diamond crystal dissolution under the achieved conditions corresponds to an octahedroid with trigonal etching layers, which is confirmed by photogoniometry. Diamonds with similar morphology are common in kimberlite pipes, especially in mantle xenoliths from kimberlites. It was concluded that diamonds with this shape did not undergo natural dissolution in a kimberlite magma, but, similar to flat-faced octahedra, were probably isolated from it in xenoliths. Therefore, the higher the content of octahedroid-shaped diamonds with trigonal layers in a deposit, the smaller the direct influence of an aggressive kimberlite magma on the diamond content.
DS201804-0740
2018
Pomazanskiy, B.S.Sonin, V.M., Zhimulev, E.I., Pomazanskiy, B.S., Zemnuhov, A.L., Chepurov, A.A., Afanasiev, V.P., Chepurov, A.I.Morphological features of diamond crystals dissolved in Fe0.7 S0.3 melt at 4GPa and 1400.Geology of Ore Deposits, Vol. 60, pp. 82-92.Technologydiamond morphology

Abstract: An experimental study of the dissolution of natural and synthetic diamonds in a sulfur-bearing iron melt (Fe0.7S0.3) with high P-T parameters (4 GPa, 1400°?) was performed. The results demonstrated that under these conditions, octahedral crystals with flat faces and rounded tetrahexahedral diamond crystals are transformed into rounded octahedroids, which have morphological characteristics similar to those of natural diamonds from kimberlite. It was suggested that, taking into account the complex history of individual natural diamond crystals, including the dissolution stages, sulfur-bearing metal melts up to sulfide melts were not only diamond-forming media during the early evolution of the Earth, but also natural solvents of diamond in the mantle environment before the formation of kimberlitic melts.
DS201412-0683
2014
Pomazansky, B.S.Petrovsky, V.A., Silaev, V.I., Sukharev, A.E., Vasilyev, E.A., Pomazansky, B.S., Zemnukhov, A.L.Yakutites: mineralogical geochemical properties and new version of the genesis. Part 1.Izvestiya VUZ'ov Geologia I Razvedka ** in Russia Courtesy of Felix, No. 3, pp. 24-33.Russia, YakutiaCarbonado, with lonsdaleite
DS201412-0825
2014
Pomazansky, B.S.Silaev, V.I., Petrovsky, V.A., Sukharev, A.E., Smoleva, I.V., Pomazansky, B.S., Zemnukhov, A.L.Yakutites: mineralogical geochemical properties and new version of the genesis. Part 2.Izvestiya VUZ'ov Geologia I Razvedka ** in Russia Courtesy of Felix, No. 4, pp. 12-22.TechnologyYakutites
DS201702-0235
2016
Pomazansky, B.S.Rakin, V.I., Kovalchuk, O.Y., Pomazansky, B.S.Dissymmetrization of artificial and natural diamonds,Doklady Earth Sciences, Vol. 471, 2, pp. 1303-1306.TechnologyDiamond crystallography

Abstract: The occurrence rates of combinatorial types of simple polyhedra {111} are analyzed for natural and artificial diamonds. The empirical occurrence rates of 14 possible polyhedra in an isotropic environment are obtained based on numeral simulation of growth forms of octahedral crystals by the Monte-Carlo method. The phenomenon of dissymmetrization by Curie’s principle related to the crystallization conditions is established for artificial and natural diamonds.
DS202012-2256
2020
Pomazansky, B.S.Zedgenizov, D.A., Skuzovatov, S.Y., Griffin, W.L., Pomazansky, B.S., Ragozin, A.:., Kalinina, V.V.Diamond forming HDFs tracking episodic mantle metasomatism beneath Nyurbinskaya kimberlite pipe (Siberian craton).Contributions to Mineralogy and Petrology, Vol. 175, 106, 21p. PdfRussiadeposit - Nyurbinskaya

Abstract: We present a new dataset on the composition of high-density fluids (HDFs) in cloudy (n?=?25), coated (n?=?10) and cuboid (n?=?10) diamonds from the Nyurbinskaya kimberlite pipe. These diamonds represent different populations each showing distinct growth histories. The cores of coated diamonds display multiple growth stages and contrasting sources of carbon. Fibrous coats and cuboid diamonds have similar carbon isotopes and nitrogen systematics, suggesting their formation in the last metasomatic events related to kimberlite magmatism, as is common for most such diamonds worldwide. The HDFs in most of these diamonds span a wide range from low-Mg carbonatitic to hydrous silicic compositions. The major- and trace-element variations suggest that the sources for such HDFs range in composition between the depleted mantle and more fertile mantle reservoirs. Hydrous-silicic HDFs could originate from a 13C-enriched source, which originates through subduction of crustal metasedimentary material. Percolation of such HDFs through carbonated eclogites and peridotites facilitates the formation of cuboid diamonds and fibrous coats in the mantle section beneath the corresponding area of the Siberian craton. Cloudy diamonds represent an apparently older population, reflecting continuous diamond formation predominantly from high-Mg carbonatitic HDFs that caused discrete episodes of diamond precipitation. Their high Mg# and enrichment in incompatible elements support a metasomatized peridotitic source for these HDFs.
DS1988-0403
1988
Pomchalov, A.V.Laptev, V.A., Pomchalov, A.V., Samoilovich, M.I.Diamond crystallization characteristics in a system consisting of a meta land difficulty graphitizable carbonaceous substances. (Russian)Sverkhtverd. Mater., (Russian), No. 4, pp. 13-17RussiaDiamond morphology
DS2001-0548
2001
Pomeroy, J.W.Jones, H.G., Pomeroy, J.W., Walker, D.A., Hoham, R.W.Snow ecology: an inter disciplinary examination of snow-covered ecosystems. BOOK REVIEW Cambridge Univ. Press, 378p. @ 80.00 USGeoscience Canada, Vol.29,2, June pp. 89-90.CanadaBook - review, Snow ecosystem
DS200612-1159
2006
Pomi, P.F.Richardson, S.H., Harris, J.W., Pomi, P.F.Antiquity of harzburgitic diamonds from the Venetia kimberlite, Limpopo Belt, Kaapvaal Craton.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 17. abstract only.Africa, South AfricaDeposit - Venetia,diamond genesis
DS200912-0626
2009
Pomi, P.F.Richardson, S.H., Pomi, P.F., Shirey, S.B., Harris, J.W.Age and origin of peridotite diamonds from Venetia, Limpopo belt, Kaapval- Zimbabwe Craton.Lithos, In press available, 35p.Africa, South AfricaDeposit - Venetia
DS201012-0592
2010
Pommier, A.Pommier, A., Gaillard, F., Pichavant, M.Time dependent changes of the electrical conductivity of basaltic melts with redox state.Geochimica et Cosmochimica Acta, Vol. 74, 5, pp. 1653-1671.MantleRedox
DS201412-0702
2014
Pommier, A.Pommier, A., Garnero, E.J.Petrology based modeling of mantle melt electrical conductvity and joint interpretation of electromagnetic and seismic results.Journal of Geophysical Research,, Vol. 119, 5, pp. 4001-4016.MantleGeophysics - EM, Seismics
DS201901-0056
2018
Pommier, A.Pommier, A., Roberts, J.Understanding electrical signals from below Earth's surface. SIGMELTS ( peridotite San Carlos)Geochimica et Cosmochimica Acta, Vol. 242, pp. 165-190.United States, Arizonaperidotite

Abstract: Scientists have known for a long time that various types of rock conduct current differently and that these differences are even more pronounced as the temperatures and pressures increase farther beneath Earth’s surface. They also know that unusual changes in electrical conductivity can signal activity down below, like migrating magma or a release of trapped fluids. Thus, electrical measurements can uncover clues about the events that trigger earthquakes and volcanic eruptions here on the surface. They can also give clues to the mantle’s structure and dynamics. However, interpreting these signals is far from straightforward. Earth scientists increasingly use electrical observations made in the field to image Earth’s crust and mantle, in particular, at subduction zones and mid-ocean ridges. An effective means of interpreting these electrical images and placing them into context with other geological observations is key to translating raw data into usable knowledge. Such knowledge includes assessing potential hazards by investigating, for example, links between fluid release and earthquake generation or the production and transport of magmatic melt from its source region to an eventual eruption. SIGMELTS is a freely available app that helps to characterize electrically conductive or resistive features detected at depth using electromagnetic observations. The objective of this Web application is to facilitate the elaboration of models of the electrical properties of crust and mantle materials, which, in turn, is used to improve the interpretation of field electromagnetic observations. A new version of SIGMELTS is now available.
DS201907-1589
2019
Pommier, A.Zhang, Z., Qin, T., Pommier, A., Hirschmann, M.M.Carbon storage in Fe-Ni-S liquids in the deep upper mantle and its relation to diamond and Fe-Ni alloy precipitation.Earth and Planetary Science Letters, Vol. 520, pp. 164-174.Mantlediamond genesis

Abstract: To better understand the role of sulfide in C storage in the upper mantle, we construct a thermodynamic model for Fe-Ni-S-C sulfide melts and consider equilibrium between sulfide melts, mantle silicates, Fe-Ni alloy, and diamond. The sulfide melt model is based upon previous parameterization of Fe-Ni-S melts calibrated at 100 kPa, which we have extended to high pressure based on volumetric properties of end-member components. We calculate the behavior of C in the sulfide melt from empirical parameterization of experimental C solubility data. We calculate the continuous compositional evolution of Fe-Ni sulfide liquid and associated effects on carbon storage at pressure and redox conditions corresponding to mantle depths of 60 to 410 km. Equilibrium and mass balance conditions were solved for coexisting Fe-Ni-S melt and silicate minerals (olivine [(Mg,Fe,Ni)2SiO4], pyroxene [(Mg,Fe)SiO3]) in a mantle with 200 ppmw S. With increasing depth and decreasing oxygen fugacity (fO2), the calculated melt (Fe+Ni)/S atomic ratio increases from 0.8-1.5 in the shallow oxidized mantle to 2.0-10.5 in the reduced deep upper mantle (>8 GPa), with Fe-Ni alloy saturation occurring at >10 GPa. Compared to previous calculations for the reduced deep upper mantle, alloy saturation occurs at greater depth owing to the capacity of sulfide melt to dissolve metal species, thereby attenuating the rise of Fe and Ni metal activities. The corresponding carbon storage capacity in the metal-rich sulfide liquid rises from negligible below 6 GPa to 8-20 ppmw at 9 GPa, and thence increases sharply to 90-110 ppmw at the point of alloy saturation at 10-12 GPa. The combined C storage capacity of liquid and solid alloy reaches 110-170 ppmw at 14 GPa. Thus, in the deep upper mantle, all carbon in depleted sources (10-30 ppmw C) can be stored in the sulfide liquid, and alloy and sulfide liquids host a significant fraction of the C in enriched sources (30-500 ppmw C). Application of these results to the occurrences of inferred metal-rich sulfide melts in the Fe-Ni-S-C system and inclusions in diamonds from the mantle transition zone suggests that oxidization of a reduced metal-rich sulfide melt is an efficient mechanism for deep-mantle diamond precipitation, owing to the strong effect of (Fe+Ni)/S ratio on carbon solubility in Fe-Ni-S melts. This redox reaction likely occurs near the boundary between oxidized subducted slabs and the reduced ambient peridotitic mantle.
DS200812-0105
2008
Pomorski, M.Berderman, E., Caragheorgheopol, A., Clobanu, M., Pomorski, M., Pullia, A., Riboldi, S.,Traeger, M., Weick, H.Ion spectroscopy - a diamond characterization tool.Diamond and Related Materials, Vol. 17, 7-10, pp. 1159-1163.TechnologySpectroscopy
DS1994-1395
1994
Pomposiello, M.C.Pomposiello, M.C., et al.MT studies in the southeast region of Tucuman Plain, ArgentinaJournal of South American Earth Sciences, Vol. 7, No. 3, April pp. 101-108ArgentinaStructure
DS1997-0993
1997
Pomposiello, M.C.Sainato, C.M., Pomposiello, M.C.Two dimensional magnetotelluric and gravity models of the Tuzgle Volcano Zone Jujuy ProvinceJournal of South American Earth Sciences, Vol. 10, No. 3-4, pp. 247-262ArgentinaGeophysics - magnetics, gravity
DS1992-1217
1992
Ponahlo, J.Ponahlo, J.Cathodluminescence (CL) and CL spectra of de Beers' experimental syntheticdiamondsJournal of Gemology, Vol. 23, No. 1, January pp. 3-18GlobalSynthetic diamonds, Chlorine, Cathodluminescence
DS1993-0116
1993
Ponahlo, J.Bezborodov, S.M., Garanin, V.K., Kudryavtseva, G.P., Ponahlo, J.Find of eclogite with two diamond generations in the Udachnaya kimberlitepipeDoklady Academy of Sciences USSR, Earth Science Section, Vol. 317 A February Publishing date pp. 190-194Russia, YakutiaDiamond morphology, Deposit -Udachnaya
DS1991-0116
1991
Ponailo, I.Bezborodov, S.M., Garanin, V.K., Kudryavtseva, G.P., Ponailo, I.Discovery of eclogite with generations of diamond in the Udachnaya kimberlite pipe. (Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 317, No. 3, pp. 714-717RussiaDiamond genesis, Eclogite
DS1970-0176
1970
Ponamarenko, A.I.Ponamarenko, A.I., Pankratov, A.A., Poberezhskiy, V.A.Occurrence of Kimberlite Magmatism on the Southern Slope Of the Anabar Anticlise (uplift).In: Geology, Petrography And Mineralogy of Magmatic Formatio, PP. 33-47.RussiaBlank
DS1970-0384
1971
Ponamarenko, A.I.Ponamarenko, A.I.A Deep Seated Inclusion of Phlogopite-olivine-picroilmenite rock in the Yakutian Kimberlite and its Relation to Pyrope Or Peridotite.Doklady Academy of Sciences Nauk SSSR., Vol. 200, No. 6, PP. 1429-1432.RussiaBlank
DS1970-0385
1971
Ponamarenko, A.I.Ponamarenko, A.I., Kharkiv, A.D.Xenoliths of Rocks of the Trap Formation in Kimberlite Pipes of the Malo-botuobia Diamondiferous Region. In: Trappy Sibirskoy Platformy.....Unknown, PP. 43-44.RussiaBlank
DS1992-1743
1992
Ponamarenko, A.I.Zhuravlev, A.Z., Lazko, E.E., Ponamarenko, A.I.Ancient depleted subcontinental lithosphere under Siberian platform:Proceedings of the 29th International Geological Congress. Held Japan, Vol. 1, abstract p. 179Russia, YakutiaGeochronology, Mir pipe
DS2002-0581
2002
Ponce, D.A.Glen, J.M.G., Ponce, D.A.Large scale fractures related to inception of the Yellowstone hotspotGeology, Vol. 30, No. 7, July pp. 647-50.Idaho, Oregon, NevadaPaleomagnetics
DS201610-1895
2016
Ponce, D.A.Peacock, J.R., Denton, K.M., Ponce, D.A.Magnetotelluric imaging of a carbonatite terrane in the southeast Mojave desert, California and Nevada.ASEG-PESA-AIG 2016 25th Geophysical Conference, abstract 5p.United States, California, NevadaCarbonatite

Abstract: The southeast Mojave Desert hosts one of the world’s largest rare earth element (REE) deposits at Mountain Pass, California. Although surface geology has been studied, a full understanding of the carbonatite and associated intrusive suite complex requires subsurface geophysical characterization. In this study, a combination of geophysical methods, including magnetotelluric (MT), magnetics, and gravity are used to create a two-dimensional (2D) geophysical model to a depth of about 10 km. An electrically conductive body is found 2-3 km below and west of the deposit that is associated with a magnetic high that could be connected to a deeper (10 km) conductive body related to possible intrusions or hydrothermal systems. The carbonatite body coincides with a steep magnetic gradient and a bench or terrace in the gravity data that may reflect relative lower-density intrusive rocks. Although carbonatite rocks are typically magnetic, the carbonatite rocks, associated intrusive suite, and host rocks in this area are essentially non-magnetic. Combined geophysical data indicate that the enriched REE deposit may be related to a regional extensive hydrothermal alteration event.
DS201904-0757
2019
Poncet, F.Malavergegne, V., Bureau, H., Raepsaet, C., Gaillard, C., Poncet, F., Surble, M., Sifre, S., Shcheka, D., Fourdrin, S., Deldicque, C., Khodja, D., HichamExperimental constraints on the fate of H and C during planetary core-mantle differentiation. Implications for the Earth.Icarus - New York, Vol. 321, 1, pp. 473-485.Mantlecarbon

Abstract: Hydrogen (H) and carbon (C) have probably been delivered to the Earth mainly during accretion processes at High Temperature (HT) and High Pressure (HP) and at variable redox conditions. We performed HP (1-15?GPa) and HT (1600-2300°C) experiments, combined with state-of-the-art analytical techniques to better understand the behavior of H and C during planetary differentiation processes. We show that increasing pressure makes H slightly siderophile and slightly decreases the highly siderophile nature of C. This implies that the capacity of a growing core to retain significant amounts of H or C is mainly controlled by the size of the planet: small planetary bodies may retain C in their cores while H may have rather been lost in space; larger bodies may store both H and C in their cores. During the Earth's differentiation, both C and H might be sequestrated in the core. However, the H content of the core would remain one or two orders of magnitude lower than that of C since the (H/C)core ratio might range between 0.04 and 0.27.
DS200512-0866
2005
Pond, M.Pond, M.What is the Ontario mining act?Canadian Diamonds, Summer, p.16, 18.Canada, OntarioNews item - legal
DS1985-0426
1985
Pondaga, M.H.Mauritsch, H.J., Pondaga, M.H.Paleomagnetic Investigations on the East African Rift in Northern Tanzania.Journal of GEODYNAMICS, Vol. 2, No. 2-3. JUNE PP. 265-274.Central Africa, TanzaniaPaleomagnetics, Tectonics
DS1987-0382
1987
Pondaga, M.M.Krs, M., Pondaga, M.M., Savary, B.P.Geophysical investigation of the ring structure at Zanzui, NorthernTanzaniaPhysics of the Earth and Planetary Interiors, Vol.45, pp. 294-303TanzaniaGeophysics, Structure
DS2003-1164
2003
Poniatowski, B.T.Rikhotso, C.T., Poniatowski, B.T., Hetman, C.M.Overview of the exploration, evaluation and geology of the Gahcho Kue kimberlites8th. International Kimberlite Conference Large Core Exhibit volume, 8p.Northwest TerritoriesGeology - description, Deposit - Gahcho Kue, 5034, Hearne, Tuzo, Tesla
DS200412-1668
2003
Poniatowski, B.T.Rikhotso, C.T., Poniatowski, B.T., Hetman, C.M.Overview of the exploration, evaluation and geology of the Gahcho Kue kimberlites, Northwest Territories.8th. International Kimberlite Conference Large Core Exhibit volume, 8p.Canada, Northwest TerritoriesGeology - description Deposit - Gahcho Kue, 5034, Hearne, Tuzo, Tesla
DS1970-0247
1971
PonikarBorodin, L.S., Gopal, V., Moralev, V.M., Suramanian, V., PonikarPrecambrian Carbonatites of Tamil Nadu, South IndiaGeological Society INDIA Journal, Vol. 12, No. 2, PP. 101-112.India, Tamil NaduPetrography, Analyses
DS201705-0884
2017
Ponkratov, K.Ugapeva, S., Goryainov, S., Afanasiev, V., Ponkratov, K.Raman mapping of mechanical stress field in diamond around a chromite inclusion.European Geosciences Union General Assembly 2017, Vienna April 23-28, 1p. 11676 AbstractTechnologyDiamond inclusions
DS200812-0728
2008
PonkratzMcCammon, C., Kantor, I., Narygina, O., Roquette, J., Ponkratz, Sergieev, Mezouar, Prakapenka, DubrovinskyStable intermediate spin ferrous iron in lower mantle perovskite.Nature Geoscience, Vol. 1, 10, pp. 684-687.MantlePerovskite
DS200612-0468
2006
PonomarchukGladkochub, D.P., Wingate, M.T.D., Pisarevsky, S.A., Donskaya, T.V., Mazukababzov, Ponomarchuk, StanevichMafic intrusions in southwestern Siberia and implications for a Neoproterozoic connection with Laurentia.Precambrian Research, Vol. 147, 3-4, July 5, pp. 260-278.Russia, CanadaMagmatism
DS200612-0469
2006
PonomarchukGladkochub, D.P., Wingate, M.T.D., Pisarevsky, S.A., Donskaya, T.V., Mazukabzov, Ponomarchuk, StanevichMafic intrusions in southwestern Siberia and implications for a Neoproterozoic connection with Laurentia.Precambrian Research, In press, availableRussia, SiberiaGeochronology, Biryusa, magmatism
DS201712-2678
2017
Ponomarchuk, A.V.Chebotarev, D.A., Doroshkevich, A.G., Sharygin, V.V., Yudin, D.S., Ponomarchuk, A.V., Sergeev, S.A.Geochronology of the Chuktukon carbonatite massif, Chadobets uplift ( Krasnoyarsk Territory).Russian Geology and Geophysics, Vol. 58, pp. 1222-1231.Russiacarbonatite

Abstract: We present results of U-Pb (SHRIMP II) and Ar-Ar geochronological study of the rocks of the Chuktukon massif, which is part of the Chadobets alkaline-carbonatite complex, and of the weathering crust developed after them. Perovskite from picrites and monazite from the weathering crust were dated by the U-Pb (SHRIMP II) method, and rippite from carbonatites, by the Ar-Ar method. Rippite has first been used as a geochronometer. The estimated ages (252 ± 12 and 231 ± 2.7 Ma) testify to two magmatism pulses close in time (within the estimation error) to the stages of alkaline magmatism in the Siberian Platform (250-245 and 238-234 Ma). These pulses characterize, most likely, the processes accompanying and completing the activity of the mantle superplume that formed the Siberian Igneous Province at 250-248 Ma. The monazite-estimated age (102.6 ± 2.9 Ma) reflects the time of formation of the ore-bearing weathering crust on the massif rocks.
DS201803-0443
2018
Ponomarchuk, A.V.Doroshkevich< A.G., Prokopyev, I.R., Izokh, A.E., Klemd, R., Ponomarchuk, A.V., Nikolaeva, I.V., Vladykin, N.V.Isotopic and trace element geochemistry of the Seligdar magnesiocarbonatites ( South Yakutia, Russia): insights regarding the mantle evolution beneath the Aldan Stanovoy shield.Journal of Asian Earth Sciences, Vol. 154, pp. 354-368.Russia, Yakutiacarbonatite -Seligdar

Abstract: The Paleoproterozoic Seligdar magnesiocarbonatite intrusion of the Aldan-Stanovoy shield in Russia underwent extensive postmagmatic hydrothermal alteration and metamorphic events. This study comprises new isotopic (Sr, Nd, C and O) data, whole-rock major and trace element compositions and trace element characteristics of the major minerals to gain a better understanding of the source and the formation process of the carbonatites. The Seligdar carbonatites have high concentrations of P2O5 (up to 18?wt%) and low concentrations of Na, K, Sr and Ba. The chondrite-normalized REE patterns of these carbonatites display significant enrichments of LREE relative to HREE with an average La/Ybcn ratio of 95. Hydrothermal and metamorphic overprints changed the trace element characteristics of the carbonatites and their minerals. These alteration processes were responsible for Sr loss and the shifting of the Sr isotopic compositions towards more radiogenic values. The altered carbonatites are further characterized by distinct 18O- and 13C-enrichments compared to the primary igneous carbonatites. The alteration most likely resulted from both the percolation of crustal-derived hydrothermal fluids and subsequent metamorphic processes accompanied by interaction with limestone-derived CO2. The narrow range of negative ?Nd(T) values indicates that the Seligdar carbonatites are dominated by a homogenous enriched mantle source component that was separated from the depleted mantle during the Archean.
DS202008-1426
2020
Ponomarchuk, A.V.Nikolenko, A.M., Doroshkevich, A.G., Ponomarchuk, A.V., Redina, A.A., Prokopyev, I.R., Vladykin, N.V., Nikolaeva, I.V.Ar-Ar geochronology and petrogenesis of the Mushgai-Khudag alkaline-carbonatite complex 9 southern Mongolia).Lithos, Vol. 372-372, 105675 15p. PdfAsia, Mongoliacarbonatite

Abstract: The Mushgai-Khudag alkaline?carbonatite complex, located in southern Mongolia within the Central Asian Orogenic Belt (CAOB), comprises a broad range of volcanic and subvolcanic alkaline silicate rocks (melanephelinite-trachyte and shonkinite-alkaline syenite, respectively). Magnetite-apatite rocks, carbonatites, and fluorite mineralization are also manifested in this area. The complex formed between 145 and 133 Ma and is contemporaneous with late Mesozoic alkaline-carbonatite magmatism within the CAOB. Major and trace element characteristics of silicate rocks in the Mushgai-Khudag complex imply that these rocks were formed by the fractional crystallization of alkaline ultramafic parental magma. Magnetite-apatite rocks may be a product of silicate-Ca-Fe-P liquid immiscibility that took place during the alkaline syenite crystallization stage. The Mushgai-Khudag rocks have variable and moderately radiogenic Sr (87Sr/86Sr(i) = 0.70532-0.70614), ?Nd(t) = ?1.23 to 1.25) isotopic compositions. LILE/HFSE values and SrNd isotope compositions indicate that the parental melts of Mushgai-Khudag were derived from a lithospheric mantle source that was affected by a metasomatic agent in the form a mixture of subducted oceanic crust and its sedimentary components. The ?18OSMOW and ?18CPDB values for calcites in carbonatites range from 16.8‰ to 19.2‰ and from ?3.9‰ to 2.0‰, respectively. CO covariations in calcites of the Mushgai-Khudag carbonatites can be explained by the slight host limestone assimilation.
DS1991-1737
1991
Ponomarchuk, V.A.Tolstykh, N.D., Krivenko, A.P., Elisafenko, V.N., Ponomarchuk, V.A.Mineralogy of apatite-bearing carbonatites from Kuznetsk AlatauSoviet Geology and Geophysics, Vol. 32, No. 11, pp. 41-48RussiaCarbonatite, Mineralogy
DS2002-0837
2002
Ponomarchuk, V.A.Khabarov, E.M., Ponomarchuk, V.A., Morozova, J.P.Strontium isotopic evidence for supercontinental breakup and formation in the Riphean Western Margin of the Siberian Craton.Russian Journal of Earth Science, Vol. 4, 4, AugustRussia, SiberiaGeochronology
DS200612-0740
2006
Ponomarchuk, V.A.Kovalenko, V.I., Yarmolyuk, Salnikova, Kozlovski, Kotov, Kovach, Vladykin, Savatenkov, V.M., Ponomarchuk, V.A.Geology and age of Khan-Bogdinsky massif of alkaline granitoids in southern Mongolia.Vladykin: VI International Workshop, held Mirny, Deep seated magmatism, its sources and plumes, pp. 17-45.Asia, MongoliaAlkaline rocks, granites
DS200712-0363
2007
Ponomarchuk, V.A.Gladkochub, D.P., Donskaya, T.V., Mazukabzov, A.M., Stanevich, A.M., Sklyarov, E.V., Ponomarchuk, V.A.Signature of Precambrian extension events in the southern Siberian Craton.Russian Geology and Geophysics, Vol. 48, pp. 17-31.RussiaDike swarm, rifting, Rodinia
DS200712-1064
2007
Ponomarchuk, V.A.Talibova,A.G., Ponomarchuk, V.A., Semenova, D.V.EA-IRMS: analysis of graphite and diamond.Plates, Plumes, and Paradigms, 1p. abstract p. A997.TechnologyDiamond
DS200912-0686
2009
Ponomarchuk, V.A.Semenova, D.V., Ponomarchuk, V.A.Carbon isotopic composition in diamonds and crystalline graphite - continuous flow GB-IRMS method.Goldschmidt Conference 2009, p. A1193 Abstract.TechnologyChemistry
DS202006-0946
2020
Ponomarchuk, V.A.Ponomarchuk, V.A., Dobretsov, N.L. , Lazareva, E.V., Zhmodik, S.M., Karmanov, N.S., Tolstov, A,V., Pyryaev, A.N.Evidence of microbial-induced mineralization in rocks of the Tomtor carbonatite complex ( Arctic Siberia).Doklady Earth Science, Vol. 490, 2, pp. 76-80.Russia, Siberiacarbonatite

Abstract: Carbonates of the Tomtor complex of ultramafic alkaline rocks and carbonatites (the northern part of the Republic of Sakha Yakutia) are distinguished by a wide range of carbon isotopic composition ?13C from +2 to -59.9‰. The geological position, localization patterns, mineral and chemical compositions and the relationship with REE mineralization of samples with values of ?13C carbonates from -25 to -59‰ are characterized. The formation of abnormally low ?13C in carbonates is determined by the biogenic oxidation of methane from ?13Cmet to -70‰.
DS202104-0571
2021
Ponomarchuk, V.A.Dobretsov, N.L., Zhmodik, S.M., Lazareva, E.V., Bryanskaya, A.V., Ponomarchuk, V.A., Saryg-ool, B. Yu., Kirichenko, I.S., Tolstov, A.V., Karmanov, N.S.Structural and morphological features of the participation of microorganisms in the formation of Nb-REE-rich ores of the Tomtor field, Russia.Doklady Earth Sciences, Vol. 496, pp. 135-138. Russiadeposit - Tomtor

Abstract: Data indicating the important role of microorganisms in the redistribution of REEs in the weathering crust and the decisive role in the concentration of REEs during the formation of ores in the upper ore horizon of the Tomtor field are obtained. The uptake of REEs was carried out by the community of microorganisms, such as phototrophs, methanogens, methanotrophs, and proteobacteria, which form the basis of the microbiocenosis for this paleoecosystem. The isotopic composition of C carbonates in all samples studied with fossilized microorganisms corresponds to the biogenic one, and the isotopic composition ?18?SMOW (from 7 to 20‰) indicates the endogenous (hydrothermal) and, to a lesser extent, exogenous nature of the solutions. The low (87Sr/86Sr)I values of carbonates (~0.7036-0.7042) exclude the participation of seawater.
DS1970-0386
1971
Ponomarenko, A.I.Ponomarenko, A.I., Ponomarenko, G.A., Kharkiv, A.D., et al.Inclusions of Ilmenite-bearing Ultrabasic Rocks in the Kimberlites of Yakutia.Sovetsk. Geol., No. 10, PP. 102-111.RussiaBlank
DS1975-0383
1976
Ponomarenko, A.I.Ponomarenko, A.I., et al.Diamond bearing grospidite and diamond bearing kyanite eclogite from Udachnaya kimberlite pipe, Yakutia.Doklady Academy of Sciences, Vol. 226, pp. 158-61.Russia, YakutiaMineralogy, Deposit - Udachnaya
DS1975-0384
1976
Ponomarenko, A.I.Ponomarenko, A.I., et al.Rock Forming Minerals of Diamond Bearing Eclogite from Richpipes Yakutia.Vyssh. Uchebn. Zaved. Izv. Geol. Razed., 1976, No. 7, PP. 47-50.RussiaBlank
DS1975-1184
1979
Ponomarenko, A.I.Ponomarenko, A.I.First find of diamond bearing garnet ilmenite peridotite in the Mirkimberlite pipe.Doklady Academy of Sciences, Vol. 235, pp. 153-6.Russia, YakutiaMineralogy, Deposit - Mir
DS1981-0392
1981
Ponomarenko, A.I.Spetsius, Z.V., Ponomarenko, A.I.Vitrified Eclogite, Representative of the Earth's Asthenosphere.Doklady Academy of Science USSR, Earth Science Section., Vol. 248, No. 1-6, PP. 115-118.RussiaBlank
DS1982-0411
1982
Ponomarenko, A.I.Matsyuk, S.S., Platonov, A.N., Ponomarenko, A.I., Kharkiv, A.D.Color of Garnet As Criterion of Presence of Diamond in Eclogitic Paragenesis of Kimberlite Pipes.Zap. Vses. Mineral. Obshch., Vol. 111, No. 2, PP. 159-166.RussiaBlank
DS1982-0501
1982
Ponomarenko, A.I.Ponomarenko, A.I., Spetsius, Z.V.Mineral Rims on Diamonds from KimberlitesInternational Geology Review, Vol. 24, No. 7, PP. 829-834.RussiaEvaluation, Carbonate, Genesis, Analyses, Microprobe, Crystallography
DS1982-0502
1982
Ponomarenko, A.I.Ponomarenko, A.I., Spetsius, Z.V., Sobolev, N.V.New Type of Diamond Bearing Rock- Garnet PyroxeniteDoklady Academy of Science USSR, Earth Science Section., Vol. 251, No. 2, PP. 89-91.RussiaPetrography
DS1987-0592
1987
Ponomarenko, A.I.Ponomarenko, A.I., Tsepin, A.I.First diamond bearing phlogopite pyroxenite find.Axenolith from the Mir kimberlite pipe, YakutiaDoklady Academy of Science USSR, Earth Science Section, Vol. 297, No. 6, Nov-Dec pp. 155-159RussiaXenolith, Phlogopite pyroxenite
DS1987-0593
1987
Ponomarenko, A.I.Ponomarenko, A.I., Tsepin, A.I.1st occurrence of diamond bearing phlogopite xenolith from the pipe Yakutia.(Russian)Dokl. Akad. Sci. SSSR, (Russian), Vol. 297, No. 5, pp. 1210-1213RussiaBlank
DS1988-0548
1988
Ponomarenko, A.I.Ponomarenko, A.I.Conversion of kyanite (Al/2SIO/5) to corundum (Al/2O/3) and SiO/2Dokl. Acad. Sciences USSR Earth Science Section, Vol. 303, No. 6, pp. 103-106GlobalExperimental petrology, aluminum, Eclogite
DS1989-1231
1989
Ponomarenko, A.I.Ponomarenko, A.I., Tsepin, A.I.First diamond bearing phlogopite pyroxenite find ( axenolith from the Mirkimberlite pipe (Yakutia)Doklady Academy of Science USSR, Earth Science Section, Vol. 297, No. 1-6, pp. 153-159RussiaDiamond morphology, Diamond inclusions
DS1991-1627
1991
Ponomarenko, A.I.Sobolev, N.V., Zuev, V.M., Bezborodov, S.M., Ponomarenko, A.I.Eclogite paragenesis of diamonds from Udachnaya and Mir pipes, YakutiaProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, p. 391RussiaXenoliths, Omphacites
DS1991-1935
1991
Ponomarenko, A.I.Zhuravlev, A.Z., Lazko, E.E., Ponomarenko, A.I.Ancient depleted subcontinental lithosphere under Siberian platform: neodymium-SrProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 581-583RussiaXenoliths, Petrology, geochemistry
DS1992-1744
1992
Ponomarenko, A.I.Zhuravlev, A.Z., Lazko, Ye.Ye., Ponomarenko, A.I.Radiogenic isotopes and rare earth elements (REE) in garnet peridotite xenoliths from the Mirkimberlite pipe, YakutiaGeochemistry International, Vol. 29, No. 2, pp. 45-55RussiaGeochemistry, Deposit -Mir pipe
DS1995-1584
1995
Ponomarenko, A.I.Roden, M.F., Lazko, E.E., Ponomarenko, A.I., Serenko, V.P.Mineralogy of peridotite xenoliths from the Mir kimberlite Yakutia, Russia.Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 462-464.Russia, YakutiaXenoliths, Deposit -Mir
DS1970-0386
1971
Ponomarenko, G.A.Ponomarenko, A.I., Ponomarenko, G.A., Kharkiv, A.D., et al.Inclusions of Ilmenite-bearing Ultrabasic Rocks in the Kimberlites of Yakutia.Sovetsk. Geol., No. 10, PP. 102-111.RussiaBlank
DS200712-0857
2007
Ponomarenko, V.A.Pribavkin, S.V., Ronkiv, Yu.L., Travin, A.V., Ponomarenko, V.A.New dat a on the age of lamproite-lamprophyre magmatism in the Urals.Doklady Earth Sciences, Vol. 413, 2, pp. 213-215..Russia, UralsLamproite
DS201905-1068
2019
Ponomarev, J.D.Prokopyev, I.R., Doroshkevich, A.G., Sergeev, S.A., Ernst, R.E., Ponomarev, J.D., Redina, A.A., Chebotarev, D.A., Nikolenko, A.M., Dultsev, V.F., Moroz, T.N., Minakov, A.V.Petrography, mineralogy and SIMS U-Pb geochronology of 1.0 - 1.8 Ga carbonatites and associated alkaline rocks of the Central Aldan magnesiocarbonatite province ( South Yakutia, Russia).Mineralogy and Petrology, Doi.org/a0.1007/ s00710-019-00661-3 24p.Russiacarbonatites
DS201906-1339
2019
Ponomarev, J.D.Prokopyev, I.R., Doroshkevich, A.G., Sergeev, S.A., Ernst, R.E., Ponomarev, J.D., Redina, A.A., Chebotarev, D.A., Nikolenko, A.M., Dultsev, V.F., Moroz, T.N., Minakov, A.V.Petrography, mineralogy and SIMS U-Pb geochronology of 1.9-1.8 Ha carbonatites and associated alkaline rocks of the Central-Aldan magnesiocarbonatite province ( South Yakutia, Russia).Mineralogy and Petrology, Vol. 113, pp. 329-352.Russia, Yakutiacarbonatites
DS200512-0405
2005
Ponomarev, P.Harris, J.R., Ponomarev, P., Shang, J.A comparison of methods for extracting end members from airborne hyper spectral data: application to geologic mapping in Canada's Arctic.GAC Annual Meeting Halifax May 15-19, Abstract 1p.Canada, Nunavut, Northwest TerritoriesRemote sensing
DS200612-0536
2006
Ponomarev, P.Harris, J.R., Ponomarev, P., Shang, S., Budkewitsch, P., Rogge, D.A comparison of automatic and supervised methods for extracting lithological end members from hyper spectral data: application to southern Baffin Island, Nunavut.Geological Survey of Canada Current Research, 2006-C4 19p.Canada, NunavutHyperspectral - technology
DS201809-2070
2018
Pons, M-L.McCoy-West, A.J., Fitton, J.G., Pons, M-L., Inglis, E.C., Williams, H.M.The Fe and Zn isotope composition of deep mantle source regions: insight from Baffin Island picrites.Geochimica et Cosmochimica Acta, Vol. 238, pp. 542-562.Canada, Nunavut, Baffin Islandpicrites

Abstract: Young (61?Ma) unaltered picrites from Baffin Island, northeast Canada, possess some of the highest 3He/4He (up to 50?Ra) seen on Earth, and provide a unique opportunity to study primordial mantle that has escaped subsequent chemical modification. These high-degree partial melts also record anomalously high 182W/184W ratios, but their Sr-Nd-Hf-Pb isotopic compositions (including 142Nd) are indistinguishable from those of North Atlantic mid-ocean ridge basalts. New high precision Fe and Zn stable isotope analyses of Baffin Island picrites show limited variability with ?56Fe ranging from ?0.03‰ to 0.13‰ and ?66Zn varying from 0.18‰ to 0.28‰. However, a clear inflection is seen in both sets of isotope data around the composition of the parental melt (MgO?=?21?wt%; ?56Fe?=?0.08?±?0.04‰; and ?66Zn?=?0.24?±?0.03‰), with two diverging trends interpreted to reflect the crystallisation of olivine and spinel in low-MgO samples and the accumulation of olivine at higher MgO. Olivine mineral separates are significantly isotopically lighter than their corresponding whole rocks (?56Fe????0.62‰ and ?66Zn????0.22‰), with analyses of individual olivine phenocrysts having extremely variable Fe isotope compositions (?56Fe?=??0.01‰ to ?0.80‰). By carrying out modelling in three-isotope space, we show that the very negative Fe isotope compositions of olivine phenocryst are the result of kinetic isotope fractionation from disequilibrium diffusional processes. An excellent correlation is observed between ?56Fe and ?66Zn, demonstrating that Zn isotopes are fractionated by the same processes as Fe in simple systems dominated by magmatic olivine. The incompatible behaviour of Cu during magmatic evolution is consistent with the sulfide-undersaturated nature of these melts. Consequently Zn behaves as a purely lithophile element, and estimates of the bulk Earth Zn isotope composition based on Baffin Island should therefore be robust. The ancient undegassed lower mantle sampled at Baffin Island possesses a ?56Fe value that is within error of previous estimates of bulk mantle ?56Fe, however, our estimate of the Baffin mantle ?66Zn (0.20?±?0.03‰) is significantly lower than some previous estimates. Comparison of our new data with those for Archean and Proterozoic komatiites is consistent with the Fe and Zn isotope composition of the mantle remaining constant from at least 3?Ga to the present day. By focusing on large-degree partial melts (e.g. komatiites and picrites) we are potenitally biasing our record to samples that will inevitably have interacted with, entrained and melted the ambient shallow mantle during ascent. For a major element such as Fe, that will continuosly participate in melting as it rises through the mantle, the final isotopic compositon of the magama will be a weighted average of the complete melting column. Thus it is unsuprising that minimal Fe isotope variations are seen between localities. In contrast, the unique geochemical signatures (e.g. He and W) displayed by the Baffin Island picrites are inferred to solely originate from the lowermost mantle and will be continuously diluted upon magma ascent.
DS1982-0503
1982
Ponsard, J.F.Ponsard, J.F., Lesquer, A., Villeneuve, M.Une Suture Panafricaine sur la Bordure Occidentale du Craton Ouest Africain.Comptes Rendus Seances Academy of Science Ser. 2, Mec. Phys. Chim. S, Vol. 295, No. 13, PP. 1161-1164.West Africa, Guinea, Sierra Leone, Mali, GermanyTectonics
DS2000-0773
2000
Ponte-Neto, C.F.Ponte-Neto, C.F., Ernesto, M.Paleomagnetism of the Cambrian dike swarm from Itabuna, southeastern border of Sao Francisco Craton.Igc 30th. Brasil, Aug. abstract only 1p.Brazil, BahiaMagnetism, Dike swarm
DS200612-1101
2006
Pontevivo, A.Pontevivo, A., Thybo, H.Test of the upper mantle low velocity layer in Siberia with surface waves.Tectonophysics, Vol. 416, 1-4, April 5, pp. 113-131.Russia, SiberiaGeophysics - seismics
DS1992-1218
1992
Ponzini, G.Ponzini, G., Tosi, N.A technique to test finite difference schemes to model some geophysical processes in a geological structureMathematical Geology, Vol. 24, No. 4, pp. 499-537GlobalGeophysics, Computer modeling
DS1989-1232
1989
Pool, R.Pool, R.Cold fusion: end of act IScience, Research News, Vol. 24, June 2, pp. 1039-1040. Database # 17978GlobalCold fusion, Brief overview
DS1990-1193
1990
Pool, R.Pool, R.Diamond films sparkle as they come to marketScience, Vol. 249, July 6, pp. 27, 28GlobalEconomics, CVD Chemical vapor deposi
DS1982-0627
1982
Pooley, G.D.Wass, S.Y., Pooley, G.D.Fluid Activity in the Mantle Evidence from Large Lherzolitexenoliths.Proceedings of Third International Kimberlite Conference, TERRA COGNITA, ABSTRACT VOLUME., Vol. 2, No. 3, P. 229, (abstract.).AustraliaKimberlite
DS1995-0682
1995
Pooley, G.D.Griffin, B.J., Rissanen, J., Pooley, G.D., Lee, DearnA new Diamondiferous eclogite bearing kimberlitic occurrence from FinlandProceedings of the Sixth International Kimberlite Conference Extended Abstracts, p. 198-200.FinlandEclogite
DS200512-0867
2005
Pooley, G.D.Pooley, G.D.Weathering of chromite.World Diamond Conference Nov. 23, Perth, 2p.Geochemistry - chromium spinel
DS2003-0575
2003
Pooley, S.Hell, A.J., Ramsay, W.R.H., Rheinberger, G., Pooley, S.The geology, age, mineralogy and near surface features of the Merlin kimberlites8ikc, Www.venuewest.com/8ikc/program.htm, Session 1 POSTER abstractAustraliaKimberlite geology and economics, Deposit - Merlin
DS200412-1618
2003
Pooley, S.Ramsay, W.R.H., Hell, A., Reinberger, G., Pooley, S.The geology, age, near surface features and mineralogy of the Merlin kimberlite field, Northern Territory, Australia.Geological Society of Australia Abstracts, Vol. 70, p. 54. 1p.Australia, Northern TerritoryDeposit overview - Merlin
DS201901-0087
2018
Poon, T.Wang, W., Poon, T.Canary yellow diamonds. Gems & Gemology, Sixth International Gemological Symposium Vol. 54, 3, Fall 1p. Abstract p. 262-3Africa, Sierra Leonedeposit - Zimmi

Abstract: Isolated nitrogen is one of the major defects in producing yellow color in natural diamonds. In regular type Ib yellow diamonds, isolated nitrogen is normally the dominant form, with limited aggregations in A centers (nitrogen pairs). Type Ib diamonds normally experienced strong plastic deformations. In addition to vacancy clusters, many other optic centers were introduced during annealing over their long geological history, such as GR1, NV, and H3 centers. Diamonds from the Zimmi area of West Africa are a typical example (Smit et al., 2016). As a result, clear brownish and greenish hues are common among these diamonds, so most do not possess true “canary” yellow color. Here we studied more than 2,000 diamonds with real canary yellow color. Their color origin and relationship with type Ib diamonds were explored. Sizes of the studied diamonds ranged from 0.01 to about 1.0 ct. They showed pure yellow color, with grades of Fancy Intense or Fancy Vivid yellow. Infrared absorption analysis showed that they were all type IaA with very high nitrogen concentrations, but a very weak absorption from isolated nitrogen at 1344 cm–1 was detected in all samples. Concentration of isolated nitrogen was estimated at ~2–3 ppm. This isolated nitrogen created smooth absorption in the ultraviolet-visible (UV-Vis) region, increasing gradually to the high-energy side. No other defects were detected using UV-Vis absorption spectroscopy, which explained the pure yellow color we observed. Fluorescence imaging revealed multiple nucleation centers with dominant green color, which was attributed to the S3 defects confirmed through photoluminescence analysis. Compared with natural type Ib diamonds, an outstanding feature of the studied samples is the absence of plastic deformation. For this reason, other vacancy-related defects were not introduced to these diamond lattices over the geological period after their formation. Sulfide inclusions are common in type Ib diamonds, but they were not observed in these canary stones. Instead, some calcite inclusions were observed. All the observations from this study indicated that the canary diamond samples were formed in a different geological environment than type Ib diamonds.
DS201112-0813
2011
Poore, H.Poore, H., White, N., Maclennan, J.Ocean circulation and mantle melting controlled by radial flow of hot pulses in the Iceland plume.Nature Geoscience, in press availableMantle, Europe, IcelandMelting
DS1984-0592
1984
Poornachandra, R.G.V.S.Poornachandra, R.G.V.S., Murthi, C.S., Bhalia, M.S.Paleomagnetism of Kimberlites Around Wajrakarur Anantapur District, Andhra Pradesh.Geophysical Research. Bulletin., Vol. 22, No. 2-3, PP. 105-116.India, Andhra PradeshGeophysics, Kimberlite
DS1992-1598
1992
Poorter, R.P.E.Varekamp, J.C., Kreulen, R., Poorter, R.P.E., Van bergen, M.J.Carbon sources in arc volcanism, with implications for the carbon cycleTerra Nova, Vol. 4, pp. 363-373GlobalArc volcanism., Carbon cycle
DS200812-0498
2008
Popa, C.Iancu, O.G., Cossio, R., Korsakov, A.V., Compagnoni, R., Popa, C.Cathodluminesence spectra of diamonds in UHP rocks from the Kokchetav Massif, Kazakhstan.Journal of Luminescence, Vol. 128, 10, pp. 1684-1688.Russia, KazakhstanSpectroscopy
DS1993-1212
1993
Popdkuyko, Yu.A.Pechnikov, V.A., Bobrov, V.A., Popdkuyko, Yu.A.Isotope composition of diamond and accompanying graphite from metamorphic rocks of northern Kazakhstan.(Russian)Geochemistry International (Geokhimiya), (Russian), Vol. 1993, No. 1, pp. 150-154.Russia, Kazakhstan, Commonwealth of Independent States (CIS)Geochronology, Diamond
DS1992-1219
1992
Pope, A.J.Pope, A.J., Thirlwall, M.F.Tectonic setting, age, and regional correlation of ultrabasic-ultrapotassic dykes in the northern Purcell Mountains, southeast British ColumbiaCanadian Journal of Earth Sciences, Vol. 29, No. 3, March pp. 523-530British ColumbiaUltrapotassic, Cross Creek kimberlite
DS1998-1179
1998
Pope, D.C.Pope, D.C., Willett, S.D.Thermal mechanical model for crustal thickening in the central Andes driven by ablative subductionGeology, Vol. 26, No. 6, June pp. 511-4Andes, Bolivia, ChileBolivian Altiplano, Western Cordillera, Chilean Puna, Orogenic belt, structure, lithosphere
DS201212-0667
2012
Pope, E.Sleep, N.H., Bird, D.K., Pope, E.Paleontology of Earth's mantle.Annual Review of Earth and Planetary Sciences, Vol. 40, pp. 277-300.MantlePaleontology
DS201312-0833
2013
Pope, E.Sleep, N.H., Bird, D.K., Pope, E.Paleontology of Earth's mantle. Mentions keywords as kimberlite, carbonatiteAnnual Review of Earth and Planetary Sciences, Vol. 40, pp. 277-300.MantleKimberlite, carbonatite
DS200712-1238
2007
Pope, E.C.Zhao, R., Zhang, R.Y., Liou, J.G., Booth, A.L., Pope, E.C., Chamberlain, C.P.Petrochemistry oxygen isotopes and U-Pb SHRIMP geochronology of mafic ultramafic bodies from the Sulu UHP terrane, China.Journal of Metamorphic Geology, Vol. 25, 2, pp. 207-224.ChinaUHP
DS201905-1082
2019
Pope, E.C.van der Meer, Q.H.A., Scott, J.M., Serre, S.H., Whitehouse, M.J., Kristoffersen, M., Le Roux, P.J., Pope, E.C.Low delta 18 O zircon xenocrysts in alkaline basalts; a window into the complex carbonatite-metasomatic history of the Zealandia lithospheric mantle.Geochimica et Cosmochimica Acta, Vol. 254, pp. 21-39.New Zealandmetasomatism

Abstract: Megacrystic zircon grains from alkaline basaltic fields are rare but can provide fundamental insights into mantle metasomatic processes. Here, we report in-situ U-Pb ages, trace element concentrations and hafnium and oxygen isotopes for fourteen zircon megacrysts from two intraplate alkaline basalt locations in New Zealand. U-Pb ages indicate the zircons crystallised between 12.1 and 19.8 Ma. Zircon oxygen isotopic compositions range from low to mantle-like compositions (grain average ? ą? O = 3.8-5.1‰). Hafnium isotopes (?Hf (t) = +3.3 to +10.4) mostly overlap with intraplate mafic rocks and clinopyroxene in metasomatized peridotitic mantle xenoliths but show no correlation with most trace element parameters or oxygen isotopes. The zircons are interpreted to have formed by the reaction between low-degree melts derived from pre-existing mantle metasomes and the depleted mantle lithosphere prior to eruption and transport to the surface. The low Hf concentration, an absence of Eu anomalies, and elevated U/Yb compared to Nb/Yb in the megacrystic zircons are interpreted to show that the source metasomes comprised subduction- and carbonatite-metasomatised lithospheric mantle. As these trace element characteristics are common for megacrystic zircon in intra-plate basaltic fields globally, they suggest the prevalence of subduction- and carbonatite-metsasomatised mantle under these intraplate volcanic regions. The unusually low ? ą? O was likely present prior to metasomatic enrichment and may have resulted from high-temperature hydrothermal alteration during initial mantle lithosphere formation at a mid ocean ridge or, possibly, during subduction-related processes associated with continent formation. The combination of proportionally varied contributions from carbonatite- and subduction-metasomatised lithospheric melts with asthenospheric melts may explain the variety of primitive intraplate basalt compositions, including low ? ą? O reported for some local intraplate lavas.
DS200712-0850
2006
Pope, S.Pope, S.High pressure, high temperature (HPHT) diamond processing: what is this technology and how does it affect colour?Gems & Gemology, 4th International Symposium abstracts, Fall 2006, p.120, abstract onlyTechnologyDiamond color
DS201912-2821
2019
Popescue, C.Sanatmaria-Perez, D., Ruiz-Fuertes, J., Pena-Alvarez, M., Chulia-Jordan, R., Marquerno, T., Zimmer, D., Guterrez-Cano, V., Macleod, S., Gregoryanz, E., Popescue, C., Rodriguez-Herandez, P., Munoz, A.Post-tilleyite, a dense calcium silicate carbonate phase.Nature Scientific Reports, Vol. 9, 11p. PdfMantletilleyite

Abstract: Calcium carbonate is a relevant constituent of the Earth’s crust that is transferred into the deep Earth through the subduction process. Its chemical interaction with calcium-rich silicates at high temperatures give rise to the formation of mixed silicate-carbonate minerals, but the structural behavior of these phases under compression is not known. Here we report the existence of a dense polymorph of Ca5(Si2O7)(CO3)2 tilleyite above 8 GPa. We have structurally characterized the two phases at high pressures and temperatures, determined their equations of state and analyzed the evolution of the polyhedral units under compression. This has been possible thanks to the agreement between our powder and single-crystal XRD experiments, Raman spectroscopy measurements and ab-initio simulations. The presence of multiple cation sites, with variable volume and coordination number (6-9) and different polyhedral compressibilities, together with the observation of significant amounts of alumina in compositions of some natural tilleyite assemblages, suggests that post-tilleyite structure has the potential to accommodate cations with different sizes and valencies.
DS201711-2500
2017
Pophare, A.M.Asthana, D., Kumar, S., Kumar Vind, A., Zehra, F., Kumar, H., Pophare, A.M.Geochemical fingerprinting of ~ 2.5 Ga forearc-arc-backarc related magmatic suites in the Bastar Craton, central India.Journal of Asian Earth Sciences, in press available, 17p.Indiageodynamics

Abstract: The Pitepani volcanic suite of the Dongargarh Supergroup, central India comprises of a calc-alkaline suite and a tholeiitic suite, respectively. The rare earth element (REE) patterns, mantle normalized plots and relict clinopyroxene chemistry of the Pitepani calc-alkaline suite are akin to high-Mg andesites (HMA) and reveal remarkable similarity to the Cenozoic Setouchi HMA from Japan. The Pitepani HMAs are geochemically correlated with similar rocks in the Kotri-Dongargarh mobile belt (KDMB) and in the mafic dykes of the Bastar Craton. The rationale behind lithogeochemical correlations are that sanukitic HMAs represent fore-arc volcanism over a very limited period of time, under abnormally high temperature conditions and are excellent regional and tectonic time markers. Furthermore, the tholeiitic suites that are temporally and spatially associated with the HMAs in the KDMB and in the mafic dykes of the Bastar Craton are classified into: (a) a continental back-arc suite that are depleted in incompatible elements, and (b) a continental arc suite that are more depleted in incompatible elements, respectively. The HMA suite, the continental back-arc and continental arc suites are lithogeochemically correlated in the KDMB and in the mafic dykes of the Bastar Craton. The three geochemically distinct Neoarchaean magmatic suites are temporally and spatially related to each other and to an active continental margin. The identification of three active continental margin magmatic suites for the first time, provides a robust conceptual framework to unravel the Neoarchaean geodynamic evolution of the Bastar Craton. We propose an active continental margin along the Neoarchaen KDMB with eastward subduction coupled with slab roll back or preferably, ridge-subduction along the Central Indian Tectonic Zone (CITZ) to account for the three distinct magmatic suites and the Neoarchean geodynamic evolution of the Bastar Craton.
DS201805-0933
2018
Pophare, A.M.Asthana, D., Kumar, S., Vind, A.K., Zehra, F., Kumar, H., Pophare, A.M.Geochemical fingerprinting of ~2.5 Ga forearc-arc-backarc related magmatic suites in the Bastar Craton, central India.Journal of Asian Earth Sciences, Vol. 157, pp. 218-234.IndiaCraton

Abstract: The Pitepani volcanic suite of the Dongargarh Supergroup, central India comprises of a calc-alkaline suite and a tholeiitic suite, respectively. The rare earth element (REE) patterns, mantle normalized plots and relict clinopyroxene chemistry of the Pitepani calc-alkaline suite are akin to high-Mg andesites (HMA) and reveal remarkable similarity to the Cenozoic Setouchi HMA from Japan. The Pitepani HMAs are geochemically correlated with similar rocks in the Kotri-Dongargarh mobile belt (KDMB) and in the mafic dykes of the Bastar Craton. The rationale behind lithogeochemical correlations are that sanukitic HMAs represent fore-arc volcanism over a very limited period of time, under abnormally high temperature conditions and are excellent regional and tectonic time markers. Furthermore, the tholeiitic suites that are temporally and spatially associated with the HMAs in the KDMB and in the mafic dykes of the Bastar Craton are classified into: (a) a continental back-arc suite that are depleted in incompatible elements, and (b) a continental arc suite that are more depleted in incompatible elements, respectively. The HMA suite, the continental back-arc and continental arc suites are lithogeochemically correlated in the KDMB and in the mafic dykes of the Bastar Craton. The three geochemically distinct Neoarchaean magmatic suites are temporally and spatially related to each other and to an active continental margin. The identification of three active continental margin magmatic suites for the first time, provides a robust conceptual framework to unravel the Neoarchaean geodynamic evolution of the Bastar Craton. We propose an active continental margin along the Neoarchaen KDMB with eastward subduction coupled with slab roll back or preferably, ridge-subduction along the Central Indian Tectonic Zone (CITZ) to account for the three distinct magmatic suites and the Neoarchean geodynamic evolution of the Bastar Craton.
DS1982-0504
1982
Popivnyak, I.V.Popivnyak, I.V., Simkiv, ZH. A.Soluable Components of Mantle Derived Mineral Forming MediaDoklady Academy of Science USSR, Earth Science Section., Vol. 256, No. 4, PP. 181-184.RussiaSytykan, Pyrope, Garnet, Kimberlite, Analyses, Fluid Inclusions
DS201412-0703
2013
Popkin, G.Popkin, G.Earth's plate boundaries may nurture diamond formation.Proceedings of National Academy of Science USA, 1p. Brief overviewMantleGeodynamics
DS1960-0728
1966
Popoff, C.C.Popoff, C.C.Computing reserves of mineral deposits : principles and conventionalmethods.out of print -xerox availableUsbm Information Circular, No. 8283, 113pUnited StatesReserves, Usa
DS1988-0549
1988
Popoff, M.Popoff, M.Benue trough oblique rifting, northeast Brasil interior basins and the geodynamic evolution of the equatorial domainof the south Atlantic.(in Portugese).Revista Brasileira de Geociencias, (in Portugese)., Vol. 18, No. 3, September p. 315. (abstract.)BrazilTectonics, Rifting
DS1975-0218
1976
Popolitov, E.I.Abramov, V.A., Popolitov, E.I.Geochemical Properties of Xenoliths of Upper Mantle RocksDoklady Academy of Science USSR, Earth Science Section., Vol. 231, No. 1-6, PP. 172-175.RussiaGeochemistry, Kimberlite, Garnet
DS200412-2180
2004
Popolitov, K.E.Yegorova, T.P., Stephenson, R.A., Kostyuchenko, S.L., Baranova, E.P., Satrostenko, V.I., Popolitov, K.E.Structure of the lithosphere below the southern margin of the East European Craton ( Ukraine and Russia) from gravity and seismiTectonophysics, Vol. 381, 1-4, pp. 81-100.Europe, UkraineTectonics
DS201806-1237
2018
Popov, A.A.Osei Tutu, A., Sobolev, S.V., Steinberger, B., Popov, A.A., Rogozhina, I.Evaluating the influence of plate boundary friction and mantle viscosity on plate velocities.Geochemistry, Geophysics, Geosystems, Vol. 19, 3, pp. 642-666.Mantlegeophysics - seismic
DS201603-0410
2015
Popov, A.G.Paktovskiy, Yu.G., Popov, A.G., Chaykovskiy, I.I. .New deposits in the Devonian diamond reservoirs of the northern Urals. *** IN RUSSIANProblems of Mineralogy, petrography and metallogeny , No. 18, pp. 286-289.RussiaDiamond occurrences ***
DS1991-1366
1991
Popov, A.M.Popov, A.M., Kiselev, A.I., Lepina, S.V.Magnetotelluric investigations in the Baikal region: deep structureSoviet Geology and Geophysics, Vol. 32, No. 4, pp. 93-100Russia, Lake BaikalTectonics, Structure
DS1992-0868
1992
Popov, A.M.Kiselev, A.I., Popov, A.M.Asthenospheric diapir beneath the Baikal rift: petrological constraintsTectonophysics, Vol. 208, pp. 287-295Russia, AsiaTectonics, Baikal rift, kimberlites
DS2000-0504
2000
Popov, A.M.Kislev, A.I., Popov, A.M.The Baikal Rift as a portrayal of dynamic, structural and compositional differences between lithosphere...Doklady Academy of Sciences, Vol. 371, No. 2, pp. 226-229.Russia, Siberia, AsiaSiberian Platform, Central Asian Mobile Belt, Geodynamics, Rifting
DS201312-0539
2013
Popov, D.Liang, Q., Meng, Y., Yan, C., Krasnicki, S., Lai, J., Hemawan, K., Shu,H., Popov, D., Yu,T., Yang, W., Mao, H., Hemley, R.Developments in synthesis, characterization, and application of large high-quality CVD single crystal diamond.Journal of Superhard Materials, Vol. 35, 4, pp. 195-213.TechnologyDiamond synthetics
DS2002-0124
2002
Popov, K.V.Bazylev, B.A., Popov, K.V., Shcherbakov, V.P.Petrographic features of oceanic peridotites as reflected by their magnetic characteristics.Russian Journal of Earth Science, Vol. 4, 3, JuneGlobalPetrography, Peridotites
DS202103-0400
2021
Popov, M.Popov, M., Bondarenko, M., Kulnitskiy, B., Zholudev, S., Blank, V., Terentyev, S.Impulse laser cutting of diamond accompanied by phase transitions to fullerene -type onion.Diamond & Related Materials, Vol. 113, 108281, 6p. PdfGlobalraman spectroscopy
DS1985-0339
1985
Popov, M.G.Khazov, R.A., Popov, M.G., Biske, N.S.Diatremes in Karelia.(russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 285, No. 4, pp. 975-977RussiaBlank
DS1993-0812
1993
Popov, M.G.Khazov, Ra., Biske, N.S., Popov, M.G.Megacrysts from explosion pipes of KareliaDoklady Academy of Sciences USSR, Earth Science Section, Vol. 318, No. 5, pp. 180-183Russia, Commonwealth of Independent States (CIS), Baltic ShieldMineralogy, Ladogite
DS1993-0813
1993
Popov, M.G.Khazovk, R., Biske, N.S., Popov, M.G.Megacrysts from explosion pipes of KareliaDoklady Academy of Sciences USSR, Earth Science, Vol. 318, pp. 180-184.RussiaBaltic shield
DS201312-0325
2013
Popov, M.G.Gorkovets, V.Y., Rudashevski, N.S., Rudashevski, V.N., Popov, M.G., Antonov, A.V.Indicator minerals of diamond in the lamproitic diatreme, Kostomuksha region, Karelia.Doklady Earth Sciences, Vol. 450, 1, pp. 475-478.Russia, KareliaLamproite
DS201807-1493
2013
Popov, M.G.Gorkovets, V.Ya., Rudashevskii, N.S., Rudashevsky, V.N., Popov, M.G., Antonov, A.A.Indicator minerals in the lamproitic diatreme, Kostomuksha region, Karelia. Doklady Earth Sciences , Vol. 450, 1, pp. 79-90.Russialamproite

Abstract: The mineralogy of a new lamproitic diatreme 200-250 m in diameter and 3 ga in area is studied in detail. The chemical and 3-D mineralogical analysis identify the diatreme rocks as strongly altered olivine lamproites with a large volume (50-60%) of xenoliths of strongly altered spinel (garnet) lherzolites and harzburgites-dunites. Numerous grains-xenocrysts of indicator minerals of diamond have been extracted from the heavy concentrates (the weight of the initial product is 742 g and the size is 100-500 ?m) as a result of hydroseparation: (1) subcalcium (CaOav. 2.6 wt %) high-Cr (Cr2O3 av. 5.3 wt %) pyrope (50 grains); (2) chrome diopside (7 and 8 mol % of kosmochlor and jadeite components, respectively, >40 grains); (3) high-Cr chromite (Cr2O3 > 62 wt %); and (4) picroilmenite (MgO 12-13.8 wt %) and Cr-rutile (Cr2O3 1.1 wt %). Xenocrysts prove the mantle endogene (the level of garnet lherzolites) source of the magmatic center of lamproites and forecast the diamond potential of the new diatreme in the Kostomuksha ore district.
DS1975-0385
1976
Popov, M.I.Popov, M.I., Asatkin, V.B.The Nature of Deformation in Kimberlite Pipes and Veins Using the Siberian Region As an Example.Akad. Nauk Sssr Izv. Ser. Geol., Vol. 1976, No. 11, PP. 19-24.RussiaKimberlite
DS1975-0834
1978
Popov, M.I.Popov, M.I., Asatkin, V.B.Nature of deformation of channels of kimberlite pipes and veins ( in a region of Siberia).International Geology Review, Vol. 20, No. 8, pp. 942-6.Russia, SiberiaPipe - Pulses, Torn Bedding, Broken Bedding
DS201901-0008
2018
Popov, M.Y.Blank, V.D., Churkin, V.D., Kulnitsky, B.A., Perezhogin, I.A., Kirichenko, A.N., Erohin, S.V., Sorokin, P.B., Popov, M.Y.Pressure induced transformation of graphite and diamond to onions.Crystals MDPI, Vol. 8, 2, 8p. Doi.org/10.3390/cryst8020068Russiacarbon nanotubes

Abstract: In this study, we present a number of experiments on the transformation of graphite, diamond, and multiwalled carbon nanotubes under high pressure conditions. The analysis of our results testifies to the instability of diamond in the 55-115 GPa pressure range, at which onion-like structures are formed. The formation of interlayer sp3-bonds in carbon nanostructures with a decrease in their volume has been studied theoretically. It has been found that depending on the structure, the bonds between the layers can be preserved or broken during unloading.
DS202112-1953
2018
Popov, V.Ugapeval, S., Molotkov, A., Popov, V.Vibration spectroscopy of central olivine inclusions in a diamond.Mineral Processing, conf. paper 7p. PdfRussiadeposit - Sytykan

Abstract: The results of studying characteristics of IR and Raman spectra of a diamond plate from the Sytykan pipe with central olivine inclusions are presented. The correlation between changes in the content of nitrogen defects and the internal stress of individual diamond growth zones is provided by IR spectroscopy. The total nitrogen content as A and B1 defects has a range from 81 ppm to 1075 ppm. Area of decreased nitrogen defects concentration in the centre of the diamond plate corresponds to the local pressure around the olivine inclusion. The results of the Raman spectroscopy of this sample showed that the olivine inclusion is stressed. In this connection, the maximum shift of the most intensive bands of SiO4 stretching vibrations is ?? = 5 ± 0.09 and 4 ± 0.12 cm-1, which corresponds to the internal residual pressure in the inclusion of Pi = 1.64 ± 0.1 GPa calculated by formulas given in (Izraeli, 1999; Yasuzuka, 2009). According to Izraeli, E. S. (1999) and the obtained results of Pi the pressure of diamond crystallization Pf = 6,4 ± 0,5 GPa at the model growth temperature of 1200°C is calculated. The area of diamond and inclusion contact zone is identified (bright yellow) by the Raman mapping, it exhibits wide bands 655 - 792 cm-1, typical for non-crystalline material such as Si2O(OH)6 dimers and Si(OH)4 monomers in an aqueous fluid (Nimis et al., 2016).
DS200512-0781
2005
Popov, V.A.Nikiforov, A.V., Bolonin, A.V., Sugorakova, A.M., Popov, V.A., Lykhin, D.A.Carbonatites of central Tuva: geological structure and mineral and chemical composition.Geology of Ore Deposits, Vol. 47, 4, pp. 326-345.RussiaCarbonatite, geochemistry
DS200612-0980
2005
Popov, V.A.Nikiforov, A.V., Bolonin, A.V., Sugorakova, A.M., Popov, V.A., Lykhin, D.A.Carbonatites of central Tuva: geological structure and mineral and chemical composition.Geology of Ore Deposits, Vol. 47, 4, pp. 326-345.RussiaGeochemistry - carbonatites
DS200512-0929
2004
Popov, V.K.Sakhno, V.G., Maksimov, S.O., Popov, V.K., Sandimirova, G.P.Leucite basanites and potassium shonkinites of the Uglovoe Basin, southern Primorye.Doklady Earth Sciences, Vol. 399A, Nov-Dec. pp. 1322-1326.RussiaBasanites, Foidites
DS200612-0853
2006
Popov, V.K.Maksimov, S.O., Popov, V.K.The first finding of carbonatite tuffs in Cenozoic basaltic volcano of southeastern Primorye.Doklady Earth Sciences, Vol. 408, 4, pp. 617-622.RussiaCarbonatite
DS200712-0261
2007
Popov, V.L.Dobtresov, V.Y., Psakhe, S.G., Popov, V.L., Shilko, E.V., Granin, Timofeev,Astafurov, Dimaki, StarchevichIce cover of Lake Baikal as a model for studying tectonic processes in the Earth's crust.Doklady Earth Sciences, Vol. 413, 2, pp. 155-159.RussiaGeomorphology
DS1997-1025
1997
Popov, V.N.Sharapov, V.N., Cherepanov, A.N., Popov, V.N., Lobov, A.G.Dynamics of basic melt cooling during the filling of a funnel shaped intrusive chamber.Geochemistry International, Vol. 35, No. 1, pp. 10-22.GlobalMagma chambers, Experimental petrology
DS1970-0583
1972
Popov, V.S.Popov, V.S.Globular Texture in LamprophyresZap. Vses. Miner. Obshch., Vol. 101, No. 6, PP. 370-379.RussiaRelated Rocks
DS1991-1367
1991
Popov, V.S.Popov, V.S.The origin of primary crustal acid igneous rocksInternational Geology Review, Vol. 33, No. 2, Feb. pp. 150-161RussiaMantle, Ultramafic, boninite
DS1993-1255
1993
Popov, V.S.Popov, V.S., Yuzhu LiThe basanites of the Nuishan volcanic cone, east China, as a result of the partial melting of primitive lherzolites.Geochemistry International, Vol. 30, No. 4, pp. 45-53.ChinaBasanite
DS200812-0725
2008
Popova, D.M.Mavrin, S.A., Denisov, V.N., Popova, D.M., Skryleva, Kuznetsov, Nosukhin, Terentiev, Blank,V.D.Boron distribution in the subsurface region of heavily doped IIb type diamond.Physics and Chemistry of the Earth Parts A,B,C, Vol. 372, 21, pp. 3914-3918.TechnologyType IIb diamonds
DS201703-0429
2017
Popova, E.Popova, E., Lushnikov, S.G., Yakovenchuk, V.N.The crystal structure of loparite: a new acentric variety.Mineralogy and Petrology, in press availablePerovskite, REE

Abstract: The crystal structure of the cubic modification of the natural mineral loparite has been studied for the first time by the methods of the X-ray diffraction analysis (?MoK ? radiation, 105 independent reflections with I > 3?(I), R = 0.041 in the anisotropic approximation). The structure belongs to the perovskite type (ABO 3) with the double period of the cubic unit cell, a = 7.767(1) Ĺ (sp. gr. Pn3m; Z = 2 for the composition (Ca,Na,Ce)(Na,Ce)3(Ti,Nb)2Ti2O12. Period doubling is explained by ordering of cations both in the A and the B positions.
DS201801-0049
2017
Popova, E.A.Popova, E.A., Lushnikov, S.G., Yakovenchuk, V.N., Krivovichev, S.V.The crystal structure of loparite: a new acentric variety.Mineralogy and Petrology, Vol. 111, pp. 827-832.Russia, Kola Peninsuladeposit - Khibiny

Abstract: The crystal structure of a new structural variety of loparite (Na0.56Ce0.21La0.14Ca0.06Sr0.03Nd0.02Pr0.01)?=1.03(Ti0.83Nb0.15)?=0.98O3 from the Khibiny alkaline massif, Kola peninsula, Russia, was solved by direct methods and refined to R1 = 0.029 for 492 unique observed reflections with I > 2?(I). The mineral is orthorhombic, Ima2, a = 5.5129(2), b = 5.5129(2) and c = 7.7874(5) Ĺ. Similarly to other perovskite-group minerals with the general formula ABO3, the crystal structure of loparite is based upon a three-dimensional framework of distorted corner-sharing BO6. The A cations are coordinated by 12 oxygen atoms and are situated in distorted cuboctahedral cavities. In contrast to the ideal perovskite-type structure (Pm3?m), the unit cell is doubled along the c axis and the a and b axes are rotated in the ab plane at 45o. The BO6 octahedron displays distortion characteristic for the d0 transition metal cations with the out-of-center shift of the B site. The symmetry reduction is also attributable to the distortion of the BO6 octahedra which are tilted and rotated with respect to the c axis. The occurrence of a new acentric variety of loparite can be explained by the pecularities of its chemical composition characterized by the increased content of Ti compared to the previously studied samples.
DS201701-0018
2016
Popova, L.P.Kargin, A.V., Nosova, A.A., Postnikov, A.V., Chugaev, A.V., Postnikova, O.V., Popova, L.P., Poshibaev, V.V., Sazonova, L.V., Dokuchaev, A.Ya., Smirnova, M.D.Devonian ultramafic lamprophyre in the Irkineeva Chadobets trough in the southwest of the Siberian platform: age, composition, and implications for diamond potential prediction.Geology of Ore Deposits, Vol. 58, 5, pp. 383-403.RussiaLamprophyre - aillikite

Abstract: The results of geochronological, mineralogical, petrographical, and geochemical study of the Ilbokich ultramafic lamprophyre are reported. The specific features in the mineral and chemical compositions of the studied ultramafic lamprophyre indicate that it can be regarded as a variety similar to aillikite, while other differences dominated by K-feldspar can be referred to damtjernite. According to Rb-Sr analysis, ultramafic lamprophyre dikes intruded at the turn of the Early and Middle Devonian, about 392 Ma ago. This directly proves the existence of Early Paleozoic alkali-ultramafic magmatism in the northern part of the southwest Siberian Platform. A finding of Devonian alkali-ultramafic lamprophyre is of dual predictive importance. On the one hand, it is indicative of the low probability of finding large diamond-bearing deposits in close association with aillikite. On the other hand, it can be indicative of a possible large Devonian diamond province in the studied territory, where diamondiferous kimberlite is structurally separated from aillikite.
DS201802-0223
2018
Popova, M.N.Boldyrev, K.N., Mavrin, B.N., Sherin, P.S., Popova, M.N.Bright luminescence of diamonds with GeV centers.Journal of Luminescence, Vol. 193, pp. 119-124.Technologyluminescence

Abstract: We report on the quantum yield (?) and decay time (?) measurements at room temperature for the bright red-orange (602 nm) luminescence from new germanium-vacancy (Ge-V) centers in nano- and microcrystalline diamonds synthesized at high pressure and high temperature. The values ? = 3 ± 1% and ? = 6.2±0.2 ns were found. The Stokes shift measured as the energy difference between the maxima of the luminescence and luminescence excitation spectra is negligible. The relative intensity of the zero-phonon line constitutes up to 70% from the total intensity of the luminescence. Results of our ab initio DFT calculations for the ground-state electronic and vibrational structure of (Ge-V)? in diamond are presented and discussed.
DS200412-0696
2004
Popovchenko, S.E.Gornostayev, S.S., Walker, R.J., Hanski, E.J., Popovchenko, S.E.Evidence for the emplacement of ca. 3.0 Ga mantle derived mafic ultramafic bodies in the Ukrainian Shield.Precambrian Research, Vol. 132, 4, July 15, pp.349-362.Europe, UkraineTectonics, chromitite
DS1995-1511
1995
Popovici, G.Popovici, G., Wilson, R.G., Sung, T.Diffusion of boron, lithium, oxygen, hydrogen and nitrogen in type IIA natural diamonds.Journal of Applied Physics, Vol. 77, No. 10, May 15, pp. 5103-5106.GlobalDiamond, Mineralogy
DS2001-0355
2001
PoppGao, S., Kern, H., Jin, Popp, Jin, Zhang, ZhangPoisson's ratio of eclogite: the role of retrogressionEarth and Planetary Science Letters, Vol. 192, No. 4, pp. 523-31.GlobalEclogite - geochemistry, Poisson ratio
DS201012-0399
2010
Popp, F.Koller, F., Palfi, A.G., Szabo, Cs., Niku-Paavola, V., Popp, F.Alkaline rocks in the Aris area, central Namibia, Africa.International Mineralogical Association meeting August Budapest, abstract p. 571.Africa, NamibiaAlkaline rocks, phonolite chemistry
DS1992-1220
1992
Popp, R.K.Popp, R.K., Bryndzia, L. T.Statistical analysis of Fe3, Ti, and OH in kaersutite from alkalic Igneous rocks and mafic mantle xenoliths.American Mineralogist, Vol. 77, No. 11-12, November-December, pp. 1250-1257.GlobalMineralogy, Mantle xenoliths
DS1992-1221
1992
Popp, R.K.Popp, R.K., Bryndzia, L.T.Statistical analysis of iron, Ti and OH in kaersutite from alkalic igneous rocks and mafic mantle xenoliths.American Mineralogist, Vol. 77, pp. 1250-57.MantleXenoliths
DS2000-0982
2000
Popp, R.K.Virgo, D., Popp, R.K.Hydrogen deficiency in mantle derived phlogopitesAmerican Mineralogist, Vol. 85, pp. 753-9.NamibiaOkenyenya Igneous Complex - lamprophyre dyke, Kaersutite
DS200912-0423
2009
Popp, R.K.Lamb, W.M., Popp, R.K.Amphibole equilibration temperatures in mantle rocks: determining values of mantle alpha H2O and implications for mantle H2O contents.American Mineralogist, Vol. 94, 1, pp. 41-52.MantleWater
DS1992-0271
1992
Poppe, L.J.Commeau, J.A., Poppe, L.J., Commeau, R.F.Seperation and identification of the silt sized heavy mineral fraction insedimentsUnited States Geological Survey (USGS) Circ, No. 1071, 13pGlobalHeavy mineral sampling - not specific to diamonds, General interest ref
DS2001-0133
2001
PoppiBrigatti, M.F., Medici, L., Poppi, VaccaroCrystal chemistry of trioctahedral micas 1M from the Alto Paranaiba igneous provinceCanadian Mineralogist, Vol. 39, No. 5, Oct. pp. 1333-46.BrazilAlkaline rocks, Carbonatite
DS1993-0163
1993
Poppi, L.Brigatti, M.F., Contini, S., Capedri, S., Poppi, L.Crystal chemistry and cation ordering in pseudobrookite and armalcolite from Spanish lamproitesEuropean Journal of Mineralogy, Vol. 5, pp. 73-84GlobalLamproites, Geochemistry
DS200412-0207
2004
Poppi, L.Brigatti, M.R., Malferrari, D., Medici, L., Ottolini, L., Poppi, L.Crystal chemistry of apatites from the Tapira carbonatite complex, Brazil.European Journal of Mineralogy, Vol. 16, 4,pp. 677-685.South America, BrazilMineral chemistry
DS1991-1368
1991
Popplewell, G.Popplewell, G., Abate, R.The application of modular plants to diamond recovery #1The Canadian Mining and Metallurgical Bulletin (CIM Bulletin) ., Session, Vol. 84, No. 947, March p. 99. AbstractGlobalDiamond recovery, Mining applications-processing
DS1992-1222
1992
Popplewell, G.Popplewell, G., Smith, J.The application of modular plants to diamond recovery #2The Canadian Mining and Metallurgical Bulletin (CIM Bulletin), Vol. 85, No. 956, January pp. 58-63GlobalDiamond processing, Diamond recovery
DS1994-0761
1994
Popplewell, G.Henharen, P.A., Popplewell, G., Shirley, J.M., Stephenson, M.Diamond processing - design considerations for the Northwest TerritoriesBateman Preprint paper handout at The Canadian Institute of Mining, 40p.Northwest TerritoriesDiamond recovery, Mineral processing
DS1997-0990
1997
Popplewell, G.Rylatt, M.G., Poling, G.W., Popplewell, G.The northwest Territories diamonds project - diamond processing in the Canadian arcticThe Canadian Mining and Metallurgical Bulletin (CIM Bulletin) ., Vol. 90, No. 1015, Nov-Dec. p. 33.(paper 24p.)Northwest TerritoriesMineral processing, Deposit - Ektaki
DS201609-1737
2010
Popplewell, G.Popplewell, G.Orapa 3 plant conceptual design evolution in action ( let the ore dictate the plant that you build!!)The 4th Colloquium on Diamonds - source to use held Gabarone March 1-3, 2010, 28p.Africa, BotswanaDeposit - Orapa

Abstract: Commencing with the Pre-Feasibility Study (PFS) conclusions, the Orapa 3 process design evolved through a phase of value-engineering studies. An overall re-evaluation of the originally proposed process design was necessary both in order to address the interim increase in target throughput from 9.8 Mtpa to 12 Mtpa as well as to increase capital efficiency. In the interests of clarity, the PFS process design for Orapa 3 has been omitted from this paper, as it is no longer relevant. Recognition is however due to those engaged in earlier phases of the Orapa 3 project with respect to fundamental mass~balancing modelling; and ore and diamond characterisation, which fanned the basis for the process design that has evolved from feasibility study activities. The background context for Orapa 3 is of an operation expected to yield operating utilisation and revenue improvements relative to the Orapa 2 operation. Delivering these without undue penalties to capital and operating cost required a shift in thinking, trading excess installed capacity for flexible circuit configuration. The process design adopted is "layered", with the purpose of preserving Run Of Mine (ROM) throughput by reducing in-circuit arisings - particularly to the Dense Medium Separation (DMS) section - rather than simply installing additional DMS capacity on the expectation of low DMS availability. Elsewhere, the ability to monitor and maintain critical sizing activities - particularly desanding - without impact on overall plant throughput is intended to motivate operators to avoid the temptation to trade quality for quantity. At present, since an overall dynamic simulation of the Orapa 3 operation has still to be carried out, the design mass balance has been based on a relatively onerous combination of worst case feed type with 100% front-line process capacity in all plant sections. This means that, whilst the installed DMS capacity is based on routing 100% of sized scrubbing section product directly to the DMS, and with one DMS module always unavailable, the High Pressure Rolls Crushing (HPRC) capacity is based on allowing for 50% of this stream to be instead routed first to the HPRC section, at no more than 75% of maximum roll speed for the two units installed. This is an obvious "belt and braces" approach. Following the dynamic simulation exercise (currently in progress), it is likely that a less conservative approach will be taken. This will not affect the conceptual design of the process plant, being mostly an exercise in refining the number of DMS modules to be installed, and possibly reducing slightly the size of the HPRC roll units. Both of these will have positive capital and operating cost impacts. Page 215 The Southern African Institute of Mining and Metallurgy Diamonds - Source to Use 2010 G Popp/ewell andB Hae/else DMS capacity, despite being split into coarse and fiaes streams, consists of identical modules. Two of the nine modules are set-up to receive either coarse or fine feed, the only difference being that fines modules are rated at lower capacity than the same modules treating coarse feed. Final recovery section capacity is based on entirely wet primary diamond recovery technology. This greatly reduces both the cost of drying. a large amount of recovery section feed and the dust• management issues associated with dry recovery technology. In contrast to the Orapa 2 operations, a scavenginglauditgrease belt section is included as a diamond recovery "goal-keeper" and to provide a process assurance function.
DS1988-0550
1988
Popplewell, G.M.Popplewell, G.M., Burks, F.B.J.M.A review of the development of dense medium plant design in the diamond mining industry.Van Eck and Lurie, paper given at Third Samancor Symposium, 33p.GlobalDMS, rotary plans, jigs, Mineral processing - review
DS1999-0620
1999
Popplewell, G.M.Rylatt, M.G., Popplewell, G.M.Ekati diamond mine - background and developmentMining Engineering, Vol. 51, No. 1, Jan. pp. 37-43.Northwest TerritoriesMining, mineral processing, Deposit - Ekati
DS1983-0521
1983
Poprzeczny, J.Poprzeczny, J.Perth to Sparkle as Gem Centre #2Sunday Times (western Australia), JUNE 12TH.AustraliaDiamond Cutting, Industry
DS200612-1102
2005
Popular SciencePopular ScienceDoes life lurk in Earth's mantle?Popular Science, Vol. 267, 5, p. 42.MantleBiology
DS1989-1233
1989
Porada, H.Porada, H.Pan-African rifting and orogenesis in southern to equatorial Africa and eastern BrasilPrecambrian Research, Vol. 44, No. 2, August pp. 103-136South Africa, BrazilTectonics, Pangea
DS1970-0044
1970
Porath, H.Camfield, P.A., Gough, D.I., Porath, H.Magnetometer Array Studies in the Northwestern United States and Southwestern Canada.Geophys. Journal of Res. Astron. Soc., Vol. 22, No. 2, PP. 201-221.Montana, South Dakota, North DakotaGeophysics, Mid-continent
DS1970-0177
1970
Porath, H.Porath, H.Determination of Strike of Conductive Structures from Geomagnetic Variation Anomalies.Earth and Planetary Science Letters, Vol. 9, No. 1, PP. 29-33.GlobalMid Continent
DS1970-0178
1970
Porath, H.Porath, H., Oldenburg, D.W., Gough, D.I.Seperation of Magnetic Variation Fields and Conductive Structures in the Western United States.Geophys. Journal of Res. Astron. Soc., Vol. 19, No. 3, PP. 237-260.GlobalGeophysics, Mid-continent
DS1970-0183
1970
Porath, H.Reitzel, J.S., Gough, D.I., Porath, H., Anderson, C.W.Geomagnetic Deep Sounding and Upper Mantle Structure in The western United States.Geophys. Journal of Res. Astron. Soc., Vol. 19, No. 3, PP. 213-235.GlobalGeophysics, Mid-continent
DS1970-0387
1971
Porath, H.Porath, H.Magnetic Variation Anomalies and Seismic Low Velocity Zone In the Western United States.Journal of GEOPHYSICAL RESEARCH, Vol. 76, No. 11, PP. 2643-2648.GlobalMid Continent
DS1970-0388
1971
Porath, H.Porath, H., Gough, D.I.Mantle Conductive Structures in the Western United States from magnetometer Array Studies.Roy. Astron. Soc. Geophys. Journal, Vol. 23, No. 4, PP. 387-398.GlobalGeophysics, Mid-continent
DS1989-0959
1989
PorcelliMattey, D.P., Exley, R.A., Pillinger, C.T., Menzies, M.A., PorcelliRelationships between Carbon, Heleum, Strontium and neodymium isotopes in mantle diopsidesGeological Society of Australia Inc. Blackwell Scientific Publishing, No. 14, Vol. 2, pp. 913-921GlobalMantle xenoliths
DS2001-0942
2001
Porcelli, D.Porcelli, D., Halliday, A.N.The core as a possible source of mantle heliumEarth and Planetary Science Letters, Vol. 192, No.1, pp. 45-56.MantleHelium - core, Geochemistry
DS2002-0098
2002
Porcelli, D.Ballentine, C.J., Van Keken, P.E., Porcelli, D., Hauri, E.H.Numerical models, geochemistry and the zero-paradox noble gas mantlePhilosophical Transactions, Royal Society of London Series A Mathematical, Vol.1800, pp. 2611-32.MantleGeochemistry - model
DS200412-1569
2004
Porcelli, D.Porcelli, D., Pepin, R., Halliday, A., Ballentine, C.Xe, mantle degassing and atmospheric closure.Geochimica et Cosmochimica Acta, 13th Goldschmidt Conference held Copenhagen Denmark, Vol. 68, 11 Supp. July, ABSTRACT p.A553.MantleDegassing
DS200612-1072
2006
Porcelli, D.Pepin, R.O., Porcelli, D.Xenon isotope systematics, giant impacts and mantle degassing on the early Earth.Earth and Planetary Science Letters, Vol. 250, 3-4, pp. 470-485.MantleGeochronology
DS200712-0830
2006
Porcelli, D.Pepin, R.O., Porcelli, D.Xenon isotope systematics, giant impacts, and mantle degassing on the early Earth.Earth and Planetary Science Letters, Vol. 250, 3-4, Oct. 30, pp. 470-485.MantleGeochronology
DS200812-0520
2008
Porcelli, D.Jephcoat, A.P., Bouhifd, M.A., Porcelli, D.Metal silicate element partitioning at ultrahigh pressures: He to I.Goldschmidt Conference 2008, Abstract p.A427.TechnologyLHDAC
DS200812-0910
2008
Porcelli, D.Porcelli, D., Elliott, T.The evolution of He isotopes in the convecting mantle and the preservation of high 3He 4He ratios.Earth and Planetary Science Letters, Vol. 269, 1-2, May 15, pp. 175-185.MantleNoble gases
DS202101-0035
2020
Porcelli, D.Turner, S., Turner, M., Bourdon, B., Cooper, K., Porcelli, D.Extremely young melt infiltration of the sub-continental lithospheric mantle.Physics of the Earth and Planetary Interiors, doi.org/10.1016/ j.pepi.2-19.106325 54p. PdfMantlemelting

Abstract: It has long been inferred that mantle metasomatism and the incompatible element enrichment of the continents both require movement of melts formed by very low degree melting of the mantle. Yet establishing the presence of these melts and whether this process is on-going and continuous, or spatially and temporally restricted, has proved difficult. Here we report large U-Th-Ra disequilibria in metasomatised, mantle xenoliths erupted in very young lavas from the Newer Volcanics Province in southeastern Australia. The 226Ra-230Th disequilibria appear to require reappraisal of previous estimates for the age of eruption that now seems unlikely to be more than a few kyr at most. We propose that infiltration of carbonatitic melts/fluids, combined with crystallization of pargasite, can account for the first order U-series disequilibria observations. Irrespective of the exact details of the complex processes responsible, the half-lives of the nuclides require that some of the chemical and isotopic disturbance was extremely young (« 8?kyr) and potentially on-going at the time of incorporation into the alkali basalts that transported the xenoliths to the surface. This provides evidence for the presence and possibly continuing migration of small melt fractions (~0.02%) in the upper convecting mantle that may contribute to the seismic low velocity zone. By implication, it appears that the asthenosphere must lie close to its solidus, at least in this region. Pressure-temperature estimates indicate that the small degree melts identified could infiltrate as far as 25?km upwards into the sub-continental lithospheric mantle leading to strong incompatible element enrichment and the recent timing of this event this urges a reappraisal of the meaning of 300-500?Ma Nd model ages in mantle xenoliths from this region. In principle, the resultant metasomatised mantle could provide a component for some ocean island basalts, should the sub-continental lithospheric mantle be returned to the asthenosphere by convective removal at some later time.
DS1986-0648
1986
Porcelli, D.R.Porcelli, D.R., O'Nions, R.K., O'Reilly, S.Y.Helium and strontium isotopes in ultramafic xenolithsChemical Geology, Vol. 54, pp. 237-249East Africa, Tanzania, Australia, Victoria, FranceLachaine, Pello Hill, Bulletinenmerri, Puy Beaunit, Ataq, Hot spots, Geochronology
DS1992-1223
1992
Porcelli, D.R.Porcelli, D.R., O'Nions, R.K., Galer, S.J.G., Cohen, A.S., MatteyIsotopic relationships of volatile and lithophile trace elements in continental ultramafic xenolithsContributions to Mineralogy and Petrology, Vol. 110, No. 2-3, pp. 528-538Australia, Arizona, East AfricaUltramafic xenoliths, Geochronology
DS1994-1789
1994
Porcher, C.C.Tommasi, A., Vauchez, A., Fernandes, L.A.D., Porcher, C.C.Magma assisted strain localization in an orogen parallel transcurrent shearzone of southern BrasilTectonics, Vol. 13, No. 2, April, pp. 421-437BrazilStructure, Pan African Dom Feliciano belt
DS202009-1619
2020
Porcher, C.C.Chaves, A.de O., Porcher, C.C.Petrology, geochemistry and Sm-Nd systematics of the Paleoproterozoic Itaguara retroeclogite from Sao Francisco/Congo craton: one of the oldest records of the modern style plate tectonics.Gondwana Research, in press available 44p. PdfSouth America, Brazileclogite

Abstract: Paleoproterozoic retrogressed eclogite (retroeclogite) occurs in the Itaguara Sequence included in the suture zone formed by collision between the Archean Divinópolis and Campo Belo/Bonfim Complexes in the southern Săo Francisco Craton, which represents the South American counterpart of the African Congo Craton. The Itaguara retroeclogite contains scarce omphacite and phengite but abundant garnet porphyroblasts embedded in a fine-grained, amphibole, biotite and quartz-bearing matrix. The 2.20 ± 0.05 Ga eclogitization event (garnet and whole rock Sm-Nd isochronic age) of the E-MORB protolith (TDM ~ 2.47 Ga) is recorded by omphacite formation during high-pressure prograde stage in amphibole eclogite facies due to ~70 km depth subduction process. Amphibole eclogite facies metamorphic peak stage of 17-20 kbar and 600-700 °C occurred during ~2.1 Ga continental collision. Tectonic exhumation-related decompression during collision probably triggered partial melting of the eclogitic rock. Finally, decompression late stage estimated between 5 and 8 kbar and 550-650 °C under amphibolite facies overprint during orogenic collapse was responsible for appearance of kelyphitic reaction rims (symplectite) around garnet crystals. As its Paleoproterozoic contemporary analogues from Congo Craton, the Itaguara retroeclogite is one of the oldest records of the modern-style plate tectonics.
DS202012-2211
2020
Porcher, C.C.de Oliveira Chaves, A., Porcher, C.C.Petrology, geochemistry and Sm-Nd systematics of the Paleoproterozoic Itagurra retroeclogite from Sao Francisco/Congo craton: one of the oldest records of the modern-style plate tectonics.Gondwana Research, Vol. 87, pp. 224-237. pdfSouth America, Brazileclogites
DS1989-0842
1989
Poreda, R.Lal, D., Craig, H., Wacker, J.F., Poreda, R.He-3 diamonds- the cosmogenic component (letter)Geochimica et Cosmochimica Acta, Vol. 53, No. 2, Feb. pp. 569-574GlobalDiamond morphology
DS1996-0107
1996
Poreda, R.J.Becker, L., Poreda, R.J., Bada, J.L.Extraterrestrial helium trapped in fullerenes in the Sudbury ImpactStructureScience, Vol. 272, April 12, pp. 249-252OntarioSIC, Impact crater
DS2000-0417
2000
Poreda, R.J.Hoke, L., Lamb, S., Poreda, R.J.Southern limit of mantle derived geothermal helium emissions in Tibet: implications for lithospheric ...Earth and Planetary Science Letters, Vol. 180, No. 3-4, pp.297-308.Tibet, MantleGeothermometry
DS200512-0927
2005
Poreda, R.J.Saha, A., Basu, A.R., Jacobsen, S.B., Poreda, R.J., Yin, Q.Z., Yogodzinski, G.M.Slab devolatization and Os and Pb mobility in the mantle wedge of the Kamchatka arc.Earth and Planetary Science Letters, Advanced in press,Russia, KamchatkaGeochronology, slab
DS200712-0585
2007
Porosev, V.V.Kuper, K.E., Zedgenizov, D.A., Ragozin, A.L., Shatsky, V.S., Porosev, V.V., Zolotarev, K.V., Baibchev, IvanovThree dimensional distribution of minerals in Diamondiferous eclogites, obtained by the method of high resolution X-ray computed tomography.Nuclear Instruments and Methods in Physics Research Section A., Vol. 575, 1-2, pp. 255-258.TechnologyDiamond genesis
DS1996-1130
1996
Poroshin, K.K.Poroshin, K.K.Mineral paragenesis and Uralian shoshonite-latites and problems of theirorigin.International Geological Congress 30th Session Beijing, Abstracts, Vol. 2, p. 385.Russia, UralsShoshonites
DS1982-0505
1982
Poroshin, YE.YE.Poroshin, YE.YE., Bagdasarov, E.A.Accessory Chrome Spinellids from Volcanic Rocks of the Uraland Altai-sayan Fold Systems.Doklady Academy of Science USSR, Earth Science Section., Vol. 257, No. 6, PP. 152-154.Russia, UralsPetrography
DS1991-1369
1991
Porovskiy, B.G.Porovskiy, B.G., Andreyeva, Y.D.Petrography and isotope geochemistry of melilite rocks associated with the Patyn pluton #2International Geology Review, Vol. 33, No. 9, Sept. pp. 689-703RussiaMelilite, Patyn pluton, Petrography, geochemistry
DS200712-0138
2007
Porporato, A.Camporeale, C., Perona, P., Porporato, A., Ridolfi, L.Hierarchy of models for meandering rivers and related morphodynamic processes.Reviews of Geophysics, Vol. 45, 1, RG1001TechnologyGeomorphology
DS200812-0911
2008
Porrier, L.A.Porrier, L.A., Cas, R.A.F., Crawford, B.B.Reply to discussion by Brown et al. In-vent column collapse as an alternative model for massive volcaniclastic kimberlite emplacement ( Fox at Ekati).Journal of Volcanology and Geothermal Research, in press available 4p.Canada, Northwest TerritoriesVolcanism
DS201312-0717
2013
Porrit, L.A.Porrit, L.A., Russell, J.K.A phreatomagmatic kimberlite: the A418 kimberlite pipe, Northwest Territories, Canada.Proceedings of the 10th. International Kimberlite Conference, Vol. 2, Special Issue of the Journal of the Geological Society of India,, Vol. 2, pp. 97-107.Canada, Northwest TerritoriesDeposit - A418
DS201412-0704
2013
Porrit, L-A.Porrit, L-A., Russell, J.K., McLean, H., Fomradas, G., Eichenberg, D.A phreatomagmatic kimberlite: the 418A kimberlite pipe, Northwest Territories, Canada.Proceedings of the 10th. International Kimberlite Conference, Vol. 2, pp. 97-108.Canada, Northwest TerritoriesDeposit - 418A
DS200612-0286
2006
Porritt, L.Crawford, B.B., Porritt, L., Nowicki, T., Carlson, J.A.Key geological characteristics of the Koala kimberlite, Ekati diamond mine, Canada.Emplacement Workshop held September, 5p. extended abstractCanada, Northwest TerritoriesDeposit - Koala, pipe morphology
DS200612-0991
2006
Porritt, L.Nowicki, T., Porritt, L., Crawford, B.Geochemical trends in kimberlites from Ekati, NWT: insights on volcanic and resedimentation processes.Emplacement Workshop held September, 5p. abstractCanada, Northwest TerritoriesDeposit - Lac de Gras field, magmatic, volcaniclastic
DS200812-0184
2008
Porritt, L.Cas, R., Porritt, L., Pittari, A., Hayman, P.A new approach to kimberlite facies terminology using a revised general approach to the nomenclature of all volcanic rocks and deposits: description to genetic.Journal of Volcanology and Geothermal Research, Vol. 174, 1-3, pp. 226-240.MantleAlteration, descriptive, genetic
DS200812-0185
2008
Porritt, L.Cas, R.A.F., Hayman, P., Pittari, A., Porritt, L.Some major problems with existing models and terminology associated with kimberlite pipes from a volcanological perspective, and some suggestions.Journal of Volcanology and Geothermal Research, Vol. 174, 1-3, pp. 209-225.Africa, CanadaVolcanology, original textures, alteration, terminology
DS200812-0807
2008
Porritt, L.Nowicki, T., Porritt, L., Crawford, B., Kjarsgaard, B.Geochemical trends in kimberlites of the Ekati property, Northwest Territories, Canada: insight on volcanic and resedimentation processes.Journal of Volcanology and Geothermal Research, Vol. 174, 1-3, pp. 117-127.Canada, Northwest TerritoriesGeochemistry, volcaniclastic, coherent eruption,fractionation
DS201012-0091
2009
Porritt, L.Cas, R.A.F., Porritt, L., Pittari, A., Hayman, P.C.A practical guide to terminology for kimberlite facies: a systematic progression from descriptive to genetic, including a pocket guide.Lithos, Vol. 112 S pp. 183-190.TechnologyTerminology
DS201112-0814
2011
Porritt, L.Porritt, L.Ash aggregates in kimberlites.IUGG Held July 6, AbstractCanada, Northwest TerritoriesDiavik
DS201412-0759
2014
Porritt, L.Russell, K., Brett, C., Jones, T., Andrews, G., Porritt, L.Kimberlite ascent.Goldschmidt Conference 2014, 1p. AbstractMantleKimberlite genesis
DS201812-2852
2018
Porritt, L.Moss, S., Porritt, L., Pollock, K., Fomradas, G., Stubley, M., Eichenberg, D., Cutts, J.Diavik deposit: Geology, mineral chemistry, and structure of the kimberlites at Diavik diamond mine: indicators of cluster-scale cross-fertilization, mantle provenance, and pipe morphology.Society of Economic Geology Geoscience and Exploration of the Argyle, Bunder, Diavik, and Murowa Diamond Deposits, Special Publication no. 20, pp. 287-318.Canada, Northwest Territoriesdeposit - Diavik
DS200612-0229
2006
Porritt, L.A.Cas, R.A.F., Hayman, P.C., Pittari, A., Porritt, L.A.The problems with existing volcanological models and related terminology for kimberlite pipes.Emplacement Workshop held September, 5p. extended abstractGlobal, Africa, CanadaInterpretations, models, eruption processes
DS200612-1103
2006
Porritt, L.A.Porritt, L.A., Cas, R.F., Crawford, B.B.The origin and implications of the TK like infill of the Fox kimberlite, Ekati diamond mine, NWT, Canada.Emplacement Workshop held September, 5p. abstractCanada, Northwest TerritoriesDeposit - Fox, morphology, structure, geology
DS200812-0912
2008
Porritt, L.A.Porritt, L.A., Cas, R.F., Crawford, B.B.In vent column collapse as an alternative model for massive volcaniclastic kimberlite emplacement: an example from the Fox kimberlite, Ekati diamond mine.Journal of Volcanology and Geothermal Research, Vol. 174, 1-3, pp. 90-102. reply in press 17p.Canada, Northwest TerritoriesVolcanology, eruption, column collapse.
DS200912-0591
2009
Porritt, L.A.Porritt, L.A., Cas, R.A., Ailleres, L., Oshust, P.The influence of volcanological and sedimentalogical processes on diamond distribution: example from the Ekati diamond mine, NWT Canada.GAC/MAC/AGU Meeting held May 23-27 Toronto, Abstract onlyCanada, Northwest TerritoriesDeposit - Ekati
DS200912-0592
2009
Porritt, L.A.Porritt, L.A., Cas, R.A.F.Reconstruction of a kimberlite eruption using an integrated volcanological geochemical and numerical approach: a case study of the Fox kimberlite, NWT CanadaJournal of Volcanology and Geothermal Research, Vol. 179, 3-4, pp. 241-254.Canada, Northwest TerritoriesDeposit - Fox
DS201112-0815
2011
Porritt, L.A.Porritt, L.A., Cas, R.A.F.The influence of complex intra and extra vent processes on facies characteristics of the Koala kimberlite, NWT, Canada: volcanology, sedimentology, intrusive processesBulletin of Volcanology, Vol. 73, 6, pp. 717-735.Canada, Northwest TerritoriesDeposit - Koala
DS201212-0567
2012
Porritt, L.A.Porritt, L.A., Cas, R.A.F., Ailleres, L., Oshust, P.The influence of volcanological and sedimentaological processes on diamond grade distribution in kimberlites: examples from the Ekati diamond mine, NWT, Canada.Bulletin of Volcanology, Vol. 73, 8, pp. 1085-1105.Canada, Northwest TerritoriesDiamond grade
DS201212-0568
2012
Porritt, L.A.Porritt, L.A., Cas, R.A.F., Schaefer, B., McKnight, S.W.Textural analysis of strongly altered kimberlite: examples from the Ekati diamond mine, Northwest Territories, Canada.Canadian Mineralogist, Vol. 50, 3, June pp. 625-641.Canada, Northwest TerritoriesDeposit - Ekati
DS201212-0569
2012
Porritt, L.A.Porritt, L.A., Russell, J.K., McLean, H., Fomrades, G., Eicheberg,D.Geology and volcanology of the A418 kimberlite pipe, NWT, Canada10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractCanada, Northwest TerritoriesDeposit - A418
DS201212-0610
2012
Porritt, L.A.Russell, J.K., Porritt, L.A., Lavallee, Y., Dingwell, D.Kimberlite ascent by assimilation fueld bouyancy.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractGlobalDiamond genesis
DS201312-0763
2013
Porritt, L.A.Russell, J.K., Porritt, L.A., Hilchie, L.Kimberlite: rapid ascent of lithospherically modified carbonatitic melts.Proceedings of the 10th. International Kimberlite Conference, Vol. 1, Special Issue of the Journal of the Geological Society of India,, Vol.1, pp. 195-210.TechnologyGenesis - melts
DS200612-1130
2006
Porschke, A.Ratschbacher, L., Franz, L., Enkelmann, E., Jonckheere, R., Porschke, A., Hacker, B.R., Dong, S., Zhang, Y.The Sino-Korean Yangtze suture, the Huwan detachment and the Paleozoic Tertiary exhumation of ultra high pressure rocks along the Tongbai Xinxian Dabie Mtns.Geological Society of America, Special Paper, No. 403, pp. 45-76.ChinaUHP
DS2001-0121
2001
PortaraBonatti, E., Brunelli, Fabretti, Ligi, Portara, SeylerSteady state creation of crust free lithosphere at cold spots in mid-ocean ridgesGeology, Vol. 29, No. 11, Nov. pp. 979-82.MantlePeridotites, flow
DS200512-0674
2005
Portella, P.Madore, C., Annesley, I.R., Portella, P.Geology and thermotectonic evolution of the western margin of the Trans-Hudson Orogen: evidence from the eastern sub-Athabasca basement, Saskatchewan.Canadian Journal of Earth Sciences, Vol. 42, 4, April pp. 573-597.Canada, SaskatchewanGeothermometry
DS1860-0476
1885
Porter, D.A.Porter, D.A.Diamond. In: Notes on Some Mineral Localities in the Northern Districts of New South Wales.Royal Society New South Wales Transactions, Vol. 18, P. 79.Australia, New South WalesDiamond Occurrence
DS1860-1042
1898
Porter, D.A.Porter, D.A.On the Occurrence of Diamonds at InverellInstitute of Mining and Metallurgy. (London) Transactions, Vol. 6, PP. 273-277.Australia, New South WalesDiamond Occurrence
DS1981-0339
1981
Porter, I.Porter, I.Bougainville Steepens Cra's DiveThe Age (melbourne), AUGUST 20TH. P.Australia, Western AustraliaArgyle, Profits, Investments
DS1981-0340
1981
Porter, I.Porter, I.Litigation Holds Up AshtonThe Age (melbourne), SEPT. 1ST. P. 25.Australia, Western AustraliaSmoke Creek, Argyle, Investment, Markets
DS1994-1396
1994
Porter, J.A.Porter, J.A.Reconciliation of mining with the concept of sustainable development: MinasGerais, BrasilMining in Latin America, Institute of Mining and Metallurgy (IMM)., pp. 381-390BrazilEnvironmental Legal, Mining
DS200412-2111
2004
Porter, K.White, W.M., Porter, K.Preferential U recycling does not resolve the kappa conundrum.Geochimica et Cosmochimica Acta, 13th Goldschmidt Conference held Copenhagen Denmark, Vol. 68, 11 Supp. July, ABSTRACT p.A554.MantleUranium thorium, subduction
DS201603-0413
2016
Porter, R.Porter, R., Liu, Y., Holt, W.E.Lithospheric records of orogeny within the continental US.Geophysical Research Letters, Vol. 43, 1, pp. 144-153.United StatesGeophysics - gradiometry

Abstract: In order to better understand the tectonic evolution of the North American continent, we utilize data from the EarthScope Transportable Array network to calculate a three-dimensional shear velocity model for the continental United States. This model was produced through the inversion of Rayleigh wave phase velocities calculated using ambient noise tomography and wave gradiometry, which allows for sensitivity to a broad depth range. Shear velocities within this model highlight the influence of orogenic and postorogenic events on the evolution of the lithosphere. Most notable is the contrast in crustal and upper mantle structure between the relatively slow western and relatively fast eastern North America. These differences are unlikely to stem solely from thermal variations within the lithosphere and highlight both the complexities in lithospheric structure across the continental U.S. and the varying impacts that orogeny can have on the crust and upper mantle.
DS2002-1276
2002
Porter, T.Porter, T., Kennedy, J.Is it the right kind of big? Fort a la Corne is one of the largest kimberlite discoveries, ever. Could it become a mine?Canadian Diamonds, Winter, pp. 28-33., 48.SaskatchewanNews item, Kensington Resources
DS200412-1570
2002
Porter, T.Porter, T., Kennedy, J.Is it the right kind of big? Fort a la Corne is one of the largest kimberlite discoveries, ever. Could it become a mine?Canadian Diamonds, Winter, pp. 28-33., 48.Canada, SaskatchewanNews item Kensington Resources
DS202007-1171
2020
Portner, D.E.Portner, D.E., Rodriguez, E.E., Beck, S., Zandt, G., Scire, A., Rocha, M.P.Detailed structure of the subducted Nazca slab into the lower mantle derived from continent scale teleseismic P wave tomography.Journal of Geophysical Research: Solid Earth, Vol. 125, e2019JB017884.Mantle, South Americasubduction

Abstract: Nazca subduction beneath South America is one of our best modern examples of long?lived ocean?continent subduction on the planet, serving as a foundation for our understanding of subduction processes. Within that framework, persistent heterogeneities at a range of scales in both the South America and Nazca plates is difficult to reconcile without detailed knowledge of the subducted Nazca slab structure. Here we use teleseismic travel time residuals from >1,000 broadband and short?period seismic stations across South America in a single tomographic inversion to produce the highest?resolution contiguous P wave tomography model of the subducting slab and surrounding mantle beneath South America to date. Our model reveals a continuous trench?parallel fast seismic velocity anomaly across the majority of South America that is consistent with the subducting Nazca slab. The imaged anomaly indicates a number of robust features of the subducted slab, including variable slab dip, extensive lower mantle penetration, slab stagnation in the lower mantle, and variable slab amplitude, that are incorporated into a new, comprehensive model of the geometry of the Nazca slab surface to ~1,100 km depth. Lower mantle slab penetration along the entire margin suggests that lower mantle slab anchoring is insufficient to explain along strike upper plate variability while slab stagnation in the lower mantle indicates that the 1,000 km discontinuity is dominant beneath South America.
DS1982-0506
1982
Portnov, A.M.Portnov, A.M.Self Oxidation of Mantle Fluid and the Genesis of Diamond Of Kimberlites.Doklady Academy of Sciences AKAD. NAUK SSSR., Vol. 267, No. 4, PP. 942-945.RussiaBlank
DS1984-0593
1984
Portnov, A.M.Portnov, A.M.Self Oxidation of Mantle Fluid and the Genesis of Kimberlite Diamonds.Doklady Academy of Science USSR, Earth Science Section., Vol. 267, No. 1-6, JUNE PP. 166-168.RussiaInclusions, Mineral Chemistry
DS1984-0594
1984
Portnov, A.M.Portnov, A.M.Fluidal Diapirism and Diamond Genesis in KimberlitesBulletin. MOSK. OBSCH. ISPYT. PRIR, OTDEL. GEOL., Vol. 59, No. 6, PP. 42-49.RussiaUltramafics, Geochemistry
DS1992-0589
1992
Portnov, A.M.Gorobets, B.S., Portnov, A.M.Luminescent anomalies in the earth crust during distant searching fororesRussian Geology and Geophysics, Vol. 33, No. 2, pp. 37-43Russia, Commonwealth of Independent States (CIS)Photoluminescent, Carbonatite
DS1996-1131
1996
Portnov, A.M.Portnov, A.M.Kimberlites as mantle fluodizitesInternational Geological Congress 30th Session Beijing, Abstracts, Vol. 2, p. 391.RussiaKimberlites, Diapirs -fluid
DS1998-0192
1998
Portnov, A.M.Bushev, A.G., Portnov, A.M., Rogozhin, A.A., et al.Photoluminescent mineral haloes around kimberlite pipesIma 17th. Abstract Vol., p. A125, abstractRussia, ArkangelskMineralogy, Photoluminesence
DS200512-0088
2005
PortnyaginBindeman, I.N., Eiler, J.M., Yogodzinski, Y., Stern, C.R., Grove, T.L., Portnyagin, Hoernle, DanyushevskyOxygen isotope evidence for slab melting in modern and ancient subduction zones.Earth and Planetary Science Letters, Vol. 235, 3-4, July 15, pp. 480-496.MantleSubduction
DS1991-0816
1991
Portnyagin, A.L.Kadik, A.A., Lukanin, O.A., Portnyagin, A.L.Magma generation during rise of mantle material temperatures and composition of melts formed by adiabatic decompression of mantle ultrabasitesGeochemistry International, Vol. 28, No. 4, pp. 40-52RussiaMantle, Ultrabasites
DS200512-0696
2005
Portnyagin, M.Matveev, S., Portnyagin, M., Ballhaus, C., Brooker, R., Geiger, C.A.Spectrum of phenocryst olivine as an indicator of silica saturation in magmas.Journal of Petrology, Vol. 46, 3, pp. 603-614.MantleMagmatism
DS200712-0851
2007
Portnyagin, M.Portnyagin, M., Hoernie, K., Plechov, P., Mironov, N., Khubunaya, S.Constraints on mantle melting and composition and nature of slab components in volcanic arcs from volatiles ( H2) S Cl F) and trace elements in melt inclusions from the Kamchatka Arc.Earth and Planetary Science Letters, Vol. 255, 1-2, pp. 53-69.Russia, KamchatkaGeochemistry
DS201907-1576
2019
Portnyagin, M.Sobolev, A.V., Asafov, E., Arndt, N., Portnyagin, M., Guenko, A.A., Batanova, G., Garbe-Schonberg, D., Wilson, A.H., Byerly, G., Batanova, V.Deep hydrous mantle reservoir provides evidence for crustal recycling before 3.3 billion years ago.Nature, 32p. Pdf availableMantlewater

Abstract: H2O strongly influences physical properties of the mantle and its ability to melt or convect and can trace recycling of surface reservoirs down to the deep mantle1,2. This makes knowledge of water content in the Earth's interior and its evolution through time crucial to understanding global geodynamics. Komatiites (MgO-rich ultramafic magmas) result from high-degree mantle melting at high pressures3 and thus are excellent probes of H2O contents in the deep mantle. A significant excess of H2O over elements of similar geochemical behavior during mantle melting (e.g. Ce) was recently found in melt inclusions in the most Mg-rich olivine in 2.7 Ga old komatiites from Canada4 and Zimbabwe5. These data were taken as evidence for a deep hydrated mantle reservoir, probably the transition zone, in the Neoarchean time. In this paper we confirm the mantle source of this H2O by measurement of deuterium to hydrogen ratios in these melt inclusions and present similar data for 3.3 Ga old komatiites from the Barberton Greenstone Belt. Using hydrogen isotopes, we show that the mantle sources of these melts contained excess H2O which implies that a deep mantle hydrated reservoir has been present in the Earth's interior at least since the Paleoarchean. The reconstructed initial hydrogen isotope composition of komatiites is significantly more depleted in deuterium than all surface reservoirs and typical mantle but resembles that in dehydrated subducted slabs. Together with a significant excess of chlorine and a temporal trend of Pb/Ce in the mantle sources of komatiites, these results argue that lithosphere recycling into the deep mantle, arguably via subduction, started before 3.3 Ga. (a un-reviewed version of the manuscript accepted for publication in Nature magazine).
DS1993-0770
1993
Portnyagin, M.V.Kamenetskiy, V.S., Portnyagin, M.V., Sobolev, A.V., DanyushevskiyMagma composition and crystallization conditions of the picrite-basalt suite in the Tumrok Ridge, East KamchatkaGeochemistry International, Vol.30, No. 3, March pp. 58-73RussiaPicrites
DS201605-0903
2016
Portnyagin, M.V.Sobolev, A.V., Asafov, E.V., Gurenko, A.A., Arndt, N.T., Batanova, V.G., Portnyagin, M.V., Garbe-Schonberg, D., Krasheninnikov, S.P.Komatites reveal a hydrous Archaen deep mantle reservoir.Nature, Vol. 531, Mar. 31, pp. 628-632.MantleMelting

Abstract: Archaean komatiites (ultramafic lavas) result from melting under extreme conditions of the Earth’s mantle. Their chemical compositions evoke very high eruption temperatures, up to 1,600 degrees Celsius, which suggests even higher temperatures in their mantle source1, 2. This message is clouded, however, by uncertainty about the water content in komatiite magmas. One school of thought holds that komatiites were essentially dry and originated in mantle plumes3, 4, 5, 6 while another argues that these magmas contained several per cent water, which drastically reduced their eruption temperature and links them to subduction processes7, 8, 9. Here we report measurements of the content of water and other volatile components, and of major and trace elements in melt inclusions in exceptionally magnesian olivine (up to 94.5?mole per cent forsterite). This information provides direct estimates of the composition and crystallization temperature of the parental melts of Archaean komatiites. We show that the parental melt for 2.7-billion-year-old komatiites from the Abitibi greenstone belt in Canada contained 30 per cent magnesium oxide and 0.6 per cent water by weight, and was depleted in highly incompatible elements. This melt began to crystallize at around 1,530 degrees Celsius at shallow depth and under reducing conditions, and it evolved via fractional crystallization of olivine, accompanied by minor crustal assimilation. As its major- and trace-element composition and low oxygen fugacities are inconsistent with a subduction setting, we propose that its high H2O/Ce ratio (over 6,000) resulted from entrainment into the komatiite source of hydrous material from the mantle transition zone10. These results confirm a plume origin for komatiites and high Archaean mantle temperatures, and evoke a hydrous reservoir in the deep mantle early in Earth’s history.
DS201907-1527
2019
Portnyagin, M.V.Batanova, V.G., Thompson, J.M., Danyushevsky, L.V., Portnyagin, M.V., Garbe-Schonberg, D., Hauri, E., Kimura, J-I., Chang, Q., Senda, R., Goemann, K., Chauvel, C., Campillo, S., Ionov, D.A., Sobolev,A.V.New olivine reference material for in situ microanalysis.Geostandards and Geoanalytical Research, in press available, 21p.Asia, Mongoliaolivine

Abstract: A new olivine reference material - MongOL Sh11?2 - for in situ analysis has been prepared from the central portion of a large (20 × 20 × 10 cm) mantle peridotite xenolith from a ~ 0.5 My old basaltic breccia at Shavaryn?Tsaram, Tariat region, central Mongolia. The xenolith is a fertile mantle lherzolite with minimal signs of alteration. Approximately 10 g of 0.5-2 mm gem quality olivine fragments were separated under binocular microscope and analysed by EPMA, LA?ICP?MS, SIMS and bulk analytical methods (ID?ICP?MS for Mg and Fe, XRF, ICP?MS) for major, minor and trace elements at six institutions world?wide. The results show that the olivine fragments are sufficiently homogeneous with respect to major (Mg, Fe, Si), minor and trace elements. Significant inhomogeneity was revealed only for phosphorus (homogeneity index of 12.4), whereas Li, Na, Al, Sc, Ti and Cr show minor inhomogeneity (homogeneity index of 1-2). The presence of some mineral and fluid?melt micro?inclusions may be responsible for the inconsistency in mass fractions obtained by in situ and bulk analytical methods for Al, Cu, Sr, Zr, Ga, Dy and Ho. Here we report reference and information values for twenty?seven major, minor and trace elements.
DS202008-1411
2020
Portnyagin, M.V.Korneeva, A.A., Nikolai, N.A., Kamenetsky, V.S., Portnyagin, M.V., Savelyev, D.P., Krasheninnikov, S.P., Abersteiner, A., Kamenetsky, M.B., Zelenski, M.E., Shcherbakov, V.D., Botcharnikov, R.E.Composition, crystallization conditions and genesis of sulfide saturated parental melts of olivine-phyric rocks from Kamchatsky Mys ( Kamchatka, Russia).Lithos, 10.1016/j.lithos.2020.105657Russia, Kamchatkapicrites

Abstract: Sulfide liquids that immiscibly separate from silicate melts in different magmatic processes accumulate chalcophile metals and may represent important sources of the metals in Earth's crust for the formation of ore deposits. Sulfide phases commonly found in some primitive mid-ocean ridge basalts (MORB) may support the occurrence of sulfide immiscibility in the crust without requiring magma contamination and/or extensive fractionation. However, the records of incipient sulfide melts in equilibrium with primitive high-Mg olivine and Cr-spinel are scarce. Sulfide globules in olivine phenocrysts in picritic rocks of MORB-affinity at Kamchatsky Mys (Eastern Kamchatka, Russia) represent a well-documented example of natural immiscibility in primitive oceanic magmas. Our study examines the conditions of silicate-sulfide immiscibility in these magmas by reporting high precision data on the compositions of Cr-spinel and silicate melt inclusions, hosted in Mg-rich olivine (86.9-90 mol% Fo), which also contain globules of magmatic sulfide melt. Major and trace element contents of reconstructed parental silicate melts, redox conditions (?QFM = +0.1 ± 0.16 (1?) log. units) and crystallization temperature (1200-1285 °C), as well as mantle potential temperatures (~1350 °C), correspond to typical MORB values. We show that nearly 50% of sulfur could be captured in daughter sulfide globules even in reheated melt inclusions, which could lead to a significant underestimation of sulfur content in reconstructed silicate melts. The saturation of these melts in sulfur appears to be unrelated to the effects of melt crystallization and crustal assimilation, so we discuss the reasons for the S variations in reconstructed melts and the influence of pressure and other parameters on the SCSS (Sulfur Content at Sulfide Saturation).
DS202004-0516
2020
Porto, C.G.Giovannini, A.L., Mitchell, R.H., Bastos Neto, A.C., Moura, C.A.V., Pereira, V.P., Porto, C.G.Mineralogy and geochemistry of the Morro dos Seis Lagos siderite carbonatite, Amazonas, Brazil.Lithos, vol. 360-361, 105433 20p. PdfSouth America, Brazil, Amazonascarbonatite

Abstract: The Morro dos Seis Lagos niobium rare earth element, Ti-bearing lateritic deposit (Amazonas, Brazil) is derived from a primary siderite carbonatite. The complex is the only example of a Nb deposit in which Nb-rich rutile is the main Nb ore mineral. Apart from the laterites, at the current level of exposure the complex consists only of siderite carbonatite; silicate rocks are absent. Three types of siderite carbonatite are recognized: (1) a brecciated and oxidized core siderite carbonatite consisting of up to 95 vol% siderite together with: hematite; pyrochlore; Nb-brookite; Ti-maghemite; and thorobastnäsite; (2) a REE- and P-rich variety of the core siderite carbonatite consisting of siderite (up to 95 vol%), hematite, minor pyrochlore, monazite and bastnäsite; (3) a border hydrothermal siderite carbonatite with ~70 vol% siderite, barite (~15 vol%), gorceixite (~7 vol%) and minor rhabdophane and pyrochlore. The country rock gneiss in which the carbonatite was emplaced was affected by potassic fenitization, with the formation of phlogopite and orthoclase together with monazite, fluorapatite and bastnäsite. The siderite carbonatites exhibit a wide variation of ?13C (?5.39‰ to ?1.40‰), accompanied by a significant variation in ?18O (17.13‰ to 31.33‰), especially in the REE-rich core siderite carbonatite, and are explained as due to the presence of both H2O and CO2 in the magma. The core siderite carbonatite is the richest in Fe (48.64-70.85 wt% Fe2O3) and the poorest in Ca (up 0.82 wt% CaO) example of a siderite carbonatite yet recognized The ferrocarbonatite has significant contents of Mn, Ba, Th, Pb and LREE, and a very high Nb (up to 7667 ppm) content due to the presence of Nb-brookite. The substitution 3Ti4+ = Fe2+ + 2Nb5+ recognized in Nb-rich brookite explains enrichment of Nb in the core siderite carbonatite and indicates formation in a reducing environment. The high Nb/Ta ratio (1408-11,459) of the carbonatite is compatible with residual liquids derived by fractional crystallization. The 87Sr/86Sr (0.70411-0.70573) and 144Nd/143Nd (0.512663-0.512715) isotopic data suggest the carbonatite is mantle-derived with essentially no crustal contamination and is younger than the maximum age of 1328 ± 58 Ma (UPb in zircon). We suggest that the Morro dos Seis Lagos carbonatite complex represents the upper-most parts of a differentiated carbonatite magmatic system, and that the siderite carbonatite is related to late-magmatic-to-carbo-hydrothermal processes.
DS202107-1099
2021
Porto, C.G.Giovannini, A.L., Bastos Neto, A.C., Porto, C.G., Takehara, L., Pereira, V.P., Bidone, M.H.REE mineralization (primary, supergene and sedimentary) associated to the Morro dos Seis Lagos Nb( REE, Ti) deposit (Amazonas, Brazil).Ore Geology Reviews, doi.org/10.1016/ j.oregeorev. 2021.104308 59p. PdfSouth America, BrazilREE

Abstract: In the Morro dos Seis Lagos Nb (Ti, REE) deposit (MSLD), Amazonas state, Brazil, there are four types of REE mineralization: primary, associated to siderite carbonatite; supergene, associated to laterite profile; and sedimentary (detrital and authigenic). The mineralogical and geochemical evolutions of the REE in these domains are integrated into a comprehensible metallogenic model. The main primary ore in the core siderite carbonatite is 52 m thick with 1.47 wt% REE2O3 mainly in monazite-(Ce) and bastnäsite. However, considering the entire section intersected in the core siderite carbonatite, the average grade drops to 0.7 wt% REE2O3 mainly contained in thorbastnasite. In the border siderite carbonatite, the REE mineralization is hydrothermal [rhabdophane-(Ce) and REE-rich gorceixite]. The LREE and phosphates are concentrated at the reworked laterites from where the HREE were leached. With the advance of lateritization, pyrochlore was completely decomposed. The final secondary Ce-pyrochlore was progressively enriched in Ce4+ with loss in REE3+, resulting in the breakdown of the structure and release Ce under strongly oxidizing conditions (high Ce4+/Ce3+) thus forming extremely pure cerianite-(Ce). This mineral occurs intercalated with goethite bands in the lower part of the weathering profile, represented by the brown laterite, and forms intergrowth with hollandite in the manganiferous laterite, formed in a more alkaline environment closer to the water table. The brown laterite has 1.30 wt% REE2O3, the manganese laterite has 1.54 wt% REE2O3, of which 1.42 wt% is Ce2O3. Tectonic and karstic processes over the carbonatite formed several sedimentary basins. In the Esperança Basin, the sedimentary record (233 m thick) shows the whole evolution of the MSLD. The base of the basin (layer 5) is formed by abundant carbonatite fragments, have florencite-(Ce) mineralization with 1.07 wt% REE2O3; layer 4 is formed by carbonatite fragments interbedded with clayey bed; layer 3 is a rhythmite deposited in a lacustrine environment, with clasts of ferruginous materials related to early stages of carbonatite alteration; layer 2 is made up by clays, is rich in organic matter, has authigenic florencite-(Ce), florencite-(La) and base metals. This layer marks the inversion of the relief and the input into the basin of REE leached from the upper laterites, carried by the groundwater flow; layer 1 was formed by the oxidation of the upper part of layer 2. Layers 1 + 2 have 73 m thick and average of 1.72 wt% REE2O3.
DS200612-1104
2006
Porwal, A.Porwal, A., Carranza, E.J.M., hale, M.Bayesian network classifiers for mineral potential mapping.Computers & Geoscience, Vol. 32, 1, Feb. pp. 1-16.India, Aravalli ProvinceGIS - not specific to diamonds
DS202105-0765
2021
Porwal, A.Gonzalez-Alvarez, I., Stoppa, F., Yang, X.Y., Porwal, A.Introduction to the special issue, insights on carbonatites and their mineral exploration approach: a challenge towards resourcing critical metals.Ore Geology Reviews, Vol. 133, 104073, 7p. PdfGlobalcarbonatites

Abstract: Population growth and technological progress in the last 50 years have resulted in the global demand for mineral resources increasing by 400% since 1970, and it is further expected to almost double by 2050. This context forecasts a never-seen-before market for some specific mineral commodities, termed critical metals. The resource and supply flow of critical metals would be decisive for the economic well-being of economies in near future. Carbonatites are the most prospective host rocks for Rare Earth Elements (REEs), which constitute some of the most important critical elements. This special issue aims to contribute to the debate on understanding the genesis of carbonatites and their prospectivity for REEs (including exploration strategies), by presenting a wide variety of studies on carbonatites from around the globe.
DS1994-1430
1994
Porwal, B.Ramchnadran, K.T., Porwal, B.Famous diamonds... mainly Indian... listed with weight and shape .. briefhistory.Indian Gemologist, Vol. 4, No. 1, pp. 20-3.GlobalHistory, Famous diamonds, diamonds notable
DS1991-0128
1991
PosaBlonda, P.N., Pasquariello, G., Losito, S., Mori, A., PosaAn experiment for the interpretation of multitemporal remotely sensed images based on a fuzzy logic approachInternational Journal of Remote Sensing, Vol. 12, No. 3, March pp. 463-476GlobalRemote sensing, Fuzzy logic
DS1989-1234
1989
Posa, D.Posa, D.Conditioning of the stationary kriging matrices for some well known covariance modelsMathematical Geology, Vol. 21, No. 7, October pp. 755-766GlobalComputer, Geostatistics
DS1991-1370
1991
Posa, D.Posa, D.Limiting stochastic operations for stationary spatial processesMathematical Geology, Vol. 23, No. 5, July pp. 695-702GlobalGeostatistics, Spatial processes
DS1992-1224
1992
Posa, D.Posa, D., Marcotte, D.Robustness of kriging weights to non-bias conditionsMathematical Geology, Vol. 24, No. 7, pp. 759-774GlobalGeostatistics, Kriging
DS1992-1297
1992
Posa, D.Rossi, M., Posa, D.A non-parametric bivariate entropy estimator for spatial processesMathematical Geology, Vol. 24, No. 4, pp. 539-553GlobalComputers -semivariograms, Gaussian distribution
DS1860-0477
1885
Posewitz, T.Posewitz, T.Das Diamant vorkommen im Borneo. Appendix in Vol. 1, Of: Diezinninseln im Indischen Oceane.Budpest: Mitteilungen Aus Dem Jahebuche Der Kon. Ung. Geol., Vol. 7, No. 4, PP. 153-192.Asia, Indonesia, Borneo, KalimantenDiamond Occurrence
DS1860-0522
1886
Posewitz, T.Posewitz, T.Die Diamant felder in BorneoAusland., Vol. 59, SEPT. 6, PP. 705-708.Asia, BorneoDiamond Occurrence
DS1991-1140
1991
Posey, E.F.Meyer, H.O.A., Waring, M., Posey, E.F.Diamond deposits of the Santo Inacio River amd the Vargem intrusions nearCoromandel, Minas GeraisFifth International Kimberlite Conferences Field Excursion Guidebook, Servico Geologico do Brasil (CPRM) Special, pp. 57-58BrazilVargem intrusions, Alluvial diamonds
DS201701-0018
2016
Poshibaev, V.V.Kargin, A.V., Nosova, A.A., Postnikov, A.V., Chugaev, A.V., Postnikova, O.V., Popova, L.P., Poshibaev, V.V., Sazonova, L.V., Dokuchaev, A.Ya., Smirnova, M.D.Devonian ultramafic lamprophyre in the Irkineeva Chadobets trough in the southwest of the Siberian platform: age, composition, and implications for diamond potential prediction.Geology of Ore Deposits, Vol. 58, 5, pp. 383-403.RussiaLamprophyre - aillikite

Abstract: The results of geochronological, mineralogical, petrographical, and geochemical study of the Ilbokich ultramafic lamprophyre are reported. The specific features in the mineral and chemical compositions of the studied ultramafic lamprophyre indicate that it can be regarded as a variety similar to aillikite, while other differences dominated by K-feldspar can be referred to damtjernite. According to Rb-Sr analysis, ultramafic lamprophyre dikes intruded at the turn of the Early and Middle Devonian, about 392 Ma ago. This directly proves the existence of Early Paleozoic alkali-ultramafic magmatism in the northern part of the southwest Siberian Platform. A finding of Devonian alkali-ultramafic lamprophyre is of dual predictive importance. On the one hand, it is indicative of the low probability of finding large diamond-bearing deposits in close association with aillikite. On the other hand, it can be indicative of a possible large Devonian diamond province in the studied territory, where diamondiferous kimberlite is structurally separated from aillikite.
DS1993-0859
1993
Poskukojovsky, T.V.Krot, A.N., Poskukojovsky, T.V., Guseva, E.V., Galimov, E.M., Botkunov, A.I. et.Genesis of the garnets containing hydrocarbon inclusions (Mir kimberlitepipe). (Russian)Geochemistry International (Geokhimiya), (Russian), No. 6, June pp. 891-899RussiaGeochemistry -garnets, Deposit -Mir
DS2002-0044
2002
Posokhov, V.F.Andreev, G.V., Posokhov, V.F.Rb Sr age of metasomatic rocks from the southern Saku Massif of alkaline rocksGochemistry International, Vol.40, 3, pp.306-8.RussiaGeochronology, Alkaline rocks, rubidium, strontium, stable isotope geochronology
DS200912-0628
2009
Posokhov, V.F.Ripp, G.S., Doroshkevick, A.G., Posokhov, V.F.Age of carbonatite magmatism in Transbaikalia.Petrology, Vol. 17, 1, pp. 73-89.RussiaCarbonatite
DS201504-0186
2015
Posokhov, V.F.Burtseva, M.V., Ripp, G.S., Posokhov, V.F., Zyablitsev, A.Yu., Murzintseva, A.E.The sources of fluids for the formation of nephritic rocks of the southern folded belt of the Siberian craton.Doklady Earth Sciences, Vol. 460, 1, pp. 82-86.Russia, SiberiaAlkaline rocks, nephrites
DS2002-0045
2002
Posokohov, V.F.Andreev, G.V., Posokohov, V.F.Rb Sr age of metasomatic rocks from the southern Saku Massif of alkaline rocksGeochemistry International, Vol.40,3,pp.306-8., Vol.40,3,pp.306-8.RussiaAlkaline rocks, Saku Massif
DS2002-0046
2002
Posokohov, V.F.Andreev, G.V., Posokohov, V.F.Rb Sr age of metasomatic rocks from the southern Saku Massif of alkaline rocksGeochemistry International, Vol.40,3,pp.306-8., Vol.40,3,pp.306-8.RussiaAlkaline rocks, Saku Massif
DS200812-0913
2008
Pospeeva, E.V.Pospeeva, E.V.Application of medium scale magnetotelluric sounding to identify deep criteria for promising areas for kimberlite exploration.Russian Journal of Pacific Geology, Vol. 2, 3, pp. 205-217.RussiaGeophysics - magnetotellurics
DS1988-0551
1988
Pospejeva, E.V.Pospejeva, E.V.Mathematical modeling in solving direct problem of DMTS for Malo-Botuobinsk diamond bearing region.(Russian)Geologii i Geofiziki, (Russian), No. 9, (344) September pp. 106-108RussiaGeophysics, Deposit -Malo-Botuobinsk
DS1981-0387
1981
Pospelova, L.N.Sobolev, N.V., Efimova, E.S., Pospelova, L.N.Native Iron in Diamonds of Yakutiya and Its ParagenesisSoviet Geology And Geophysics, Vol. 22, No. 12, PP. 18-21.RussiaKimberlite, Inclusion, Crystallography
DS1983-0641
1983
Pospelova, L.N.Yefimova, E.S., Sobolev, N.V., Pospelova, L.N.Sulfide Inclusions in Diamonds and their Paragenesis.(russian)Zap. Vses Mineral. Obshch., (Russian), Vol. 112, No. 3, pp. 300-310RussiaInclusions, Diamond Morphology
DS1998-1328
1998
Pospelova, L.N.Sharygin, V.V., Pospelova, L.N.Sulfide inclusions in early lamproite minerals7th International Kimberlite Conference Abstract, pp. 794-6.Montana, Australia, SpainLamproites, Olivine hyalolamprite, orendite, sulfide inclusions
DS200512-0967
2003
Pospelova, L.N.Sharygin, V.V., Pospelova, L.N., Smirnov, S.Z., Vladykin, N.V.Ni rich sulfide inclusions in early lamproite minerals.Russian Geology and Geophysics, Vol. 44, 9, pp. 817-828.RussiaLamproite - inclusions
DS1989-1128
1989
Pospeyev, V.I.Nikulin, V.I., Yerkhov, V.A., Pospeyev, V.I.Criteria for the prognosis of kimberlite fieldsInternational Geology Review, Vol. 31, No. 2, February pp. 186-195RussiaExploration, Kimberlite fields
DS201212-0339
2012
Posser, A.Jelsma, H.,Krishnan, S.U., Perritt, S.,Kumar, M., Preston, R., Winter, F., Lemotlo, L., Costa, J., Van der Linde, G., Facatino, M., Posser, A., Wallace, C., Henning, A., Joy, S., Chinn, I., Armstrong, R., Phillips, D.Kimberlites from central Angola: a case stidy of exploration findings.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractAfrica, AngolaOverview of kimberlites
DS201412-0427
2013
Posser, A.Jelsma, H., Krishnan, U., Perritt, S., Preston, R., Winter, F., Lemotlo, L., van der Linde, G., Armstrong, R., Phillips, D., Joy, S., Costa, J., Facatino, M., Posser, A., Kumar, M., Wallace, C., Chinn, I., Henning, A.Kimberlites from central Angola: a case study of exploration findings.Proceedings of the 10th. International Kimberlite Conference, Vol. 2, pp. 173-190.Africa, AngolaExploration - kimberlites
DS2001-0357
2001
PossoukhovaGaranin, V.K., Kudryavtseva, Possoukhova, TikhovaTwo types of the Diamondiferous kimberlites from the Arkangelsk province, RussiaMineral deposits 21st. century, pp. 955-8.Russia, ArkangelskTectonics, Deposit - Zolotitsa
DS1999-0563
1999
Possoukhova, T.V.Possoukhova, T.V., Kudryavtseva, G.P., Garanin, V.K.Diamonds and accompanying minerals from Arkangelsk kimberlite, RussiaStanley, SGA Fifth Biennial Symposium, pp. 667-70.Russia, Arkangelsk, Kola PeninsulaMineralogy, Deposit - Arkangel
DS2002-1003
2002
Possoukhova, T.V.Maslennikova, Y.V., Kolume, F.N., Possoukhova, T.V., Novgorodova, M.L.Diamonds and accompanying minerals from the Sierra Leone placers18th. International Mineralogical Association Sept. 1-6, Edinburgh, abstract p.148.Sierra LeoneDiamond - morphology, alluvials
DS1998-0468
1998
Possukhova, T.V.Garanin, V.K., Kudriavtseva, G.P., Possukhova, T.V.Diamonds of Arkhangelsk kimberlite province ( review)7th International Kimberlite Conference Abstract, pp. 233-235.Russia, Arkangelsk, Kola PeninsulaDiamond morphology, Deposit - Lomonosov
DS1998-0148
1998
PossuklovaBovkun, A.V., Garanin, V.K., Kudriavtseva, PossuklovaChemical genetic classification of microcrystalline oxides from kimberlite groundmass - system prospecting7th International Kimberlite Conference Abstract, pp. 91-93.Russia, Arkangelsk, Kola PeninsulaMicroprobe analyses, Deposit - Zolitskoye, Verkhotinskoye, Kepinskoye, Touri
DS1998-0149
1998
PossuklovaBovkun, A.V., Garanin, V.K., Kudriavtseva, PossuklovaDiamonds from Timan placers: morphology, spectroscopy and genesis7th International Kimberlite Conference Abstract, pp. 97-99.Russia, TimanPLacers, alluvials, Diamond morphology - types
DS1998-0150
1998
PossuklovaBovkun, A.V., Garanin, V.K., Kudriavtseva, PossuklovaChemical genetic classification of oxides from kimberlite groundmass as basis - evaluation of diamond7th International Kimberlite Conference Abstract, pp. 94-96.Russia, Yakutia, AikalHigh magnesian - spinels, Deposit - Obnazhenna, Mir, Udachnaya, Morkokka
DS2002-1251
2002
Post, J.Peslier, A.H., Luhr, J.F., Post, J.Low water contents in pyroxenes from spinel peridotites of the oxidized, sub arc mantle wedge.Earth and Planetary Science Letters, Vol. 201, 1, July 15, pp. 69-86.MantleMineralogy, Subduction
DS201012-0215
2010
Post, J.Gaillou, E., Rost, D., Post, J., Butler, J.Quantifying boron in natural type IIb blue diamonds.Goldschmidt 2010 abstracts, abstractTechnologyDiamond morphology
DS1986-0649
1986
Post, J.E.Post, J.E., Burnham, C.W.Modeling tunnel cation displacements in Hollandites using structureenergy calculationsAmerican Mineralogist, Vol. 71, pp. 1178-1185GlobalPriderite, Mineralogy
DS200612-0363
2006
Post, J.E.Eaton-Magana, S., Post, J.E., Freitas, J.A., Klein, P.B., Walters, R.A., Heaney, P.J, Butler, J.E.Luminescence of the Hope diamond and other blue diamonds.GIA Gemological Research Conference abstract volume, Held August 26-27, p. 32. 1/2p.TechnologySpectroscopy
DS200712-0283
2006
Post, J.E.Eaton-Magana, S., Post, J.E., Walters, R.A., Heaney, P.J., Butler, J.E.Fluoresence of fancy color natural diamonds.Gems & Gemology, 4th International Symposium abstracts, Fall 2006, p.131-2. abstract onlyTechnologyDiamond colour - UV radiation
DS200812-0309
2008
Post, J.E.Eaton-Magana, S., Post, J.E., Heaney, P.J., Frietas, J., Klein, P., Walters, R., Butler, J.E.Using phosphorescence as a fingerprint for the Hope and other blue diamonds.Geology, Vol. 36, 1, pp.TechnologyDiamond morphology
DS200812-0310
2007
Post, J.E.Eaton-Magana, S., Post, J.E., Heaney, P.J., Walters, R.A., Breeding, C.M., Butler, J.E.Fluorescence spectra of colored diamonds using a rapid, mobile spectrometer.Gems & Gemology, Vol. 43, 4, Winter pp. 332-351.TechnologyType 1 a diamonds
DS200812-0376
2007
Post, J.E.Gaillou, E., Post, J.E.An examination of the Napoleon diamond necklace.Gems & Gemology Lab Notes, Vol. 43, 4, Winter pp. 352-357.TechnologyType 1a and 11a diamonds
DS201012-0214
2010
Post, J.E.Gaillou, E., Post, J.E., Bassim, N.D., Zaitsev, A.M., Rose, T., Fries, M.D., Stroud, R.M., Steele, A., Butler, J.E.Spectroscopic and microscopic characterizations of color laminae in natural pink diamonds.Diamond and Related Materials, Vol. 19, 10, pp. 1207-1220.TechnologySpectroscopy
DS201012-0216
2010
Post, J.E.Gaillou, E., Wang, W., Post, J.E., King, J.M., Butler, J.E., Collins, A.T., Moses, T.M.The Wittelsbach-Graff and Hope diamonds: not cut from the same rough.Gems & Gemology, Vol. 46, 2, pp. 80-88.TechnologyDiamonds notable
DS201012-0767
2010
Post, J.E.Sucher, S.D., Attaway, S.W., Attaway, N.L., Post, J.E.Possible sister stones of the Hope diamond.Gems & Gemology, Vol. 46, 1, Spring pp. 28-35.TechnologyDiamond notable - Hope
DS201112-0341
2011
Post, J.E.Gaillou, E., Post, J.E., Butler, J.E.On the pecularities of Australian and Venezuelan pink diamonds: influence of the geologic settings.Goldschmidt Conference 2011, abstract p.882.Australia, South America, VenezuelaArgyle, Santa Elena, high thermal events
DS201212-0195
2012
Post, J.E.Farges, F., Vinson, J., Rehr, J.R., Post, J.E.Spectroscopy of B doped diamonds: experiment vs. theory. Hope, Tavernier Blue, French Blueemc2012 @ uni-frankfurt.de, 1p. AbstractTechnologyDiamond - colour
DS201212-0225
2012
Post, J.E.Gaillou, E.,Post, J.E., Rost, D., Butler, J.E.Boron in natural type 11b blue diamonds: chemical and spectroscopic measurements.American Mineralogist, Vol. 97, pp. 1-18.TechnologyBlue diamond
DS201412-0261
2014
Post, J.E.Galillou, E., Post, J.E., Steele, A., Butler, J.E.Constrains on highly strained pink diamonds by high spatial resolution FTIR and Raman mapping.Geological Society of America Conference Vancouver Oct. 19-22, 1p. AbstractTechnologyPink diamond colour
DS201412-0705
2014
Post, J.E.Post, J.E., Farges, F.The Hope diamonds: rare gem, historic jewel.Rocks and Minerals, Jan.-Feb. pp. 16-26.TechnologyDiamonds notable - Hope
DS201503-0144
2015
Post, J.E.Gaillou, E., Post, J.E., Byne, K.S., Butler, J.E.Study of the Blue Moon diamond. ( from Cullinan)Gems & Gemology, Vol. 50, 4, winter 2014, 9p.Africa, South AfricaDiamonds notable

Abstract: The Blue Moon diamond, discovered in January 2014 at the historic Cullinan mine in South Africa, is of significance from both trade and scientific perspectives. The 29.62 ct rough yielded a 12.03 ct Fancy Vivid blue, Internally Flawless gem. The authors were provided the opportunity to study this rare diamond at the Smithsonian Institution before it went on exhibit at the Natural History Museum of Los Angeles County. Infrared spectroscopy revealed that the amount of uncompensated boron in the diamond was 0.26 ± 0.04 ppm, consistent with measurements of several large type IIb blue diamonds previously studied. After exposure to short-wave ultraviolet light, the Blue Moon displayed orange-red phosphorescence that remained visible for up to 20 seconds. This observation was surprising, as orange-red phosphorescence is typically associated with diamonds of Indian origin, such as the Hope and the Wittelsbach-Graff. Time-resolved phosphorescence spectra exhibited peaks at 660 and 500 nm, typical for natural type II blue diamonds. As with most natural diamonds, the Blue Moon showed strain-induced birefringence.
DS201608-1434
2016
Post, J.E.Post, J.E., Gaillou, E., Butler, J.E., Byrne, K.S.Investigations into luminescence properties and compositions of colored diamonds.GSA Annual Meeting, Abstract, 1p.TechnologyLuminescence

Abstract: The Smithsonian’s National Gem Collection includes the Hope Diamond and an assortment of other significant fancy-colored diamonds, providing a unique opportunity to conduct detailed and sustained studies on an unprecedented selection of these rare and valuable stones. We present an overview and recent results from our work on pink, blue and chameleon diamonds. Boron causes the blue color of the Hope Diamond and other type IIb diamonds, but scarcity, high value, and the low concentration of B has inhibited B analyses of natural IIb diamonds. We used FTIR and ToF-SIMS to measure concentrations and distributions of B in the Hope and other blue diamonds. ToF-SIMS analyses gave spot B concentrations as high as 8.4 ± 1.1 ppm for the Hope Diamond to less than 0.08 ppm in other blue diamonds and revealed strong zoning of B in some diamonds, which was confirmed by mapping using synchrotron FTIR. Boron is also responsible for the phosphorescence emissions of IIb diamonds, at 660 nm and 500 nm; the emissions are likely caused by donor-acceptor pair recombination processes involving B and other defects. Approximately 50 type I natural pink diamonds were compared using UV-Vis, FTIR, and CL spectroscopies. All stones exhibit pink color zoning, ~1µm thick [111] lamellae, in otherwise colorless diamond. The pink diamonds fall into two groups: 1) those from Argyle in Australia and Santa Elena in Venezuela, and 2) those from other localities. TEM imaging from FIB sections revealed that twinning is the likely mechanism by which plastic deformation is accommodated for the pink diamonds. The deformation creates new centers, including the one responsible for the pink color, which remains unidentified. The differences in the plastic deformation features for the two groups might correlate to the particular geologic conditions under which the diamonds formed. Fluorescence and thermoluminescence experiments on natural chameleon diamonds reveal that an emission band, peaking near 556nm, may be stimulated via a number of different mechanisms. We discuss the implications of our observations for the electronic structure of the 556nm-fluorescing defect center, and the connections to the unidentified color center responsible for chameleon color changes.
DS201610-1900
2016
Post, J.E.Post, J.E., Gaillou, E., Butler, J.E., Byrne, K.S.Investigations into the luminescence properties and compositions of colored diamonds. ( blue and pink)GSA Annual Meeting, 1/2p. abstractTechnologyColoured diamonds

Abstract: The Smithsonian’s National Gem Collection includes the Hope Diamond and an assortment of other significant fancy-colored diamonds, providing a unique opportunity to conduct detailed and sustained studies on an unprecedented selection of these rare and valuable stones. We present an overview and recent results from our work on pink, blue and chameleon diamonds. Boron causes the blue color of the Hope Diamond and other type IIb diamonds, but scarcity, high value, and the low concentration of B has inhibited B analyses of natural IIb diamonds. We used FTIR and ToF-SIMS to measure concentrations and distributions of B in the Hope and other blue diamonds. ToF-SIMS analyses gave spot B concentrations as high as 8.4 ± 1.1 ppm for the Hope Diamond to less than 0.08 ppm in other blue diamonds and revealed strong zoning of B in some diamonds, which was confirmed by mapping using synchrotron FTIR. Boron is also responsible for the phosphorescence emissions of IIb diamonds, at 660 nm and 500 nm; the emissions are likely caused by donor-acceptor pair recombination processes involving B and other defects. Approximately 50 type I natural pink diamonds were compared using UV-Vis, FTIR, and CL spectroscopies. All stones exhibit pink color zoning, ~1µm thick [111] lamellae, in otherwise colorless diamond. The pink diamonds fall into two groups: 1) those from Argyle in Australia and Santa Elena in Venezuela, and 2) those from other localities. TEM imaging from FIB sections revealed that twinning is the likely mechanism by which plastic deformation is accommodated for the pink diamonds. The deformation creates new centers, including the one responsible for the pink color, which remains unidentified. The differences in the plastic deformation features for the two groups might correlate to the particular geologic conditions under which the diamonds formed. Fluorescence and thermoluminescence experiments on natural chameleon diamonds reveal that an emission band, peaking near 556nm, may be stimulated via a number of different mechanisms. We discuss the implications of our observations for the electronic structure of the 556nm-fluorescing defect center, and the connections to the unidentified color center responsible for chameleon color changes.
DS201703-0442
2017
Post, J.E.Zubkov, V.I., Solomnikova, A.V., Post, J.E., Gaillou, E., Butler, J.E.Characterization of electronic properties of natural type 11b diamonds.Diamond and Related Materials, Vol. 72, pp. 87-93.TechnologyDiamonds - type 11b

Abstract: Precision admittance spectroscopy measurements were carried out over wide temperature and frequency ranges for a set of natural single crystal type IIb diamond samples. Peaks of conductance spectra vs. temperature and frequency were used to compute the Arrhenius plots, and activation energies were derived from these plots. The capacitance-voltage profiling was used to estimate the majority charge carrier concentration and its distribution into depth of the samples. Apparent activation energies between 315 and 325 meV and the capture cross section of about 10? 13 cm2 were found for samples with uncompensated boron concentrations in the range of 1 to 5 × 1016 cm? 3 (0.06-0.3 ppm). The obtained boron concentrations are in good coincidence with FTIR results for the samples. Also, a reason for the difference between the observed admittance activation energy and the previously reported ionization energy for the acceptor boron in diamond (0.37 eV) is proposed.
DS201802-0224
2018
Post, J.E.Byrne, K.S., Butler, J.E., Wang, W., Post, J.E.Chameleon diamonds: thermal processes governing luminescence and model for the color change.Diamond & Related Materials, Vol. 81, pp. 45-53.Technologyluminescence

Abstract: To date, the eponymous color-changing behavior of chameleon diamonds lacks an explanation in terms of an identified diamond defect structure or process. Well known, however, is that this color-change is driven by the influence of both light and heat. In this paper, we present observations of how luminescence emission in chameleon diamonds responds to temperature changes and optical pumping. Fluorescence, phosphorescence, and thermoluminescence experiments on a suite of natural chameleon diamonds reveal that a specific emission band, peaking near 550 nm, may be stimulated by several different mechanisms. We have observed thermal quenching of the 550 nm emission band with an activation energy of 0.135 eV. The 550 nm band is also observed in phosphorescence and thermoluminescence. Thermoluminescence spectra suggest the presence of low lying acceptor states at 0.7 eV above the valence band. When excited with 270 nm light, we observe emission of light in two broad spectral bands peaking at 500 and 550 nm. We suggest that the 550 nm emission band results from donor—acceptor pair recombination (DAPR) from low lying acceptor states at ca. 0.7 eV above the valence band and donor states approximately 2.5 to 2.7 eV above the valence band. We do not identify the structure of these defects. We propose a speculative model of the physics of the color change from ‘yellow’ to ‘green’ which results from increased broad-band optical absorption in the near-IR to visible due to transitions from the valence band into un-ionized acceptor states available in the ‘green’ state of the chameleon diamond. We report near-IR absorption spectra confirming the increased absorption of light in the near-IR to visible in the ‘green’ when compared to the ‘yellow’ state with a threshold at ca. 0.65 eV, supporting the proposed model.
DS201804-0676
2017
Post, J.E.Butler, J.E., Post, J.E., Wang, W.The Foxfire diamond revisited. Diavik ( using DiamondView phosphoresence)Gems & Gemology Lab Notes, Vol. 53, 4, pp. 479-481.Canada, Northwest Territoriesdiamond notable - Foxfire

Abstract: The largest gem-quality rough diamond found in Canada, reported earlier in Gems & Gemology (Summer 2016 GNI, pp. 188-189), has revealed remarkable responses to excitation with long- and mid-wave UV light. This 187.63 ct diamond (figure 1) was extracted from the Diavik mine in the Canadian Arctic in the spring of 2015. Aptly named for the aurora borealis, the “Foxfire” displays unusual fluorescence and phosphorescence behavior upon exposure to ultraviolet light. As previously reported, this type Ia diamond has a high concentration of nitrogen impurities, a weak hydrogen-related absorption at 3107 cm-1, and typical "cape" absorption lines.
DS201901-0011
2018
Post, J.E.Butler, J.E., Byrne, K.S., Wang, W., Post, J.E.Complex charge transfer in chameleon diamonds: a model of the color-change process,Gems & Gemology, Sixth International Gemological Symposium Vol. 54, 3, 1p. Abstract p. 303.Globaldiamond color

Abstract: A group of natural diamonds known as chameleon diamonds change color from green to yellow based on their exposure to light and heat. These diamonds also emit long-lived phosphorescence after UV excitation. We have observed the optical response of these diamonds to optical and thermal excitation and developed a model to explain the observed phenomena. A principal element of the model is the proposal of an acceptor state (figure 1), which should be observable in the near-infrared (NIR) region. Subsequently, we have observed the NIR absorption to this acceptor state, supporting our model of charge-transfer processes in these diamonds.
DS202004-0530
2020
Post, J.E.Post, J.E., Feather, R., Butler, J.E.Kimberley diamond acquired by the Smithsonian Institution and its flourescence and phosphorescence characteristics revealed. 55.08 ctJournal of Gemmology, Vol. 37, 1, pp. 14, 15.Africa, South Africa, United Statesflourescence
DS1950-0420
1958
Post, L.V.D.Post, L.V.D.The Lost World of the KalahariHogarth Press, 256P.BotswanaTravelogue, Ethnography, Philosophy
DS2001-0943
2001
Postle, J.Postle, J., Haystead, B.Evolution of the The Canadian Institute of Mining, Metallurgy and Petroleum (CIM) standing committee on reserve definition. Cost reporting, CIMVAl.The Canadian Mining and Metallurgical Bulletin (CIM Bulletin) ., Vol. 94, No. 1047, Feb. p.34-7.CanadaLegal, Laws - regulatory
DS200612-1105
2006
Postle, J.Postle, J.Towards a set of harmonized definitions of mineral resources and reserves.Canadian Institute of Mining and Metallurgy, Vol. 1, 1, Feb. pp. 12-13.GlobalOre reserve - definition
DS1991-1371
1991
Postle, J.T.Postle, J.T.The Canadian Institute of Mining, Metallurgy and Petroleum (CIM) Special committee on reserve definitionsThe Canadian Mining and Metallurgical Bulletin (CIM Bulletin), August , brief mentionCanadaGeostatistics, Ore reserve -definition
DS1997-0918
1997
Postle, J.T.Postle, J.T., Roscoe, W.E.Independent geological and engineering reportsInsight Press, Canada, GlobalEconomics, Due diligence, legal, geostatistics
DS201312-0718
2013
Postlewaithe, B.Postlewaithe, B.Velocity structure of the crust across Canada.GEM Diamond Workshop Feb. 21-22, Noted onlyCanadaGeophysics - seismics
DS1996-1132
1996
Postma, D.Postma, D., Jakobsen, R.Redox zonation: equilibrium constraints on the iron (III) SO4 reductioninterface.Geochimica et Cosmochimica Acta, Vol. 60, No. 17, pp. 3169-75.GlobalGeochemistry - redox not specific to diamonds
DS201212-0745
2012
Postma, G.Van Dijk, M., Kleinhans, M.G., Postma, G., Kraal, E.Contrasting morphodynamics in alluvial fans and fan deltas: effect of the Down stream boundary.Sedimentology, in press availableGlobalGeomorphology
DS201212-0746
2012
Postma, G.Van Dijk, M., Kleinhans, M.G., Postma, G., Kraal, E.Contrasting morphodynamics in alluvial fans and fan deltas: effect of the Down stream boundary.Sedimentology, Vol. 59, 7, Dec. pp. 2125-2145.TechnologyGeomorphology - fans
DS2002-0200
2002
Postnikov, A.V.Bozhko, N.A., Postnikov, A.V., Shchipanski, A.A.Formation of the East European platform basement: a geodynamic modelDoklady Earth Sciences, Vol. 387,8, pp. 875-79.Europe, Kola PeninsulaTectonics
DS201701-0018
2016
Postnikov, A.V.Kargin, A.V., Nosova, A.A., Postnikov, A.V., Chugaev, A.V., Postnikova, O.V., Popova, L.P., Poshibaev, V.V., Sazonova, L.V., Dokuchaev, A.Ya., Smirnova, M.D.Devonian ultramafic lamprophyre in the Irkineeva Chadobets trough in the southwest of the Siberian platform: age, composition, and implications for diamond potential prediction.Geology of Ore Deposits, Vol. 58, 5, pp. 383-403.RussiaLamprophyre - aillikite

Abstract: The results of geochronological, mineralogical, petrographical, and geochemical study of the Ilbokich ultramafic lamprophyre are reported. The specific features in the mineral and chemical compositions of the studied ultramafic lamprophyre indicate that it can be regarded as a variety similar to aillikite, while other differences dominated by K-feldspar can be referred to damtjernite. According to Rb-Sr analysis, ultramafic lamprophyre dikes intruded at the turn of the Early and Middle Devonian, about 392 Ma ago. This directly proves the existence of Early Paleozoic alkali-ultramafic magmatism in the northern part of the southwest Siberian Platform. A finding of Devonian alkali-ultramafic lamprophyre is of dual predictive importance. On the one hand, it is indicative of the low probability of finding large diamond-bearing deposits in close association with aillikite. On the other hand, it can be indicative of a possible large Devonian diamond province in the studied territory, where diamondiferous kimberlite is structurally separated from aillikite.
DS201701-0018
2016
Postnikova, O.V.Kargin, A.V., Nosova, A.A., Postnikov, A.V., Chugaev, A.V., Postnikova, O.V., Popova, L.P., Poshibaev, V.V., Sazonova, L.V., Dokuchaev, A.Ya., Smirnova, M.D.Devonian ultramafic lamprophyre in the Irkineeva Chadobets trough in the southwest of the Siberian platform: age, composition, and implications for diamond potential prediction.Geology of Ore Deposits, Vol. 58, 5, pp. 383-403.RussiaLamprophyre - aillikite

Abstract: The results of geochronological, mineralogical, petrographical, and geochemical study of the Ilbokich ultramafic lamprophyre are reported. The specific features in the mineral and chemical compositions of the studied ultramafic lamprophyre indicate that it can be regarded as a variety similar to aillikite, while other differences dominated by K-feldspar can be referred to damtjernite. According to Rb-Sr analysis, ultramafic lamprophyre dikes intruded at the turn of the Early and Middle Devonian, about 392 Ma ago. This directly proves the existence of Early Paleozoic alkali-ultramafic magmatism in the northern part of the southwest Siberian Platform. A finding of Devonian alkali-ultramafic lamprophyre is of dual predictive importance. On the one hand, it is indicative of the low probability of finding large diamond-bearing deposits in close association with aillikite. On the other hand, it can be indicative of a possible large Devonian diamond province in the studied territory, where diamondiferous kimberlite is structurally separated from aillikite.
DS1995-1512
1995
Posukhova, L.F.Posukhova, L.F., Dobrzhinnetskaya, Nadezhdina, ShadrinaMorphology and growth conditions of diamonds in metamorphic rocksProceedings of the Sixth International Kimberlite Conference Abstracts, pp. 452-454.Russia, Kazakhstan, ChinaMetamorphic, Diamond genesis
DS201412-0706
2014
Posukhova, T.Posukhova, T.Diamonds and accompanying minerals in the North Yakutian placers, Russia.ima2014.co.za, PosterRussiaAlluvials
DS1984-0595
1984
Posukhova, T.V.Posukhova, T.V., Bocharova, G.I., Kudryavtseva, G.P., Soshkina.Features of Morphology and Internal Structure of Ilmenite from kimberlites of the Malo Botuobinskii Region of Yakutia.Moscow University Geol. Bulletin., Vol. 39, No. 6, PP. 36-44.Russia, YakutiaMicroscopy, Mineralogy, Amaka Pipe, Taezhnyi
DS1986-0263
1986
Posukhova, T.V.Garanin, V.K., Kudryavtseva, G.P., Posukhova, T.V., Afanasjev, V.P.Morphology of kimberlite minerals: its usage for predicting and searchingfor diamond depositsProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, pp. 457-459RussiaDiamond exploration
DS1990-1083
1990
Posukhova, T.V.Nadezhdina, Ye.D., Posukhova, T.V.The morphology of diamond crystals from metamorphic rocks.(Russian)Mineral. Zhurn., (Russian), Vol. 12, No. 2, pp. 3-15RussiaDiamond morphology, Metamorphic rocks
DS1995-0582
1995
Posukhova, T.V.Garanin, V.K., Posukhova, T.V.Morphology and growth history of diamonds in Arkhangelsk kimberlite pipeProceedings of the Sixth International Kimberlite Conference Extended Abstracts, p. 175-6.Russia, ArkangelskDiamond morphology, Deposit - Zolotitskoye, Verhotinskoye, Kepinskoye
DS1995-0583
1995
Posukhova, T.V.Garanin, V.K., Posukhova, T.V.Typomorphism of microcrystalline oxides from kimberlite groundmass in Arkhangel kimberlite province.Proceedings of the Sixth International Kimberlite Conference Extended Abstracts, p. 177-8.Russia, ArkangelskDiamond morphology, Deposit - Zolotitskoye, Verhotinskoye, Kepinskoye
DS1996-1133
1996
Posukhova, T.V.Posukhova, T.V., et al.Morphogenetic classification of the minerals on the base of microtopography characteristics (Au, Ag, diamond)International Geological Congress 30th Session Beijing, Abstracts, Vol. 2, p. 517.RussiaMIcrotopography, Diamondiferous deposits
DS1997-0369
1997
Posukhova, T.V.Garanin, V.K., Kudryavtseva, G.P., Posukhova, T.V.Indicators of diamond preservation in kimberlitePapunen: 4th. Biennial SGA Meeting, pp. 767-770.Russia, ArkangelskDiamond exploration, Thermodynamics, microcrystalline oxides
DS1998-0470
1998
Posukhova, T.V.Garanin, V.K., Posukhova, T.V.Unusual diamonds from Arkhangelsk kimberlite provinceIma 17th. Abstract Vol., p. A15. poster abstractRussia, Arkangelsk, Kola PeninsulaDiamond morphology, Deposit - Pioneerskaya
DS200612-0747
2006
Posukhova, T.V.Kudrayvtseva, G.P., Posukhova, T.V., Polazchenko, O.Diamonds from the V Grib pipe: internal structure and origin.International Mineralogical Association 19th. General Meeting, held Kobe, Japan July 23-28 2006, Abstract p. 140.RussiaGrip - diamond morphology
DS200612-1106
2006
Posukhova, T.V.Posukhova, T.V., Malakhova, F., Dorokhova, G.I.X ray computer microtomography - effective method of the investigation of the inclusion in diamond.International Mineralogical Association 19th. General Meeting, held Kobe, Japan July 23-28 2006, Abstract p.TechnologyDiamond inclusions
DS200712-0852
2007
Posukhova, T.V.Posukhova, T.V.Morphogenesis of diamond and associated minerals from Diamondiferous deposits in the Urals and Timan.Moscow University Geology Bulletin, Vol. 62, 3, pp. 198-205.Russia, Urals, TimanDiamond morphology
DS200812-0914
2008
Posukhova, T.V.Posukhova, T.V., Xiaoying, G.Mineralogical features of the Chin a kimberlites - comparison with Arkangelsk Diamondiferous province.9IKC.com, 3p. extended abstractChina, RussiaCraton, Hua Bei, Fu Xian
DS200912-0593
2009
Posukhova, T.V.Posukhova, T.V., Kolume, F.N.Diamonds from placers in western and central Africa: a problem of primary sources.Moscow University Geology Bulletin, Vol. 64, 3, pp. 177-186.Africa, Sierra Leone, Democratic Republic of CongoDeposit - Koidu, Chikapa
DS201012-0593
2010
Posukhova, T.V.Posukhova, T.V.Morphogenetic evidence of the mantle fluid activity. Mentions diamond and water.International Mineralogical Association meeting August Budapest, abstract p. 156.Russia, Kola Peninsula, Archangel, Africa, Sierra LeoneDiamond morphology
DS201012-0594
2010
Posukhova, T.V.Posukhova, T.V., Dorofeev, S.A., Gao, Y.Mineralogy of the wastes from diamond bearing mines. Arkangelsk LiaoninInternational Mineralogical Association meeting August Budapest, abstract p. 349.Russia, ChinaMining - recycling
DS202008-1457
2020
Posukhova, T.V.Vorobei, S.S., Garanin, V.K., Minervina, E.A., Posukhova, T.V., Weisheng, X.The mineralogy and geochemistry of mantle xenoliths from diamondiferous kimberlite of China and Russia.Moscow University Geology Bulletin, Vol. 75, 2, pp. 128-135. pdfRussia, Chinadeposit - Mir, Shandong, Liaoning

Abstract: enoliths from the Mir pipe and from the Shandong and Liaoning provinces were studied by the methods of EMPA and ICP-MS. Their mineralogical, geochemical, and genetic features were revealed. Minerals of diamondiferous paragenesis were detected in xenoliths from the Mir pipe, while they were not found in xenoliths of China. All xenoliths are characterized by secondary alterations, which are more intense in xenoliths of China. The distribution of REEs shows the involvement of subduction processes in the formation of xenoliths from the Mir pipe. The influence of metasomatism is clearly evident in xenoliths from China. The calculated P-T parameters (? = 600-700°C, P = 2-2.5 GPa) are not consistent with the mantle environments that correspond to the metasomatic conditions.
DS1994-0955
1994
Posukhova, Ye.V.Krot, A.N., Posukhova, Ye.V., Guseva, E.M., et al.Origin of garnets containing hydrocarbon inclusions in the Mir kimberlitepipe.Geochemistry International, Vol. 31, No. 1, pp. 122-130.Russia, YakutiaDiamond morphology, Deposit -Mir
DS201012-0864
2010
Posukkhova, T.V.Xiaoying, G., Posukkhova, T.V.Chromium spinels in north Chinese kimberlites , Huabei platform.Moscow University Geology Bulletin, Vol. 65, 4, pp. 234-243.China, RussiaMengyin, Fuxian, Arkangel
DS201412-0566
2013
Potapin, V.McCammon, C., Glazyrin, K., Kantor, A., Kantor, I., Kupenko, I., Narygina, O., Potapin, V., Vasily, P., Sinmyo, C., Chumakov, Ruffer, Sergueev, Smirnov, DubrovinskyIron spin state in silicate perovskite at conditions of Earth's deep interior.International Journal of High Pressure Research, Vol. 33, 3, pp. 663-672.MantlePerovskite
DS201312-0720
2014
Potapkin, V.Prescher, C., Weigel, C., McCammon, C., Narygina, O., Potapkin, V., Kupenko, I., Sinmyo, R., Chumakov, A.I., Dubrovinsky, L.Iron spin state in silicate glass at high pressure: implications for melts in the Earth's lower mantle.Earth and Planetary Science Letters, Vol. 385, pp. 130-136.MantleUHP
DS202009-1624
2020
Potapkin, V.Dorfman, S.M., Potapkin, V., Lv, M., Greenberg, E., Kupenko, I., Chumakov, A.I., Bi, W., Alp, E.E., Liu, J., Magrez, A., Dutton, S.E., Cava, R.J., McCammon, C.A., Gillet, P.Effects of composition and pressure on electronic states of iron in bridgmanite.American Mineralogist, Vol. 105, pp. 1030-1039. pdfMantleredox

Abstract: Electronic states of iron in the lower mantle's dominant mineral, (Mg,Fe,Al)(Fe,Al,Si)O3 bridgmanite, control physical properties of the mantle including density, elasticity, and electrical and thermal conductivity. However, the determination of electronic states of iron has been controversial, in part due to different interpretations of Mössbauer spectroscopy results used to identify spin state, valence state, and site occupancy of iron. We applied energy-domain Mössbauer spectroscopy to a set of four bridgmanite samples spanning a wide range of compositions: 10-50% Fe/total cations, 0-25% Al/total cations, 12-100% Fe3+/total Fe. Measurements performed in the diamond-anvil cell at pressures up to 76 GPa below and above the high to low spin transition in Fe3+ provide a Mössbauer reference library for bridgmanite and demonstrate the effects of pressure and composition on electronic states of iron. Results indicate that although the spin transition in Fe3+ in the bridgmanite B-site occurs as predicted, it does not strongly affect the observed quadrupole splitting of 1.4 mm/s, and only decreases center shift for this site to 0 mm/s at ~70 GPa. Thus center shift can easily distinguish Fe3+ from Fe2+ at high pressure, which exhibits two distinct Mössbauer sites with center shift ~1 mm/s and quadrupole splitting 2.4-3.1 and 3.9 mm/s at ~70 GPa. Correct quantification of Fe3+/total Fe in bridgmanite is required to constrain the effects of composition and redox states in experimental measurements of seismic properties of bridgmanite. In Fe-rich, mixed-valence bridgmanite at deep-mantle-relevant pressures, up to ~20% of the Fe may be a Fe2.5+ charge transfer component, which should enhance electrical and thermal conductivity in Fe-rich heterogeneities at the base of Earth's mantle.
DS1989-1235
1989
Potapoff, P.Potapoff, P.The Martison carbonatite deposit, OntarioPhosphate deposits of the World, Vol. 2, pp. 71-78OntarioCarbonatite, Martison
DS201312-0719
1989
Potapoff, P.Potapoff, P.The Martinson carbonatite deposit, Ontario CanadaPhosphate Deposits of the world, ed. Notholt, A.J.G., Sheldon, R.P., Davidson, D.F., Vol. 2, no. 10, pp. 71-79. copy donated by R. SageCanada, OntarioCarbonatite
DS200812-0465
2008
Potapov, A.Herbst, J., Potapov, A., Hambidge, G., Rademan, J.Modeling of diamond liberation and damage for Debswana kimberlitic ores.Minerals Engineering, Vol. 21, 11, October pp. 766-789.Africa, BotswanaMining - mineral processing
DS1987-0346
1987
Potapov, E.E.Kharkiv, A.D., Serenko, V.P., Zinchuk, N.N., Potapov, E.E.Xenoliths of deep seated rocks in the Mir pipe.(Russian)Izv. Akad. Nauk SSR ser. geol., (Russian), No. 1, pp. 290-37RussiaPetrology
DS1960-0687
1966
Potapov, S.V.Kaminsky, F.V., Potapov, S.V.Methods of Prospecting Kimberlitic Bodies on the Eastern Margin of the Aldan Shield.Razv. Okhr. Nedr., No. 8, PP. 14-17.RussiaBlank
DS1960-0849
1967
Potapov, S.V.Kaminsky, F.V., Potapov, S.V.Absolute Age Determinations of KimberlitesAkad. Nauk Sssr, Ser. Geol., No. 5, PP. 143-145.RussiaBlank
DS1960-0968
1968
Potapov, S.V.Kaminskiy, F.V., Potapov, S.V.Petrography and Mineralogy of the Kimberlite Rocks of the Ingili District, Eastern Aldan Shield.Geologii i Geofiziki, No. 1, PP. 50-55.RussiaBlank
DS1960-0969
1968
Potapov, S.V.Kaminskiy, F.V., Potapov, S.V.Kimberlite Bodies of in Ingili Region on the Eastern Margin of the Aldan Shield.Geologii i Geofiziki, No. 11, PP. 30-36.RussiaBlank
DS1960-0970
1968
Potapov, S.V.Kaminskiy, F.V., Potapov, S.V.A New Kimberlite Province of Precambrian Age on the Eastern margin of the Aldan Shield.Second All-union Conference, Geol. Diamond Deposits, PERM.RussiaBlank
DS202010-1840
2020
Potapov, S.V.Dymshits, A., Sharygin, I., Malkovets, V., Yakovlev, I.V., Gibsher, A.A., Alifirova, T.A., Vorobei, S.S., Potapov, S.V., Garanin, V.K.Thermal state, thickness and composition of the lithospheric mantle beneath the Upper Muna kimberlite field, Siberian Craton, constrained by clinopyroxene xenocrysts and comparison with Daldyn and Mirny fields.Minerals, 10.1039/DOJA00308E 20p. PdfRussiadeposit - Muna

Abstract: To gain better insight into the thermal state and composition of the lithospheric mantle beneath the Upper Muna kimberlite field (Siberian craton), a suite of 323 clinopyroxene xenocrysts and 10 mantle xenoliths from the Komsomolskaya-Magnitnaya (KM) pipe have been studied. We selected 188 clinopyroxene grains suitable for precise pressure (P)-temperature (T) estimation using single-clinopyroxene thermobarometry. The majority of P-T points lie along a narrow, elongated field in P-T space with a cluster of high-T and high-P points above 1300 °C, which deviates from the main P-T trend. The latter points may record a thermal event associated with kimberlite magmatism (a “stepped” or “kinked” geotherm). In order to eliminate these factors, the steady-state mantle paleogeotherm for the KM pipe at the time of initiation of kimberlite magmatism (Late Devonian-Early Carboniferous) was constrained by numerical fitting of P-T points below T = 1200 °C. The obtained mantle paleogeotherm is similar to the one from the nearby Novinka pipe, corresponding to a ~34-35 mW/m2 surface heat flux, 225-230 km lithospheric thickness, and 110-120 thick "diamond window" for the Upper Muna field. Coarse peridotite xenoliths are consistent in their P-T estimates with the steady-state mantle paleogeotherm derived from clinopyroxene xenocrysts, whereas porphyroclastic ones plot within the cluster of high-T and high-P clinopyroxene xenocrysts. Discrimination using Cr2O3 demonstrates that peridotitic clinopyroxene xenocrysts are prevalent (89%) among all studied 323 xenocrysts, suggesting that the Upper Muna mantle is predominantly composed of peridotites. Clinopyroxene-poor or -free peridotitic rocks such as harzburgites and dunites may be evident at depths of 140-180 km in the Upper Muna mantle. Judging solely from the thermal considerations and the thickness of the lithosphere, the KM and Novinka pipes should have excellent diamond potential. However, all pipes in the Upper Muna field have low diamond grades (<0.9, in carats/ton), although the lithosphere thickness is almost similar to the values obtained for the high-grade Udachnaya and Mir pipes from the Daldyn and Mirny fields, respectively. Therefore, other factors have affected the diamond grade of the Upper Muna kimberlite field.
DS1993-1796
1993
Potapova, T.A.Yefimov, A.A., Potapova, T.A.high pressure metamorphic rocks of a new type: the lherzolite-gabbro-granulite series in the base of the ultramafic section in the Voykar ophiolite allochthon PolarDoklady Academy of Sciences USSR, Earth Science Section, Vol. 318, No. 6, pp. 148-153.Russia, Commonwealth of Independent States (CIS), Polar UralsOphiolite, Eclogites
DS200512-1131
2005
Potashnikov, A.K.Vedin, A.T., Vorobev, V.V., Emelyanov, E.L., Makhrachev, A.F., Potashnikov, A.K., Shlyufman, E.M.X ray luminescence diamond separator with digital signal.Journal of Mining Science, Vol. 40, 6, pp. 633-638.Mining -5 + 2mm in size concentrates
DS200812-1175
2007
Potashnikov, A.K.Tirmyaev, A.F., Kulikov, R.V., Potashnikov, A.K., Sysoev, E.V.Enhancing the selectivity of the X-ray luminescence separation of diamonds by digital processing of signals.Journal of Mining Science, Vol. 43, 5, pp. 555-564.TechnologyDiamond processing
DS1993-1256
1993
Potdevin, J-L.Potdevin, J-L.Gresens 92 : a simple Macintosh program of the Gresens methodComputers and Geosciences, Vol. 19, No. 9, pp. 1229-1238GlobalComputer, Program -Gresens 92
DS202001-0032
2020
Pote, J.W.Otamonga, J-P., Pote, J.W.Abandoned mines and artisanal and small scale mining in Democratic Republic of Congo ( DRC): survey and agenda for future research.Journal of Geochemical Exploration, Vol. 208, 106394Africa, Democratic Republic of Congoalluvials

Abstract: The Democratic Republic of the Congo (DRC) has a long history of mining activities. However, environmental and socio-economic problems associated with abandoned mines as well as activities including Artisanal and Small-Scale Mining (ASM) remain very concerning issues throughout the country. In this paper, we review abandoned mines, Artisanal and Small-Scale Mining (ASM), environmental and human impact assessment, conflict-minerals, and perspectives for future researches on mining activities in DRC, by selecting 26 significant and relevant peer-reviewed papers. With the recent mining boom in DRC, the issue of social and environmental impacts of abandoned mines and ASM has become a matter of concern for Congolese people. This actual development of several mining projects has driven the development of regulation, monitoring and impact assessment, and scientific publications of these activities. However, the findings from multiple studies regarding the impacts of abandoned mines and artisanal and small-scale mining on the environment and human health across the country has not yet been sufficiently brought together in a reliable way. Focusing on health, social and environmental issues, this mini-review aims to increase awareness of negative impacts of mining operations and promote further collaborative between citizens, mining companies, government institutions and other stakeholders with the hope to reduce negative impacts associated with minerals and metals mining and to extend the benefits to the surrounding Congolese communities. The overarching objective of this paper is to characterize the existing studies in the field of the impact assessment of abandoned mines and ASM on public health and environment with a view to stimulate research, guide development of policies and implementation of appropriate interventions. This report draws from material published and available in the public domain over the past years. It also explores the response of the state and the mining companies to these issues, exploring responses such as regulatory changes and implementations of existing legislation. According to the results, additional studies that examine the relationship between minerals mining, bioremediation processes, training and dialogue aspects and the associated adverse environmental and health outcomes are needed to more adequately characterize the impact of mining activities on health and environment, in order to increase formalization of artisanal and small-scale mining sector while strengthening their social and environmental responsibility, and promoting sustainable mining practice standards that improve people lives and respect the environment in DRC.
DS200912-0594
2009
Poteete, A.Poteete, A.Is development path dependent or political? A reinterpretation of mineral dependent development in Botswana.Journal of Development Studies. Routledge Publishers, Vol. 45, 4, April pp. 544-571.Africa, BotswanaEconomics
DS201012-0237
2010
Potekhina, I.A.Gladkov, A.S., Makovchuk, I.V., Lunina, O.V., Bornyakov, S.A., Potekhina, I.A.The Yubieinaya kimberlite pipe site, Russia: 3 D model of the fault block structure.Geology of Ore Deposits, Vol. 52, 3, pp. 234-251.RussiaStructure
DS200912-0595
2009
Potgeiter, J.Potgeiter, J., Sommer, H., Regenauer-Lieb, K., Gasharova, B., Purchase, M.OH and CO2 diffusion profiles in garnets from eclogite xenoliths from the Rovic diamond mine, South Africa. ( Unesco IGCP 557)Goldschmidt Conference 2009, p. A1046 Abstract.Africa, South AfricaDeposit - Rovic
DS200912-0603
2009
Potgeiter, J.Purchase, M., Sommer, H., Regenauer-Lieb, K., Gasharova, B., Potgeiter, J.OH partitioning coefficient between garnets and melt inclusions in lherzolite xenoliths from the Kimberley diamond mine, South Africa.Goldschmidt Conference 2009, p. A1059 Abstract.Africa, South AfricaDeposit - Kimberley
DS201112-0816
2011
Potgeiter, J.Potgeiter, J., Sommer, H., Regenauer-Lieb, K., Jung, H., Gasharova, B.The formation of microdiamonds in cracks caused by C-O-H rich fluid under medium to low pressure conditions.Goldschmidt Conference 2011, abstract p.1662.Africa, South AfricaVictor
DS200912-0596
2008
Potgeter, J.Potgeter, J., Sommer, H., Regenauer-Lieb, K., Gasharova, B.Oh and CO2 diffusion profiles in garnets from eclogitic xenoliths from the Victor mine, South Africa.American Geological Union, Fall meeting Dec. 15-19, Eos Trans. Vol. 89, no. 53, meeting supplement, 1p. abstractAfrica, South AfricaDeposit - Roberts Victor
DS200812-0022
2008
Pothin, K.B.Allialy, M.E., Djro, S.C., Yavouba, C., Konamelan, A.N., Pothin, K.B., Yao, D.B., Yobou, R.Comparative geochemistry of Seguela kimberlites, South Africa Group II kimberlites and other worldwide kimberlites.9IKC.com, 3p. extended abstractAfrica, West Africa, Ivory CoastDeposit - Bobi, Toubabouko
DS201909-2078
2019
Pothuri, R.C.P.Pothuri, R.C.P., Madabhooshi, S.Petrogenesis of a newly discovered diamondiferous chloritised kimberlite at Dibbasanipalli, Wajrakarur field, southerm India.Goldschmidt2019, 1p. Poster abstractIndiadeposit - Dibbasanipalli

Abstract: Petrogenesis of a newly discovered diamondiferous kimberlite pipe (3-021) by the Rio Tinto Group, ~2 km east of Dibbasanipalli, Wajrakarur Kimberlite Field, eastern Dharwar craton is attempted. The pipe is located in field based on published literature and consultation with local villagers [1,2]. Local geology is dominated by Archaean basement granitoids and genisses intruded by younger nordmarkites and dolerites. The rock is highly chloritised giving rise to poor preservation of kimberlitic matrix. However, olivine pseudomorphs are distinctly visible in thin sections. The rock possesses crustal xenoliths of granite, syenite, dolerite etc. with petrographic similarities to Khaderet pipe (3-106). Geochemically, the kimberlite is silica undersaturated (SiO2 39.32-45.67 wt%), MgO rich (26.51- 28.82 wt%) with K2O (1-88-2.1 wt%) higher than Na2O (0.29-0.39 wt%), akin to archetypal Group-I variety. High amounts of MgO and Mg# correspond to enrichment of magnesium bearing mineral phases like olivine and to some extent Mg-ilmenite. The higher concentration of elements Ba, Cr, Co, Nb, Ni, V, Zr is attributed to enrichment of mantle originated xenocrysts like chromite, perovskite, pyrope, Crdiopside. Based on trace element content, the kimberlite appears to be of magmatic origin within a stable continental geological set up. The enrichment of LREE over HREE supports inferior degree of partial melting (0.1-2%) indicating a metasomatically enriched phlogopite bearing garnet lherzolite source, inturn indicating a deep seated and depleted mantle origin, within an estimated temperature range of 1150- 1280oC and low viscosity (0.05 Pa s).
DS201312-0111
2013
Potoszil, C.Burnham, A.D., Kohn, S.C., Potoszil, C., Walter, M.J., Bulanova, G.P., Thomson, A.R., Smith, C.B.The redox state of diamond forming fluids: constraints from Fe3/Fe2+ of garnets.Goldschmidt 2013, AbstractMantleGeothermometry
DS1992-0064
1992
Pototskiy, Yu.P.Bagdasarov, Yu.A., Pototskiy, Yu.P., Zinkova, O.N.Baddeleyite-containing stratiform bodies in old carbonate sequences - a possible new genetic type of zirconium depositsDoklady Academy of Sciences USSR, Earth Science Section, Vol. 315, No. 3, pp. 144-147RussiaCarbonatite, Geochemistry
DS1998-1180
1998
Potrel, A.Potrel, A., Peucat, J.J., Fanning, C.M.Archean crustal evolution of the West African Craton: example of the Amsagaarea (Reguibat Rise).Precamb. Res., Vol. 90, No. 3-4, July 1, pp. 107-118.West AfricaCraton, crustal growth, recycling, subduction, Geochronology
DS1986-0598
1986
Potter, C.Nelson, K.D., Allmendinger, R., Potter, C., Hauser, E., Brown, L.Reflection character of the continental MOHO and its tectonicsignificanceGeological Society of America (GSA) Abstract Volume, Vol. 18, No. 6, p. 704. (abstract.)GlobalTectonics
DS1991-1913
1991
Potter, C.J.Yoos, T.R., Potter, C.J., Thigpen, J.L., Brown, L.D.The Cordilleran foreland thrust belt in northwestern Montana and northern Idaho from COCORP and industry seismic reflection dataAmerican Association Petrol. Geol, Vol. 75, No. 6, June pp. 1089-1106Montana, IdahoGeophysics -seismics, Tectonics
DS1995-1513
1995
Potter, C.J.Potter, C.J., Goldhaber, M.B., Heigold, P.C., Drahovzal, J.Structure of the Reelfoot Rough Creek Rift System, Fluorspar area fault complex and Hicks Dome...United States Geological Survey (USGS) Prof. paper, No. 1538- Q, 20p.Midcontinent, Illinois, KentuckyGeophysics - seismics
DS201112-0817
2002
Potter, E.Potter, E.Composition of spinel in some kimberlites from the Lac de Gras kimberlites.Thesis, 'BSc. Lakehead University, Canada, Northwest TerritoriesThesis - note availability based on request to author
DS1998-1181
1998
Potter, J.Potter, J., Rankin, A.H., NI, P.A preliminary study of methane inclusions in alkaline igneous rocks of Kola igneous Province: implications...Eur. Journal of Mineralogy, Vol. 10, No. 6, Nov. 1, pp. 1167-80.Russia, Kola PeninsulaAlkaline rocks, Methane
DS1999-0564
1999
Potter, J.Potter, J., Rankin, A.H., Treloar, P.J.The relationship between CH4 and CO2 inclusions and iron O S mineralization in intrusions Kola alkaline provinceStanley, SGA Fifth Biennial Symposium, pp. 87-90.Russia, Kola PeninsulaAlkaline rocks, Geochronology
DS200512-0868
2004
Potter, J.Potter, J., Rankin, A.H., Treloar, P.J.Abiogenic Fischer-Topsch synthesis of hydrocarbons in alkaline igneous rocks: fluid inclusions, textural and isotopic evidence from the Lovozero complex, NW Russia.Lithos, Vol. 75, 3-4, pp. 311-358.RussiaAlkalic
DS201112-0818
2011
Potter, J.Potter, J.Unravelling the stable isotopic evidence for the origin of hydrocarbons in peralkaline complexes: new dat a from the Lovozero and Strange Lake peralkaline plutons.Peralk-Carb 2011, workshop held Tubingen Germany June 16-18, AbstractRussia, CanadaGeochronology
DS200712-0853
2007
Potter, K.Potter, K.Saskatchewan's love affair with diamonds.... Saskatchewan Research Council meets growing needs of province's mining boom.Diamonds in Canada Magazine, Northern Miner, June pp. 26-31.Canada, SaskatchewanResearch Council
DS1994-1397
1994
Potter, L.S.Potter, L.S.Influence of the North American craton margin on chemical and isotopic variation along strike Eastern Alkalic Belt, Trans Pecos.Geological Association of Canada (GAC) Abstract Volume, Vol. 19, p.GlobalCraton, Magmatic Province, Geochronology
DS1996-1134
1996
Potter, L.S.Potter, L.S.Chemical variation along strike in feld pathoidal rocks of the eastern Alkalic Belt, Trans-Pecos magmatic ProvinceCanadian Mineralogist, Vol. 34, pt. 2, April pp. 241-264.Texas, New MexicoAlkaline rocks
DS201708-1738
2017
Potter, N.Potter, N.Inclusions in perovskite magnetite silicate rocks from Afrikanda, Russia: clues to the early history of carbonatites.11th. International Kimberlite Conference, PosterRussiacarbonatites
DS201611-2133
2016
Potter, N.J.Potter, N.J., Kamenetsky, V.S., Simonetti, A., Goemann, K.Different types of liquid immiscibility in carbonatite magmas: a case study of the Oldoinyo Lengai 1993 lava and melt inclusions.Chemical Geology, in press available 9p.Africa, TanzaniaDeposit - Oldoinyo Lengai

Abstract: Oldoinyo Lengai is situated within the Gregory Rift Valley (northern Tanzania) and is the only active volcano erupting natrocarbonatite lava. This study investigates the texture and mineralogy of the June 1993 lava at Oldoinyo Lengai, and presents petrographic evidence of liquid immiscibility between silicate, carbonate, chloride, and fluoride melt phases. The 1993 lava is a porphyritic natrocarbonatite consisting of abundant phenocrysts of alkali carbonates, nyerereite and gregoryite, set in a quenched groundmass, composed of sodium carbonate, khanneshite, Na-sylvite and K-halite, and a calcium fluoride phase. Dispersed in the lava are silicate spheroids (< 2 mm) with a cryptocrystalline silicate mineral assemblage wrapped around a core mineral. We have identified several textural features preserved in the silicate spheroids, melt inclusions, and carbonatite groundmass that exhibit evidence of silicate-carbonate, carbonate-carbonate and carbonate-halide immiscibility. Rapid quenching of the lava facilitated the preservation of the end products of these liquid immiscibility processes within the groundmass. Textural evidence (at both macro- and micro-scales) indicates that the silicate, carbonate, chloride and fluoride phases of the lava unmixed at different stages of evolution in the magmatic system.
DS201707-1357
2017
Potter, N.J.Potter, N.J., Kamenetsky, V.S., Simonetti, A., Goemann, K.Different types of liquid immiscibility in carbonatite magmas: a case stufy of the Oldoinyo Lengai 1993 lava and melt inclusions.Chemical Geology, Vol. 455, pp. 376-384.Africa, Tanzaniadeposit - Oldoinyo Lengai

Abstract: Oldoinyo Lengai is situated within the Gregory Rift Valley (northern Tanzania) and is the only active volcano erupting natrocarbonatite lava. This study investigates the texture and mineralogy of the June 1993 lava at Oldoinyo Lengai, and presents petrographic evidence of liquid immiscibility between silicate, carbonate, chloride, and fluoride melt phases. The 1993 lava is a porphyritic natrocarbonatite consisting of abundant phenocrysts of alkali carbonates, nyerereite and gregoryite, set in a quenched groundmass, composed of sodium carbonate, khanneshite, Na-sylvite and K-halite, and a calcium fluoride phase. Dispersed in the lava are silicate spheroids (< 2 mm) with a cryptocrystalline silicate mineral assemblage wrapped around a core mineral. We have identified several textural features preserved in the silicate spheroids, melt inclusions, and carbonatite groundmass that exhibit evidence of silicate-carbonate, carbonate-carbonate and carbonate-halide immiscibility. Rapid quenching of the lava facilitated the preservation of the end products of these liquid immiscibility processes within the groundmass. Textural evidence (at both macro- and micro-scales) indicates that the silicate, carbonate, chloride and fluoride phases of the lava unmixed at different stages of evolution in the magmatic system.
DS201901-0057
2018
Potter, N.J.Potter, N.J., Ferguson, M.R.M., Kamenetsky, V.S., Chakhmouradian, A.R., Sharygin, V.V., Thompson, J.M., Goemann, K.Textural evolution of perovskite in the Afrikanda alkaline-ultramafic complex, Kola Peninsula.Contributions to Mineralogy and Petrology, Vol. 173, 12, pp. 106-Russia, Kola Peninsuladeposit - Afrikanda

Abstract: Perovskite is a common accessory mineral in a variety of mafic and ultramafic rocks, but perovskite deposits are rare and studies of perovskite ore deposits are correspondingly scarce. Perovskite is a key rock-forming mineral and reaches exceptionally high concentrations in olivinites, diverse clinopyroxenites and silicocarbonatites in the Afrikanda alkaline-ultramafic complex (Kola Peninsula, NW Russia). Across these lithologies, we classify perovskite into three types (T1-T3) based on crystal morphology, inclusion abundance, composition, and zonation. Perovskite in olivinites and some clinopyroxenites is represented by fine-grained, equigranular, monomineralic clusters and networks (T1). In contrast, perovskite in other clinopyroxenites and some silicocarbonatites has fine- to coarse-grained interlocked (T2) and massive (T3) textures. Electron backscatter diffraction reveals that some T1 and T2 perovskite grains in the olivinites and clinopyroxenites are composed of multiple subgrains and may represent stages of crystal rotation, coalescence and amalgamation. We propose that in the olivinites and clinopyroxenites, these processes result in the transformation of clusters and networks of fine-grained perovskite crystals (T1) to mosaics of more coarse-grained (T2) and massive perovskite (T3). This interpretation suggests that sub-solidus processes can lead to the development of coarse-grained and massive perovskite. A combination of characteristic features identified in the Afrikanda perovskite (equigranular crystal mosaics, interlocked irregular-shaped grains, and massive zones) is observed in other oxide ore deposits, particularly in layered intrusions of chromitites and intrusion-hosted magnetite deposits and suggests that the same amalgamation processes may be responsible for some of the coarse-grained and massive textures observed in oxide deposits worldwide.
DS202003-0357
2020
Potter, N.J.Potter, N.J., Kamenetsky, V.S., Chakhmouradian, A.R., Kamenetsky, M.B., Goemann, K., Rodemann, T.Polymineralic inclusions in oxide minerals of the Afrikanda alkaline ultramafic complex: implications for the evolution of perovskite mineralization.Contributions to Mineralogy and Petrology, Vol. 175, 13p. PdfRussiaperovskite

Abstract: The exceptional accumulation of perovskite in the alkaline-ultramafic Afrikanda complex (Kola Peninsula, Russia) led to the study of polymineralic inclusions hosted in perovskite and magnetite to understand the development of the perovskite-rich zones in the olivinites, clinopyroxenites and silicocarbonatites. The abundance of inclusions varies across the three perovskite textures, with numerous inclusions hosted in the fine-grained equigranular perovskite, fewer inclusions in the coarse-grained interlocked perovskite and rare inclusions in the massive perovskite. A variety of silicate, carbonate, sulphide, phosphate and oxide phases are assembled randomly and in variable proportions in the inclusions. Our observations reveal that the inclusions are not bona fide melt inclusions. We propose that the inclusions represent material trapped during subsolidus sintering of magmatic perovskite. The continuation of the sintering process resulted in the coarsening of inclusion-rich subhedral perovskite into inclusion-poor anhedral and massive perovskite. These findings advocate the importance of inclusion studies for interpreting the origin of oxide minerals and their associated economic deposits and suggest that the formation of large scale accumulations of minerals in other oxide deposits may be a result of annealing of individual disseminated grains.
DS1994-1398
1994
Potter, P.E.Potter, P.E.Modern sands of South America: composition, provenance and globalsignificanceGeologische Rundschau, Vol. 83, pp. 212-232South America, Venezuela, Peru, Argentina, BrazilSedimentology, Soils, Climatology, Mineral associations
DS1997-0919
1997
Potter, P.E.Potter, P.E.The Mesozoic and Cenozoic paleodrainage of South America: a naturalhistory.Journal of South American Earth Sciences, Vol. 10, No. 5-6, pp. 331-344.Brazil, Uruguay, Argentina, South AmericaGeomorphology - drainage, Overview
DS2001-0944
2001
Potter, P.E.Potter, P.E., Huh, Y., Edmond, J.M.Deep freze petrology of Lena River sand, SiberiaGeology, Vol. 29, No. 11, Nov. pp. 999-1002.Russia, SiberiaGeomorphology - modern sand not specific to diamonds
DS2003-1233
2003
Potter, P.E.Schneider Santos, J.O., Potter, P.E., Reis, N.J., Hartmann, L.A., Fletcher, I.R.Age, source and regional stratigraphy of the Roriama Supergroup and Roraima likeGeological Society of America Bulletin, Vol. 115, 3, pp. 331-48.Guyana Shield, Pacaraima PlateauGeochronology, Amazon Craton, zircon
DS2003-1243
2003
Potter, P.E.Scneider Santos, J. Orestes, Potter, P.E., Reiss, N.J., Hartmann, L.A., FletcherAge, source and regional stratigraphy of the Roraima Supergroup and Roraima likeGeological Society of America Bulletin, Vol. 115, 3, pp. 331-348.Guyana Shield, South America, BrazilAmazon Craton, baddeleyite, diamond, geochronology
DS200412-1762
2003
Potter, P.E.Schneider Santos, J.O., Potter, P.E., Reis, N.J., Hartmann, L.A., Fletcher, I.R., McNaughton, N.J.Age, source and regional stratigraphy of the Roriama Supergroup and Roraima like outliers in northern South America based on U PGeological Society of America Bulletin, Vol. 115, 3, pp. 331-48.South America, GuyanaGeochronology, Amazon Craton, zircon
DS2001-0945
2001
Potts, A.Potts, A.Crystal clear... site visit to InternatsionalnayaWorld Mining Equipment, Sept. pp. 26-8.Russia, SiberiaMining, Deposit - Internatsionalnaya
DS1994-1399
1994
Potts, D.Potts, D.Risk management in the markets for metals and mineralsRisk Assessment in the extractive industries March 23-24th. 1994, 13pGlobalEconomics, ore reserve evaluation, Stabilization programs
DS1994-1400
1994
Potts, D.Potts, D.Factors affecting the valuation of metals and minerals operationsMinerals Industry International, No. 1020, September pp. 17-21GlobalEconomics, Ore reserves, geostatistics, valuation techniques
DS1975-0157
1975
Potts, P.J.Paul, D.K., Potts, P.J., Gibson, I.L., Harris, P.G.Rare Earth Abundances in Indian KimberlitesEarth and Planetary Science Letters, Vol. 25, PP. 151-158.IndiaRare Earth Elements (ree), Geochemistry
DS1975-0378
1976
Potts, P.J.Paul, D.K., Potts, P.J.Rare Earth Abundances in Kimberlites from Greenland and Zambia.Chemical Geology, Vol. 18, No. 2, PP. 161-167.Greenland, Zambia, Central AfricaRare Earth Elements (ree), Geochemistry
DS1981-0333
1981
Potts, P.J.Paul, D.K., Potts, P.J.Rare Earth Abundances and Origin of Some Indian LamprophyresGeological Magazine., Vol. 118, No. 4, PP. 393-399.IndiaGeochemistry
DS1996-1135
1996
Potts, P.J.Potts, P.J., Bowles, J.F., Reed, S.J.B., Cave, M.R.Microprobe techniques in the earth sciencesChapman Hall, MSA., MSA No. 6, 420p. approx. 80.00 United StatesGlobalBook - table of contents, Microprobe techniques, review
DS1996-1136
1996
Potts, P.J.Potts, P.J., Bowles, J.F.W., Reed, S.J.B., Cave, M.R.Microprobe techniques in the earth sciencesMineralogical Soc. Series, No. 6, 410p. approx. $60.00USGlobalMicroprobe techniques, Various chapters techniques - not specific to diamond
DS201212-0570
2012
Potts, P.J.Potts, P.J.A proposal for the publication of Geochemical dat a in the scientific literature.Geostandards and Geoanalytical Research, in press availableTechnologyGeochemisty
DS1982-0507
1982
Potts, R.B.Potts, R.B.Satellite Image Map of KentuckyGeological Survey of KENTUCKY, MAP 1:1, 000, 000United States, Kentucky, AppalachiaTectonics, Structural Geology
DS201112-1154
2011
Potuzak, M.Zavada, P., Dedecek, P., Mach, K., Lexa, O., Potuzak, M.Emplacement dynamics of phonolite magma into maar-diatreme structures - correlation of field, thermal modeling and AMS analogue modeling data.Journal of Volcanology and Geothermal Research, Vol. 201, 1-4, pp. 210-226.EuropeGeodynamics - not specific to diamonds
DS2001-0276
2001
Potvin, J.Dumont, R., Coyle, M., Potvin, J.High resolution aeromagnetic dataGeological Survey of Canada (GSC) Open File, No. 4029-56. $ 20. eachOntario, northernGeophysics - total field magnetic
DS2001-0277
2001
Potvin, J.Dumont, R., Coyle, M.J., Potvin, J.High resolution aeromagnetic data.. total field. parts of NTS 42 B, G. OGeological Survey of Canada (GSC) Open File, No. 4029-56, 1:50,000 $ 20.00 eachOntarioGeophysics - magnetics, Specific areas - not all Quebec
DS2001-0278
2001
Potvin, J.Dumont, R., Coyle, M.J., Potvin, J.High resolution aeromagnetic data.. first vertical derivative. parts of NTS 42 B, G. OGeological Survey of Canada (GSC) Open File, No. 4057-84, 1:50,000 $ 20.00 eachOntarioGeophysics - magnetics, Specific areas - not all Quebec
DS2001-0279
2001
Potvin, J.Dumont, R., Coyle, M.J., Potvin, J.Aeromagnetic total field map, QuebecGeological Survey of Canada (GSC) Open File, No. 4126-55, 1:50,000 $ 20.00 eachQuebecGeophysics - magnetics, Specific areas - not all Quebec
DS200412-1571
2004
Poucler, A.Poucler, A., Allialy, M., Daouda-Yao, B., Esso, B.Discovery of a diamond bearing kimberlite diatreme at Seguela in Ivory Coast.Comptes Rendus Geoscience, Vol. 336, 1, Jan. pp. 9-17.Africa, Ivory CoastLamproite, dikes
DS1983-0522
1983
Pouclet, A.Pouclet, A., Menot, R.P., Piboule, M.Le magmatism Alaclin Potassique de L'aire Volcanique des ViBulletin. MINERALOGIQUE., Vol. 106, PP. 607-622.East AfricaRift, Melilite, Leucite, Related Rocks
DS1989-0933
1989
Pouclet, A.Marcelot, G., Dupuy, C., Dostal, J., Rancan, J.P., Pouclet, A.Geochemistry of mafic volcanic rocks from the Lake Kivu (Zaire and Rwanda)section of the western branch Of the African riftJournal of Volcanology and Geothermal Research, Vol. 39, No. 1, October pp. 73-88Democratic Republic of CongoTectonics, Rifting
DS1996-1247
1996
Pouclet, A.Salah Ama, I., Liegeois, J-P., Pouclet, A.Evolution d'un arc insulaire oceanique birimien precoce au Liptako nigerien(Sirba) geologie, geochronologieJournal of African Earth Sciences, Vol. 22, No. 3, pp. 235-254Nigeria, West Africa, Burkina FasoBirimian Domain, Magma
DS2002-1148
2002
Pouclet, A.Nomade, S., Feraud, G., Chen, Y., Pouclet, A.Thermal and tectonic evolution of the Paleoproterozoic Transamazonian orogen as deduced from 40 Ar 39Ar, AMSPrecambrian Research, Vol. 114, No. 1-2, pp. 35-53.French GuianaGeochronology, Oyapok river
DS2002-1150
2002
Pouclet, A.Nomade, S., Pouclet, A., Chen, Y.The French Guyana doleritic dykes: geochemical evidence of three populations and new dat a for the Jurassic Central Atlantic Magmatic Province.Journal of Geodynamics, Vol. 34, 5, Dec. pp. 595-614.French GuianaDykes - not specific to diamonds
DS2002-1151
2002
Pouclet, A.Nomade, S., Pouclet, A., Chen, Y.The French Guyana doleritic dykes: geochemical evidence of three populations and new dat a for the Jurassic Central Atlantic Magmatic Province.Journal of Geodynamics, Vol. 34, 5, Dec. pp. 595-614.French Guiana, Ivory Coast, South AmericaGeochemistry, Magmatism
DS200412-1442
2002
Pouclet, A.Nomade, S., Pouclet, A.,Chen, Y.The French Guyana doleritic dykes: geochemical evidence of three populations of new dat a for Jurassic Central Atlantic MagmaticJournal of Geodynamics, Vol. 34, 5, Dec. pp. 595-614.South America, French GuianaDykes - not specific to diamonds
DS201412-0707
2004
Pouclet, A.Pouclet, A., Allialy, M., Daouda-Yao, Esso, B.Decouverte d'un diatreme de kimberlite diamantifere a Seguela en Cote-d'Ivoire.Comptes Rendus Geoscience, Vol. 336, pp. 9-17.Africa, Ivory CoastDiatreme
DS2001-0873
2001
Poudjom DjomaniO'Reilly, S.Y., Griffin, W.L., Poudjom Djomani, MorganAre lithospheres forever? Tracking changes in subcontinental lithospheric mantle through time.Gsa Today, Vol. 11, No. 4, April pp. 4-9.MantleLithosphere - tomography, boundary
DS1998-1102
1998
Poudjom Djomani, Y.O'Reilly, S.Y., Griffin, W.L., Poudjom Djomani, Y.Are lithospheres forever? #17th. Kimberlite Conference abstract, pp. 646-8.MantleLithosphere mapping, Geophysics - seismics
DS200612-0783
2006
Poudjom Djomani, Y.H.Lee, C-T., Poudjom Djomani, Y.H., Rondenay, S.Geochemical and geophysical probing of continental dynamics.Goldschmidt Conference 16th. Annual, S5-03 theme abstract 1/8p. goldschmidt2006.orgMantleConvection
DS200912-0042
2009
Poudjom DjomeniBegg, G.C., Griffin, W.L., Natapov, O'Reilly, Grand, O'Neill, Hronsky, Poudjom Djomeni, Swain, Deen, BowdenThe lithospheric architecture of Africa: seismic tomography, mantle petrology, and tectonic evolution.Geosphere, Vol. 5, pp. 23-50.AfricaGeophysics - seismic, tectonics
DS2003-1097
2003
Poudjom Dojomani, Y.H.Poudjom Dojomani, Y.H., O'Reilly, S.Y., Griffin, W.L., Doyle, B.J.Geophysical analysis of the lithosphere beneath the Slave Craton8 Ikc Www.venuewest.com/8ikc/program.htm, Session 9, POSTER abstractNorthwest TerritoriesGeophysics
DS200412-1572
2003
Poudjom Dojomani, Y.H.Poudjom Dojomani, Y.H., O'Reilly, S.Y., Griffin, W.L., Doyle, B.J.Geophysical analysis of the lithosphere beneath the Slave Craton.8 IKC Program, Session 9, POSTER abstractCanada, Northwest TerritoriesCraton studies Geophysics
DS1960-0083
1960
Pough, F.H.Pough, F.H.Do It Yourself Diamond MiningJewellers Circular Keystone., Vol. 130, No. 5, Feb., PP. 90-92; P. 116.United States, Gulf Coast, Arkansas, PennsylvaniaNews Item
DS1960-0872
1967
Pough, F.H.Pough, F.H.The Story of Gems and Semiprecious StonesNew York: Harvey House., 142P.GlobalKimberlite
DS1988-0552
1988
Pough, F.H.Pough, F.H.More or less: altering the color of diamondsLapidary Journal, Vol. 41, No. 12, March pp. 28-32GlobalDiamond morphology, Colour alteration
DS2003-0394
2003
Pouissineau, S.Faure, M., Lin, W., Monie, P., Le Breton, N., Pouissineau, S., Panis, D., Deloule, E.Exhumation tectonics of the ultrahigh pressure metamorphic rocks in the Qinling orogenTectonics, Vol. 22, 3, 10.1029/2002TC001450ChinaTectonics - subduction
DS2003-0395
2003
Pouissineau, S.Faure, M., Lin, W., Monie, P., Le Breton, N., Pouissineau, S., Panis, D., Deloule, E.Exhumation tectonics of the ultrahigh pressure metamorphic rocks in the Qinling orogenTectonics, Vol. 22, 3, 10.1029/2002TC001450China, ShandongUHP
DS200412-0537
2003
Pouissineau, S.Faure, M., Lin, W., Monie, P., Le Breton, N., Pouissineau, S., Panis, D., Deloule, E.Exhumation tectonics of the ultrahigh pressure metamorphic rocks in the Qinling orogen in east China: new petrological structuraTectonics, Vol. 22, 3, 10.1029/2002TC001450China, ShandongUHP
DS2002-1277
2002
Poujol, M.Poujol, M., Robb, L.J., Anhaeusser, C.R., Gericke, B.Geochronologic constraints on the evolution of the Kaapvaal Craton, South AfricaEconomic Geology Research Institute, EGRU Wits, Information Circular, No. 360, 37p.South AfricaGeochronology, craton, terrane, magmatism - not specific to diamonds
DS2003-1098
2003
Poujol, M.Poujol, M., Robb, L.J., Anhaeusser, C.R., Gericke, B.A review of the geochronological constraints on the evolution of the Kaapvaal CratonPrecambrian Research, Vol. 127, 1-2, Nov. pp. 181-213.South AfricaGeochronology
DS200412-1573
2003
Poujol, M.Poujol, M., Robb, L.J., Anhaeusser, C.R., Gericke, B.A review of the geochronological constraints on the evolution of the Kaapvaal Craton, South Africa.Precambrian Research, Vol. 127, 1-2, Nov. pp. 181-213.Africa, South AfricaGeochronology
DS200412-1589
2004
Poujol, M.Prevec, S.A., Anhaeusser, C.R., Poujol, M.Origin and evolution of late mafic dykes in an Archean gneissic assemblage, Kaapvaal Craton, South Africa.Economic Geology Research Institute Information Circular, Information Circular 380, 11p.Africa, South AfricaEcologitic lithosphere, lamprophyres
DS200512-0858
2005
Poujol, M.Pilet, S., Hernadez, J., Sylvester, P., Poujol, M.The metasomatic alternative for ocean island basalt chemical heterogeneity.Earth and Planetary Science Letters, Advanced in press,MantleSubduction, metasomatism
DS200512-0869
2005
Poujol, M.Poujol, M.A review of the geochronological constraints on the evolution of the Kaapvaal Craton, southern Africa.GAC Annual Meeting Halifax May 15-19, Abstract 1p.Africa, South AfricaGeochronology
DS200612-1107
2005
Poujol, M.Poujol, M., Kiefer, R., Robb, L.J., Anhaesser, C.R., Armstrong, R.A.New U pb dat a on zircons from the Amalia greenstone belt southern Africa: insights into the Neoarchean evolution of the Kaapvaal Craton.South African Journal of Geology, Vol. 108, 3, pp. 317-332.Africa, South AfricaGeochronology
DS201506-0271
2015
Poujol, M.Gueydan, F., Pitra, P., Afiri, A., Poujol, M., Essaifi, A., Paquette, J-L.Oligo-Miocene thinning of the Beni Bousera peridotites and their Variscan crustal host rocks, Internal Rif, Morocco.Tectonics, Vol. 34, pp.1244-1268.Africa, MoroccoPeridotite
DS201906-1277
2019
Poujol, M.Boulvais, P., Ntiharirizwa, S., Branquet, Y., Poujol, M., Moreli, C., Ntungwanayo, J., Midende, G.Geology and U-Th dating of the Gakara REE deposit.GAC/MAC annual Meeting, 1p. Abstract p. 64.Africa, BurundiREE

Abstract: The Gakara Rare Earth Elements (REE) deposit is one of the world’s highest grade REE deposits, likely linked to a carbonatitic magmatic-hydrothermal activity. It is located near Lake Tanganyika in Burundi, along the western branch of the East African Rift. Field observations suggest that the mineralized veins formed in the upper crust. Previous structures inherited from the Kibaran orogeny may have been reused during the mineralizing event. The paragenetic sequence and the geochronological data show that the Gakara mineralization occurred in successive stages in a continuous hydrothermal history. The primary mineralization in bastnaesite was followed by an alteration stage into monazite. The U-Th-Pb ages obtained on bastnaesite (602 ± 7 Ma) and on monazite (589 ± 8 Ma) belong to the Pan-African cycle. The emplacement of the Gakara REE mineralization most likely took place during a pre-collisional event in the Pan-African belt, probably in an extensional context.
DS202001-0040
2019
Poujol, M.Smithies, R.H., Lu, Y., Johnson, T.E., Kirkland, C.L., Cassidy, K.F., Champion, D.C., Mole, D.R., Zibra, I., Gessner, K., Sapkota, J., De Paoli, M.C., Poujol, M.No evidence for high pressure melting of Earth's crust in the Archean.Nature Communicatons, Vol. 10, 555912p. PdfAustraliamelting

Abstract: Much of the present-day volume of Earth’s continental crust had formed by the end of the Archean Eon, 2.5 billion years ago, through the conversion of basaltic (mafic) crust into sodic granite of tonalite, trondhjemite and granodiorite (TTG) composition. Distinctive chemical signatures in a small proportion of these rocks, the so-called high-pressure TTG, are interpreted to indicate partial melting of hydrated crust at pressures above 1.5?GPa (>50?km depth), pressures typically not reached in post-Archean continental crust. These interpretations significantly influence views on early crustal evolution and the onset of plate tectonics. Here we show that high-pressure TTG did not form through melting of crust, but through fractionation of melts derived from metasomatically enriched lithospheric mantle. Although the remaining, and dominant, group of Archean TTG did form through melting of hydrated mafic crust, there is no evidence that this occurred at depths significantly greater than the ~40?km average thickness of modern continental crust.
DS200512-0875
2004
Poujot, M.Prevec, S.A., Anhaeusser, C.R., Poujot, M.Evidence for Archean lamprophyres from the Kaapvaal Craton, South Africa.South African Journal of Science, Vol. 100, 11/12, pp. 549-555.Africa, South AfricaLamprophyre
DS1997-0920
1997
Poukhovski, D.A.Poukhovski, D.A., Bise, C.J.A computer based hazard awareness assessment program for surface MinesSociety for Mining, Metallurgy and Exploration (SME) Preprint, No. 97-120, 6pGlobalEnvironment, Mining, computer Program
DS201112-0505
2011
Poulet, T.Karrech, A., Regenauer-Lieb, K., Poulet, T.Continuum damage mechanics for the lithosphere.Journal of Geophysical Research, Vol, 116, B4, B04205.MantleTectonics
DS1995-1207
1995
Poulin, R.McDonald, D., Poulin, R.Gainsharing, incentive plans and mining: an introductionThe Canadian Mining and Metallurgical Bulletin (CIM Bulletin), Vol. 88, No. 988, March pp. 92-94CanadaMining -bonus plans
DS1996-1319
1996
Poulin, R.Sinding, K., Poulin, R., MacDonald, D.Property rights for mineral resourcesJournal of Mineral Policy, Vol. 12, No. 1, pp. 24-29GlobalLegal, Mineral resources - property rights
DS1996-1320
1996
Poulin, R.Sinding, K., Poulin, R., MacDonald, D.Property rights for mineral resources.... not specific to diamonds but ofinterest.Journal of Mineral Policy, Vol. 12, No. 1, pp. 24-29.GlobalLegal, Property rights
DS1998-1281
1998
Poulin, R.Samis, M., Poulin, R.Valuing management flexibility: a basis to compare the standard DCF and MAP valuation frameworksThe Canadian Mining and Metallurgical Bulletin (CIM Bulletin), Vol. 91, No. 1019, Apr. pp. 69-74CanadaEconomics, reserves, valuations, discoveries, DCF, MAP, option pricing
DS1989-0333
1989
Poulsen, K.H.Davis, D.W., Poulsen, K.H., Kamo, S.L.New insights into Archean crustal development from geochronology in the Rainy Lake area, Superior province CanadaJournal of Geology, Vol. 97, No. 4, pp. 379-398OntarioGeochronology, Structure-Rainy Lake-Quetico
DS1992-1225
1992
Poulsen, K.H.Poulsen, K.H., Card, K.D., Franklin, J.M.Archean tectonic and metallogenic evolution of the Superior Province of the Canadian ShieldPrecambrian Research, Vol. 58, pp. 25-54OntarioMetallogeny, Superior Province
DS1996-0228
1996
Poulsen, K.H.Card, K.D., Frith, R.A., Poulsen, K.H.Preliminary litho-tectonic map of the Superior ProvinceGeological Survey of Canada, Open File, No. 3227, 1:2, 500, 000 $ 20.00OntarioLithology, stratigraphy, Superior, Map -ad
DS202006-0926
2020
Poulsen, M.D.Keulen, N., Thomsen, T.B., Schumacher, J.C., Poulsen, M.D., Kalvig, P., Vennemann, T., Salimi, R.Formation, origin and geographic typing of corundum ( ruby and pink sapphire) from the Fiskenaesst complex, Greenland.Lithos, Vol. 366-367, 26p. PdfEurope, Greenlandruby

Abstract: Metamorphic petrology observations on rubies found in-situ in their host-rock are combined with geochemical measurements and optical microscopy observations on the same rubies, with the aim of connecting the ruby-forming metamorphic reaction to a unique fingerprint for these minerals. The Fiskenćsset complex in Greenland is used as an area of this case study. Isochemical pressure-temperature sections were calculated based on electron microprobe and whole-rock geochemistry analyses, and compared to field observations. Rubies formed from reaction between olivine/serpentine and anorthite, triggered by the intrusion of a 2.71 Ga pegmatite. Al is sourced from the anorthite reacting to calcic amphibole, silica from the pegmatite reacts with olivine/serpentine to anthophyllite, Cr3+ is mobile in the pegmatitic fluid, giving colour to the rubies. The ruby-forming reaction occurs at about 640 °C and 7 kbar. In order to establish the unique fingerprint for this ruby-bearing ultramafic complex, laser-ablation inductively-coupled-plasma mass-spectrometry trace-element measurements, oxygen isotope compositions, optical microscopy and scanning electron microscopy were applied. Due to the setting in an ultramafic rock-anorthosite-leucogabbro complex, the fingerprint of the rubies from the Fiskenćsset complex is rather unique. Compared to rubies from other localities, Fiskenćsset complex rubies contain high Cr, intermediate Fe, and low V, Ga, and Ti concentrations, low oxygen isotope values (1.6-4.2‰) and a rarely-observed combination of optical growth features and mineral inclusions like anthophyllite+biotite. Results for other Greenland localities are presented and discussed as well. Even though these are derived from ultramafic rock settings too, they record different trace-element ratios and oxygen isotope values, resulting from variations in the Archaean ruby-forming reaction.
DS201904-0750
2019
Poulsen, R.Jerram, D.A., Sharp, I.R., Torsvik, T.H., Poulsen, R., Machado, V.Volcanic constraints on the unzipping of Africa from South America: insights from new geochronological controls along the Angola margin.Tectonophysics, in press available 27p.Africa, Angola, South Americageochronology

Abstract: The breakup of Africa from South America is associated with the emplacement of the Paraná-Etendeka flood basalt province from around 134?Ma and the Tristan da Cunha plume. Yet many additional volcanic events occur that are younger than the main pulse of the Paraná-Etendeka and straddle the rift to drift phases of the main breakup. This contribution reports on new geochronological constraints from the Angolan part of the African Margin. Three coastal and one inland section have been sampled stretching across some 400?Km, with 39Ar/40Ar, U-Pb and Palaeontology used to provide age constraints. Ages from the new data range from ~100 to 81?Ma, with three main events (cr. 100, 91 and 82-81?Ma). Volcanic events are occurring within the Early to Late Cretaceous, along this part of the margin with a general younging towards Namibia. With the constraints of additional age information both onshore and offshore Angola, a clear younging trend at the early stages of rift to drift is recorded in the volcanic events that unzip from North to South. Similar age volcanic events are reported from the Brazilian side of the conjugate margin, and highlight the need to fully incorporate these relatively low volume volcanic pulses into the plate tectonic breakup models of the South Atlantic Margin.
DS1998-0209
1998
Poulsen. H.K.Card, K., Poulsen. H.K.Archean and Early Proterozoic geology and metallogeny of the Southern Canadian shieldPros. Developers Assoc, Short course pp. 3-62OntarioMetallogeny, Proterozoic, Archean
DS1999-0114
1999
Poulsen. K.H.Card, K.R., Frith, R.A., Poulsen. K.H., Ciesieski, A.Lithotectonic map of the Superior Province, Canada and adjacent parts Of the United States.Geological Survey of Canada Map, No. 1948A. 1: 2m approx. $ 13.00OntarioMap, Tectonics
DS201012-0595
2010
Poulson, D.Poulson, D., Curtis, A.Dynamics of uncertainty in geological interpretation.Journal of the Geological Society, Vol. 167, 1, pp. 5-10.TechnologyData interpretation - not specific to diamonds
DS201812-2823
2018
Poulson, R.Jerram, D.A., Sharp, T.H., Torsvik, T.H., Poulson, R., Watton, T.H., Freitag, U., Halton, A., Sherlock, S.C., Malley, J.A.S., Finley, A., Roberge, J., Swart, R., Fabregas, P., Ferreira, C.H., Machado, V.Volcanic constraints on the unzipping of Africa from South America: insights from new geochronological controls alone the Angola margin.Tectonophysics, doi.org/10.1016/ j.tecto.2018.07.027 33p.Africa, Angola, South Americageochronology

Abstract: The breakup of Africa from South America is associated with the emplacement of the Paraná-Etendeka flood basalt province from around 134 Ma and the Tristan da Cunha plume. Yet many additional volcanic events occur that are younger than the main pulse of the Paraná-Etendeka and straddle the rift to drift phases of the main breakup. This contribution reports on new geochronological constraints from the Angolan part of the African Margin. Three coastal and one inland section have been sampled stretching across some 400 Km, with 39Ar/40Ar, U-Pb and Palaeontology used to provide age constraints. Ages from the new data range from ~100 to 81 Ma, with three main events (cr. 100, 91 and 82-81 Ma). Volcanic events are occurring within the Early to Late Cretaceous, along this part of the margin with a general younging towards Namibia. With the constraints of additional age information both onshore and offshore Angola, a clear younging trend at the early stages of rift to drift is recorded in the volcanic events that unzip from North to South. Similar age volcanic events are reported from the Brazilian side of the conjugate margin, and highlight the need to fully incorporate these relatively low volume volcanic pulses into the plate tectonic breakup models of the South Atlantic Margin.
DS1997-0862
1997
Pound, K.S.O'Dea, M.G., Lister, G.S., Betts, P.G., Pound, K.S.A shortened intraplate rift system in the Proterozoic Mount Isa terrane, northwestQueensland, AustraliaTectonics, Vol. 16, No. 3, June, pp. 425-441AustraliaProterozoic
DS201602-0232
2016
Pounds, J.Pounds, J.The diamond market.PDAC 2016, 1p. AbstractGlobal, Canada, Northwest TerritoriesMarkets
DS201904-0729
2019
Poupart, N.Desharnais, G., Paiement, J.P., Hatfield, D., Poupart, N.Mining BIG data: the future of exploration targeting using machine learning.PDAC Short Course, 5p. PdfGlobaldata sets
DS2003-1099
2003
Poupinet, G.Poupinet, G., Arndt, N., Vacher, P.Seismic tomography beneath stable tectonic regions and the origin and composition ofEarth and Planetary Science Letters, Vol. 212, 1-2, pp. 89-101.MantleTectonics
DS200412-1574
2003
Poupinet, G.Poupinet, G., Arndt, N., Vacher, P.Seismic tomography beneath stable tectonic regions and the origin and composition of the continental lithospheric mantle.Earth and Planetary Science Letters, Vol. 212, 1-2, pp. 89-101.MantleGeophysics - seismics Tectonics
DS200912-0597
2009
Poupinet, G.Poupinet, G., Shapeiro, N.M.Worldwide distribution of ages of the continental lithosphere derived from a global seismic tomographic model.Lithos, Vol. 109, 1-2, pp. 125-130.MantleGeochronology
DS201911-2543
2019
Pour, O.Magna, T., Viladkar, S., Rappirich, V., Pour, O., Cejkova, B.Nb-V enriched sovites of the northeastern and eastern part of the Amba Dongar carbonatite ring dike, India - a reflection of post emplacement hydrothermal overprint.Chemie der Erde, in press available 11p. Indiadeposit - Amba Dongar
DS202102-0204
2020
Pour, O.Magna, T., Viladar, S., Rapprich, V., Pour, O., Hopp, J., Cejkova, B.Nb-V enriched sovites of the northeastern and eastern part of the Amba Dongar carbonatite ring dike, India - a reflection of post-emplacement hydrothermal overprint?Geochemistry, Vol. 80, doi.org/10.1016 /j.chemer.2019 .125534 11p. PdfIndiadeposit - Amba Dongar

Abstract: Wakefieldite-(Ce,La) and vanadinite in coarse-grained calciocarbonatites (sovites) are for the first time reported from the northeastern part of the worldwide largest fluorite deposit at the Amba Dongar carbonatite ring dike, India. Sovite in this part of the carbonatite ring dike is rich in pyrochlore, calcite and magnetite. Pyrochlore makes up almost 50% of some sovite samples and shows core-to-rim compositional changes. The core of pyrochlore consists of primary fluorcalciopyrochlore with high F and Na contents while the margins gained elevated amounts of Pb, La and Ce with the associated loss of F and Na due to circulation of hydrothermal solutions. The presence of wakefieldite-(Ce,La) and vanadinite points to an exceptionally high V abundance in hydrothermal solutions formed towards the end of the carbonatite magma activity. This investigation thus opens new promising areas for Nb and REE prospection in the eastern part of the Amba Dongar carbonatite body.
DS200612-0731
2006
Pourmalek, S.Kopylova, M.G., Pourmalek, S.Textural classification of the Jericho kimberlite, Nunavut, Canada.Emplacement Workshop held September, 5p. extended abstractCanada, NunavutDeposit - Jericho, petrography, volcaniclastics
DS201112-0819
2007
Pourmalek, S.Pourmalek, S.Chemical evolution of Jericho kimberlite magma, NWT.University of British Columbia, Hon. thesis, 94p.Canada, NunavutThesis - note availability based on request via author
DS202104-0570
2021
Pourret, O.Charles, N., Tuduri, J., Lefebvre, G., Pourret, O., Gaillard, F., Goodenough, K.Ressources en terres rares de l'Europe et du Groenland: un potential minier remarquable mais tabou?In: Boulvais, P., Decree, S. Eds. Ressources metalliques: cadre geodynamique et exemples remarquables. ISTE Science Pub. Researchgate, 97p. pdfEurope, GreenlandREE
DS202008-1384
2020
Pourteau, A.Doucet, L.S., Li, Z-X., Gamel El Dien, H., Pourteau, A., Murphy, B., Collins, W.J., Mattielli, N., Olierook, H.K.H., Spencer, C.J., Mitchell, R.N.Distinct formation history for deep mantle domains reflected in geochemical differences.Nature Geoscience, Vol. 13, pp. 511-515. pdfMantlegeochemistry

Abstract: The Earth’s mantle is currently divided into the African and Pacific domains, separated by the circum-Pacific subduction girdle, and each domain features a large low shear-wave velocity province (LLSVP) in the lower mantle. However, it remains controversial as to whether the LLSVPs have been stationary through time or dynamic, changing in response to changes in global subduction geometry. Here we compile radiogenic isotope data on plume-induced basalts from ocean islands and oceanic plateaus above the two LLSVPs that show distinct lead, neodymium and strontium isotopic compositions for the two mantle domains. The African domain shows enrichment by subducted continental material during the assembly and breakup of the supercontinent Pangaea, whereas no such feature is found in the Pacific domain. This deep-mantle geochemical dichotomy reflects the different evolutionary histories of the two domains during the Rodinia and Pangaea supercontinent cycles and thus supports a dynamic relationship between plate tectonics and deep-mantle structures.
DS202009-1625
2020
Pourteau, A.Doucet, L.S., Li, Z-X., GamelEl Dien, H., Pourteau, A., Murphy, J.B., Collins, W.J., Mattielli, N., Olierook, H.K.H., Spencer, C.J., Mitchell, R.N.Distinct formation history for deep mantle domains reflected in geochemical differences.Nature Geoscience, Vol. 13, July pp. 511-515. pdfMantlegeochemistry

Abstract: The Earth’s mantle is currently divided into the African and Pacific domains, separated by the circum-Pacific subduction girdle, and each domain features a large low shear-wave velocity province (LLSVP) in the lower mantle. However, it remains controversial as to whether the LLSVPs have been stationary through time or dynamic, changing in response to changes in global subduction geometry. Here we compile radiogenic isotope data on plume-induced basalts from ocean islands and oceanic plateaus above the two LLSVPs that show distinct lead, neodymium and strontium isotopic compositions for the two mantle domains. The African domain shows enrichment by subducted continental material during the assembly and breakup of the supercontinent Pangaea, whereas no such feature is found in the Pacific domain. This deep-mantle geochemical dichotomy reflects the different evolutionary histories of the two domains during the Rodinia and Pangaea supercontinent cycles and thus supports a dynamic relationship between plate tectonics and deep-mantle structures.
DS2001-0946
2001
Poustovetov, A.A.Poustovetov, A.A., Roeder, P.L.The distribution of chromium between basaltic melt and chromian spinel as an oxygen geobarometer.Canadian Mineralogist, Vol. 39, No. 2, Apr. pp. 309-317.MantleMelting, chromium, oxides - not specific to diamonds
DS2001-0947
2001
Poustovetov, A.A.Poustovetov, A.A., Roeder, P.L.Numerical modeling of major element distribution between chromian spinel and basaltic melt, MORBSContributions to Mineralogy and Petrology, Vol. 142, No. 1, Oct. pp. 58-71.MantleMORBS - chemistry
DS202009-1673
2020
Pouteau, A.Volante, S., Pouteau, A., Collins, W.J., Blereau, E., Li, Z-X., Smit, M., Evans, N.J., Nordsvan, A.R., Spencer, C.J., McDonald, B.J., Li, J., Gunter, C.Multiple P-T-d-t paths reveal the evolution of the final Nuna assembly in northeast Australia. Georgetown InlierJournal of Metamorphic Geology, Vol. 38, pp. 593-627.Australiageochronology

Abstract: The final assembly of the Mesoproterozoic supercontinent Nuna was marked by the collision of Laurentia and Australia at 1.60 Ga, which is recorded in the Georgetown Inlier of NE Australia. Here, we decipher the metamorphic evolution of this final Nuna collisional event using petrostructural analysis, major and trace element compositions of key minerals, thermodynamic modelling, and multi?method geochronology. The Georgetown Inlier is characterised by deformed and metamorphosed 1.70-1.62 Ga sedimentary and mafic rocks, which were intruded by c. 1.56 Ga old S?type granites. Garnet Lu-Hf and monazite U-Pb isotopic analyses distinguish two major metamorphic events (M1 at c. 1.60 Ga and M2 at c. 1.55 Ga), which allows at least two composite fabrics to be identified at the regional scale—c. 1.60 Ga S1 (consisting in fabrics S1a and S1b) and c. 1.55 Ga S2 (including fabrics S2a and S2b). Also, three tectono?metamorphic domains are distinguished: (a) the western domain, with S1 defined by low?P (LP) greenschist facies assemblages; (b) the central domain, where S1 fabric is preserved as medium?P (MP) amphibolite facies relicts, and locally as inclusion trails in garnet wrapped by the regionally dominant low?P amphibolite facies S2 fabric; and (c) the eastern domain dominated by upper amphibolite to granulite facies S2 foliation. In the central domain, 1.60 Ga MP-medium?T (MT) metamorphism (M1) developed within the staurolite-garnet stability field, with conditions ranging from 530-550°C at 6-7 kbar (garnet cores) to 620-650°C at 8-9 kbar (garnet rims), and it is associated with S1 fabric. The onset of 1.55 Ga LP-high?T (HT) metamorphism (M2) is marked by replacement of staurolite by andalusite (M2a/D2a), which was subsequently pseudomorphed by sillimanite (M2b/D2b) where granite and migmatite are abundant. P-T conditions ranged from 600 to 680°C and 4-6 kbar for the M2b sillimanite stage. 1.60 Ga garnet relicts within the S2 foliation highlight the progressive obliteration of the S1 fabric by regional S2 in the central zone during peak M2 metamorphism. In the eastern migmatitic complex, partial melting of paragneiss and amphibolite occurred syn? to post? S2, at 730-770°C and 6-8 kbar, and at 750-790°C and 6 kbar, respectively. The pressure-temperature-deformation-time paths reconstructed for the Georgetown Inlier suggest a c. 1.60 Ga M1/D1 event recorded under greenschist facies conditions in the western domain and under medium?P and medium?T conditions in the central domain. This event was followed by the regional 1.56-1.54 Ga low?P and high?T phase (M2/D2), extensively recorded in the central and eastern domains. Decompression between these two metamorphic events is ascribed to an episode of exhumation. The two?stage evolution supports the previous hypothesis that the Georgetown Inlier preserves continental collisional and subsequent thermal perturbation associated with granite emplacement.
DS1984-0298
1984
Povaremnykh, A.S.Gerasimov, A.YU., Povaremnykh, A.S., Matsyuk, S.S., Kharkiv, A.Hardness of Chromium Containing Garnets from KimberlitesMineral. Zhur., Vol. 6, No. 2, PP. 42-50.RussiaMineralogy
DS1984-0299
1984
Povarennykh, S.S.Gerasimov, A.YU., Povarennykh, S.S., Matsyuk, S.S., Kharkiv, A.The Hardness of Chromium Bearing Garnets from KimberlitesMineral. Zhurn., Vol. 6, No. 2, PP. 42-50.RussiaBlank
DS1988-0718
1988
Povondra, P.Ulrych, J., Pivec, E., Povondra, P., Rutsek, J.Perovskite from melilite rocks, Osecna complex, NorthernBohemia, CzechoslovakiaNeues Jahrbuch f?r Mineralogie Abh, No. 2, February pp. 81-95GlobalBlank
DS1998-0017
1998
PowellAlard, O., Luguet, Lorand, Powell, O'Reilly, GriffinFurther insights on S content and behaviour in the lithospheric mantleMineralogical Magazine, Goldschmidt abstract, Vol. 62A, pp. 29-30.Australia, FranceSulphide mineralogy, Xenoliths
DS201910-2244
2019
Powell, C.Basu, U., Powell, C.Pn tomography and anisotropy study of the Central United States.Journal of Geophysical Research: Solid Earth, Vol. 124, 7, pp. 7105-7119.United Statesgeophysics - seismic

Abstract: Detailed P wave velocity and anisotropy structure of the uppermost mantle below the central United States is presented based on a tomographic inversion of Pn traveltimes for earthquakes in the range 2 to 14°. Dense raypath coverage throughout the northern Mississippi Embayment is obtained using the Northern Embayment Lithosphere Experiment and U.S. Transportable Array data sets. A detailed analysis of the trade?off between velocity and anisotropy variations demonstrates that both are well resolved over most of the study area. Anomalously fast Pn velocities are identified below the northern Mississippi Embayment, centered on the New Madrid seismic zone. A prominent region of low velocity coincides with the southwestern margin of the Illinois basin. Pn anisotropy displays complex patterns and differs from absolute plate motion directions and SKS splitting directions. A circular pattern of fast anisotropy directions is centered on the New Madrid seismic zone and may be related to the presence of the mafic “rift pillow.”
DS1995-2142
1995
Powell, C. McA.Zheng Xiang Li, Linghua Zhang, Powell, C. McA.South Chin a in Rodinia: part of the missing link between Australia - East Antarctica and Laurentia.Geology, Vol. 23, No. 5, May pp. 407-410.China, AntarcticaGondwanaland, Tectonics
DS1995-2143
1995
Powell, C. McA.Zheng Xiang Li, Zhang, L., Powell, C. McA.South Chin a in Rodinia: part of the missing link between Australia -East Antarctica and Laurentia?Geology, Vol. 23, No. 5, May pp. 407-410ChinaCraton, Gondwanaland
DS1996-0844
1996
Powell, C. McA.Li, Z.X., Zhang, L., Powell, C. McA.Positions of the East Asian cratons in the Neoproterozoic supercontinentRodinia.Australian Journal of Earth Sciences, Vol. 43, pp. 593-604.China, Australia, Asia, RodiniaTectonics, Tarim, Technostratigraphy
DS1996-1137
1996
Powell, C. McA.Powell, C. McA.Breakup and dispersal of the Rodinia supercontinent: implications for resource exploration.Geological Society of Australia 13th. Convention held Feb., No. 41, abstracts p. 351.AustraliaTectonics, Gondwanaland, Rodinia
DS1999-0412
1999
Powell, C. McA.Li, Z.X., Powell, C. McA.Paleomagnetic study of Neoproterozoic glacial rocks of the Yangzi Block:paleolatitude and configuration...Precambrian Research, Vol. 94, No. 1-2, Mar. pp. 1-6.ChinaTectonics, Geophysics
DS2001-0948
2001
Powell, C. McA.Powell, C. McA., Jones, D.L., Pisarevsky, S., WingatePaleomagnetic constraints on the position of the Kalahari craton in RodiniaPrecambrian Research, Vol. 110, pp. 33-46.South Africa, Rodinia, GondwanaPaleomagetisM., Craton - Kalahari
DS1994-1401
1994
Powell, C.A.Powell, C.A., Bollinger, G.A., et al.A seismotectonic model for the 300 kilometer long Eastern Tennessee seismiczone.Science, Vol. 264, April 29, pp. 686-688.GlobalGeophysics -seismics
DS1991-1787
1991
Powell, C.M.Veevers, J.J., Powell, C.M., Roots, S.R.Review of seafloor spreading around Australia: 1. synthesis of patterns ofspreading.Australian Journal of Earth Sciences, Vol. 38, No. 4, pp. 373-89.AustraliaTectonics, arcs
DS2003-0910
2003
Powell, C.M.McElhinny, M.W., Powell, C.M., Pisarevsky, S.A.Paleozoic terranes of eastern Australia and the drift history of GondwanaTectonophysics, Vol. 362, 1-4, pp. 41-65.AustraliaTectonics
DS1994-1847
1994
Powell, C.McA.Veevers, J.J., Powell, C.McA.Permian-Triassic Pangean basins and foldbelts along the Panthalassan Margin of GondwanalandGeological Society of America, Memoir 184, 372pBook -ad, Basins, sedimentation
DS200412-0345
2003
Powell, C.McA.Collins, A.S., Johnson, S., Fitzimmona, I.C.W., Powell, C.McA., Hulscher, B., Abello, J., Razakamana, T.Neoproterozoic deformation in central Madagascar: a structural section through part of the East African orogen.Proterozoic East Gondwana: Supercontinent assembly and Breakup. Ed. Yoshida , Geological Society of London Spe, No. 206, pp. 363-380.Africa, MadagascarPlume, tectonics
DS200412-1553
2003
Powell, C.McA.Pisarevsky, S.A., Wingate, M.T.D., Powell, C.McA., Johnson, S., Evans, D.A.D.Models of Rodinia assembly and fragmentation.Proterozoic East Gondwana: Supercontinent assembly and Breakup. Ed. Yoshida , Geological Society of London Spe, No. 206, pp. 35-56.GondwanaPlume, tectonics
DS2002-1278
2002
Powell, C.McA. PowellPowell, C.McA. Powell, Pisarevsky, S.A.Late Neoproterozoic assembly of East GondwanaGeology, Vol. 30, No. 1, Jan. pp. 3-6.Australia, IndiaCongo, Sao Francisco blocks, Rodinia, Tectonics
DS1991-1372
1991
Powell, C.S.Powell, C.S.Trends in geophysics - peering inwards. Overview for non-professionalsScientific American, Vol. 264, No. 6, June pp. 100-111GlobalGeophysics, Popular overview
DS1991-1373
1991
Powell, C.S.Powell, C.S.Trends in geophysics- peering inwardsScientific American, Vol. 264, No. 6, June pp. 100-111GlobalGeophysics, Popular overview
DS1960-1093
1969
Powell, D.G.Dawson, J.B., Powell, D.G.Mica in the Upper MantleContributions to Mineralogy and Petrology, Vol. 22, No. 3, PP. 233-237.South AfricaPetrography, Mineralogy
DS1970-0063
1970
Powell, D.G.Dawson, J.B., Powell, D.G.The Natron Engaruka Explosion Crater Area Northern TanzaniaBulletin. VOLCANOLOGIQUE., Vol. 33, No. 3, PP. 791-817.Tanzania, East AfricaRelated Rocks, Geology
DS1970-0064
1970
Powell, D.G.Dawson, J.B., Powell, D.G., Reid, A.M.Ultrabasic Lava and Xenoliths from the Lashaine Volcano, Northern Tanganyika.Journal of PETROLOGY, Vol. 11, PP. 519-548.Tanzania, East AfricaRelated Rocks, Geology
DS1980-0256
1980
Powell, J.D.Nishimori, R.K., Powell, J.D.Uranium in Carbonatites, United States (us) Final ReportN.u.r.e. Report, No. GJBX 147-80, 180P.United States, Gulf Coast, Arkansas, Hot Spring CountyMagnet Cove Discussed
DS1960-0729
1966
Powell, J.L.Powell, J.L., Hurley, P.M., Fairbairn, H.W.The Strontium Isotopic Composition and Origin of CarbonatiteInterscience Publishing, PP. 365-378.United States, Gulf Coast, Arkansas, Hot Spring County, Canada, QuebecGeochronology, Spitzkop, Oka, Magnet Cove
DS1970-0179
1970
Powell, J.L.Powell, J.L., Bell, K.Strontium Isotopic Studies of Alkalic Rocks; Localities From Australia, Spain and Western United States.Contributions to Mineralogy and Petrology, Vol. 27, PP. 1-10.Australia, Western Australia, Wyoming, United States, Rocky MountainsKimberlite, Leucite, Lamproite, Leucite Hills, Fitzroy Valley
DS201912-2778
2019
Powell, L.Falck, H., Elliott, B., Cairns, S., Powell, L.NWT mineral exploration and mining overview 2019.Yellowknife Forum NWTgeoscience.ca, abstract volume p. 27.Canada, Northwest Territorieseconomics

Abstract: In spite of a poor year for sales of rough diamonds globally, diamond mining continues to provide a foundation for the NWT economy. Gahcho Kué mine, which has been operating slightly ahead of plan, announced the discovery of the diamondiferous Wilson kimberlite within the current mine plan area. Consistently high forecasts for zinc demand have encouraged both the rejuvenation of Pine Point by Osisko Metals Inc. and NorZinc Ltd.’s ongoing efforts to bring Prairie Creek into production. Gold prices have been buoyed by safe-haven sentiment after concerns over economic growth, tariffs and trade wars with China. Advanced projects have benefited with an improving investment climate encouraging on-going exploration by Nighthawk Gold Corp. and TerraX Minerals Inc. However, many smaller projects were suspended as the companies were not able to raise sufficient funds on in the investment market. This was particularly true for the commodities targeting green energy and battery technologies. Most of the projects focusing on lithium, cobalt and vanadium started the year strongly but were dormant by the summer. A notable exception was the reactivation of Avalon’s Nechalacho project with an infusion of resources from Cheetah Resources of Australia. One of the indicators of exploration activity – claims staked vs. lapsed – continued an upward trend that began in 2017. In 2018, a total of 268 claims covering 184,985 hectares were added and 70 claims covering 58, 876 hectares were released. In the first three quarters of 2019, 120 claims covering 45,000 Ha were added but a nearly equivalent area 55,000 Ha in 85 claims and leases were cancelled. There are also 37 active Prospecting Permits this year. New staking included large areas in the Mackenzie Mountains, the additional ground at Pine Point, re-staking of claims in the Lac de Gras region and expansion of claims in the Yellowknife area. In 2019-2020, the Government of Northwest Territories invested nearly $1 million in grassroots mineral exploration through the Mining Incentive Program. This funding was dispersed to 19 exploration projects comprising twelve prospectors and seven companies. The Mineral Resources Act has passed the legislature marking the NWT’s first-ever stand-alone Act governing mining in the territory.
DS2002-0622
2002
Powell, M.Gupta, A.K., Chattopadhyay, B., Fyfe, W.S., Powell, M.Experimental studies on three potassium rich ultramafic rocks from Damodar Valley, East India.Mineralogy and Petrology, Vol. 74, 2-4, pp. 343-60.India, eastAlkaline rocks
DS1993-0474
1993
Powell, M.A.Fyfe, W.S., Powell, M.A., Hart, B.R., Ratanasthien, B.A global crisis: energy in the futureNonrenewable Resources, Vol. 2, No. 3, Fall pp. 187-196GlobalEnergy crisis
DS1994-1006
1994
Powell, McA.Leaman, D.E., Baillie, P.W., Powell, McA.Precambrian Tasmania: a thin skinned devilExploration Geophysics, Australian Bulletin, Vol. 25, No. 1, March pp. 19-24TasmaniaGeophysics, Tectonics, Precambrian
DS1990-1300
1990
Powell, R.Sandiford, M., Powell, R.Some isostatic and thermal consequences of the vertical strain geometry in convergent orogensEarth and Planetary Science Letters, Vol. 98, pp. 154-165GlobalOrogeny, Tectonics
DS1992-0660
1992
Powell, R.Hand, M., Dirks, P.H.G.M., Powell, R., Buick, I.S.How well established is isobaric cooling in Proterozoic orogenic belts? an example from the Arunta inlierGeology, Vol. 20, No. 7, July pp. 649-652Australiametamorphism, Proterozoic belts
DS2002-1318
2002
Powell, R.Rebay, G., Powell, R.The formation of eclogite facies metatroctolites and a general petrogenetic grid in Na2O CaO FeO MgO AL2O3 SiO2 H2O ( NCFMASH).Journal of Metamorphic Geology, Vol. 20, 9, pp. 813-26.GlobalEclogites, Petrology
DS2003-1466
2003
Powell, R.Wei, C.J., Powell, R., Zhang, L.F.Eclogites from the south Tienshan, NW China: petrological characteristic and calculatedJournal of Metamorphic Geology, Vol. 21, 3, pp. 163-80.China, northwestPetrology - eclogites
DS200512-0707
2005
Powell, R.McLaren, S., Sandiford, M., Powell, R.Contrasting styles of Proterozoic crustal evolution: a hot plate tectonic model for Australian terranes.Geology, Vol. 33, 8, August pp. 673-676.AustraliaTectonics, rheology, geothermometry
DS200612-0510
2006
Powell, R.Guirand, M., Powell, R.P V T relationships and mineral equilibration temperatures in inclusions in minerals.Earth and Planetary Science Letters, Vol. 244, 3-4, Apr.30, pp. 683-694.TechnologyDiamond, coesite, mineral inclusions
DS200612-1376
2006
Powell, R.Stipska, P., Pitra, P., Powell, R.Separate or shared metamorphic histories of eclogites and surrounding rocks? an example from Bohemian Massif.Journal of Metamorphic Geology, Vol. 24, 3, pp. 219-240.EuropeEclogite - not specific to diamonds
DS200712-0047
2007
Powell, R.Baldwin, J.A., Powell, R., Williams, M.L., Goncalves, P.Formation of eclogite and reaction during exhumation to mid-crustal levels, Snowbird Tectonic zone, Western Canadian Shield.Journal of Metamorphic Geology, Vol. 25, 9, pp. 953-974.Canada, Saskatchewan, AlbertaEclogite
DS200812-0915
2008
Powell, R.Powell, R., Holland, T.J.B.On thermobarometry.Journal of Metamorphic Geology, Vol. 26, 2, pp. 155-179.TechnologyGeothermometry
DS200812-1291
2008
Powell, R.Yang, J.J., Powell, R.Ultrahigh pressure garnet peridotites from the devolatization of sea floor hydrated ultramafic rocks.Journal of Metamorphic Geology, Vol. 26, 6, pp. 695-716.ChinaQaidiam - peridotites
DS201012-0615
2010
Powell, R.Rebay, G., Powell, R., Diener, J.F.A.Calculated phase equilibration temperatures for a morb compositoon in a P-T range, 450-650 C and 18-28 kbar: the stability of eclogite.Journal of Metamorphic Geology, Vol. 28, 6, pp. 635-645.MantleEclogite
DS201112-0441
2011
Powell, R.Holland, T.B.J., Powell, R.An improved and extended internally consistent thermodynamic data set for phases of petrological interest, involving a new equation of state for solids.Journal of Metamorphic Geology, in print availableMantleGeodynamics
DS201112-0442
2011
Powell, R.Holland, T.J.B., Powell, R.An improved and extended internally consistent thermodynamic data set for phases of petrological interest, involving a new equation of state for solids.Journal of Metamorphic Geology, Special issue,TechnologyPetrology - dataset not specific to diamonds
DS201212-0162
2012
Powell, R.Diener, J.F.A., Powell, R.Revised activity - composition models for clinopyroxene and amphibole.Journal of Metamorphic Geology, Vol. 30, 2, pp. 131-142.TechnologyClassification
DS201312-0399
2013
Powell, R.Holland, T.J.B., Hudson, N.F.C., Powell, R., Harte, B.How irreversible heat transport processes drive Earth's interdependent thermal, structural and chemical evolution.Journal of Petrology, Vol. 54, pp. 1901-1920.MantleGeothermometry
DS201412-0382
2014
Powell, R.Huang, M-X., Yang, J-J., Powell, R., Mo, X.High pressure metamorphism of serpentinzed chromitite at Luobusha ( southern Tibet).American Journal of Science, Vol. 314, pp. 400-433.Asia, TibetDiamond and coesite
DS201512-1916
2015
Powell, R.Evans, K.A., Powell, R.The effect of subduction on sulphur, carbon and redox budget of lithospheric mantle.Journal of Metamorphic Geology, Vol. 33, 6, pp. 649-670.MantleSubduction

Abstract: Subduction of hydrated lithospheric mantle introduces Hinline imageO, ferric iron, oxidized carbon and sulphur to the subduction zone system. The fate of these components is poorly known, but is intimately linked to the global geochemical cycles of iron, carbon and sulphur, the genesis of arc-related ore deposits, the temporal evolution of mantle redox state and subduction-related earthquakes and magmatism. thermocalc is used to provide first-order constraints on the effect of subduction zone metamorphism on metamorphic redistribution of iron, carbon, sulphur and water in ultramafic rocks via construction of P?T and T-X(O) pseudosections with open system calculation of the effect of fluid loss. The calculations replicate observed mineral assemblages in high-P to low-T ultramafic rocks at P?T conditions consistent with those suggested by other workers. The results are consistent with open system fluid loss without significant fluid infiltration. Water loss is complete by 850 inline imageC, the corresponding depth of fluid loss being consistent with that inferred for earthquakes in subducting slabs. Losses of carbon and sulphur are relatively minor, at around <5% and <1%, respectively, so it is envisaged that most carbon and sulphur subducted in ultramafic lithologies is transported to >5 GPa, below the depths of the source zone for arc volcanoes. Oxygen activity for rocks in closed systems that evolve with a fixed redox budget is calculated to change from ?FMQ ?1 at 350 inline imageC to over ?FMQ +3 at 850 inline imageC. This result emphasizes the need to consider redox budget as well as oxygen activity when the results of experiments performed at fixed oxygen activity relative to some buffer are interpreted in the context of natural systems. In open systems, devolatilization is calculated to increase the redox budget and oxygen activity of the residue via loss of methane and Hinline imageS at the brucite-out and serpentine-out reactions respectively. No fluid-induced mechanism for oxidation of sub-arc mantle by transfer of redox budget from hydrated ultramafic lithologies to the overlying sub-arc mantle was identified, although further thermodynamic data on fluid species such as Sinline image are required to confirm this.
DS201906-1337
2019
Powell, R.Powell, R., Evans, K.A., Green, E.C.R., White, R.W.The truth and beauty of chemical potentials.Journal of Metamorphic Geology, doi.org.10.1111/ jmg.12484Globalgeochemistry

Abstract: This essay in honour of Mike Brown addresses aspects of chemical equilibrium and equilibration in rocks, with a focus on the role that chemical potentials play. Chemical equilibrium is achieved by diffusive flattening of chemical potential gradients. The idea of equilibration volume is developed, and the way equilibration volumes may evolve along a pressure-temperature path is discussed. The effect of the environment of an equilibration volume is key to understanding the evolution of the equilibration volume with changing conditions. The likely behaviour of equilibration volumes is used to suggest why preservation of equilibrium mineral assemblages and mineral compositions from metamorphism tends to occur. This line of logic then provides the conceptual support to conventional equilibrium thermodynamic approaches to studying rocks, using, for example, thermobarometry and pseudosections.
DS2001-0870
2001
Powell, W.O'Reilly, S., Powell, W.Heard Island: piecing together the evolution of the Kerguelen Heard PlateauGemoc Annual Report 2000, p. 23.GlobalXenoliths
DS200412-1575
2004
Powell, W.Powell, W., Zhang, M., O'Reilly, S.Y., Tiepolo, M.Mantle amphibole trace element and isotopic signatures trace multiple metasomatic episode in lithospheric mantle, western VictorLithos, Vol. 75, 1-2, July pp. 141-171.Australia, VictoriaMetasomatism, trace element fingerprinting, petrogeneti
DS200712-0196
2007
Powell, W.Coltorti, M., Bonadiman, C., Faccini, B., Gregoire, M., OReilly, S.Y., Powell, W.Amphiboles from supra subduction and intraplate lithospheric mantle.Lithos, Vol. 99, 1-2, pp. 68-84.MantleSubduction
DS200712-0854
2006
Powell, W.Powell, W., O'Reilly, S.Y.Metasomatism and sulfide mobility in lithospheric mantle beneath eastern Australia: implications for mantle Re Os chronology.Geochimica et Cosmochimica Acta, In press availableAustraliaMetasomatism - Allyn River peridotite, geochronology
DS201112-0820
2006
Powell, W.Powell, W.Geochemically diverse domains in lithospheric mantle, eastern Australia.Thesis: Macquarie University Phd. , AustraliaThesis: note availability based on request to author
DS201312-0403
2013
Powell, W.Howell, D., Griffin, W.L., Pearson, N.J., Powell, W., Wieland, P., O'Reilly, S.Y.Trace element partitioning in mixed habit diamonds.Chemical Geology, Vol. 355, pp. 134-143.TechnologyCrystallography
DS201810-2357
2018
Powell, W.Moss, S.W., Kobussen, A., Powell, W., Pollock, K.Kimberlite emplacement and mantle sampling through time at A154N kimberlite volcano, Diavik Diamond mine: lessons from the deep.Mineralogy and Petrology, doi.org/10.1007/ s00710-018-0630-7 14p.Canada, Northwest Territoriesdeposit - Diavik

Abstract: The Diavik Diamond Mine in the NWT of Canada has produced in excess of 100 million carats from 3 kimberlite pipes since mining commenced in 2002. Here, we present new findings from deep (>400 m below surface) mining, sampling and drilling work in the A154N kimberlite volcano that require a revision of previous geological and emplacement models and provide a window into how the sub-continental lithospheric mantle (SCLM) below Diavik was sampled by kimberlite magmas through time. Updated internal geological models feature two volcanic packages interpreted to represent two successive cycles of explosive eruption followed by active and passive sedimentation from a presumed crater-rim, both preceded and followed by intrusions of coherent kimberlite. Contact relationships apparent among the geological units allow for a sequential organization of as many as five temporally-discrete emplacement events. Representative populations of mantle minerals extracted from geological units corresponding to four of the emplacement events at A154N are analyzed for major and trace elements, and provide insights into the whether or not kimberlites randomly sample from the mantle. Two independent geothermometers using clinopyroxene and garnet data indicate similar source depths for clinopyroxenes and G9 garnets (130-160 km), and suggest deeper sampling with time for both clinopyroxene and garnets. Harzburgite is limited to 110-160 km, and appears more prevalent in early, low-volume events. Variable ratios of garnet parageneses from the same depth horizons suggest random sampling by passing magmas, but deeper garnet sampling through time suggests early preferential sampling of shallow/depleted SCLM. Evaluations of Ti, Zr, Y and Ga over the range of estimated depths support models of the SCLM underlying the central Slave terrane.
DS202102-0173
2020
Powell, W.Aulbach, S., Giuliani, A., Fiorentini, M.L., Baumgartner, R.J., Davard, D., Kamenetsky, V.S., Caruso, S., Danyushevsky, L.V., Powell, W., Griffin, W.L.Siderophile and chalcophile elements in spinels, sulphides and native Ni in strongly metasomatised xenoliths from the Bultfontein kimberlite (South Africa).Lithos, doi.org/10.1016/ jlithos.2020.105880, 26p. PdfAfrica, South Africadeposit - Bultfontein

Abstract: The metasomatised continental mantle may play a key role in the generation of some ore deposits, in particular mineral systems enriched in platinum-group elements (PGE) and Au. The cratonic lithosphere is the longest-lived potential source for these elements, but the processes that facilitate their pre-concentration in the mantle and their later remobilisation to the crust are not yet well-established. Here, we report new results on the petrography, major-element, and siderophile- and chalcophile-element composition of native Ni, base metal sulphides (BMS), and spinels in a suite of well-characterised, highly metasomatised and weakly serpentinised peridotite xenoliths from the Bultfontein kimberlite in the Kaapvaal Craton, and integrate these data with published analyses. Pentlandite in polymict breccias (failed kimberlite intrusions at mantle depth) has lower trace-element contents (e.g., median total PGE 0.72 ppm) than pentlandite in phlogopite peridotites and Mica-Amphibole-Rutile-Ilmenite-Diopside (MARID) rocks (median 1.6 ppm). Spinel is an insignificant host for all elements except Zn, and BMS and native Ni account for typically <25% of the bulk-rock PGE and Au. High bulk-rock Te/S suggest a role for PGE-bearing tellurides, which, along with other compounds of metasomatic origin, may host the missing As, Ag, Cd, Sb, Te and, in part, Bi that are unaccounted for by the main assemblage. The close spatial relationship between BMS and metasomatic minerals (e.g., phlogopite, ilmenite) indicates that the lithospheric mantle beneath Bultfontein was resulphidised by metasomatism after initial melt depletion during stabilisation of the cratonic lithosphere. Newly-formed BMS are markedly PGE-poor, as total PGE contents are <4.2 ppm in pentlandite from seven samples, compared to >26 ppm in BMS in other peridotite xenoliths from the Kaapvaal craton. This represents a strong dilution of the original PGE abundances at the mineral scale, perhaps starting from precursor PGE alloy and small volumes of residual BMS. The latter may have been the precursor to native Ni, which occurs in an unusual Ni-enriched zone in a harzburgite and displays strongly variable, but overall high PGE abundances (up to 81 ppm). In strongly metasomatised peridotites, Au is enriched relative to Pd, and was probably added along with S. A combination of net introduction of S, Au +/? PGE from the asthenosphere and intra-lithospheric redistribution, in part sourced from subducted materials, during metasomatic events may have led to sulphide precipitation at ~80-120 km beneath Bultfontein. This process locally enhanced the metallogenic fertility of this lithospheric reservoir. Further mobilisation of the metal budget stored in these S-rich domains and upwards transport into the crust may require interaction with sulphide-undersaturated melts that can dissolve sulphides along with the metals they store.
DS1859-0076
1842
Powell, W.B.Powell, W.B.Geological Report upon the Fourche Cove and its Immediate Vicinity. ArkansasLittle Rock:, PRIVATELY Publishing BY AUTHOR 22P.United States, Gulf Coast, Arkansas, PennsylvaniaGeology
DS1989-1236
1989
Powell, W.G.Powell, W.G., Hodgson, C.J., Hanes, J.A.The expression of the Larder Lake Break in the Matachewan areaOntario Geological Survey miscellaneous Paper, No. 143, pp. 125-132OntarioTectonics, Fault
DS1995-1514
1995
Powell, W.G.Powell, W.G., Hodgson, C.J., Hanes, J.A., Carmichael40Ar/39 Ar geochron. evidence for multiple post metamorphic hydrothermal events focussed along faultsCanadian Journal of Earth Sciences, Vol. 32, No. 6, June pp. 768-786Ontario, QuebecGeochronology, Argon, Abitibi greenstone belt
DS1997-0647
1997
Powell, W.J.LaMoreaux, P.E., Powell, W.J., LeGrand, H.E.Environmental and legal aspects of karst areasEnvironmental Geology, Vol. 29, No. 1-2, Jan. 1, pp. 23-36GlobalEnvironment, Karst
DS1960-0340
1963
Powell.Fairbairn, H.W., Faure, G., Pinson, W.H., Hurley, P.M., Powell.Initial Ratio of Strontium 87 to Strontium 86 Whole Rock Age and Discordant Biotite in the Montregian Igneous Province Quebec.Journal of Geophysical Research, Vol. 68, PP. 6515-6522.Canada, QuebecBlank
DS1994-0735
1994
Power, G.M.Haslett, J., Power, G.M.Interactive computer graphics for a more open exploration of stream sediment geochemical dataComputers and Geosciences, Vol. 21, No. 1, pp. 77-88GlobalComputer, Program -graphics geochemistry
DS201807-1516
2018
Power, I.M.Mervine, E.M., Wilson, S.A., Power, I.M., Dipple, G.M., Turvey, C.C., Hamilton, J.L., Vanderzee, S., Raudsepp, M., Southam, C., Matter, J.M., Kelemen, P.B., Stiefenhofer, J., Miya, Z., Southam, G.Potential for offsetting diamond mine carbon emissions through mineral carbonation of processed kimberlite: an assessment of De Beers mine sites in South Africa and Canada.Mineralogy and Petrology, 10.1007/ s00710-018- 0589-4, 14p.Africa, South Africa, Canada, Northwest Territories, Ontariodeposit - Venetia, Voorspoed, Gahcho Kue, Victor, Snap Lake

Abstract: De Beers kimberlite mine operations in South Africa (Venetia and Voorspoed) and Canada (Gahcho Kué, Victor, and Snap Lake) have the potential to sequester carbon dioxide (CO2) through weathering of kimberlite mine tailings, which can store carbon in secondary carbonate minerals (mineral carbonation). Carbonation of ca. 4.7 to 24.0 wt% (average?=?13.8 wt%) of annual processed kimberlite production could offset 100% of each mine site’s carbon dioxide equivalent (CO2e) emissions. Minerals of particular interest for reactivity with atmospheric or waste CO2 from energy production include serpentine minerals, olivine (forsterite), brucite, and smectite. The most abundant minerals, such as serpentine polymorphs, provide the bulk of the carbonation potential. However, the detection of minor amounts of highly reactive brucite in tailings from Victor, as well as the likely presence of brucite at Venetia, Gahcho Kué, and Snap Lake, is also important for the mineral carbonation potential of the mine sites.
DS202008-1461
2020
Power, I.M.Zeyen, N., Wang, B., Wilson, S.A., von Gunten, K., Alessi, D.S., Paulo, C., Stubbs, A.R., Power, I.M.Cation exchange: a new strategy for mineral carbonation of smectite-rich kimberlites.Goldschmidt 2020, 1p. AbstractAfrica, South Africadeposit - Venetia

Abstract: Mineral carbonation is a form of carbon capture, utilization and storage (CCUS) that aims to transform excess CO2 into environmentally benign carbonate minerals which are geologically stable. Here, we investigated the reactivity of processed kimberlite and kimberlite ore from the Venetia Diamond Mine (South Africa). Highly reactive phases, such as brucite [Mg(OH)2], are uncommon in the samples collected from Venetia necessitating the development of new strategies for mineral carbonation. Kimberlite ore and tailings from this mine consist of a clay-rich mineral assemblage that is dominated by lizardite (a serpentine mineral) and smectites. Smectites are swelling clays that can act as a source of Mg and Ca for carbonation reactions via cation exchange, dissolution and/or direct replacement of smectites to form carbonate phases. Although carbonation of serpentine and brucite has long been a focus of CCUS in mine wastes [1], smectite carbonation has not been explored in this setting. Quantitative X-ray diffraction using Rietveld refinements coupled with Fourier-transform infrared spectroscopy indicate that smectites of stevensite-saponite composition are abundant in the Venetia samples (1.3-15.4 wt.%). Synchrotron-based X-ray fluorescence mapping correlated with scanning and transmission electron microscopy show that smectites are distributed as altered, smooth regions measuring from 1 to 20 ?m in breadth. These phases are rich in Mg and Ca and Al-poor. To better understand the behaviour/reactivity of smectites during the cation exchange process, we have used batch experiments with pure endmembers of Ca-, Mg- and Na-montmorillonite under different treatment conditions (NH4-citrate, NH4-O-acetate, NH4-Cl and Na3-citrate). After 24 hours of reaction, ICP-MS analyses reveal that the four treatments have the same efficiency for Ca and Mg exchange, while NH4-Cl and NH4- O-acetate treatments minimize calcite dissolution. Our end goals are to optimize settling time and to maximize extraction of Ca and Mg for carbonation reactions during ore processing.
DS2001-0949
2001
Power, M.Power, M.Patrimonialism and petro diamond capitalism: peace, geopolitics and economics of war in Angola.Review of African Political Policy, Vol. 90, pp. 489-502.AngolaNews item, History, conflict diamonds
DS2002-1279
2002
Power, M.Power, M., Velcourt, G.Developments in ground geophysical tecniques for kimberlite exploration30th. Yellowknife Geoscience Forum, Abstracts Of Talks And Posters, Nov. 20-22, p. 50,51. abstractNorthwest TerritoriesGeophysics - techniques
DS200512-0870
2004
Power, M.Power, M., Belcourt, G., Rockel, E.Geophysical methods for kimberlite exploration in northern Canada.Leading Edge, Vol. 23, 11, pp. 1124-1129.Canada, Northwest TerritoriesGeophysics - brief overview
DS200712-0855
2007
Power, M.Power, M., Hildes, D.Geophysical strategies for kimberlite exploration in northern Canada.Proceedings of Exploration 07 edited by B. Milkereit, pp. 1025-1031.Canada, Northwest TerritoriesGeophysics - diamond - review
DS201512-1906
2015
Power, M.Counts, B., Power, M.Proxima Diamonds Corp.: exploring for diamonds in the fertile Slave craton.43rd Annual Yellowknife Geoscience Forum Abstracts, abstract p. 33.Canada, Northwest TerritoriesProspect - Sancy

Abstract: Proxima Diamonds Corp. is a private Canadian diamond exploration company exploring diamond targets in the heart of the diamond producing region of the Slave Geological Province. The company holds 17 target-rich properties that were selected based on a review of publicly available data, a proprietary kimberlite indicator mineral sample database and a wealth of experience exploring for diamonds in Canada's north. Focused kimberlite indicator mineral (KIM) sampling conducted by Proxima in 2014 identified a potential source area on the Sancy Property, located near the northern boundary of the Ekati Diamond Mine. Follow-up ground geophysical surveys completed over the area in spring 2015 have returned compelling results. Ground gravity, total magnetic field and capacitively coupled resistivity surveys identified a large, new target approximately 300 m from the diamondiferous T-10 kimberlite pipe. On this and other Proxima properties, focused KIM till sampling is defining likely source areas which will be surveyed with ground geophysical methods this winter.
DS1994-1402
1994
Power, M.A.Power, M.A.An evaluation of ground penetrating radar as a tool in placer explorationYukon Indian and Northern Affairs, Open file 1994-1 (T), 100pYukonGeophysics -radar, Alluvials, placer
DS1994-1403
1994
Power, M.A.Power, M.A.An evaluation of ground penetrating radar as a tool in placer explorationYukon Department of Indian Affairs, Open File 1994-1, (T) 100p.YukonPlacers -not specific to diamonds, Radar
DS1998-1182
1998
Power, M.A.Power, M.A.Seismic signature of the Drybones Bay kimberlite pipe, Northwest TerritoiesThe Canadian Mining and Metallurgical Bulletin (CIM Bulletin) ., Vol. 90, No. 1017, Feb. pp. 66-69.Northwest TerritoriesGeophysics - seismic, Deposit - Drybones
DS2000-0774
2000
Power, M.R.Power, M.R., Pirrie, D., Andersen, J.C.O., Wheeler, P.D.Testing the validity of chrome spinel chemistry as a provenance and petrogenetic indicator.Geology, Vol. 28, No. 1, Nov. pp. 1027-30.ScotlandLayered intrusion - RuM., Mineral chemistry - spinels ( not specific to diamonds
DS200612-0886
2006
Power, S.E.McClelland, W.C., Power, S.E., Gilotti, J.A., Mazdab, F.K., Wopenka, B.U Pb SHRIMP geochronology and trace element geochemistry of coesite bearing zirocons, north east Greenland Caledonides.Geological Society of America, Special Paper, No. 403, pp. 23-44.Europe, GreenlandCoesite
DS1996-1510
1996
Power, W.L.Ward, M.O., Power, W.L., Ketelaar, P.A computatiuonal environment for the management processing and analysis of geological dataComputers and Geosciences, Vol. 10, pp. 1123-31GlobalComputers, GIS
DS201903-0520
2019
Powerman, V.I.Ivanov, A.V., Levitskii, I.V., Levitskii, V.I., Corfu, F., Demonterova, E.I., Reznitskii, L.Z., Pavlova, L.A., Kamenetsky, V.S., Savatenkov, V.M., Powerman, V.I.Shoshonitic magmatism in the Paleoproterozoic of the south-western Siberian Craton: an analogue of the modern post-collisiion setting.Lithos, Vol. 328-329, pp. 88-100.Russiadeposit - Sharyzhalgay

Abstract: The Siberian Craton was assembled in a Paleoproterozoic episode at about 1.88?Ga by the collision of older blocks, followed at about 1.86?Ga by post-collisional felsic magmatism. We have found a set of extremely fresh mica-bearing lamprophyre-looking rocks within the Sharyzhalgay metamorphic complex of the south-western Siberian Craton. Zircon from these rocks yields a UPb TIMS age of 1864.7?±?1.8?Ma, which coincides perfectly with the peak of the post-collisional granite ages and postdates by ~15?Ma the peak of ages obtained for metamorphism. The same ages were reported earlier for a mafic dyke with ocean island basalt (OIB) geochemical signatures and a Pt-bearing mafic-ultramafic intrusion found in the same region. Mineralogy, major and trace element geochemistry and Sr-Nd-Pb isotopes show that the studied rocks (1) have shoshonitic affinity, (2) are hybrid rocks with mineral assemblages which could not be in equilibrium, (3) where derived by recycling of an Archean crustal source and (4) resemble post-collision Tibetan shoshonitic series. The genesis of these rocks is considered to be due to melting of crustal lithologies and metasomatized lithospheric mantle within a subducted slab. Some of the resulting melts ascended through the lithospheric column and fractionated to low-Mg absarokites, whereas other melts were contaminated by orthopyroxenitic mantle material and attained unusual high-Mg mafic compositions. According to our model, the post-collisional magmatism (shoshonite- and OIB-type) occurred due to upwelling of hot asthenosphere through a slab window, when the active collision ceased as a result of the slab break off and loss of the slab pull force. Overall, our study shows that in the Paleoproterozoic shoshonitic melts were emplaced within a similar tectonic setting as seen today in modern orogenic systems.
DS1992-1226
1992
Powers, M.H.Powers, M.H., et al.GPRMODEL: one dimensional full waveform forward modeling of ground penetrating radar dataUnited States Geological Survey (USGS) Open File, No. 92-0532-A, B, $ 9.50GlobalComputer, Program -GPRMODEL
DS1992-1227
1992
Powers, P.S.Powers, P.S., Crosta, G.SCRNDIG: a Basic program for digitizing from a screen image on a DOS-basedcomputerUnited States Geological Survey (USGS) Open File, No. 92-0522 A, B, $ 12.75GlobalComputer, Program - SCRNDIG
DS1995-1515
1995
Powers, P.S.Powers, P.S.SCRNDIGW: a windows screen digitizing ProgramUnited States Geological Survey (USGS) Open file, No. 94-0697 A, B. $ 13.50GlobalComputer, Program -SCRNDIGW.
DS2001-0185
2001
PowisChiarenzeli, J., Aspler, Dunn, Cousens, Osarko, PowisMulti element and rare earth element composition of lichens, mosses and vascular plants from Barrenlands.Applied Geochem., Vol. 16, No. 2, pp. 245-70.Northwest Territories, NunavutGeochemistry - biochemistry
DS1960-1204
1969
Pozharitskaya, L.K.Samoylov, V.S., Pozharitskaya, L.K.Temperature Facies of Metasomatites in Carbonatite Intrusions in Eastern Siberia.Doklady Academy of Science USSR, Earth Science Section., Vol. 188, No.1-6, PP. 173-176.RussiaKimberlite
DS1986-0837
1986
Pozharitskaya, L.K.Vilkovich, R.V., Pozharitskaya, L.K.Composition evolution of carbonatites from the Chernigov zone(Azovsea).(Russian)Geochemistry International (Geokhimiya), (Russian), No. 3, pp. 318-327RussiaCarbonatite
DS1986-0838
1986
Pozharitskaya, L.K.Vilkovich, R.V., Pozharitskaya, L.K.Compositional evolution of carbonatites in the Chernigov zone,AzovregionGeochemistry International, Vol. 23, No. 7, pp. 92-100RussiaCarbonatite
DS1950-0319
1957
Pozidaeva, V.F.Bobrievich, A.P., Khar'kiv, A.D., Pozidaeva, V.F.The Geological Features of the Mir KimberliteNauchNo. Tetch. Info. Bulletin., No. 3.RussiaBlank
DS1984-0197
1984
Pozzibon, L.Connellan, M., Pozzibon, L.The Australian Ideal Design for Round BrilliantsAust. Gemologist., Vol. 15, No. 7, PP. 219-226; PP. 243-246.GlobalDiamond Cutting
DS201212-0571
2012
Pozzo, M.Pozzo, M., Davies, C., Gubbins, D., Alfe, D.Thermal and electrical conductivity of iron at Earth's core.Nature, in press availableMantleGeothermometry
DS201412-0708
2014
Pozzo, M.Pozzo, M., Davies, C., Gubbins, D., Alfe, D.Thermal and electrical conductivity of solid iron and iron-silicon mixtures at Earth's core conditions.Earth and Planetary Science Letters, Vol. 393, pp. 159-165.MantleGeothermometry
DS201509-0392
2015
Pozzo, M.Davies, C., Pozzo, M., Gubbins, D., Alfe, D.Constraints from material properties on the dynamics and evolution of Earth's core.Nature Geoscience, Vol. 8, pp. 678-785.MantleHT - core evolution

Abstract: The Earth’s magnetic field is powered by energy supplied by the slow cooling and freezing of the liquid iron core. Efforts to determine the thermal and chemical history of the core have been hindered by poor knowledge of the properties of liquid iron alloys at the extreme pressures and temperatures that exist in the core. This obstacle is now being overcome by high-pressure experiments and advanced mineral physics computations. Using these approaches, updated transport properties for FeSiO mixtures have been determined at core conditions, including electrical and thermal conductivities that are higher than previous estimates by a factor of two to three. Models of core evolution with these high conductivities suggest that the core is cooling much faster than previously thought. This implies that the solid inner core formed relatively recently (around half a billion years ago), and that early core temperatures were high enough to cause partial melting of the lowermost mantle. Estimates of core-mantle boundary heat flow suggest that the uppermost core is thermally stratified at the present day.
DS1900-0445
1906
Praagh, L.V.Praagh, L.V.Diamonds in the TransvaalLondon: Transvaal And Its Mines, PP. 623-628.Africa, South AfricaKimberley, History
DS202105-0777
2021
Prabaharan, S.R.S.Modise, E.G., Zungeru, M.A., Chuma, J.M., Prabaharan, S.R.S., Mtengi, B., Ude, A., Nedev, Z.The new paradox of dual modality x-ray diamond sorting.IEEE Photonics Journal, Researchgate 35102286, April, 28p. PdfGloballuminescence

Abstract: Modern-day diamond sorting is achieved through the application of x-ray luminescence (XRL) and x-ray transmission (XRT) techniques. Sorting with XRL is limited to the class range of 1.25mm to 32mm because of self-absorption associated with larger diamonds, greater than 32mm. The effect of self-absorption is also a high-energy phenomenon in XRL. XRT is limited to sorting large size diamonds as the technique suffers poor contrast for diamonds smaller than 10mm. XRT measurements are immune to self-absorption for all sample sizes, while XRL measurements have good contrast for particles smaller than 32mm. The applications of these techniques have hitherto been used independently of each other and have subsequently progressed mutually exclusively. Here we analytically show a new paradox of a dual-modality X-ray diamond sorting combining XRL and XRT techniques' strengths. Key features of our new paradoxical model performance are contrast mitigation for small particles and self-absorption rejection for a large particle at high energy as well as improved particle detectability and classification.
DS201412-0709
2014
Prabhakar, N.Prabhakar, N., Bhattacharya, A., Sathyanarayanan, M., Mukherjee, P.K.Structural, petrological and chronological constraints from eastern India and implications for the ~1.0 Ga assembly of greater India.Journal of Geology, Vol. 122, 4, pp. 411-432.IndiaGeochronology
DS201112-0715
2011
Prabhakar Rao, M.R.K.Nageswara Rao, B., Kumar, N., Singh, A.P., Prabhakar Rao, M.R.K., Mall, D.M., Singh, B.Crustal density structure across the Central Indian shear zone from gravity data.Journal of Asian Earth Sciences, Vol. 42, 3, pp. 341-353..IndiaGeophysics - Bundelkhand Craton
DS1975-1194
1979
Prabhakara, R.P.Raju, K.C.C., Kareemuddin, M.D., Prabhakara, R.P.Operation AnantapurIndia Geological Survey Miscellaneous Publishing, No. 47, PP. 12-16.India, Andhra PradeshBlank
DS202103-0416
2021
Prabhu, A.Thomson, A.R., Kohn, S.C., Prabhu, A., Walter, M.J.Evaluating the formation pressure of diamond-hosted majoritic garnets; a machine learning majorite barometer.Journal of Geophysical Research, Solid Earth, in press available, 34p.Globaldiamond inclusions

Abstract: Natural diamonds, as well as being a cherished commodity, are valuable for scientists studying the Earth's interior because they only grow at depths greater than 140 km. When diamonds grow, they may trap tiny fragments of surrounding materials as sub?millimetre defects. Study of these inclusions can provide insights into the materials and processes occurring deep inside our planet. Sub?lithospheric diamonds are a relatively rare subset of natural diamonds, believed to have grown deeper than 250 km, and are thought to be the deepest Earth materials that have been transported to the surface. Ideally, we would be able to estimate their formation depths accurately. Inclusions of majoritic garnet provide a unique opportunity for this, as their chemistry is known to change systematically with formation depth. However, this behaviour is highly complex, and previous attempts to parameterise the depth dependence of inclusion chemistries have limitations. Here we have used data science to train a "Machine Learning" algorithm that improves the accuracy of estimating the formation pressures of majoritic garnet inclusion. The approach confirms that many natural diamonds containing inclusions of majoritic garnet must have originally formed at depths of 400 - 660 km.
DS202105-0796
2021
Prabhu, A.Thomson, A.R., Kohn, S.C., Prabhu, A., Walter, M.J.Evaluating the formation pressure of diamond-hosted majoritic garnets: a machine leaning majorite barometer.Journal of Geophysical Research Physical Review B., http://doi.org/10 /1029/2020JB020 604 21p. PdfMantlediamond inclusions

Abstract: Natural diamonds, as well as being a cherished commodity, are valuable for scientists studying the Earth's interior because they only grow at depths greater than 140 km. When diamonds grow, they may trap tiny fragments of surrounding materials as sub?millimeter defects. Study of these inclusions can provide insights into the materials and processes occurring deep inside our planet. Sub?lithospheric diamonds are a relatively rare subset of natural diamonds, believed to have grown deeper than 250 km, and are thought to be the deepest Earth materials that have been transported to the surface. Ideally, we would be able to estimate their formation depths accurately. Inclusions of majoritic garnet provide a unique opportunity for this, as their chemistry is known to change systematically with formation depth. However, this behavior is highly complex, and previous attempts to parameterize the depth dependence of inclusion chemistries have limitations. Here we have used data science to train a "machine learning" algorithm that improves the accuracy of estimating the formation pressures of majoritic garnet inclusion. The approach confirms that many natural diamonds containing inclusions of majoritic garnet must have originally formed at depths of 400-660 km.
DS201709-2035
2017
Prabhu, E.A.Morrison, S.M., Liu, C., Prabhu, E.A., Li, C., Downs, R.J., Golden, J.J., Fox, P., Hummer, D.R., Meyer, M.B., Hazen, R.M.Network analysis of mineralogical systems.American Mineralogist, in press availableTechnologydata sets

Abstract: A fundamental goal of mineralogy and petrology is the deep understanding of mineral phase relationships and the consequent spatial and temporal patterns of mineral coexistence in rocks, ore bodies, sediments, meteorites, and other natural polycrystalline materials. The multi-dimensional chemical complexity of such mineral assemblages has traditionally led to experimental and theoretical consideration of 2-, 3-, or n-component systems that represent simplified approximations of natural systems. Network analysis provides a dynamic, quantitative, and predictive visualization framework for employing “big data” to explore complex and otherwise hidden higher-dimensional patterns of diversity and distribution in such mineral systems. We introduce and explore applications of mineral network analysis, in which mineral species are represented by nodes, while coexistence of minerals is indicated by lines between nodes. This approach provides a dynamic visualization platform for higher-dimensional analysis of phase relationships, because topologies of equilibrium phase assemblages and pathways of mineral reaction series are embedded within the networks. Mineral networks also facilitate quantitative comparison of lithologies from different planets and moons, the analysis of coexistence patterns simultaneously among hundreds of mineral species and their localities, the exploration of varied paragenetic modes of mineral groups, and investigation of changing patterns of mineral occurrence through deep time. Mineral network analysis, furthermore, represents an effective visual approach to teaching and learning in mineralogy and petrology.
DS201801-0051
2017
Pradeepkumar, A.P.Rajesh, S., Pradeepkumar, A.P.Carbonatite occurrences in Munnar area, Kerala, southern India.Carbonatite-alkaline rocks and associated mineral deposits , Dec. 8-11, abstract p. 36-37.Indiacarbonatites

Abstract: Carbonatites, usually associated with alkaline complexes and emplaced within continental rifting environment, are the rarest of all the igneous rocks. Carbonatite and alkaline intrusive complexes, as well as their weathering products, are the primary sources of REEs (Long et.al. 2010). Carbonatites are defined by the International Union of Geological Sciences (IUGS) system of igneous rock classification as having more than 50 modal percent primary carbonate minerals, such as calcite, dolomite, and ankerite, and less than 20 percent SiO2 (Le Maitre, 2002). Southern India has several carbonatite occurrences and the alkaline complex of Munnar in southern India comprises of an alkali granite plutons with minor patches of charnockite, syenite and carbonatite emplaced within Precambrian gneisses (Nair et.al., 1983, 1984; Santosh et.al., 1987, Nair et.al., 1984). Gneissic layering and foliation are apparent in all but the least deformed granitic rocks in the study area. The Munnar granite body is situated in the western part of the Madurai block in Southern Granulite Terrane (SGT) of Peninsular India, within the newly defined Western Madurai Domain. The complex is spatially related to the intersection zone of Karur-Kambam-Painavu-Trissur lineament. The alkali granite of the complex has been dated at 740±30 my (Odom, 1982) and 804±6 Ma (Brandt et. al., 2014). Present study deals with examining the nature of the carbonatites and takes a relook at its major and REE contents, and for the first time, looks at the stable isotope signatures of these rocks, in an attempt to check whether these rocks are indeed carbonatites. The geology and geochemistry of the rock types in and around Munnar area have been mapped with special focus on carbonatites. Extensive field mapping was carried out and a base map was prepared and all the geological and structural features were recorded in the base map. Intra- and inter-relationships of various rock units were examined. Field photographs of interesting geological features have been recorded. Carbonatites in Munnar area are exposed as two minor patches. The one which occurs towards north of the Munnar town and is seen as patches, lens and veins of 30 cm to 1 m thickness, cutting coarse grained syenite which occurs as a NW- SE along a body. Exposures are found about 15 km from Munnar on the Udumalpet road. The second exposure occurs towards the east of the Munnar town, near at the Ellapatty estate 24 km from Munnar on the road to top station where coarse grained cabonatites occurs as lenticular bodies up to 1.5 m thick within granite. In both the localities, the carbonatite bodies show sharp and discordant margins with absence of any pseudomorphs within them. Fenitisation is characterised by the development of pink K-feldspar megacrystals in the country rock at the contact. The carbonatites are fresh and homogenous and represent two varieties. A coarse grained holocrystalline type and yellowish calcite crystals constituting 90% of the rock, with pyroxene apatite and magnetite correspond to sovite (Streckeisen, 1979). The second variety which contains highly coarse calcite crystals (up to 1 cm) and associated dolomite with mafic minerals constituting 30% of the rock corresponds to alvikite. The sovite exhibits an interlocking crystals mosaic of calcite in thin section. The calcite crystals of alvikite show exsolution blebs of dolomite. The major mafic component in both varieties is aegirine-augite which forms euhedral- subhedral laths (Santosh et al., 1984). The opaque phase is dominantly magnetite. Rarely phlogopite, biotite and minor laths of albite are also noted, small crystals of euhedral apatite are found occluded in calcite grain although alkaline complexes with carbonatite of Munnar devoid of related mafic differentiates like gabbros or lamprophyres may be considered unique. The immiscibility of carbonatitic and alkalic silicate liquids can be physically explained as the separation of a less viscous carbonate liquid from a more viscous polymerized silicate phase. The carbonate liquid would be lower in density because of higher content of H2O and this contrast in density could cause phase separation due to earth’s gravitational field alone (Moller et al., 1980). The pre-requisite to establish separation of immiscible silicate-saturated carbonatite liquid and the associated carbonate-saturated silicate melt is achieved as follows; Large-scale volatile outgassing occurs during crustal wrapping and distention prior to rifting which trigger mantle degassing (Bailey, 1974). An imprint of such large-scale volatile influx is recognised in the Kerala region (Nair et al., 1984). Rapid ascent volatiles enriched in CO2 liberated from the mantle cause partial melting at shallower levels of the mantle.
DS202009-1630
2020
Pradeepkumar, A.P.Hegner, E., Rajesh, S., Willbold, M., Muller, D., Joachimiski, M., Hofmann, M., Linnemann, U., Zieger, J., Pradeepkumar, A.P.Sediment derived origin of the putatative Munnar carbonatite, South India.Journal of Asian Earth Science, Vol. 200, 104432, 18p. PdfIndiadeposit - Munnar

Abstract: Metacarbonate assemblages in high-grade metamorphic terranes often pose challenges when trying to distinguish between mantle-derived carbonatite and sedimentary carbonate protoliths. We present a study of granulite-facies metacarbonate samples of the putative Munnar carbonatite described as decimeter-thick dikes and veins, and layers of a meter-thick metacarbonate and calc-silicate assemblage, respectively. Thin sections of the metacarbonate dike samples show absence of pyrochlore and ubiquitous scapolite, titanite, wollastonite, and detrital zircons are compatible with impure limestone protoliths. Nd and Sr isotope compositions indicate protoliths with Paleoproterozoic crustal residence times which contrast the mantle sources of Indian and global carbonatites. Trace-element patterns display the characteristics of upper crust, and Ce- and Y-anomalies in a number of samples suggest protolith formation under marine conditions. Carbon and oxygen isotope compositions of the metacarbonate samples interlayered with calc-silicate rocks are similar to those in marine limestone. The metacarbonate dikes, however, show mantle-like compositions which are interpreted as reflecting equilibration with mantle-derived CO2 during granulite-facies metamorphism. The dikes yielded a U-Pb zircon crystallization age of 1020 ± 70 Ma and a cross-cutting quartz syenite, thought to be cogenetic, a magmatic age of 620 ± 35 Ma; the hosting gneiss provided a magmatic age of 2452 ± 14 Ma. We conclude that the layered metacarbonate and calc-silicate rocks represent a former marine limestone and marl sequence and the metacarbonate dikes and veins small-volume melts of crust-derived carbonate-rich sediment.
DS201112-0662
2011
Pradham, V.R.Meert, J.G., Pandit, M.K.,Pradham, V.R., Kamenov, G.Preliminary report on the paleomagnetism of 1.88 Ga dykes from the Bastar and Dharwar cratons, Peninsular India.Gondwana Research, Vol. 20, 2-3, pp. 335-343.IndiaDyke system
DS201212-0572
2012
Pradham, V.R.Pradham, V.R., Meert, J.G., Pandit, M.K., Kamenov, G., Mondal, E.F.A.Paleomagnetic and geochronological studies of the mafic dyke swarms of Bundelk hand craton, central India: implications for the tectonic evolution and paleogeographic reconstructions.Precambrian Research, in press available, 80p.IndiaDeposit - Bunder
DS200612-0497
2006
Pradhan, V.Gregory, L.C., Meert, J.G., Pradhan, V., Pandit, M.K., Tamrat, E., Malone, S.J.A paleomagnetic and geochronologic study of the Majhgawan kimberlite. India: implications for the age of the Upper Vindhyan Supergroup.Precambrian Research, Vol. 149, 1-2, pp. 65-75.IndiaDeposit - Majhgawan, geophysics, geochronology
DS201012-0490
2010
Pradhan, V.R.Meert, J.G., Pandit, M.K., Pradhan, V.R., Banks, J., Sirianni, R., Stroud, M., Newstead, B., Gifford, J.Precambrian crustal evolution of Peninsular India: a 3.0 billion year odyssey.Journal of Asian Earth Sciences, Vol. 39, 6, pp. 483-515.IndiaGeodynamics, tectonics
DS201012-0596
2010
Pradhan, V.R.Pradhan, V.R., Meert, J.G., Pandit, M.K., Kamenov, G., Gregory, L.C., Malone, S.J.India's changing place in global Proterozoic reconstructions: a review of geochronologic constraints and paleomagnetic poles from the Dharwar Bundelk hand and MarwarJournal of Geodynamics, Vol. 50, 3-4, pp. 224-242.IndiaCraton, crustal evolution
DS200912-0753
2009
Pradsad, B.R.Tewari, H.C., Surya Prakasa Rao, G., Pradsad, B.R.Uplifted crust in parts of western India.Journal of the Geological Society of India, Vol. 73, no. 4, April pp. 479-488.IndiaReunion Plume, geophysics - seismics
DS1996-0646
1996
Praegel, N.O.Holm, P.M., Praegel, N.O., Brooks, C.K., Nielsen, T.F.D.Lithosphere derived basaltic and lamprophyric low - from the Tertiary east Greenland rifted margin.International Geological Congress 30th Session Beijing, Abstracts, Vol. 2, p. 356.GreenlandLamprophyres
DS1996-1485
1996
Praekeit, H.E.Visser, J.N.J., Praekeit, H.E.Subduction, mega shear systems and Late Paleozoic basin development in the African segment of Gondwana.Geol. Rundchau, Vol. 85, No.4, pp. 632-646.Africa, GondwanaTectonics, Subduction
DS1997-0921
1997
Prager, S.Prager, S.Changing North America's mind set about miningEngineering and Mining Journal, Vol. 198, No. 2, Feb. pp. 36, 37, 38, 40, 42, 44British Columbia, Vancouver IslandPublic awareness, Legal - environmental
DS200812-0728
2008
PrakapenkaMcCammon, C., Kantor, I., Narygina, O., Roquette, J., Ponkratz, Sergieev, Mezouar, Prakapenka, DubrovinskyStable intermediate spin ferrous iron in lower mantle perovskite.Nature Geoscience, Vol. 1, 10, pp. 684-687.MantlePerovskite
DS200812-0959
2008
PrakapenkaRicolleau, A., Fei, Cottrell, Watson, Zhang, Fiquet, Auzende, Roskosz, Morard, PrakapenkaNew constraints on the pyrolitic model under lower mantle conditions.Goldschmidt Conference 2008, Abstract p.A795.MantleX-ray diffraction
DS200412-2098
2004
Prakapenka, V.Wenk, H.R., Lonardeli, I., Pehl, J., Devine, J., Prakapenka, V., Shen, G., Mao, H-K.In situ observation of texture development in olivine, ringwoodite, magnesiowustite and silicate perovskite at high pressure.Earth and Planetary Science Letters, Vol. 226, 3-4, Oct. 15, pp.507-519.Mantle, United States, New MexicoMagnesium silicates, San Carlos
DS200812-0301
2008
Prakapenka, V.Duffy, T.S., Kubo, A., Shieh, S., Dorfman, S., Prakapenka, V.High pressure phases in the MgO FeO Al2O3 SiO2 system: implications for the deep mantle.Goldschmidt Conference 2008, Abstract p.A230.MantlePetrology
DS201312-0247
2013
Prakapenka, V.Ernok, A., Boffa Ballaran, T., Caracas, R., Miyajima, N., Bykova, E., Prakapenka, V., Liermann, H-P., Dubrovinsky, L.Pressure induced phase transitions in coesite.Goldschmidt 2013, AbstractTechnologyCarbonatite
DS201809-2086
2018
Prakapenka, V.Shim, S-H., Nisr, C., Chen, H., Leinenweber. K., Chizmeshya, A., Prakapenka, V., Kunz, M., Bechtel, H., Liu, Z.Hydrous silica in the lower mantle. BridgemaniteGoldschmidt Conference, 1p. AbstractMantlewater

Abstract: While mineral phases stable in the mantle transition zone (such as wadsleyite and ringwoodite) can store up to 3 wt% H2O, those in the lower mantle such as bridgmanite and ferropericlase can contain a very small amount (<50 ppm). While such dramatic differences can lead to dehydration/hydration and hydrous melting at 660-km depth in the mantle [1,2] it is uncertain how much water can be transported and stored at these depths. In order to answer this question, we have conducted a series of high pressure experiments in laser-heated diamondanvil cell and multi-anvil press combined with X-ray diffraction, infrared spectroscopy, laser Raman spectroscopy, and secondary ion mass spectrometry. Initially we examined the water storage capacity of dense (Al free) silica polymorphs at high pressure and temperature. We found that water can dramatically reduce the rutile-type to CaCl2-type phase transition from 55 GPa to 25 GPa and stabilize a new "disordered inverse" inverse NiAs-type phase at pressures above 50 GPa, which is not stable in dry SiO2 system. The CaCl2-type and NiAs-type silica polymorphs contain up to 8 wt% of H2O at 1400-2100 K up to at least 110 GPa. We next explored the effects of water on the mineralogy of the lower mantle and found that hydrous Mg2SiO4 ringwoodite (1 wt% H2O) breaks down to silica + bridgmanite + ferropericlase at pressures up to 60 GPa and 2100 K. The recovered silica samples contain 0.3-1.1 wt% H2O, suggesting that water stabilizes silica even under Si-undersaturated systems because of their large water storage capacity. Therefore, our observations support the stability of silica in hydrous regions in the pyrolitic lower mantle. In the subducting oceanic crust (basalt and sediment), silica represents 20-80% of the mineralogy. Because its stability range spans the mantle transition zone to the deep mantle, hydrous silica is expected to play a major role in the transport and storage of water in the deep mantle.
DS201907-1560
2019
Prakapenka, V.Martirosyan, N.S., Litasov, K.D., Lobanov, S.S., Goncharov, A.F., Shatskiy, A., Ohfuji, H., Prakapenka, V.The Mg carbonate Fe interaction: implication for the fate of subducted carbonates and formation of diamond in the lower mantle.Geoscience Frontiers, Vol. 10, pp. 1449-1458.Mantlecarbon cycle

Abstract: The fate of subducted carbonates in the lower mantle and at the core-mantle boundary was modelled via experiments in the MgCO3-Fe0 system at 70-150 GPa and 800-2600 K in a laser-heated diamond anvil cell. Using in situ synchrotron X-ray diffraction and ex situ transmission electron microscopy we show that the reduction of Mg-carbonate can be exemplified by: 6MgCO3 + 19Fe = 8FeO +10(Mg0.6Fe0.4)O + Fe7C3 + 3C. The presented results suggest that the interaction of carbonates with Fe0 or Fe0-bearing rocks can produce Fe-carbide and diamond, which can accumulate in the D’’ region, depending on its carbon to Fe ratio. Due to the sluggish kinetics of the transformation, diamond can remain metastable at the core-mantle boundary (CMB) unless it is in a direct contact with Fe-metal. In addition, it can be remobilized by redox melting accompanying the generation of mantle plumes.
DS201908-1778
2019
Prakapenka, V.Hao, M., Pierotti, C., Tkachev, S., Prakapenka, V., Zhang, J.The anisotropic omphacite in the Earth's upper mantle: implications for detecting eclogitic materials inside the Earth.www.minsocam.org /MSA/Centennial/ MSA_Centennial _Symposium.html The next 100 years of mineral science, June 20-21, p. 27. AbstractMantleeclogites

Abstract: Omphacite is a clinopyroxene solid solution of Fe-bearing diopside and jadeite, and is stable up to about 500 km depth in the Earth’s interior. It is also a major mineral component of eclogite (up to 75 vol%). Basalt, which makes up most of the Earth’s oceanic crust, transforms into eclogite at the depth > ~60 km. Due to the ~20% higher density of eclogite, it is considered one of the main driving forces for the slab subduction. Subducted eclogite is also an important source of the chemical heterogeneities in the Earth’s mantle, which are the potential reservoirs for the enriched geochemical components. Thus, studying the geophysical properties of omphacite at elevated pressure-temperature conditions is of great interest for both the geophysical and geochemical community. Previous studies have proposed to utilize the unique anisotropic seismic properties of eclogite to identify possible subduction channels and eclogite-rich regions in the Earth’s interior. Due to the elastically isotropic nature of garnet and the relatively small proportion (< 10 vol%) of the silica minerals in eclogite, the seismic anisotropy of eclogite is primarily caused by the lattice preferred orientation of omphacite. Thus, in this study, in addition to determining the densities, and isotropic velocities of omphacite at the high pressuretemperature condition, we also paid special attention to the elastic anisotropy of omphacite. We combined the synchrotron single-crystal X-ray diffraction at Advanced Photon Source, Argonne National Laboratory with offline Brillouin spectroscopy experiments at University New Mexico to investigate the anisotropic thermoelastic properties of omphacite. Incorporated with the preexisting thermoelastic database of other relevant mantle mineral phases, we compared the anisotropic seismic properties of eclogite (slab crust) with pyrolite (ambient mantle) along mantle geotherms down to 500 km depth. The maximum isotropic and anisotropic velocities contrast between pyrolite and eclogite is at 310-410 km, making it an optimal depth range for seismologists to search for eclogite-rich heterogeneities in the Earth’s interior. The ~5%-7% velocity difference between eclogite and pyrolite also needs to be taken into account when estimating the slab temperatures between 310-410 km depth. Otherwise, the slab temperature could be underestimated by a few hundred K without considering the possible lithology difference.
DS202006-0927
2020
Prakapenka, V.Ko, B., Prakapenka, V., Kunz, M., Prescher, C., Leinenweber, K., Shim, S-H.Mineralogy and density of Archean volcanic crust in the mantle transition zone.Physics of the Earth and Planetary Interiors, Vol. 305, 13p. PdfMantledensity

Abstract: The composition of Archean volcanic crust can be characterized by a higher Mg/Si ratio than modern mid-ocean ridge basalt (MORB), because of the higher degree melting from the warmer mantle in the Archean. Although modern MORB may become less dense than the surrounding mantle beneath the mantle transition zone (MTZ), the Mg-rich composition of Archean volcanic crust may result in the different density, and therefore different sinking behavior near the MTZ. In order to understand the compositional effect of Archean volcanic crust on the sinking behaviors and the scale of mantle mixing in the Archean, we investigated the mineralogy and density of Archean volcanic crust near the MTZ (470-910 km-depth). We conducted experiments at 19-34 GPa and 1400-2400 K using the laser-heated diamond anvil cell (LHDAC) combined with in-situ X-ray diffraction (XRD). The in-situ XRD and the chemical analysis revealed that Archean volcanic crust forms garnet and ringwoodite (84 and 16 vol%, respectively), which gradually transforms to Brg and CaPv (82 and 18 vol%, respectively) at 23-25 GPa and 1800 K. Our in-situ XRD experiments allowed us to measure the volumes of stable phases and to estimate their densities at high pressure and temperature. The results suggest that Archean volcanic crust maintains greater density than the pyrolitic mantle in the Archean regardless of temperature at 20-34 GPa (570-850 km-depth), promoting further sinking into the deeper mantle in the Archean. We also considered the density of the subducting slab in the Archean. The density model showed that the subducting slab is still denser or at least equally dense as the surrounding pyrolitic mantle in the Archean.
DS202008-1410
2020
Prakapenka, V.Ko, B., Prakapenka, V., Kunz, M., Prescher, C., Leinenweber, K., Shim, S-H.Mineralogy and density of Archean volcanic crust in the mantle transition zone.Physics of the Earth and Planetary Interiors, Vol. 305, 13p. PdfMantlesubduction

Abstract: The composition of Archean volcanic crust can be characterized by a higher Mg/Si ratio than modern mid-ocean ridge basalt (MORB), because of the higher degree melting from the warmer mantle in the Archean. Although modern MORB may become less dense than the surrounding mantle beneath the mantle transition zone (MTZ), the Mg-rich composition of Archean volcanic crust may result in the different density, and therefore different sinking behavior near the MTZ. In order to understand the compositional effect of Archean volcanic crust on the sinking behaviors and the scale of mantle mixing in the Archean, we investigated the mineralogy and density of Archean volcanic crust near the MTZ (470-910 km-depth). We conducted experiments at 19-34 GPa and 1400-2400 K using the laser-heated diamond anvil cell (LHDAC) combined with in-situ X-ray diffraction (XRD). The in-situ XRD and the chemical analysis revealed that Archean volcanic crust forms garnet and ringwoodite (84 and 16 vol%, respectively), which gradually transforms to Brg and CaPv (82 and 18 vol%, respectively) at 23-25 GPa and 1800 K. Our in-situ XRD experiments allowed us to measure the volumes of stable phases and to estimate their densities at high pressure and temperature. The results suggest that Archean volcanic crust maintains greater density than the pyrolitic mantle in the Archean regardless of temperature at 20-34 GPa (570-850 km-depth), promoting further sinking into the deeper mantle in the Archean. We also considered the density of the subducting slab in the Archean. The density model showed that the subducting slab is still denser or at least equally dense as the surrounding pyrolitic mantle in the Archean.
DS202010-1832
2020
Prakapenka, V.Chen, H., Leinenweber, K., Prakapenka, V., Kunz, M., Bechtel, H.A., Liu, Z., Shim, S-H.Phase transformation of hydrous ringwoodite to the lower-mantle phases and the formation of hydrous silica.American Mineralogist, Vol. 105, pp. 1342-1348. pdfMantlebridgmanite

Abstract: To understand the effects of H2O on the mineral phases forming under the pressure-temperature conditions of the lower mantle, we have conducted laser-heated diamond-anvil cell experiments on hydrous ringwoodite (Mg2SiO4 with 1.1 wt% H2O) at pressures between 29 and 59 GPa and temperatures between 1200 and 2400 K. Our results show that hydrous ringwoodite (hRw) converts to crystalline dense hydrous silica, stishovite (Stv) or CaCl2-type SiO2 (mStv), containing 1 wt% H2O together with Brd and MgO at the pressure-temperature conditions expected for shallow lower-mantle depths between approximately 660 to 1600 km. Considering the lack of sign for melting in our experiments, our preferred interpretation of the observation is that Brd partially breaks down to dense hydrous silica and periclase (Pc), forming the phase assembly Brd + Pc + Stv. The results may provide an explanation for the enigmatic coexistence of Stv and Fp inclusions in lower-mantle diamonds.
DS200612-0863
2006
Prakapenka, V.B.Mao, W.L., Mao, H-K., Sturhahn, W., Zhao, J., Prakapenka, V.B., Meng, Y., Shu, J., Hemley, R.J.Iron rich post perovskite and the origin of ultralow-velocity zones.Science, Vol. 312, April 28, pp. 564-565.MantleGeophysics - seismics, silicate
DS201112-0154
2011
Prakapenka, V.B.Catalli, K., Shim, S-H., Dera, P., Prakapenka, V.B., Zhao, J., Sturhahn, W., Chow, P., Xiao, Y., Cynn, H., Evans, W.J.Effects of the Fe3 +spin transition on the properties of aluminous perovskite - new insights for lower mantle seismic heterogeneities.Earth and Planetary Science Letters, Vol. 310, 3-4, pp. 293-302.MantlePerovskite
DS201112-0729
2011
Prakapenka, V.B.Naygina, O., Dubrovinsky, L.S., McCammon, C.A., Kurnosov, A., Kantor, I.Y., Prakapenka, V.B., Dubrovinskaia, N.A.X-ray diffraction and Mossbauer spectroscopy study of fcc iron hydride FeH at high pressures and implications for the composition of the Earth's core.Earth and Planetary Science Letters, Vol. 307, 3-4, pp. 409-414.MantleHydrogen budget
DS201412-0547
2014
Prakapenka, V.B.Mao, Z., Lin, J-F., Yang, J., Bian, H., Liu, J., Watson, H.C., Huang, S., Chen, J., Prakapenka, V.B., Xiao, Y., Chow, P.Fe, Al bearing post-perovskite in the Earth's lower mantle.Earth and Planetary Science Letters, Vol. 403, pp. 157-163.MantlePerovskite
DS201412-0711
2014
Prakapenka, V.B.Prescher, C., Langenhorst, F., Dubrovinsky, L.S., Prakapenka, V.B., Miyajima, N.The effect of Fe spin crossovers on its partitioning behavior and oxidation state in a pyrolitic Earth's lower mantle system.Earth and Planetary Science Letters, Vol. 399, pp. 86-91.MantleOxidation
DS201610-1893
2016
Prakapenka, V.B.Pamato, M.G., Kurnosov, A., Boffa Ballaran, T., Frost, D.J., Ziberna, L., Gianni, M., Speziale, S., Tkachev, S.N., Zhuravlev, K.K., Prakapenka, V.B.Single crystal elasticity of majoritic garnets: stagnant slabs and thermal anomalies at the base of the transition zone.Earth and Planetary Science Letters, Vol. 451, pp. 114-124.MantleSubduction

Abstract: The elastic properties of two single crystals of majoritic garnet (Mg3.24Al1.53Si3.23O12 and Mg3.01Fe0.17Al1.68Si3.15O12), have been measured using simultaneously single-crystal X-ray diffraction and Brillouin spectroscopy in an externally heated diamond anvil cell with Ne as pressure transmitting medium at conditions up to ?30 GPa and ?600 K. This combination of techniques makes it possible to use the bulk modulus and unit-cell volume at each condition to calculate the absolute pressure, independently of secondary pressure calibrants. Substitution of the majorite component into pyrope garnet lowers both the bulk (KsKs) and shear modulus (G ). The substitution of Fe was found to cause a small but resolvable increase in KsKs that was accompanied by a decrease in ?Ks/?P?Ks/?P, the first pressure derivative of the bulk modulus. Fe substitution had no influence on either the shear modulus or its pressure derivative. The obtained elasticity data were used to derive a thermo-elastic model to describe VsVs and VpVp of complex garnet solid solutions. Using further elasticity data from the literature and thermodynamic models for mantle phase relations, velocities for mafic, harzburgitic and lherzolitic bulk compositions at the base of Earth's transition zone were calculated. The results show that VsVs predicted by seismic reference models are faster than those calculated for all three types of lithologies along a typical mantle adiabat within the bottom 150 km of the transition zone. The anomalously fast seismic shear velocities might be explained if laterally extensive sections of subducted harzburgite-rich slabs pile up at the base of the transition zone and lower average mantle temperatures within this depth range.
DS201710-2219
2017
Prakapenka, V.B.Cerantola, V., Bykova, E., Kupenko, I., Merlini, M., Ismailova, L., McCammon, C., Bykov, M., Chumakov, A.I., Petitgirard, S., Kantor, I., Svityk, V., Jacobs, J., Hanfland, M., Mezouar, M., Prescher, C., Ruffer, R., Prakapenka, V.B., Duvbovinsky, L.How iron carbonates help form diamonds.Nature Communications, July 18 #15960Mantlecarbonate inclusions
DS201804-0686
2018
Prakapenka, V.B.Dorfman, S.M., Badro, J., Nabiel, F., Prakapenka, V.B., Cantoni, M., Gillet, P.Carbonate stability in the reduced lower mantle.Earth and Planteray Science Letters, Vol. 489, pp. 84-91.Mantlecarbonate

Abstract: Carbonate minerals are important hosts of carbon in the crust and mantle with a key role in the transport and storage of carbon in Earth's deep interior over the history of the planet. Whether subducted carbonates efficiently melt and break down due to interactions with reduced phases or are preserved to great depths and ultimately reach the core-mantle boundary remains controversial. In this study, experiments in the laser-heated diamond anvil cell (LHDAC) on layered samples of dolomite (Mg,?Ca)CO3 and iron at pressure and temperature conditions reaching those of the deep lower mantle show that carbon-iron redox interactions destabilize the MgCO3 component, producing a mixture of diamond, Fe7C3, and (Mg,?Fe)O. However, CaCO3 is preserved, supporting its relative stability in carbonate-rich lithologies under reducing lower mantle conditions. These results constrain the thermodynamic stability of redox-driven breakdown of carbonates and demonstrate progress towards multiphase mantle petrology in the LHDAC at conditions of the lowermost mantle.
DS201805-0981
2018
Prakapenka, V.B.Sun, N., Wei, W., Han, S., Song, J., Li, X., Duan, Y., Prakapenka, V.B., Mao, Z.Phase transition and thermal equations of state of (Fe, Al) -bridgmanite and post perovskite: implication for the chemical heterogeneity at the lowermost mantle.Earth Planetary Science Letters, Vol. 490, pp. 161-169.Mantleperovskite
DS201805-0984
2018
Prakapenka, V.B.Tschauner, O., Huang, S., Greenberg, E., Prakapenka, V.B., Ma, C., Rossman, G.R., Shen, A.H., Zhang, D., Newville, M., Lanzirotti, A., Tait, K.Ice-VII inclusions in diamonds: evidence for aqueous fluid in the Earth's deep mantle. Orapa, ShandongScience, Vol. 359, pp. 1136-1139.Africa, South Africa, Botswana, Congo, Sierra Leone, Chinadiamond inclusions
DS201809-2103
2018
Prakapenka, V.B.Tschauner, O., Huang, S., Wu, Z., Gtreenberg, E., Prakapenka, V.B.Ice-VII inclusions in ultradeep diamonds. Goldschmidt Conference, 1p. AbstractAfrica, South Africa, China, United States, Canada, South Americadiamond inclusions

Abstract: We present the first evidence for inclusions of ice-VII in diamonds from southern Africa, China, North- and South-America [1]. Combining synchrotron X-ray diffraction, - X-ray fluorescence and IR spectroscopy, we show the presence of ice-VII as inclusions in diamonds that have formed at depth > 410 km to about 800 km in the Earth's mantle. What is now crystalline ice-VII, a high pressure polymorph of water-ice, was component of an aqueous fluid entrapped in the diamonds that were growing in the deep mantle. Because of the confinement by the host diamonds, the inclusions retain high pressures. The same holds for inclusions of magnesian calcite, halite, and ilmenite found in the same diamond specimens. These inclusions reflect the presence of aqueous and carbonaceous fluids in the mantle transition zone and the shallow lower mantle. Using their current residual pressures and the equations of state, we can reconstruct their recovery paths [2,3]. Further, we can use the intersection of modelled recovery paths to better constrain the encapsulation pressure and temperature of these inclusions in diamonds.
DS201901-0083
2018
Prakapenka, V.B.Sun, N., Wei, W., Han, S., Song, J., Li, X, Duan, Y., Prakapenka, V.B., Mao, Z.Phase transition and thermal equations of state of ( Fe, Al) - bridgmanite and post-perovskite: implication for the chemical heterogeneity at the lowermost mantle.Earth and Planetary Science Letters, Vol. 490, 1, pp. 161-169.Mantlegeothermometry

Abstract: In this study, we have determined the phase boundary between Mg0.735Fe0.21Al0.07Si0.965O3-Bm and PPv and the thermal equations of state of both phases up to 202 GPa and 2600 K using synchrotron X-ray diffraction in laser heated diamond anvil cells. Our experimental results have shown that the combined effect of Fe and Al produces a wide two-phase coexistence region with a thickness of 26 GPa (410 km) at 2200 K, and addition of Fe lowers the onset transition pressure to 98 GPa at 2000 K, consistent with previous experimental results. Furthermore, addition of Fe was noted to reduce the density (?) and bulk sound velocity () contrasts across the Bm-PPv phase transition, which is in contrast to the effect of Al. Using the obtained phase diagram and thermal equations of state of Bm and PPv, we have also examined the effect of composition variations on the ? and profiles of the lowermost mantle. Our modeling results have shown that the pyrolitic lowermost mantle should be highly heterogeneous in composition and temperature laterally to match the observed variations in the depth and seismic signatures of the D? discontinuity. Normal mantle in a pyrolitic composition with ?10% Fe and Al in Bm and PPv will lack clear seismic signature of the D? discontinuity because the broad phase boundary could smooth the velocity contrast between Bm and PPv. On the other hand, Fe-enriched regions close to the cold slabs may show a seismic signature with a change in the velocity slope of the D? discontinuity, consistent with recent seismic observations beneath the eastern Alaska. Only regions depleted in Fe and Al near the cold slabs would show a sharp change in velocity. Fe in such regions could be removed to the outer core by strong core-mantle interactions or partitions together with Al to the high-pressure phases in the subduction mid ocean ridge basalts. Our results thus have profound implication for the composition of the lowermost mantle.
DS201912-2799
2019
Prakapenka, V.B.Liu, J., Hu, Q., Bi, W., Yang, L., Xiao, Y., Chow, P., Meng, Y., Prakapenka, V.B., Mao, H-K., Mao, W.L.Altered chemistry of oxygen and iron under deep Earth conditionsNature Communications, 8p. PdfMantlegeochemistry

Abstract: A drastically altered chemistry was recently discovered in the Fe-O-H system under deep Earth conditions, involving the formation of iron superoxide (FeO2Hx with x?=?0 to 1), but the puzzling crystal chemistry of this system at high pressures is largely unknown. Here we present evidence that despite the high O/Fe ratio in FeO2Hx, iron remains in the ferrous, spin-paired and non-magnetic state at 60-133?GPa, while the presence of hydrogen has minimal effects on the valence of iron. The reduced iron is accompanied by oxidized oxygen due to oxygen-oxygen interactions. The valence of oxygen is not -2 as in all other major mantle minerals, instead it varies around -1. This result indicates that like iron, oxygen may have multiple valence states in our planet’s interior. Our study suggests a possible change in the chemical paradigm of how oxygen, iron, and hydrogen behave under deep Earth conditions.
DS202104-0590
2021
Prakapenka, V.B.Lv, M., Dorfman, S.M., Badro, J., Borensztajin, S., Greenberg, E., Prakapenka, V.B.Reversal of carbonate-silicate cation exchange in cold slabs in Earth's lower mantle. Nature Communications, doi.org/10.10.1038 /s41467-021-21761-9 8p. PdfMantlediamond inclusions

Abstract: The stable forms of carbon in Earth’s deep interior control storage and fluxes of carbon through the planet over geologic time, impacting the surface climate as well as carrying records of geologic processes in the form of diamond inclusions. However, current estimates of the distribution of carbon in Earth’s mantle are uncertain, due in part to limited understanding of the fate of carbonates through subduction, the main mechanism that transports carbon from Earth’s surface to its interior. Oxidized carbon carried by subduction has been found to reside in MgCO3 throughout much of the mantle. Experiments in this study demonstrate that at deep mantle conditions MgCO3 reacts with silicates to form CaCO3. In combination with previous work indicating that CaCO3 is more stable than MgCO3 under reducing conditions of Earth’s lowermost mantle, these observations allow us to predict that the signature of surface carbon reaching Earth’s lowermost mantle may include CaCO3.
DS202205-0679
2022
Prakapenka, V.B.Dutta, R., Tracy, S.J., Cohen, R.E. , Miozzi, F., Luo, K., Yang, J., Burnley, P.C., Smith, D., Meng, Y., Chariton, S., Prakapenka, V.B., Duffy, T.S.Ultrahigh-presssure disordered eight-coordinated phase of Mg2GeO4: analogue for super Earth mantles. GermaniumPNAS, https://doi.org/10.1073/pnas.2114424119Mantlegeodynamics

Abstract: Mg2GeO4 is important as an analog for the ultrahigh-pressure behavior of Mg2SiO4, a major component of planetary interiors. In this study, we have investigated magnesium germanate to 275 GPa and over 2,000 K using a laser-heated diamond anvil cell combined with in situ synchrotron X-ray diffraction and density functional theory (DFT) computations. The experimental results are consistent with the formation of a phase with disordered Mg and Ge, in which germanium adopts eightfold coordination with oxygen: the cubic, Th3P4-type structure. DFT computations suggest partial Mg-Ge order, resulting in a tetragonal I4Ż2d structure indistinguishable from I4Ż3d Th3P4 in our experiments. If applicable to silicates, the formation of this highly coordinated and intrinsically disordered phase may have important implications for the interior mineralogy of large, rocky extrasolar planets.
DS2000-0775
2000
Prakasa, R.G.S.Prakasa, R.G.S., Tewari, H.C., Rao, V.K.Velocity structure in parts of the Gondwana Godavari GrabenJournal of Geological Society India, Vol. 56, No. 4, Oct. 1, pp. 373-84.IndiaTectonics, Graben - not specific to diamonds
DS1988-0553
1988
Prakasa Rao, T.K.S.Prakasa Rao, T.K.S.Interpretation of magnetic gradient anomalies using characteristic positions of qui-angular seperation: geological contact and veinGeoexploration, Vol. 25, pp. 199-209GlobalGeophysics, Theoretical application
DS2003-0522
2003
Prakasam, K.S.Gupta, S., Rai, S.S., Prakasam, K.S., Srinagesh, D., Basal, B.K., Chadha, R.K.The nature of the crust in southern India: implications for Precambrian crustal evolutionGeophysical Research Letters, Vol. 30, 8, 10.1029/2002GLO16770IndiaTectonics
DS2003-0523
2003
Prakasam, K.S.Gupta, S., Rai, S.S., Prakasam, K.S., Sringesh, D., Chadha, R.K., Priestly, K.First evidence for anomalous thick crust beneath mid Archean western Dharwar cratonCurrent Science, Vol. 84, 9, pp. 1219-26.IndiaCraton
DS2003-1100
2003
Prakasam, K.S.Prakasam, K.S., Rai, S.S.Crustal thickening and composition in eastern Dharwar CratonMemoirs Geological Society of India, Vol. 53, pp. 115-128. Ingenta 1035483299IndiaBlank
DS200412-0750
2003
Prakasam, K.S.Gupta, S., Rai, S.S., Prakasam, K.S., Srinagesh, D., Basal, B.K., Chadha, R.K., Priestly, K., Gaur, V.K.The nature of the crust in southern India: implications for Precambrian crustal evolution.Geophysical Research Letters, Vol. 30, 8, 10.1029/2002 GLO16770IndiaTectonics
DS200412-0751
2003
Prakasam, K.S.Gupta, S., Rai, S.S., Prakasam, K.S., Sringesh, D., Chadha, R.K., Priestly, K., Gaur, V.K.First evidence for anomalous thick crust beneath mid Archean western Dharwar craton.Current Science, Vol. 84, 9, pp. 1219-26.IndiaCraton
DS200412-1576
2003
Prakasam, K.S.Prakasam, K.S., Rai, S.S.Crustal thickening and composition in eastern Dharwar Craton.Memoirs Geological Society of India, Vol. 53, pp. 115-128. Ingenta 1035483299IndiaGeochemistry
DS200912-0292
2009
Prakasam, K.S.Heintz, M., Kumar, V.P., Gaur, V.K., Priestly, K., Rai, S.S., Prakasam, K.S.Anisotropy of the Indian continental lithospheric mantle.Geophysical Journal International, Vol. 179, 3, pp. 1341-1360.IndiaGeodynamics
DS201112-0762
2011
Prakasam, K.S.Oreshin, S.I., Vinnik, L.P., Kiselev, S.G., Rai, S.S., Prakasam, K.S., Treussov, A.V.Deep seismic structure of the Indian shield, western Himalaya, Ladakh, and Tibet.Earth and Planetary Science Letters, Vol. 307, 3-4, pp. 415-429.IndiaSubduction
DS1994-1404
1994
Prakash, P.Prakash, P.Correlation of geological and aeromagnetic dat a to assess the potential for kimberlite rock.Geological Survey India Special Paper Ground evaluation Airborne Geophys, No. 35, pp. 123-130.IndiaGeophysics, Wajrakur-Lattavaram, Anantpur
DS1993-0020
1993
Pranzini, E.Alberti, A., Alessandro, V., Pieruccini, U., Pranzini, E.Land sat Thematic Mapperdat a processing for lithological discrimination in the Caraculoarea (Namibe Province, southwest Angola).Journal of African Earth Sciences, Vol. 17, No. 3, October pp. 261-274.AngolaLandsat -not specific to diamonds, Remote sensing, lithology
DS1998-1183
1998
Prasad, B.R.Prasad, B.R., Tewari, H.C., Reddy, P.R.Structure and tectonics of the Proterozoic Aravalli Delhi fold belt in northwest India from a deep seismic ....Tectonophysics, Vol. 288, No. 1-4, Mar. pp. 31-42.IndiaTectonics, Geophysics - seismic
DS200712-0870
2007
Prasad, B.R.Rao, V.V., Sain, K., Prasad, B.R.Dipping Moho in the southern part of Eastern Dharwar Craton, India as revealed by the coincident seismic reflection and refraction study.Current Science, Vol. 93, 3, Aug. 10, pp. 330-336.IndiaGeophysics - seismics
DS200612-0484
2006
Prasad, C.V.R.K.Goutham, M.R., Raghubabu, K., Prasad, C.V.R.K., Subbarao, K.V., Reddy, V.D.A Neoproterozoic geomagnetic field reversal from the Kurnool Group, India: implications for stratigraphic correlation and formation of Gondwana.Journal of the Geological Society of India, Vol. 67, 2, pp. 221-233.Asia, IndiaGeophysics - magnetics, paleomagnetism
DS1984-0596
1984
Prasad, E.A.V.Prasad, E.A.V., Saradhi, D.V.Termite Mounds in Geochemical ProspectingCurrent Science., Vol. 53, No. 12, JUNE 20TH. PP. 649-651.India, KondapalliGeochemistry
DS200612-1226
2005
Prasad, G.J.S.Sastry, C.A., Rama Rao, G., Prasad, G.J.S., Reddy, V.A.Electro probe micro analysis of indicator minerals from kimberlites of Andhra Pradesh and Karnataka.Geological Survey of India, Bulletin, C6, 282p. Cited in GJSI. 67, 2, p. 280.India, Andhra Pradesh, KarnatakaGeochemistry
DS202005-0730
2020
Prasad, G.V.R.Fareeduddin., Pant, N.C., Gupta, S., Chakraborty, P., Sensarma, S., Jain, A.K., Prasad, G.V.R., Srivastava, P., Rjan, S., Tiwari, V.M.The geodynamic evolution of the Indian subcontinent - an introduction.Episodes ( IUGS), Vol. 43, 1, pp. 1-18.Indiacarbonatite
DS202009-1627
2020
Prasad, G.V.R.Fareeduddin, Pant, N.C., Gupta, S., Chakraborty, P., Sensarma, S., Jain, A.K., Prasad, G.V.R., Srivastava, P., Rajan, S., Tiwari, V.M.The geodynamic evolution of the Indian subcontinent - an introduction.Episodes, Vol. 43, 1, pp. 8p.Indiacarbonatites
DS200612-1108
2006
Prasad, K.C.Prasad, K.C., Van Koppen, B., Strzepek, K.Equity and productivity in the Olifants River Basin, South Africa.Natural Resources Forum, Vol. 30, 1, Feb pp. 63-75.Africa, South AfricaSocial responsibility
DS201705-0815
2017
Prasad, K.R.Chandra Phani, P.R., Ningam, N., Prasad, K.R.Cr-diopsides from Lattavaram and Kalyanadurgam kimberlites, Anatapur district, Andhra Praseh, southern India: inferences from loam sampling.Department of Geophysics, University College of Science Osmania University, Hyderabad 500 007, March 16, 17, Role of Geophysics in Earth and Environmental studies: special emphasis on mineral exploration 1p. AbstractIndiaDeposit - Lattavaram, Kalyanadurgam
DS2001-0352
2001
Prasad, N.Gandhi, S.S., Mortensen, J.K., Prasad, N., Van BreemenMagmatic evolution of the southern Great Bear continental arc, northwestern Canadian shield....Canadian Journal of Earth Sciences, Vol. 38, No. 5, May, pp. 767-85.Northwest TerritoriesGeochronology - Slave Craton
DS200512-0871
2005
Prasad, R.Prasad, R.Diamond radiation detectors.Rough Diamond Review, No. 8, March pp.13-14.Technology
DS201707-1358
2017
Prasad, R.Prasad, R.Cr-diopsides from Lattavaram and Kalyanadurgam kimberlites, Anantapur district, southern India: inferences from loam sampling.Role of Geophysics in Earth and Environmental Studies , March 1p. AbstractIndiamineralogy

Abstract: A comparison of major element content in Cr-diopside mineral grains, from loam samples, of two kimberlite pipes each from Lattavaram (P-3 and P-4) and Kalyanadurgam (KL-1 and KL-2) clusters of Wajrakarur Kimberlite Field (WKF) has been presented here. The two selected Lattavaram pipes are well exposed whereas the Kalyanadurgam pipes are concealed under 1.5 to 2 meter thick alluvium and calcrete, which is endowed with easily identifiable kimberlitic indicator minerals (KIMs). The indicator minerals are mantle derived xenocrystic types like pyrope garnet, Cr-diopside, ilmenite, chromite and olivine which provide inferences on their petrogenesis. It is observed that Cr-diopside is a prominent mineral constituent in both these locations and plays a vital role in reconnaissance diamond exploration. Surface in-situ loam sampling was carried out and ~15 kg of sample has been collected, to segregate heavy minerals which were concentrated by panning and jigging. In total, 66 Cr-diopside grains in total; 26 from Lattavaram and 40 from Kalyanadurgam were picked under the microscope and studied for their major element geochemistry by EPMA. In Lattavaram area, 25 grains were identified to be of C5 class and one grain belongs to C3. In Kalyandurgam, it is observed that 39 grains belong to CP5 category and one grain to C2 class. The range of Cr2O3 weight% for Lattavaram samples is 0.94- 2.8 and that for Kalyanadurgam samples is 0.54- 6.34. It is envisaged that the entries of Fe, Al, Na, Ca, and Cr into the clinopyroxene structure are strongly affected by the P-T-X conditions during mineral crystallization. It is observed that the mantle derived kimberlitic Cr-diopside is low in Fe-content relative to that of crustal rocks. This study revealed that Cr-diopsides of investigated pipes are of kimberlitic nature and plot in the diamond inclusion field thereby signifying the prospectivity of the pipes.
DS200412-1844
2004
Prasad, R.N.Singh, Y., Singh, K.D.P., Prasad, R.N.Rb Sr whole rock isochron age of early Proterozoic potassic granite from Dharmawaram, Karimnagar district, Andhra Pradesh.Journal Geological Society of India, Vol. 64, 1, pp. 93-96.India, Andhra PradeshGeochronology - not specific to diamonds
DS1991-1374
1991
Prasada Rao, K.Prasada Rao, K., et al.Assessment of diamond resources in kimberlites of Venkatamalle-Lattavaramarea, Anatapur District, Andhra Prdesh.Records Geological Survey of India, Vol. 124, pt. 5, pp. 33-40.IndiaAlluvials, Diamonds
DS201911-2564
2019
Prasanth, M.Snatish, M., Tsunogae, T., Yang, C-X., Han, Y-S., Hari, K.R., Prasanth, M., Uthup, S.The Bastar craton, central India: a window to Archean-paleoproterozoic crustal evolution.Gondwana Research, in press available 69p. PdfIndiacraton

Abstract: The Bastar craton in central India, surrounded by cratonic blocks and Paleoproterozoic to Neoproterozoic orogenic belts, is a window to investigate the Archean-Paleoproterozoic crustal evolution and tectonic processes. Here we propose a new tectonic classification of the craton into the Western Bastar Craton (WBC), Eastern Bastar Craton (EBC), and the intervening Central Bastar Orogen (CBO). We present petrologic, geochemical and zircon U-Pb, REE and Lu-Hf data from a suite of rocks from the CBO and along the eastern margin of the WBC Including: (1) volcanic successions comprising meta-andesite and fine-grained amphibolite, representing arc-related volcanics along a convergent margin; (2) ferruginous sandstone, in association with rhyolite, representing a volcano-sedimentary succession, deposited in an active trench; and (3) metamorphosed mafic-ultramafic suite including gabbro, pyroxenite and dunite invaded by trondhjemite representing the section of sub-arc mantle and arc root adjacent to a long-lasting subduction system. Petrologic studies indicate that the mafic-ultramafic suite crystallized from an island arc tholeiitic parental magma in a suprasubduction zone environment. The chondrite-normalized and primitive mantle normalized diagrams of the mafic and ultramafic rocks suggest derivation from MORB magma. The mixed characters from N-MORB to E-MORB of the studied samples are consistent with subduction modification of a MORB related magma, involving partial melting of the metasomatized mantle wedge. Our zircon U-Pb age data suggest that the cratonic nuclei was constructed as early as Paleoarchean. We present evidence for active subduction and arc magmatism through Mesoarchean to Neoarchean and early Paleoproterozoic, with the trench remaining open until at least 2.3 Ga. Two major crust building events are recognized in the Bastar craton: during Mesoarchean (recycled Paleoarchean subduction-related as well as juvenile/depleted mantle components) and Neoarchean (accretion of juvenile oceanic crust, arc magmatism including granite batholiths and related porphyry mineralization). The final cratonization occurred during latest Paleoproterozoic, followed by collisional assembly of the craton and its incorporation within the Peninsular Indian mosaic during Mesoproterozoic. In the global supercontinent context, the craton preserves the history of Ur, the earliest supercontinent, followed by the Paleo-Mesoproterozoic Columbia, as well as minor thermal imprints of the Neoproterozoic Rodinia and associated Grenvillian orogeny.
DS202001-0037
2020
Prasanth, M.P.M.Santosh, M., Tsunogae, T., Yang, C-X., Han, T-S., Hari, K.R., Prasanth, M.P.M., Uthup, S.The Bastar craton, central India: a window to Archean - Paleoproterozic crustal evolution.Gondwana Research, Vol. 79, pp. 157-184.Indiacraton

Abstract: The Bastar craton in central India, surrounded by cratonic blocks and Paleoproterozoic to Neoproterozoic orogenic belts, is a window to investigate the Archean-Paleoproterozoic crustal evolution and tectonic processes. Here we propose a new tectonic classification of the craton into the Western Bastar Craton (WBC), Eastern Bastar Craton (EBC), and the intervening Central Bastar Orogen (CBO). We present petrologic, geochemical and zircon U-Pb, REE and Lu-Hf data from a suite of rocks from the CBO and along the eastern margin of the WBC Including: (1) volcanic successions comprising meta-andesite and fine-grained amphibolite, representing arc-related volcanics along a convergent margin; (2) ferruginous sandstone, in association with rhyolite, representing a volcano-sedimentary succession, deposited in an active trench; and (3) metamorphosed mafic-ultramafic suite including gabbro, pyroxenite and dunite invaded by trondhjemite representing the section of sub-arc mantle and arc root adjacent to a long-lasting subduction system. Petrologic studies indicate that the mafic-ultramafic suite crystallized from an island arc tholeiitic parental magma in a suprasubduction zone environment. The chondrite-normalized and primitive mantle normalized diagrams of the mafic and ultramafic rocks suggest derivation from MORB magma. The mixed characters from N-MORB to E-MORB of the studied samples are consistent with subduction modification of a MORB related magma, involving partial melting of the metasomatized mantle wedge. Our zircon U-Pb age data suggest that the cratonic nuclei was constructed as early as Paleoarchean. We present evidence for active subduction and arc magmatism through Mesoarchean to Neoarchean and early Paleoproterozoic, with the trench remaining open until at least 2.3?Ga. Two major crust building events are recognized in the Bastar craton: during Mesoarchean (recycled Paleoarchean subduction-related as well as juvenile/depleted mantle components) and Neoarchean (accretion of juvenile oceanic crust, arc magmatism including granite batholiths and related porphyry mineralization). The final cratonization occurred during latest Paleoproterozoic, followed by collisional assembly of the craton and its incorporation within the Peninsular Indian mosaic during Mesoproterozoic. In the global supercontinent context, the craton preserves the history of Ur, the earliest supercontinent, followed by the Paleo-Mesoproterozoic Columbia, as well as minor thermal imprints of the Neoproterozoic Rodinia and associated Grenvillian orogeny.
DS202111-1771
2021
Prasath, H.L.R.Kasuma, K.N., Prasath, H.L.R.Application of feature based principal component analysis (FPCA) technique on Landsat8 OLI multispectral data to map kimberlite pipes.Indian Journal of Science and Technology, 12p. PdfIndiaCraton - Dharwar

Abstract: Objectives: To map the kimberlite pipes emplaced in parts of Anantpur District, India using Landsat-8 OLI multispectral data. Kimberlite are considered as the primary host of natural diamond. Kimberlite pipes have very limited exposure and are altered, therefore the indirect surface indicators associated with kimberlite such as ferric iron bearing minerals (hematite, goethite), hydroxyl (clay) and carbonate (calcrete) minerals, were mapped to trace kimberlite pipe. Methods: Feature based Principal Component Analysis (FPCA) was applied over the OLI bands 2, 4, 5 and 6, and 2, 5, 6 and 7 to generate ferric iron (F image) and hydroxyl/carbonate image (H/C images). The color composite was generated by assigning RGB colours to F, H/C and F+H/C images. Findings: When matched with the pre-explored kimberlite pipe locations, it was observed that the kimberlitic pipes display different colours in the above colour composite. Hence, the Isodata clustering was carried out to segregate the classes, which resulted in 12 unique classes. Of these, the kimberlite pipes fall in 4 classes. However, due to the moderate resolution of OLI, false positive areas were also noted. Further the target area was found to be reduced by incorporating the structural control (lineament) over the emplacement of Kimberlite pipes. Novelty: The present work highlights the usefulness of the moderate resolution multispectral image in mapping the Kimberlite pipes in semiarid region, in absence of a hyperspectral sensor.
DS202106-0948
2021
Pratap, A. NaganjaneyuluKusham, B., Naick, P., Pratap, A. Naganjaneyulu, K.Magnetotelluric 3-D full tensor inversion in the Dharwar craton, India: mapping of subduction polarity and kimberlitic melt.Physics of the Earth and Planetary Interiors, Vol. 315, 106708, 13p. PdfIndiakimberlites

Abstract: Complex geological structures and processes that took place in the Dharwar craton formation make it difficult to understand the evolution history. 3-D magnetotelluric inversion is a challenging task for the imaging of sub-surface structures. Data at 40 stations in a gridded fashion are used in this study for inversion. A controversy exists regarding the subduction polarity between the eastern and western Dharwar craton. Based on the conductivity anomalies mapped in the sub-surface, the lithosphere can be divided into the shallower and deeper lithosphere. The study delineated several crustal and lithospheric upper mantle conductors. In the crustal region, several conductive features (~10 ?-m) are imaged in the western part, central, and eastern part of the profile. A new finding of this 3-D study is a conductor in the eastern Dharwar craton in the depth range of 65-140 km. The base of this conductor shows the graphite diamond stability field and is correlated with the kimberlites/lamproites present in the region. An uppermost mantle conductor is present at the depth range of 80-200 km in the central part of the study area. Sulphides and carbon-rich fluids could be one cause of the conductors mapped in the crust. The low electrical resistivity imaged in the deeper lithosphere could be due to the refertilization of the mantle scar in the Cretaceous age by the passage of several hotspots. The lithospheric thickness estimated beneath the Dharwar craton in this study is more than 200 km. This study reveals geophysical evidence for the eastward subduction polarity in the Dharwar craton.
DS201808-1762
2018
Pratap, B.Kusham, A., Pratap, B., Naick, P., Naganjaneyulu, K.Lithospheric architecture in the Archean Dharwar craton, India: a magnetotelluric model.Journal of Asian Earth Sciences, Vol. 183, pp. 43-53.Indiacraton

Abstract: oriented, 280?km long profile (from Yellapura to Sindhanur) with 22 magnetotelluric stations. Regional strike directions, estimated were ?5° and 13° for the crust and the lithospheric mantle respectively. Our results indicate in western Dharwar craton, presence of low resistivity zones in the crust besides two significant upper mantle conductive features within the highly resistive Archaean lithosphere. We analyze the available geophysical data that include heat flow, seismic tomography and magnetotellurics (MT) from the Dharwar craton. Our inference supports to the existence of a thick lithosphere. A thickness of more than 200?km is estimated for the lithosphere beneath the Dharwar craton by our magnetotelluric model. The study has brought out the presence of lithospheric upper mantle conductive features in the depth range of 100-200?km bounded to the west part of the magnetotelluric profile. Significant variations in conductivity are seen on either side of the Chitradurga shear zone. The conductive feature in the depth range 120-150?km is related with kimberlite melts and the conductive nature in the depth range 160-200?km is explained by refertilization process, as craton passed over the Marion (ca. 90?Ma) hotspot.
DS2002-1280
2002
Pratesi, G.Pratesi, G., Ciprani, C., Vishnevsky, S., Lo Giudice, A.FTIR spectroscopy study of impact diamonds18th. International Mineralogical Association Sept. 1-6, Edinburgh, abstract p.202.MantleImpact diamonds
DS2003-1101
2003
Pratesi, G.Pratesi, G., Lo Giudice, A., Vishnevky, S., Manfredotti, C., Cipriani, C.Cathodluminescence investigations on the Popigai Ries and Lappajarvi impactAmerican Mineralogist, Vol. 88, pp. 1778-87.Russia, Siberia, FinlandMeteorite
DS200412-1577
2003
Pratesi, G.Pratesi, G., Lo Giudice, A., Vishnevky, S., Manfredotti, C., Cipriani, C.Cathodluminescence investigations on the Popigai Ries and Lappajarvi impact diamonds.American Mineralogist, Vol. 88, pp. 1778-87.Russia, Siberia, Baltic ShieldMeteorite
DS201112-0821
2009
Pratesi, G.Pratesi, G.Impact diamonds: formation, mineralogical features and cathodluminescence properties.In: Cathodluminescence and its application in the planetary sciences, pp. 61-86.TechnologyCathodluminescence
DS202201-0035
2021
Pratesi, G.Pratesi, G., Franz, a., Hirata, A.It is hard to be a gem in a rhinestone world: a diamond Museum collection between history and science. ( Firenza)Geoheritage, Vol. 13, 103 Europe, ItalyFTIR spectroscopy

Abstract: The goal of this work is to investigate the diamond collection preserved at the Natural History Museum of the University of Firenze (MSN-FI) using a multidisciplinary approach. The mixed methods combine historical research with spectroscopic techniques to gain a deeper understanding of this collection of great historical, scientific and gemmological interest. This study concerns the analysis of 61 diamonds that are relatively small in both size and weight, mostly unworked and sometimes rich in inclusions. These specimens were acquired by MSN-FI from diverse collectors and institutions from 1824 until the most recent acquisitions in the 1990s. The FTIR spectroscopy was performed on 45 specimens. The results show the physical classification of diamonds in three groups (IaAB, IaA, and IaB) and reveal the presence of hydrogen as ethylene -CH?=?CH- or vinylidene?>?C?=?CH2 group.
DS201912-2816
2019
Prather, C.Prather, C., Mclean, S., Willis, D.Chidliak project updates.Yellowknife Forum NWTgeoscience.ca, abstract volume p. 71-72.Canada, Nunavutdeposit - Chidliak

Abstract: The Chidliak exploration site was discovered in 2005 and acquired by De Beers Canada (De Beers) in September 2018. The Project is located on the Hall Peninsula of Baffin Island in the Qikiqtani Region of Nunavut and the closest communities are the Hamlet of Pangnirtung and the City of Iqaluit. The current Chidliak exploration site is not located within Inuit Owned Lands, Territorial or National Parks and is located entirely within Crown Lands. The current Chidliak exploration site includes 30 kimberlites two of which (CH-06 and CH-07) have been tested for grade and diamond value and are considered to be at an Inferred level of resource confidence. De Beers is currently engaged in a concept study to evaluate various FutureSmart Mining methods that would minimize environment impacts and enable relatively small kimberlites (diamond bearing rock) to be mined. De Beers is conducting desktop and field studies to evaluate options for mining methods, infrastructure, processing, information technology, and employee work models. In parallel, environmental field programs were conducted in 2019 to advance the environmental data collected in 2009 to 2017 and to support the evaluation of mining options. This presentation will provide a brief synopsis of the Project and work conducted in 2019 to advance the Project.
DS201912-2817
2019
Prather, C.Prather, C., Mclean, S., Willis, D.Water monitoring at Snap Lake mine.Yellowknife Forum NWTgeoscience.ca, abstract volume p. 72.Canada, Northwest Territoriesdeposit - Snap Lake

Abstract: The Snap Lake Mine (the Mine) is a former underground diamond mine operated by De Beers Canada (De Beers), located about 220 kilometres northeast of Yellowknife in the Northwest Territories. The Snap Lake Mine operated from 2008 to 2015, and entered a Care and Maintenance mode in December 2015. In February 2017, the Mine underground workings were decommissioned and allowed to flood, in December 2017, De Beers announced the intent to enter into final closure, and in March 2019, De Beers submitted the Final Closure and Reclamation Plan for the Mine. Water management has always been an important component at the Mine and was considered in development of the Final Closure Plan to achieve the overall goal of “returning the site and affected areas around the Mine to technically viable and, where practicable, self-sustaining ecosystems that are compatible with a healthy environment and with human activities”. Water management at the Mine has changed significantly since diamond mining operations ceased. During diamond mining operations, a large volume of water was pumped from the underground to the surface for management and release to Snap Lake and the downstream environment. This mine water was relatively high in total dissolved solids and total suspended solids and therefore had to be treated prior to discharge. Now that the underground is flooded, there is no longer a need to pump mine water to the surface and water management has been greatly simplified. Since 2017, small volumes of runoff water from the North Pile (a surface disposal facility that was used for processed kimberlite, waste rock, and non-hazardous solid waste during operations) is collected for management and release to the underground and to Snap Lake. Water quality and aquatic ecosystem monitoring has been conducted yearly since pre-mining. Results of these programs have informed adaptive management at the site and informed plans for closure. The focus of this presentation is on water management and monitoring, for the Mine to the receiving environment, covering the history of the Mine to present and into planning for closure.
DS1998-1184
1998
Pratico, V.P.Pratico, V.P., Santiago, S.P.Metallic and industrial mineral assessment report on exploration for precious metals and diamond indicatorsAlberta Geological Survey, MIN 19980001, 3 CD's.Alberta, Fort McMurrayExploration - assessment
DS1930-0149
1933
PrattPrattDiamond... in Gems and Minerals of North CarolinaAmerican Mineralogist., Vol. 18, PP. 149-150.Appalachia, North CarolinaDiamond Occurrence
DS201906-1271
2019
Pratt, C.A.Barry, P.H., de Moor, J.M., Giovannelli, D., Schrenk, M., Hummer, D.R., Lopez, T., Pratt, C.A., Alpizar Segua, Y., Battaglia, A., Beaudry, A., Bini, G., Cascante, M., d'Errico, G., di Carlo, M., Fattorini, D., Fullerton, K., H+Gazel, E., Gonzalez, G., HalForearc carbon sink reduces long term volatile recycling into the mantle.Nature , 588, 7753, p. 487.Mantlecarbon

Abstract: Carbon and other volatiles in the form of gases, fluids or mineral phases are transported from Earth’s surface into the mantle at convergent margins, where the oceanic crust subducts beneath the continental crust. The efficiency of this transfer has profound implications for the nature and scale of geochemical heterogeneities in Earth’s deep mantle and shallow crustal reservoirs, as well as Earth’s oxidation state. However, the proportions of volatiles released from the forearc and backarc are not well constrained compared to fluxes from the volcanic arc front. Here we use helium and carbon isotope data from deeply sourced springs along two cross-arc transects to show that about 91 per cent of carbon released from the slab and mantle beneath the Costa Rican forearc is sequestered within the crust by calcite deposition. Around an additional three per cent is incorporated into the biomass through microbial chemolithoautotrophy, whereby microbes assimilate inorganic carbon into biomass. We estimate that between 1.2 × 108 and 1.3 × 1010 moles of carbon dioxide per year are released from the slab beneath the forearc, and thus up to about 19 per cent less carbon is being transferred into Earth’s deep mantle than previously estimated.
DS1910-0430
1914
Pratt, J.H.Pratt, J.H.The Occurrence and Utilization of Certain Mineral Resources of the Southern States.Science., Vol. 39, P. 403. ALSO: ELISHA MITCHELL SCI. SOC. Journal of, Vol.United States, Gulf Coast, Arkansas, Virginia, North Carolina, Georgia, AppalachiaDiamond Occurrences
DS1990-0679
1990
Pratt, L.M.Hayes, J.M., Pratt, L.M., Knoll, A.H.Organic geochemical and tectonic evolution of the midcontinent rift system:organic geochemistry and micropaleontology. Progress reportNational Technical Information Service DOE/ER/13978-2 22p. June 1, 1990 $ 15.00 United States, MidcontinentRift, Tectonics
DS201801-0050
2017
Pratt, M.J.Pratt, M.J., Wysession, M.E., Aleqabi, G., Wiens, D.A., Nyblade, A., Shore, P., Rambolamanana, G., Andriampenomanana, F., Rakotondraibe, T., Tucker, R.D., Barruol, G., Rindraharisaona, E.Shear velocity structure of the crust and upper mantle of Madagascar derived from surface wave tomography.Earth and Planetary Science Letters, Vol. 458, 1, pp.405-417.Africa, Madagascargeophysics - seismics

Abstract: The crust and upper mantle of the Madagascar continental fragment remained largely unexplored until a series of recent broadband seismic experiments. An island-wide deployment of broadband seismic instruments has allowed the first study of phase velocity variations, derived from surface waves, across the entire island. Late Cenozoic alkaline intraplate volcanism has occurred in three separate regions of Madagascar (north, central and southwest), with the north and central volcanism active until <1 Ma, but the sources of which remains uncertain. Combined analysis of three complementary surface wave methods (ambient noise, Rayleigh wave cross-correlations, and two-plane-wave) illuminate the upper mantle down to depths of 150 km. The phase-velocity measurements from the three methods for periods of 8-182 s are combined at each node and interpolated to generate the first 3-D shear-velocity model for sub-Madagascar velocity structure. Shallow (upper 10 km) low-shear-velocity regions correlate well with sedimentary basins along the west coast. Upper mantle low-shear-velocity zones that extend to at least 150 km deep underlie the north and central regions of recent alkali magmatism. These anomalies appear distinct at depths <100 km, suggesting that any connection between the zones lies at depths greater than the resolution of surface-wave tomography. An additional low-shear velocity anomaly is also identified at depths 50-150 km beneath the southwest region of intraplate volcanism. We interpret these three low-velocity regions as upwelling asthenosphere beneath the island, producing high-elevation topography and relatively low-volume magmatism.
DS1989-1237
1989
Pratt, T.Pratt, T., Culotta, R., Hauser, E., Nelson, D., Brown, L., Kaufman, S.Major Proterozoic basement features of the eastern midcontinent of North america revealed by recent COCORP profilingGeology, Vol. 17, No. 6, June pp. 505-509MidcontinentTectonics, Geophysics
DS1990-0378
1990
Pratt, T.Culotta, R.C., Pratt, T., Oliver, J.A tale of two sutures: COCORP's deep seismic surveys of the Grenville Province in the eastern U.S. midcontinent #2Geology, Vol. 18, No. 7, July pp. 646-649New York, Ohio, AlabamaMidcontinent, Tectonics, Geophysics-seis
DS1990-0379
1990
Pratt, T.Culotta, R.C., Pratt, T., Oliver, J.A tale of two sutures: COCORP's deep seismic surveys of the Grenville Province in the eastern U.S. midcontinent #1Geological Society of America (GSA) Abstracts with programs, Northeastern, Vol. 22, No. 2, p. 9New York, Ohio, AlabamaMidcontinent, Tectonics, Geophysics-seis
DS1991-1375
1991
Pratt, T.L.Pratt, T.L., Hauser, E.C., Hearn, T.M., Reston, T.J.Reflection polarity of the Midcrustal Surrency bright spot beneath southeastern Georgia. Testing the fluid hypothesisJournal of Geophysical Research, Vol. 96, No. B6, June 10, pp. 10, 145-10, 158GeorgiaGeophysics, Tectonics
DS1981-0243
1981
Pratt, W.P.Kisvarsanyi, E.B., Pratt, W.P., Heyl, A.V.Fluorine-thorium Rare Earth Bearing Kimberlite Carbonatite ComplexesUnited States Geological Survey (USGS) OPEN FILE REPORT., No. 81-0518, PP. 35-40.Missouri, United States, Central StatesBlank
DS1985-0541
1985
Pratt, W.P.Pratt, W.P.The midcontinent strategic and critical minerals project objectives andstatus, October 1985United States Geological Survey (USGS) Open File, No. 85-0597, 16pArkansas, Illinois, Iowa, Kansas, Kentucky, Minnesota, MissouriNebraska, Oklhaoma, South Dakota, Tennessee, Wisconsin, Midcontinent
DS1985-0542
1985
Pratt, W.P.Pratt, W.P.Midcontinent Strategic and Critical Minerals ProjectGeological Society of America (GSA), Vol. 17, No. 7, P. 692-3. (abstract.).United StatesMidcontinent, Basement Terranes
DS1987-0594
1987
Pratt, W.P.Pratt, W.P., Sims, P.K.The U.S. Midcontinent: a new frontier for mineral explorationEpsiodes, Vol. 10, No. 4, December pp. 303-307United StatesTectonics, Mid-continent
DS1989-1238
1989
Pratt, W.P.Pratt, W.P.Folio of midcontinent maps and cross sectionsUnited States Geological Survey (USGS) Open file, United States Geological Survey (USGS)-Missouri G.S. Symp: Mineral resource potential of, p. 32. (abstract.)MidcontinentList of maps
DS1989-1239
1989
Pratt, W.P.Pratt, W.P., Goldhaber, M.B.United States Geological Survey (USGS) -Missouri Geological Survey Symposium: Mineral resource potential of the mid-continentUnited States Geological Survey (USGS) Open file, No. 89-169, 45pMidcontinentResource potential
DS1990-1194
1990
Pratt, W.P.Pratt, W.P., Sims, P.K.The Midcontinent of the United States: permissive terrane for an olympic dam-type deposit?United States Geological Survey (USGS) Bulletin, No. B 1932, 81pMidcontinentCopper-uraniuM., Terrane
DS1990-1195
1990
Pratt, W.P.Pratt, W.P., Sims, P.K.The Midcontinent of the United States; permissive terrane for an Olympic Dam type deposit?United States Geological Survey (USGS) Bulletin, No. 1932, 81p. $ 4.50MidcontinentTectonics, Structure
DS1991-1376
1991
Pratt, W.P.Pratt, W.P., Siims, P.K.The Midcontinent of the United States -permissive terrane for an Olympic Dam type depositUnited States Geological Survey (USGS) Bulletin, No. 1932, 81pMissouriOlympic DaM., Copper-uraniuM.
DS1995-1516
1995
Pratt. T.L.Pratt. T.L.Crustal structure of the Mississippi embayment of the Central United States deep seismic reflection data.Geological Society of America (GSA) Abstracts, Vol. 27, No. 6, abstract p. A 194.GlobalReelfoot Rift, Tectonics
DS1998-0733
1998
PraveKennedy, M.J., Runnegar, B., Prave, Hoffmann, ArthurTwo or four Neoproterozoic glaciations?Geology, Vol. 26, No. 12, Dec. pp. 1059-63.Africa, CongoCraton - Congo, Kalahari, Geomorphology
DS1996-1138
1996
Prave, A.R.Prave, A.R.Tale of three cratons: tectonostratigraphic anatomy of the Damara Orogen in northwest Namibia ..assembly of GondwanaGeology, Vol. 24, No. 12, Dec. pp. 1115-8NamibiaGondwanaland, Tectonics, Orogeny, Craton
DS1996-1139
1996
Prave, A.R.Prave, A.R.Tale of three cratons: tectonostratigraphic anatomy of the Damara orogen:Namibia and the assembly of GondwanaGeology, Vol. 24, No. 12, Dec. pp. 1115-18.NamibiaTectonics, Congo Craton
DS1997-0300
1997
Prave, A.R.Durr, S.B., Dingeldey, D.P., Prave, A.R.Tale of three cratons: tectonostratigraphic anatomy of the Damara Orogen in northwest Namibia and the assembly ....Geology, Vol. 25, No. 12, Dec. pp. 1149-1150.NamibiaCraton, Damara Orogeny
DS201012-0346
2010
Prave, A.R.Kasemann, S.A., Prave, A.R., Fallick, A.E., Hawkesworth, C.J., Hoffmann, K-H.Neoproterozoic ice ages, boron isotopes, and ocean acidification: implications for a snowball Earth.Geology, Vol. 38, 9, pp. 775-778.MantleSnowball Earth
DS201412-0875
2014
Prave, A.R.Spencer, C.J., Cawood, P.A., Hawkesowrth, C.J., Raub, T.D., Prave, A.R., Roberts, N.M.W.Proterozoic onset of crustal reworking and collisional tectonics: reappraisal of the zircon oxygen isotope record.Geology, in press availableMantleTectonics
DS200712-0157
2007
Prave, T.Cawood, P.A., Nemchin, A.A., Strachan, R., Prave, T., Krabbendam, M.Sedimentary basin and detrital zircon record along East Laurentia and Baltica during assembly and breakup of Rodinia.Journal of the Geological Society, Vol. 164, pp. 257-275.Gondwana, Rodinia, BalticaRift basins
DS201912-2797
2019
Praveer, P.Kumar, R.K., Praveer, P., Rao, N.V.Chalapthi, Chakrabarti, R., Pandit, D.Petrogenesis of an alkaline lamprophyre ( camptonite) with ocean island basalt ( OIB)-affinity at the NW margin of the Cuddapah Basin, eastern Dharwar craton, southern India.Neues Jahbuch fur Mineralogy, Vol. 196, p2, pp. 149-177.Indiacamptonite

Abstract: We report petrology and geochemistry (including Sr and Nd isotopes) of a fresh lamprophyre at Ankiraopalli area at the north-western margin of Paleo-Mesoproterozoic Cuddapah basin, eastern Dharwar craton, southern India. Ankiraopalli samples possess a typical lamprophyre porphyritic-panidiomorphic texture with phenocrysts of kaersutite and diopside set in a plagioclase dominant groundmass. Combined mineralogy and geochemistry classify it as alkaline lampro- phyre in general and camptonite in particular. Contrary to the calc-alkaline and/or shoshonitic orogenic nature portrayed by lamprophyres occurring towards the western margin of the Cuddapah basin, the Ankiraopalli samples display trace element composition revealing striking similarity with those of ocean island basalts, Italian alkaline lamprophyres and highlights an anorogenic character. However, the87 Sr/86 Srinitial (0.710316 to 0.720016) and ?Ndinitial (- 9.54 to - 9.61) of the Ankiraopalli lamprophyre show derivation from an 'enriched' mantle source showing long term enrichment of incompatible trace elements and contrast from those of (i) OIB, and (ii) nearby Mahbubnagar alkaline mafic dykes of OIB affinity. Combining results of this study and recent advances made, multiple mantle domains are identified in the Eastern Dharwar craton which generated distinct Mesoproterozoic lamprophyre varieties. These include (i) Domain I, involving sub-continental lithospheric mantle source essentially metasomatized by subduction-derived melts/fluids (represented by orogenic calcalkaline and/or shoshonitic lamprophyres at the Mudigubba, the Udiripikonda and the Kadiri); (ii) Domain II, comprising a mixed sub-continental lithospheric and asthenospheric source (represented by orogenic-anorogenic, alkaline to calc-alkaline transitional lamprophyres at the Korakkodu), and (iii) Domain III, representing a sub-continental lithospheric source with a dominant overprint of an asthenospheric (plume) component (represented by essentially alkaline lamprophyres at the Ankiraopalli). Our study highlights the varied mantle source heterogeneities and complexity of geodynamic processes involved in the Neoarchean-Paleo/Mesoproterozoic evolution of the Eastern Dharwar craton.
DS200812-0916
2008
Prawer, S.Prawer, S., Greentree, A.D.Diamond for quantum computing.Science, Vol. 320, 5883, June 20, p. 1601-2.TechnologyComputers
DS202010-1844
2020
Prawer, S.Genish, H., Ganesan, K., Stacey, A., Prawer, S., Rosenbluh, M.Effect of radiation damage on the quantum optical properties of nitrogen vacancies in diamond.Diamond & Related Materials, Vol. 109, 108049, 6p. PdfMantlenitrogen

Abstract: Single crystal diamond (<5?ppm nitrogen) containing native NV centers with coherence time of 150??s was irradiated with 2?MeV alpha particles, with doses ranging from 1012 ion/cm2 to 1015 ion/cm2. The effect of ion damage on the coherence time of NV centers was studied using optically detected magnetic resonance and supplemented by fluorescence and Raman microscopy. A cross-sectional geometry was employed so that the NV coherence time could be measured as a function of increasing defect concentration along the ion track. Surprisingly, although the ODMR contrast was found to decrease with increasing ion induced vacancy concentration, the measured decoherence time remained undiminished at 150us despite the estimated vacancy concentration reaching a value of 40?ppm at the end of range. These results suggest that ion induced damage in the form of an increase in vacancy concentration does not necessarily result in a significant increase in the density of the background spin bath.
DS1995-1517
1995
Precambrian 95Precambrian 95International conference on tectonics and metallogeny of early/mid Precambrian orogenic beltsPrecambrian 95, Aug 28 -Sept. 1QuebecConference -ad, Tectonics, metallogeny, crust, orogeny, Craton
DS1995-1518
1995
Precambrian 95Precambrian 95Abstract volume - ore genesis, stratiform, magmatic, gold, greenstonebelts, crust, PrecambrianPrecambrian 95, Volume, $ 35.00South America, West Africa, Quebec, Abitibi, IndiaBook -table of contents, Mountain bldg., mantle, tectonics, Superior, Orogeny
DS1991-1377
1991
Precambrian Geology -the dynamic evolution of the continental crustPrecambrian Geology -the dynamic evolution of the continental crustGoodwin, A.MAcademic Press, 660p. approx. $ 200.00GlobalArchean crust, Tectonics
DS1989-1240
1989
Precambrian ResearchPrecambrian ResearchSpecial issue: Proterozoic geochemistryPrecambrian Research, Vol. 45, No. 1-3, November pp. 1-250pCanada, Sweden, Finland, Norway, Africa, Ireland, ScotlandGeochemistry, Proterozoic
DS1990-1196
1990
Precambrian ResearchPrecambrian ResearchPrecambrian ore deposits related to tectonicsPrecambrian Research, Vol. 46, No. 1-2, January pp. 1-176GlobalTectonics, Precambrian ore deposits
DS1991-1378
1991
Precambrian ResearchPrecambrian ResearchPrecambrian granitoids petrogenesis, geochemistry and metallogenyPrecambrian Research, Vol. 51, No. 1-4, June pp. 1-440Ontario, Manitoba, Australia, New Jersey, Sweden, LabradorAlkaline rocks, Structure, geochemistry, porphyry-gold, geochronology
DS1992-1228
1992
Precambrian ResearchPrecambrian ResearchThe Archean Limpopo granulite belt: tectonics and crustal processesPrecambrian Research Special Issue, Vol. 55, No. 1-4, March 1992, 600pSouth AfricaStructure, Granulites
DS1992-1229
1992
Precambrian ResearchPrecambrian Research, Special IssuePrecambrian metallogeny related to plate tectonicsPrecambrian Research, Special Issue, Vol. 58, 450pGlobalMetallogeny, Plate tectonics, areas of interest
DS1994-1405
1994
Precambrian ResearchPrecambrian ResearchProterozoic paleomagnetism and paleogeographyPrecambrian Research, Vol. 69, No. 1-4, October pp. 1-340Canada, Scandinavia, Kenya, India, South AfricaProterozoic, Geophysics -Paleomagnetism
DS200812-0917
2007
Precigout, J.Precigout, J., Gueydan, F., Gapais, D., Garrido, C.J., Eassaifi, A.Strain localization in the subcontinental mantle ?? a ductile alternative to the brittle mantle.Tectonophysics, Vol. 445, 3-4, pp. 318-336.MantleSubduction
DS200912-0598
2009
Precigout, J.Precigout, J., Gueydan, F.Mantle weakening and strain localization: implications for the long term strength of the continental lithosphere.Geology, Vol. 37, 2, pp. 147-150.MantleDelamination
DS1992-1230
1992
Preciozzi, F.Preciozzi, F., Bourne, J.H.Petrography and geochemistry of the Arroyo de la Virgen and Isla Malaplutons, southern Uruguay: early Proterozoic tectonic implicationsJournal of South American Earth Sciences, Vol. 6, No. 3, October pp. 169-182UruguayGeochemistry, Tectonics
DS201112-0065
2011
Preciozzi, F.Basei, M.A.S., Peel, E., Sanchez Bettuci, L., Preciozzi, F., Nutman, A.P.The basement of the Punta del Este Terrane (Uruguay): an African Mesoproterozoic fragment at the eastern border of the South American Rio de la Plat a craton.International Journal of Earth Sciences, Vol. 100, 2, pp. 289-304.South America, UruguayCraton, Rodinia
DS200812-0918
2007
Preece, C.A.Preece, C.A., Liebenberg, B.Cave management at Finsch mine.Journal of South African Institute of Mining and Metallurgy, Vol. 107, 12, pp. 775-781.Africa, South AfricaMining
DS1993-1079
1993
Preinfalk, C.Mortenai, G., Preinfalk, C.The laterites of Araxa and Catalao, Brasil: an example of rare earth elements (REE) enrichment during laterization of alkaline rocks.Terra Abstracts, IAGOD International Symposium on mineralization related to mafic, Vol. 5, No. 3, abstract supplement p. 35.BrazilCarbonatite, Laterites
DS1993-1257
1993
Preinfalk, C.Preinfalk, C., Morteani, G.The rare earth elements (REE) content in the laterites developed on the alkaline complexes of Araxa and Catalao (States Minas Gerais and Goias, Brasil).Rare earth Minerals: chemistry, origin and ore deposits, International Geological Correlation Programme (IGCP) Project, pp. 114-116. abstractBrazilCarbonatite, Lateritic weathering
DS1996-0996
1996
Preinfalk, C.Morteani, G., Preinfalk, C.rare earth elements (REE) distribution and rare earth elements (REE) carriers in laterites formed on the alkaline complexes of Araxa and Catalao, Brasil.Mineralogical Soc. Series, No. 7, pp. 227-256.BrazilAlkaline rocks, Deposit - Araxa, Catalao
DS201312-0615
2013
Preinfalk, C.Moteani, G., Kostitsyn, Y.A., Gilg, H.A., Preinfalk, C., Razakamanana, T.Geochemistry of phlogopite, diopside, calcite, anhydrite and apatite pegmatites and syenites of southern Madagascar: evidence for crustal silicocarbonatitic (CSC) melt formatio in a Panafrican collisional tectonic setting.International Journal of Earth Sciences, Vol. 102, 3, pp. 627-645.Africa, MadagascarCarbonatite
DS200912-0609
2009
Preistley, K.Rai, A., Gaur, V.K., Rai, S.S., Preistley, K.Seismic signatures of the Pan-African orogeny: implications for southern Indian high grade terranes.Geophysical Journal International, Vol. 176, 2, pp. 518-528.IndiaUHP
DS201112-0822
2011
Prejeant, K.Prejeant, K., Perez, M., White, J.C., Ren, M.Geology of the Elliot County kimberlite, Kentucky.Geological Society of America, Annual Meeting, Minneapolis, Oct. 9-12, abstractUnited States, KentuckyKimberlite petrology
DS201112-0823
2011
Prejeant-Dickerson, K.Prejeant-Dickerson, K., Perez, M., White, J.C., Lierman, R.T., Ren, M.Mineral geochemistry of the Elliot County kimberlite, Kentucky.Geological Society of America, Annual Meeting, Minneapolis, Oct. 9-12, abstractUnited States, KentuckyKimberlite dikes
DS200712-0714
2006
Prelas, M.A.Mendez, A.E., Prelas, M.A., Glascock, M., Ghosh, T.K.A novel method for the diffusion of boron in 60-80 micron size natural diamond Type II/A powder.Journal of Materials and Research, No. 929, pp. 155-160 Ingenta 1-64796903TechnologyType II diamonds
DS2003-1102
2003
Prelevic, D.Prelevic, D., Foley, S.F., Romer, R., Cvetkovic, V.Serbian Tertiary ultrapotassic province petrology, geochemistry and geodynamic8 Ikc Www.venuewest.com/8ikc/program.htm, Session 7, POSTER abstractSerbiaAlkaline
DS200412-1578
2004
Prelevic, D.Prelevic, D., Foley, S.F., Cvetkovic, V., Romer, R.L.Origin of minette by mixing of lamproite and dacite magmas in Veliki Majdan, Serbia.Journal of Petrology, Vol. 45, 4, pp. 759-752.Europe, SerbiaLamproite, micas, calcalkaline lamprophyres, superheat
DS200412-1579
2003
Prelevic, D.Prelevic, D., Foley, S.F., Romer, R., Cvetkovic, V.Serbian Tertiary ultrapotassic province petrology, geochemistry and geodynamic significance.8 IKC Program, Session 7, POSTER abstractEurope, SerbiaKimberlite petrogenesis Alkaline
DS200512-0200
2004
Prelevic, D.Cvetkovic, V., Downes, H., Prelevic, D., Jovanovic, M.Characteristics of the lithospheric mantle beneath East Serbia inferred from ultramafic xenoliths in Paleogene basanites.Contributions to Mineralogy and Petrology, Vol. 148, 3, pp. 335-357.Europe, SerbiaBasanites, Foidites
DS200512-0872
2005
Prelevic, D.Prelevic, D., Foley, S.F., Romer, R.L., Cvetkovic, V., Downes, H.Tertiary ultrapotassic volcanism in Serbia: constraints on petrogenesis and mantle source characteristics.Journal of Petrology, Vol. 46, 7, July pp. 1443-1487.Europe, SerbiaVolcanism
DS200612-0349
2006
Prelevic, D.Downes, H., Cvetkovic, V., Hock, V., Prelevic, D., Lazarov, M.Refertilization of highly depleted lithospheric mantle ( Balkan Peninsula, SE Europe): evidence from peridotite xenoliths.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 1, abstract only.EuropeGeochemistry
DS200712-0856
2007
Prelevic, D.Prelevic, D., Foley, S.F., Stracke, A., Romer, R.I., Conticelli, S.No need for involvement of a hidden mantle reservoir in the origin of lamproites from Mediterranean.Plates, Plumes, and Paradigms, 1p. abstract p. A809.EuropeLamproites - multi-component melts
DS200812-0919
2008
Prelevic, D.Prelevic, D., Boev, B., Zouros, N., Akai, C.Lamproites and alkaline rocks of southern Balkans and Aegean region.9th. IKC Field Trip Guidebook, CD 45p.Europe, Macedonia, Greece, TurkeyGuidebook - lamproites
DS200812-0920
2008
Prelevic, D.Prelevic, D., Foley, S.F.The origin of lamproites revisited: a Mediterranean perspective.Goldschmidt Conference 2008, Abstract p.A760.Europe, MediterraneanLamproite
DS200812-0921
2008
Prelevic, D.Prelevic, D., Foley, S.F.The origin of lamproites revisited: Mediterranean perspective.9IKC.com, 3p. extended abstractEurope, TurkeyLamproite
DS200812-0922
2008
Prelevic, D.Prelevic, D., Foley, S.F., Romer, R., Conticelli, S.Mediterranean Tertiary lamproites derived from multiple source components in Post collisional geodynamics.Geochimica et Cosmochimica Acta, 72p. in press availableEuropeLamproite
DS201012-0212
2010
Prelevic, D.Fritschle, T., Prelevic, D., Foley, S.F.Mineral variations from Mediterranean lamproites: major element compositions and first indications from trace elements in phlogopites, olivines and clinopyroxenes.Geological Society of America Abstracts, 1p.Europe, Spain, Serbia, TurkeyLamproite
DS201012-0597
2010
Prelevic, D.Prelevic, D., Akai, C., Romer, R.L., Foley, S.F.Lamproites as indicators of accretion and/or shallow subduction in the assembly of south western Anatolia, Turkey.Terra Nova, in press available,Europe, TurkeyLamproite
DS201012-0598
2010
Prelevic, D.Prelevic, D., Akal, C., Foley, S.F., Romer, R.L., Stracke, A., Van den Bogaard,P.Post collisional mantle dynamics of an orogenic lithosphere: lamproitic mafic rocks from SW Anatolia, Turkey.Geological Society of America Abstracts, 1p.Europe, TurkeyLamproite
DS201012-0599
2010
Prelevic, D.Prelevic, D., Stracke, A., Foley, S.F., Romer, R.I., Conticelli, R.S.Hf isotope compositions of Mediterranean lamproites: mixing of melts from asthenosphere and crustally contaminated mantle lithosphere.Lithos, Vol. 119, pp. 297-312.Europe, Italy, Macedonia, SerbiaLamproite
DS201112-0824
2011
Prelevic, D.Prelevic, D., Akal, C., Foley, S.F., Romer, R.R.,Stracke, A., Van den Bogaard, P.Ultrapotassic mafic rocks as geochemical proxies for post collisional dynamics of orogenic lithospheric mantle: the case of southwestern Anatolia, Turkey.Peralk-Carb 2011, workshop held Tubingen Germany June 16-18, PosterEurope, TurkeyAlkalic
DS201112-0825
2011
Prelevic, D.Prelevic, D., Akal, C., Romer, R.R., Sracke, A., Van den Bogaard, P.Ultrapotassic mafic rocks as geochemical proxies for post collisional dynamics of orogenic lithospheric mantle: the case of southwestern Anatolia, Turkey.Peralk-Carb 2011... workshop June 16-18, Tubingen, Germany, Abstract p.119-121.Europe, TurkeyLamproite
DS201112-0826
2011
Prelevic, D.Prelevic, D., Akal, C., Romer, R.R., Sracke, A., Van den Bogaard, P.Ultrapotassic mafic rocks as geochemical proxies for post collisional dynamics of orogenic lithospheric mantle: the case of southwestern Anatolia, Turkey.Peralk-Carb 2011... workshop June 16-18, Tubingen, Germany, Abstract p.119-121.Europe, TurkeyLamproite
DS201312-0271
2013
Prelevic, D.Foley, S.F., Prelevic, D., Rehfeldt, T., Jacob, D.E.Minor and trace elements in olivines as probes into early igneous and mantle melting.Earth and Planetary Science Letters, Vol. 363, pp. 181-191.MantleMetasomatism
DS201312-0280
2013
Prelevic, D.Fritschle, T., Prelevic, D., Foley, S.F., Jacob, D.E.Petrological characterization of the mantle source of Mediterranean lamproites: indications from major and trace elements of phlogopite.Chemical Geology, Vol. 353, pp. 267-279.Europe, SpainLamproite
DS201312-0904
2013
Prelevic, D.Tappe, S., Pearson, D.G., Prelevic, D.Kimberlite, carbonatite, and potassic magmatism as part of the geochemical cycle.Chemical Geology, Vol. 353, pp. 1-3 intro.MantleMelting, recyle
DS201412-0086
2014
Prelevic, D.Bussweiler, Y., Foley, S.F., Prelevic, D., Jacob, D.E., Pearson, D.G., Stachel, T.Olivine as a petrogenetic and exploration indicator in Lac de Gras kimberlites.2014 Yellowknife Geoscience Forum, p. 20, 21 abstractCanada, Northwest TerritoriesDeposit - Ekati
DS201504-0187
2015
Prelevic, D.Bussweiler, Y., Foley, S.F., Prelevic, D., Jacob, D.E.The olivine macrocryst problem: new insights from minor and trace element compositions of olivine from Lac de Gras kimberlites, Canada.Lithos, Vol. 220-223, pp. 238-252.Canada, Northwest TerritoriesDeposit - Ekati field

Abstract: This study presents detailed petrographical and geochemical investigations on remarkably fresh olivines in kimberlites from the EKATI Diamond Mine- located in the Tertiary/Cretaceous Lac de Gras kimberlite field within the Slave craton of Canada. Olivine, constituting about 42 vol.% of the analyzed samples, can be divided into two textural groups: (i) macrocrystic olivines, > 100 ?m sub-rounded crystals and (ii) groundmass olivines, < 100 ?m subhedral crystals. Olivines from both populations define two distinct chemical trends; a “ "mantle trend" with angular cores, showing low Ca (< 0.1 wt.% CaO) and high Ni (0.3-0.4 wt.% NiO) at varying Mg# (0.86-0.93), contrasts with a "melt trend" typified by thin (< 100 ?m) rims with increasing Ca (up to 1.0 wt.% CaO) and decreasing Ni (down to 0.1 wt.% NiO) contents at constant Mg# (~ 0.915). These findings are in agreement with recent studies suggesting that virtually all olivine is composed of xenocrystic (i.e. mantle-related) cores with phenocrystic (i.e. melt-related) overgrowths, thereby challenging the traditional view that the origin of kimberlitic olivine can be distinguished based on size and morphology. The two main trends can be further resolved into sub-groups refining the crystallization history of olivine; the mantle trend indicates a multi-source origin that samples the layered lithosphere below the Slave craton, whereas the melt trend represents multi-stage crystallization comprising a differentiation trend starting at mantle conditions and a second trend controlled by the crystallization of additional phases (e.g. chromite) and changing magma conditions (e.g. oxidation). These trends are also seen in the concentrations of trace elements not routinely measured in olivine (e.g. Na, P, Ti, Co, Sc, Zr). Trace element mapping with LA-ICP-MS reveals the distribution of these elements within olivine grains. The trace element distribution between the two trends appears to be consistent with phenocrystic olivine overgrowths mainly originating from dissolved orthopyroxene, showing enrichment in Zr, Ga, Nb, Sc, V, P, Al, Ti, Cr, Ca and Mn in the melt trend. In a sample of magmatic kimberlite from the Leslie pipe, the amount of xenocrystic and phenocrystic olivine is estimated to be around 23 vol.% and 19 vol.%, respectively. Subtraction of this xenocrystic olivine from the Leslie bulk composition, aimed at estimating the parental kimberlite melt, results in a minor decrease of Mg# (by about 0.01) and SiO2 content (by about 3 wt.%), whereas CaO increases (by about 3 wt.%).
DS201512-1976
2016
Prelevic, D.Tappe, S., Smart, K.A., Stracke, A., Romer, R.L., Prelevic, D., van den Bogaard, P.Melt evolution beneath a rifted carton edge: 40Ar/39/Ar geochronology and Sr-Nd-Hf-Pb isotope systematics of primitive alkaline basalts and lamprophyres from the SW Baltic Shield.Geochimica et Cosmochimica Acta, Vol. 173, pp. 1-36.Europe, SwedenAlkalic
DS201602-0244
2016
Prelevic, D.Tappe, S., Smart, K.A., Stracke, A., Romer, R.L., Prelevic, D., van den Bogaard, P.Melt evolution beneath a rifted craton edge: 40Ar/39Ar geochronology and Sr-Nd-Hf-Pb isotope systematics of primitive alkaline basalts and lamprophyres from the SW Baltic shield.Geochimica et Cosmochimica Acta, Vol. 173, pp. 1-36.EuropeGeochronology

Abstract: A new high-precision 40Ar/39Ar anorthoclase feldspar age of 176.7 ± 0.5 Ma (2-sigma) reveals that small-volume alkaline basaltic magmatism occurred at the rifted SW margin of the Baltic Shield in Scania (southern Sweden), at a time of global plate reorganization associated with the inception of Pangea supercontinent break-up. Our combined elemental and Sr-Nd-Hf-Pb isotope dataset for representative basanite and nephelinite samples (>8 wt.% MgO) from 16 subvolcanic necks of the 30 by 40 km large Jurassic volcanic field suggests magma derivation from a moderately depleted mantle source (87Sr/86Sri = 0.7034-0.7048; ?Ndi = +4.4 to +5.2; ?Hfi = +4.7 to +8.1; 206Pb/204Pbi = 18.8-19.5). The mafic alkaline melts segregated from mixed peridotite-pyroxenite mantle with a potential temperature of ?1400 °C at 2.7-4.2 GPa (?90-120 km depths), which places ultimate melt generation within the convecting upper mantle, provided that the lithosphere-asthenosphere boundary beneath the southern Baltic Shield margin was at ?100 km depth during Mesozoic-Cenozoic rifting. Isotopic shifts and incompatible element enrichment relative to Depleted Mantle reflect involvement of at least 20% recycled oceanic lithosphere component (i.e., pyroxenite) with some minor continent-derived sediment during partial melting of well-stirred convecting upper mantle peridotite. Although pargasitic amphibole-rich metasomatized lithospheric mantle is excluded as the main source of the Jurassic magmas from Scania, hydrous ultramafic veins (i.e., hornblendite) may have caused subtle modifications to the compositions of passing sublithospheric melts. For example, modeling suggests that the more radiogenic Hf (?Hfi = +6.3 to +8.1) and Pb (206Pb/204Pbi = 18.9-19.5) isotopic compositions of the more sodic and H2O-rich nephelinites, compared with relatively homogenous basanites (?Hfi = +4.7 to +6.1; 206Pb/204Pbi = 18.8-18.9), originate from minor interactions between rising asthenospheric melts and amphibole-rich metasomatic components. The metasomatic components were likely introduced to the lithospheric mantle beneath the southern Baltic Shield margin during extensive Permo-Carboniferous magmatic activity, a scenario that is supported by the geochemical and isotope compositions of ca. 286 Ma lamprophyres from Scania (87Sr/86Sri = 0.7040-0.7054; ?Ndi = +2.0 to +3.1; ?Hfi = +6.1 to +9.0; 206Pb/204Pbi = 17.8-18.2). Strong variations in lithosphere thickness and thermal structure across the southern Baltic Shield margin may have caused transient small-scale mantle convection. This resulted in relatively fast and focused upwellings and lateral flow beneath the thinned lithosphere, where mafic alkaline magmas formed by low degrees of decompression melting of sublithospheric mantle. Such a geodynamic scenario would allow for enriched recycled components with low melting points to be preferentially sampled from the more depleted and refractory convecting upper mantle when channeled along a destabilizing craton edge. Similar to the ‘lid effect’ in oceanic island volcanic provinces, lithospheric architecture may exert strong control on the mantle melting regime, and thus offer a simple explanation for the geochemical resemblance of continental and oceanic intraplate mafic alkaline magmas of high Na/K affinity.
DS201609-1727
2016
Prelevic, D.Krmicek, L., Romer, R.L.,Ulrych, J., Glodny, J., Prelevic, D.Petrogenesis of orogenic lamproites of the Bohemian Massif: Sr-Nd-Pb-Li isotope constraints for Variscan enrichment of ultra-depleted mantle domains.Gondwana Research, Vol. 35, pp. 198-216.EuropeLamproite

Abstract: During convergence of Gondwana-derived microplates and Laurussia in the Palaeozoic, subduction of oceanic and continental crusts and their sedimentary cover introduced material of regionally contrasting chemical and isotopic compositions into the mantle. This slab material metasomatised the local mantle, producing a highly heterogeneous lithospheric mantle beneath the European Variscides. The eastern termination of the European Variscides (Moldanubian and Saxo-Thuringian zones of Austria, Czech Republic, Germany and Poland) is unusual in that the mantle was modified by material from several subduction zones within a small area. Orogenic lamproites sampled this lithospheric mantle, which has a chemical signature reflecting extreme depletion (low CaO and Al2O3 contents and high Mg-number) followed by strong metasomatic enrichment, giving rise to crust-like trace element patterns, variable radiogenic 87Sr/86Sr(330) (0.7062-0.7127) and non-radiogenic Nd isotopic compositions (?Nd(330) = ? 2.8 to ? 7.8), crustal Pb isotopic compositions, and a wide range of ?7Li values (? 5.1 to + 5.1). This metasomatic signature is variably expressed in the lamproites, depending on the extent of melting and the nature of the source of the metasomatic component. Preferential melting of the metasomatically enriched (veined) lithospheric mantle with K-rich amphibole resulted in lamproitic melts with very negative, crust-like ?7Li values, which correlate positively with peralkalinity, HFSE contents and lower ?Nd. Both the higher degree of melting and progressive consumption of the metasomatic component reduce the chemical and isotopic imprints of the metasomatic end member. The very positive ?7Li values of some lamproites indicate that the source of these lamproites may have been modified by subducted oceanic lithosphere. Fresh olivine from the Brloh (Moldanubian) lamproitic dyke shows very high Fo (up to 94%) and very high Li contents (up to 25 ppm), demonstrating that the extremely depleted and later enriched lithospheric mantle may have contributed significantly to the Li budget of the lamproites. The regional distribution of lamproites with contrasting chemical and isotopic fingerprints mimics the distribution of the different Variscan subduction zones.
DS201610-1860
2016
Prelevic, D.Forster, M.W., Prelevic, D., Schmuck, H.R., Jacob, D.E.Melting and dynamic metasomatism of mixed harzburgite + glimmerite mantle source: implications for the genesis of orogenic potassic magmas.Chemical Geology, in press available 10p.MantleUltrapotassic magmas

Abstract: Tectonically young, orogenic settings are commonly the sites of post-collisional silica-rich ultrapotassic magmas with extreme K2O-contents of up to 9 wt% and K2O/Na2O > 2. Many experimental studies investigating the generation of these melts have concentrated on melting of homogenous phlogopite bearing peridotites, whereas geochemical signatures indicate the involvement of at least two types of source rocks: ultra-depleted and K and trace elements-enriched ones. We report the results of melting experiments at 1-2 GPa of mixed glimmerite and harzburgite, in which these rock types make up two halves each capsule. Melting begins in the glimmerite, and its metasomatic effects on the harzburgite are apparent at 1100 °C even before melt pools are visible. The first melts are Na-rich, seen in zoning of olivines and as growth of clinopyroxene in the harzburgite, but change at higher degrees of melting to produce a typical lamproite-like melt with K2O > 10 wt%. A major advantage of this study is the preservation of distinct melts in different parts of the capsule, which reflect a process of dynamic metasomatism: within the harzburgite matrix, the infiltrating melt derived from melting of the glimmerite changes consistently with the distance of travel through the harzburgite, enabling quantification of the metasomatic effects as an increase in SiO2 and K2O. This results principally from assimilation of orthopyroxene, which increases the Ol/Opx ratio of the residual harzburgite. The effects of quench olivine growth are recognizable and can be quantified due to a step-change in composition at the glimmerite/harzburgite border: the large total surface area of olivine and small melt fraction mean that the amount of quench olivine is high within the harzburgite, but negligible in the almost completely molten glimmerite. Melts of the glimmerite contain up to 8-10 wt% K2O and 53 wt% SiO2, which increase to 55-56 wt% after interaction with the harzburgite. Mediterranean lamproites resemble melts of glimmerite, whereas melts that have interacted with harzburgite are more similar to less potassic, but more SiO2-rich shoshonites of the Mediterranean region.
DS201706-1109
2017
Prelevic, D.Wang, Y., Foley, S.F., Prelevic, D.Potassium rich magmatism from a phlogopite free source.Geology, Vol. 45, 5, pp. 467-470.Europe, Serbiamelting

Abstract: The generation of strongly potassic melts in the mantle is generally thought to require the presence of phlogopite in the melting assemblage. In the Mediterranean region, trace element and isotope compositions indicate that continental crustal material is involved in the generation of many potassium-rich lavas. This is clearest in ultrapotassic rocks like lamproites and shoshonites, for which the relevant chemical signals are less diluted by extensive melting of peridotite. Furthermore, melting occurs here in young lithosphere, so the continental crust was not stored for a long period of time in the mantle before reactivation. We have undertaken two types of experiments to investigate the reaction between crust and mantle at 1000-1100 °C and 2-3 GPa. In the first, continental crustal metasediment (phyllite) and depleted peridotite (dunite) were juxtaposed as separate blocks, whereas in the second, the same rock powders were intimately mixed. In the first series, a clear reaction zone dominated by orthopyroxene was formed between dunite and phyllite but no hybridized melt could be found, whereas analyzable pools of hybridized melt occurred throughout the charges in the second series. Melt compositions show high abundances of Rb (100-220 ppm) and Ba (400-870 ppm), and consistent ratios of Nb/Ta (10-12), Zr/Hf (34-42), and Rb/Cs (28-34), similar to bulk continental crust. These experiments demonstrate that melts with as much as 5 wt% K2O may result from reaction between melts of continent-derived sediment and depleted peridotite at shallow mantle depths without the need for phlogopite or any other potassic phase in the residue.
DS201707-1381
2017
Prelevic, D.Wang, Y., Prelevic, D., Buhre, S., Foley, S.F.Constraints on the sources of post-collisional K rich magmatism: the roles of continental clastic sediemtns and terrigenous blueschists.Chemical Geology, Vol. 455, pp. 192-207.Mantlemagmatism

Abstract: The possible role of continental sediments in the generation of potassium-enriched lavas of the Alpine-Himalayan belt depends on their melting behaviour either during subduction or during post-collisional relaxation. Although usually classed as orogenic lavas, these volcanic rocks may result from re-melting of newly formed mantle lithosphere 30–40 million years after collision ends, and can thus be considered as the first stage of intraplate volcanism. The potassic component in these volcanics is characterized by a high Th/La signature for which there are two competing explanations: melting of subducted continental clastic sediments, and the involvement of lawsonite blueschists in the protoliths to the melting assemblages. Here, we report on a series of high-pressure experiments at 1–3 GPa and 900 to 975 °C on the melting behaviour of natural phyllite from Serbia, which serves as a proxy for Balkan upper continental crust. Hydrous granitic melts are present in all runs (68 wt% SiO2, ~ 4–5 wt% K2O, Mg# < 54 and ~ 5 wt% H2O). Garnet, quartz/coesite, plagioclase, K-feldspar, biotite/phengite, clinopyroxene and sillimanite/kyanite, and accessory phases including zircon, rutile, ilmenite, apatite and monazite occur in the charges. LA-ICP-MS analyses establish that the melts are extremely enriched in LILE (except for Sr), Th and U, but depleted in Nb and Zr, with LREE higher than HREE. Accessory phases accommodate several trace elements, especially HFSE and REE. Partition coefficients for some trace elements between residue and crustal melts are close to 1, contrasting strongly with melts of peridotite. Our dataset indicates that the direct melting of upper continental crust alone would generate siliceous, high-K magmas with enriched LILE, Th and U, but cannot explain the high Th/La fingerprint of K-rich lavas of the Alpine-Himalayan orogenic belt. We demonstrate that the Alpine-Himalayan orogenic volcanics attribute their unusual trace element geochemistry to the involvement of lawsonite blueschists that are imbricated together with extremely depleted fore-arc peridotites to form new lithosphere in the source region. There is no need or evidence for deep subduction in which a succession of additional reactions would only serve to modify and dilute the high Th/La signature.
DS201804-0689
2018
Prelevic, D.Forster, M.W., Prelevic, D., Schmuck, H.R., Buhre, S., Marschall, H.R., Mertz-Kraus, R., Jacob, D.E.Melting phologopite rich MARID: lamproites and the role of alkalis in olivine liquid Ni partioning.Chemical Geology, Vol. 476, 1, pp. 429-440.Technologylamproites

Abstract: In this study, we show how veined lithospheric mantle is involved in the genesis of ultrapotassic magmatism in cratonic settings. We conducted high pressure experiments to simulate vein + wall rock melting within the Earth's lithospheric mantle by reacting assemblages of harzburgite and phlogopite-rich hydrous mantle xenoliths. These comprised a mica-, amphibole-, rutile-, ilmenite-, diopside (MARID) assemblage at 3-5 GPa and 1325-1450 °C. Melting of the MARID assemblages results in infiltration of melt through the harzburgite, leading to its chemical alteration. At 3 and 4 GPa, melts are high in K2O (> 9 wt%) with K2O/Na2O > > 2 comparable to anorogenic lamproites. Higher pressures and temperatures (5 GPa/1450 °C) lead to increasing MgO contents of the melt and to some extent lower K2O contents (5-7 wt%) at equally high K2O/Na2O ratios. Our experiments provide insights into the role of alkalis in nickel-partitioning (DNi) between olivine and ultrapotassic melt. We observe that the high contents of Na, K, and Al are indicative of high DNi values, implying that the melt polymerization is the dominant factor influencing the olivine/melt nickel partitioning. The change of DNi as a function of melt composition results in a pressure independent, empirical geothermometer: Element oxides represent the composition of the glass (in wt%), and DNi is the liquid/olivine Ni-partitioning coefficient. We propose that this geothermometer is applicable to all natural silicate melts that crystallized olivine in a temperature interval between 1000 and 1600 °C. Application to glass-olivine pairs from calc-alkaline settings (Mexico), MORB (East Pacific Rise), and OIB (Hawaii) yielded reasonable values of 996-1199 °C, 1265 °C, and 1330 °C, respectively.
DS201902-0293
2019
Prelevic, D.Lustrino, M., Fedele, L., Agostini, S., Prelevic, D., Salari, G.Leucitites within and around the Mediterranean area. Lithos, Vol. 324-325, pp. 216-233.Europeleucitites

Abstract: Leucite-bearing volcanic rocks are commonly found within and around the Mediterranean area. A specific type of this rock group are leucitites. They are found both in a hinterland position of active and fossil subduction systems as well as in foreland tectonic settings, but none have been found in the Maghreb (N Africa) and Mashreq (Middle East) areas. Here a review of the main leucitite occurrences in the circum-Mediterranean area is presented, with new whole-rock, mineral chemical and Sr-Nd-Pb isotopic ratios on key districts, with the aim of clarifying the classification and genesis of this rock type. Many of the rocks classified in literature as leucitites do not conform to the IUGS definition of leucitite (i.e., rocks with >10?vol% modal leucite and with foids/(foids + feldspars) ratio?>?0.9, with leucite being the most abundant foid). Among circum-Mediterranean rocks classified as leucitites in the literature, we distinguish two types: clinopyroxene-olivine-phyric (COP) and leucite- phyric (LP) types. Only the second group can be truly classified as leucitite, being characterized by the absence or the very rare presence of feldspars, as well as by ultrapotassic composition. The COP group can be distinguished from the LP group on the basis of lower SiO2, Na2O?+?K2O, K2O/Na2O, Al2O3, Rb and Ba, and higher MgO, TiO2, Nb, Cr and Ni. The LP group shows multi-elemental patterns resembling magmas emplaced in subduction-related settings, while COP rocks are much more variable, showing HIMU-OIB-like to subduction-related-like incompatible element patterns. COP rocks are also characterized generally by more homogeneous isotopic compositions clustering towards low Sr and high Nd isotopic ratios, while LP leucitites plot all in the enriched Sr-Nd isotopic quadrant. LP rocks usually have lower 206Pb/204Pb and higher 207Pb/204Pb. This study shows that the geochemical signal of mantle melts does not always reflect the tectonic setting of magma emplacement, suggesting paying extreme attention in proposing geodynamic reconstructions on the basis of chemical data only.
DS201905-1030
2019
Prelevic, D.Forster, M.W., Prelevic, D., Buhre, S., Mertz-Kraus, R., Foley, S.F.An experimental study of the role of partial melts of sediments versus mantle melts in the sources of potassic magmatism.Journal of Asian Earth Sciences, Vol. 177, pp. 76-88.Mantlelamproite

Abstract: Potassium-rich lavas with K/Na of >2 are common in orogenic and anorogenic intraplate magmatic provinces. However, in the primitive mantle, the concentration of Na exceeds that of K by 10 times. The source of K-rich lavas thus needs to be either K-enriched or Na-depleted to account for high K/Na ratios. The geochemical and isotopic compositions of high 87Sr/86Sr post-collisional lavas show that their mantle source contains a recycled crustal component. These highly K-enriched lavas with crustal like trace element patterns are termed “orogenic lamproites” and are compositionally distinct from K-rich “anorogenic lamproites” that show lower 87Sr/86Sr and a trace element pattern that resembles that of primary mantle melts. For both groups the processes of K-enrichment within their source are uncertain and are thought to be linked to melts of sedimentary rocks for “orogenic lamproites” and low-degree melts of ultramafic mantle rocks for “anorogenic lamproites”. In both cases, metasomatism of the mantle lithosphere is the precursor to K-rich magmatism. In this study we experimentally determine the effects of mantle metasomatism by sediment- and hydrous mantle melts. The experiments simulate the interaction of refractory lithospheric mantle and metasomatizing melt in a 2-layer reaction experiment. The sediment/dunite reaction experiments lead to formation of a strongly K-enriched phlogopite-pyroxenite layer sandwiched between the two starting materials. The low temperature of the sediment/dunite reaction runs at <1000?°C simulates a fore-arc subduction environment, in which the melts of sediment are consumed during interaction with dunite as the temperature is below the solidus of the produced phlogopite-pyroxenites. The hydrous mantle melt/dunite reaction run is simulated by reacting a hydrated basanite with dunite. Since the temperature of the reaction is higher than the solidus of the resulting phlogopite-pyroxenites (1200?°C), the hydrous melt is not consumed but flows further, increasing in K2O and K/Na as it reacts with the refractory peridotite. In both cases, melts are enriched in K and K/Na increases by crystallizing a low K and low K/Na eclogitic residue. Compositions of glass and phlogopite from both types of reactions are comparable to glasses and phlogopites found within post-collisional lavas. Since the enrichment of K within the reaction zone is strongly controlled by the formation of low K/Na and low-K residues, metasomatic enrichment of the mantle lithosphere in K does not need a highly K-enriched metasomatic agent.
DS201912-2781
2019
Prelevic, D.Forster. M.W., Prelevic, D., Buhre, S., Mertz-Kraus, R., Foley, S.F.An experimental study of the role of partial melts of sediments versus mantle melts in the sources of potassic magmatism.Journal of Asian Earth Sciences, Vol. 177, pp. 76-88.Mantlemetasomatism

Abstract: Potassium-rich lavas with K/Na of >2 are common in orogenic and anorogenic intraplate magmatic provinces. However, in the primitive mantle, the concentration of Na exceeds that of K by 10 times. The source of K-rich lavas thus needs to be either K-enriched or Na-depleted to account for high K/Na ratios. The geochemical and isotopic compositions of high 87Sr/86Sr post-collisional lavas show that their mantle source contains a recycled crustal component. These highly K-enriched lavas with crustal like trace element patterns are termed “orogenic lamproites” and are compositionally distinct from K-rich “anorogenic lamproites” that show lower 87Sr/86Sr and a trace element pattern that resembles that of primary mantle melts. For both groups the processes of K-enrichment within their source are uncertain and are thought to be linked to melts of sedimentary rocks for “orogenic lamproites” and low-degree melts of ultramafic mantle rocks for “anorogenic lamproites”. In both cases, metasomatism of the mantle lithosphere is the precursor to K-rich magmatism. In this study we experimentally determine the effects of mantle metasomatism by sediment- and hydrous mantle melts. The experiments simulate the interaction of refractory lithospheric mantle and metasomatizing melt in a 2-layer reaction experiment. The sediment/dunite reaction experiments lead to formation of a strongly K-enriched phlogopite-pyroxenite layer sandwiched between the two starting materials. The low temperature of the sediment/dunite reaction runs at <1000?°C simulates a fore-arc subduction environment, in which the melts of sediment are consumed during interaction with dunite as the temperature is below the solidus of the produced phlogopite-pyroxenites. The hydrous mantle melt/dunite reaction run is simulated by reacting a hydrated basanite with dunite. Since the temperature of the reaction is higher than the solidus of the resulting phlogopite-pyroxenites (1200?°C), the hydrous melt is not consumed but flows further, increasing in K2O and K/Na as it reacts with the refractory peridotite. In both cases, melts are enriched in K and K/Na increases by crystallizing a low K and low K/Na eclogitic residue. Compositions of glass and phlogopite from both types of reactions are comparable to glasses and phlogopites found within post-collisional lavas. Since the enrichment of K within the reaction zone is strongly controlled by the formation of low K/Na and low-K residues, metasomatic enrichment of the mantle lithosphere in K does not need a highly K-enriched metasomatic agent.
DS201912-2827
2019
Prelevic, D.Sokol, K., Prelevic, D., Romer, R.L., Cokulov, N.Cretaceous ultrapotassic magmatism from the Sava-Vardar zone of the BalkansLithos, doi:10.1016/j.lithos.2019.105268Europemagmatism

Abstract: Late Cretaceous global plate reorganization associated with the inception of counterclockwise rotation of Africa relative to Europe initiated in the Balkan region small-volume magmatism of diverse geochemical signature along the enigmatic Sava-Vardar Zone. We study a Late Cretaceous lamprophyric sill in Ripanj village near Belgrade to constrain this magmatic episode. The lamprophyre is characterized by high contents of Na, P, Fe and Al, and low contents of K, Ca and Mg. Its original nature (Na, K, Ca and Mg) is concealed by intense alteration (albitization of feldspar and partial chloritization of phlogopite) that erased the ultrapotassic affinity of the rocks and resulted in extremely low K/Na ratios. The recalculated chemical composition demonstrates that the rocks are ultrapotassic, with K2O and MgO > 3 wt % and K2O/Na2O > 2, and belong to the durbachite-vaugnerite series, i. e., the plutonic equivalents of minettes and kersantites. Two phlogopite concentrates gave Ar-Ar ages of 86.80 ± 0.5 Ma and 86.90 ± 0.5 Ma. Our combined elemental and Sr-Nd-Pb isotope data (87Sr/86Sr 0.70667-0.70677, 143Nd/144Nd 0.512426-0.512429, 206Pb/204Pb 18.82-19.13, 207Pb/204Pb 15.67-15.68, 208Pb/204Pb 38.92-39.19) for representative lamprophyric samples suggests magma derivation from a light rare earth elements (LREE) and K enriched, metasomatized mantle source. The content of LREE of the rocks is enriched, whereas heavy rare earth elements (HREE) is depleted. Rare earth elements (REE) of the whole rock and REE of diopside all indicate that garnet was present in their source. There are two viable and mutually-excluding geodynamic scenarios for the Late Cretaceous magmatism in the Balkans: (i) If the Sava-Vardar ocean still existed in the Late Cretaceous and was subducted under the European plate with arc volcanism along the Apuseni-Banat-Timok-Panagyurishte-Srednjogorje belt, coeval magmatism in the Sava-Vardar Zone occurred in a fore-arc setting, and may be related to ridge subduction; (ii) If the Mesozoic ocean closed already during the Upper Jurassic or Lower Cretaceous, the Late Cretaceous volcanism within the Sava-Vardar Zone represents intracontinental volcanism associated with transtensional tectonics.
DS202002-0185
2020
Prelevic, D.Forster, M.W., Buhre, S., Xu, B., Prelevic, D., Mertz-Kraus, R., Foley, S.F.Two stage origin of K-enrichment in ultrapotassic magmatism simulated by melting of experimentally metasomatized mantle.MDPI Minerals, Vol. 10, 41;doe.10.3390/min10010041 21p. PdfMantlemetasomatism

Abstract: The generation of strongly potassic melts in the mantle requires the presence of phlogopite in the melting assemblage, while isotopic and trace element analyses of ultrapotassic rocks frequently indicate the involvement of subducted crustal lithologies in the source. However, phlogopite-free experiments that focus on melting of sedimentary rocks and subsequent hybridization with mantle rocks at pressures of 1-3 GPa have not successfully produced melts with K2O >5 wt%-6 wt%, while ultrapotassic igneous rocks reach up to 12 wt% K2O. Accordingly, a two-stage process that enriches K2O and increases K/Na in intermediary assemblages in the source prior to ultrapotassic magmatism seems likely. Here, we simulate this two-stage formation of ultrapotassic magmas using an experimental approach that involves re-melting of parts of an experimental product in a second experiment. In the first stage, reaction experiments containing layered sediment and dunite produced a modally metasomatized reaction zone at the border of a depleted peridotite. For the second-stage experiment, the metasomatized dunite was separated from the residue of the sedimentary rock and transferred to a smaller capsule, and melts were produced with 8 wt%-8.5 wt% K2O and K/Na of 6-7. This is the first time that extremely K-enriched ultrapotassic melts have been generated experimentally from sediments at low pressure applicable to a post-collisional setting.
DS202106-0926
2021
Prelevic, D.Casalini, M., Avanzinelli, R., Tommasini, S., Natali, C., Bianchini, G., Prelevic, D., Mattei, M., Conticelli, S.Petrogenesis of Mediterranean lamproites and associated metasomatic events in the postcollisional lithospheric upper mantle.Geological Society, London Special Publication, doi.org/10.1144/SP513-2021-36 49p. PdfEurope, Italy, France, Spain, Serbia, Macedonia, Turkeylamproites

Abstract: High-MgO lamproite and lamproite-like (i.e., lamprophyric) ultrapotassic rocks are recurrent in the Mediterranean and surrounding regions. They are associated in space and time with ultrapotassic shoshonites and high-K calc-alkaline rocks. This magmatism is linked with the geodynamic evolution of the westernmost sector of the Alpine-Himalaya collisional margin, which followed the closure of the Tethys ocean. Subduction-related lamproites, lamprophyres, shoshonites and high-K calc-alkaline suites were emplaced in the Mediterranean region in the form of shallow level intrusions (e.g., plugs, dykes, and laccoliths), and small volume lava flows, with very subordinate pyroclastic rocks, starting from the Oligocene, in the Western Alps (Northern Italy), through the Late Miocene in Corsica (Southern France) and in Murcia-Almeria (South-Eastern Spain), to the Plio-Pleistocene in Southern Tuscany and Northern Latium (Central Italy), in the Balkan peninsula (Serbia and Macedonia), and in the Western Anatolia (Turkey). The ultrapotassic rocks are mostly lamprophyric, but olivine latitic lavas with a clear lamproitic affinity are also found, as well as dacitic to trachytic differentiated products. Lamproite-like rocks range from slightly silica under-saturated to silica over-saturated composition, have relatively low Al2O3, CaO, and Na2O contents, resulting in plagioclase-free parageneses, and consist of abundant K-feldspar, phlogopite, diopsidic clinopyroxene and highly forsteritic olivine. Leucite is generally absent and it is rarely found only in the groudmasses of Spanish lamproites. Mediterranean lamproites and associated rocks share an extreme enrichment in many incompatible trace elements and depletion in High Field Strength Elements and high, and positively correlated Th/La and Sm/La ratios. They have radiogenic Sr and unradiogenic Nd isotope compositions, high 207Pb over 206Pb and high time integrated 232Th/238U. Their composition requires an originally depleted lithospheric mantle source metasomatised by at least two different agents: i) a high Th/La and Sm/La (i.e., SALATHO) component deriving from lawsonite-bearing, ancient crustal domains likely hosted in mélanges formed during the diachronous collision of the northward drifting continental slivers from Gondwana; ii) a K-rich component derived from a recent subduction and recycling of siliciclastic sediments. These metasomatic melts produced a lithospheric mantle source characterised by network of felsic and phlogopite-rich veins, respectively. Geothermal readjustment during post-collisional events induced progressive melting of the different types of veins and the surrounding peridotite generating the entire compositional spectrum of the observed magmas. In this complex scenario, orogenic Mediterranean lamproites represent rocks that characterise areas that were affected by multiple Wilson cycles, as observed in the the Alpine-Himalayan realm.
DS202107-1093
2021
Prelevic, D.Casalini, M., Avanzinellli, R., Tommasini, S., Natali, C., Bianchini, G., Prelevic, D., Mattei, M., Conticelli, S.Petrogenesis of Mediterranean lamproites and associated rocks: the role of overprinted metasomatic events in the postcollisional lithospheric upper mantle.Geological Society London Special Publication, doi.org/10.1144/SP513-2021-36. pdfMantlelamproite

Abstract: High-MgO lamproite and lamproite-like (i.e., lamprophyric) ultrapotassic rocks are recurrent in the Mediterranean and surrounding regions. They are associated in space and time with ultrapotassic shoshonites and high-K calc-alkaline rocks. This magmatism is linked with the geodynamic evolution of the westernmost sector of the Alpine-Himalaya collisional margin, which followed the closure of the Tethys ocean. Subduction-related lamproites, lamprophyres, shoshonites and high-K calc-alkaline suites were emplaced in the Mediterranean region in the form of shallow level intrusions (e.g., plugs, dykes, and laccoliths), and small volume lava flows, with very subordinate pyroclastic rocks, starting from the Oligocene, in the Western Alps (Northern Italy), through the Late Miocene in Corsica (Southern France) and in Murcia-Almeria (South-Eastern Spain), to the Plio-Pleistocene in Southern Tuscany and Northern Latium (Central Italy), in the Balkan peninsula (Serbia and Macedonia), and in the Western Anatolia (Turkey). The ultrapotassic rocks are mostly lamprophyric, but olivine latitic lavas with a clear lamproitic affinity are also found, as well as dacitic to trachytic differentiated products. Lamproite-like rocks range from slightly silica under-saturated to silica over-saturated composition, have relatively low Al2O3, CaO, and Na2O contents, resulting in plagioclase-free parageneses, and consist of abundant K-feldspar, phlogopite, diopsidic clinopyroxene and highly forsteritic olivine. Leucite is generally absent and it is rarely found only in the groudmasses of Spanish lamproites. Mediterranean lamproites and associated rocks share an extreme enrichment in many incompatible trace elements and depletion in High Field Strength Elements and high, and positively correlated Th/La and Sm/La ratios. They have radiogenic Sr and unradiogenic Nd isotope compositions, high 207Pb over 206Pb and high time integrated 232Th/238U. Their composition requires an originally depleted lithospheric mantle source metasomatised by at least two different agents: i) a high Th/La and Sm/La (i.e., SALATHO) component deriving from lawsonite-bearing, ancient crustal domains likely hosted in mélanges formed during the diachronous collision of the northward drifting continental slivers from Gondwana; ii) a K-rich component derived from a recent subduction and recycling of siliciclastic sediments. These metasomatic melts produced a lithospheric mantle source characterised by network of felsic and phlogopite-rich veins, respectively. Geothermal readjustment during post-collisional events induced progressive melting of the different types of veins and the surrounding peridotite generating the entire compositional spectrum of the observed magmas. In this complex scenario, orogenic Mediterranean lamproites represent rocks that characterise areas that were affected by multiple Wilson cycles, as observed in the the Alpine-Himalayan realm.
DS202110-1614
2021
Prelevic, D.Forster, M.W., Bussweiler, Y., Prelevic, D., Daczko, N.R., Buhre, S., Mertz-Kraus, R., Foley, S.F.Sediment-peridotite reaction controls fore-arc metasomatism and arc magma geochemical signatures.Geosciences MDPI, Vol. 11, 372, 24p. PdfMantlesubduction

Abstract: Subduction of oceanic crust buries an average thickness of 300-500 m of sediment that eventually dehydrates or partially melts. Progressive release of fluid/melt metasomatizes the fore-arc mantle, forming serpentinite at low temperatures and phlogopite-bearing pyroxenite where slab surface reaches 700-900 °C. This is sufficiently high to partially melt subducted sediments before they approach the depths where arc magmas are formed. Here, we present experiments on reactions between melts of subducted sediments and peridotite at 2-6 GPa/750-1100 °C, which correspond to the surface of a subducting slab. The reaction of volatile-bearing partial melts derived from sediments with depleted peridotite leads to separation of elements and a layered arrangement of metasomatic phases, with layers consisting of orthopyroxene, mica-pyroxenite, and clinopyroxenite. The selective incorporation of elements in these metasomatic layers closely resembles chemical patterns found in K-rich magmas. Trace elements were imaged using LA-ICP-TOFMS, which is applied here to investigate the distribution of trace elements within the metasomatic layers. Experiments of different duration enabled estimates of the growth of the metasomatic front, which ranges from 1-5 m/ky. These experiments explain the low contents of high-field strength elements in arc magmas as being due to their loss during melting of sedimentary materials in the fore-arc.
DS202112-1927
2021
Prellier, W.Gardes, E., Gilbouin, D., Radiquet, B., David, A., Prellier, W., Marquardt, K.Magnesium transport in olivine mantle: new insights from miniturized study of volume and grain boundary diffusion in Mg2Si04 bi-crystals.Contribution to Mineralogy and Petrology, Vol. 176, 99 16p. PdfMantleolivine

Abstract: We report experimental measurements of volume and grain boundary diffusion of 26Mg in Mg2SiO4 bi-crystals at asthenosphere temperatures as a ground reference for olivine. By analysis of literature and combination with previous data, we provide Arrhenius laws D = D0 exp(- E/RT) at ambient pressure for volume diffusion of Mg in Mg2SiO4 in the intrinsic regime along the three crystallographic axes as well as grain boundary diffusion.
DS201907-1535
2019
Prellwitz, H.Cole, B.G., Andrews, G.D.M., Brown, S.R., Prellwitz, H.The Masontown kimberlite, Fayette County, Pennsylvania: insights into emplacement processes by the characterization of xenocryst sizes and shapes using computed tomography.Joint 53rd Annual South-Central/53rd North Central/71st Rocky Mtn GSA section Meeting, Vol. 331 United States, Pennsylvaniadeposit - Masontown

Abstract: The late Jurassic Masontown dyke in Fayette County, SW Pennsylvania, preserves abundant rounded, mm to cm-diameter masses of olivine and serpentine cemented together in serpentine-rich kimberlite groundmass. Each mass is interpreted to be a partially serpentinized olivine xenocryst or peridotite xenocryst. Each rounded clast is jacketed by a distinct rim of serpentine; probably originally olivine. The (1) ubiquitous roundness of clasts and (2) the presence of distinct serpentine jackets around each clast, supports emplacement of the dyke by a 'kimberlite factory' (Brett et al., 2015). Due to the paucity of available samples, we have used non-destructive imaging by computed tomography (CT) at the National Energy Technology Lab in Morgantown, WV, to construct 3D models of the internal structure of hand samples loaned from the Smithsonian Institute's Museum of Natural History. MicroCT (1-3 micron resolution) and industrial CT (~15 microns resolution) serial scans processed in ImageJ and Blob3D allow for 3D characterizations of individual clasts, including their shape factors (sphericity, roughness, etc.) and sizes (i.e. crystal size distributions).
DS1994-0160
1994
Prellwitz, H.S.Bikerman, M., Prellwitz, H.S.Interpretation of new K-Ar dates on phlogopite from the Masontown Pakimberlite field.Geological Society of America Abstracts, Vol. 26, No. 3, March, p. 7. AbstractGlobalKimberlite, Geochronology
DS1994-1406
1994
Prellwitz, H.S.Prellwitz, H.S., Bikerman, M.Xenoliths from the Masontown PA kimberlite intrusions: a sample of The mantle and lower crust from western Pennsylvania?Geological Society of America Abstracts, Vol. 26, No. 3, March, p. 67. AbstractGlobalXenolith, Mantle
DS202006-0917
2020
Premasiri, R.Dushyantha, N., Batapola, N., Ilankoon, I.M.S.K., Rohitha, S., Premasiri, R., Abeysinghe, B., Ratnayake, N., Dissanayake, K.The story of rare earth elements ( REES): occurrences, global distribution, genesis, geology, mineralogy and global production.Ore Geology Reviews, Vol. 122, 17p. PdfGlobalREE

Abstract: Rare earth elements (REEs) including fifteen lanthanides, yttrium and scandium are found in more than 250 minerals, worldwide. REEs are used in various high-tech applications across various industries, such as electrical and electronics, automotive, renewable energy, medical and defence. Therefore, the demand for REEs in the global market is increasing day by day due to the surging demand from various sectors, such as emerging economies, green technology and R&D sectors. Rare earth (RE) deposits are classified on the basis of their genetic associations, mineralogy and form of occurrences. The Bayan Obo, Mountain Pass, Mount Weld and China’s ion adsorption clays are the major RE deposits/mines in the world to date and their genesis, chronology and mineralogy are discussed in this review. In addition, there are other RE deposits, which are currently being mined or in the feasibility or exploration stages. Most of the RE resources, production, processing and supply are concentrated in the Asia-Pacific region. In this regard, China holds the dominancy in the RE industry by producing more than 90% of the current rare earth requirements. Thus, REEs are used as a powerful tool by China in trade wars against other countries, especially against USA in 2019. However, overwhelming challenges in conventional RE explorations and mining make secondary RE resources, such as electric and electronic waste (e-waste) and mine tailings as promising resources in the future. Due to the supply risk of REEs and the monopoly of the REEs market, REEs recycling is currently considered as an effective method to alleviate market fluctuations. However, economical and sustainable processing techniques are yet to be established to exploit REEs via recycling. Moreover, there are growing ecological concerns along with social resistance towards the RE industry. To overcome these issues, the RE industry needs to be assessed to maintain long-term social sustainability by fostering the United Nations sustainable development goals (SDGs).
DS1987-0608
1987
Premo, W.R.Reed, J.C.Jr, Bickford, M.E., Premo, W.R., Aleinikoff, J.N.Evolution of the early Proterozoic Colorado province:constraints from uranium-lead (U-Pb) (U-Pb) geochronologyGeology, Vol. 15, No. 9, September pp. 861-865United States, Colorado, WyomingGeochronology
DS201012-0154
2010
Premo, W.R.Dewitt, E., Premo, W.R.,Klein, T.Factors controlling generation and distribution of 1400- Ma plutonism in Colorado.Geological Society of America Abstracts, 1p.United States, Colorado PlateauCarbonatite
DS1993-1258
1993
Premoli, C.Premoli, C.Mineral potential of Namibia... brief overview includes diamond miningAustralian Institute of Mining and Metallurgy (AusIMM) Bulletin, No. 3, June pp. 22-27.Namibia, Southwest AfricaNews item, Diamond mining
DS1994-1407
1994
Premoli, C.Premoli, C.Mineral potential of NamibiaMining Engineering, Vol. 46, No. 1, January pp. 39-42NamibiaEconomics, Mineralization
DS1994-1408
1994
Premoli, C.Premoli, C.Mineral potential of NamibiaMining Engineering, Vol. 46, No. 1, January pp. 39-42.NamibiaEconomics, Mineralization
DS1992-1231
1992
Premoll, C.Premoll, C.Angola emerges as an exploration targetEngineering Mining Journal, Vol. 193, No. 7, July pp. 32-37AngolaDiamonds, Overview
DS1992-1232
1992
Premoll, C.Premoll, C.Angola emerges as exploration targetEngineering and Mining Journal, Vol. 193, No. 7, July pp. 32-37AngolaExploration, Overview
DS200912-0534
2009
Prencipe, M.Nestola, F., Smyth, J.R., Parisatto, M., Secco, L., Princivalle, F., Bruno, M., Prencipe, M., Dal Negro, A.Effects of non-stochiometry on the spinel structure at high pressure: implications for Earth's mantle mineralogy.Geochimica et Cosmochimica Acta, Vol. 73, 2, pp. 489-492.MantleUHP
DS201412-0620
2014
Prencipe, M.Nestola,F., Nimis, P.,Angel, R.J., Milani, Bruno, S.,Prencipe, M., Harris, J.W.Olivine with diamond-imposed morphology included in diamonds. Syngenesis or Protogenesis.International Geology Review, Vol. 56, 13, pp. 1658-1667.RussiaDeposit - Udachnaya
DS201412-0710
2014
Prencipe, M.Prencipe, M., Bruno, M., Nestola, F., De La Pierre, M., Nimis, P.Toward an accurate ab initio estimation of compressibility and thermal expansion of diamond in the (0, 3000K) temperature and (0,30 Gpa) pressure ranges, at the hybrid HF/DFT theoretical level.American Mineralogist, Vol. 99, pp. 1147-1154.TechnologyUHP
DS201611-2116
2016
Prencipe, M.Jones, A.P., McMillan, P.F., Salzmann, C.G., Alvaro, M., Nestola, F., Prencipe, M., Dobson, D., Hazael, R., Moore, M.Structural characteristization of natural diamond shocked to 60 Gpa: implications for Earth and Planetary Systems.Lithos, in press available 25p.TechnologyNatural diamonds

Abstract: The possible presence of the high-density carbon polymorph with hexagonal symmetry known as "lonsdaleite" provides an important marker for shock impact events. It is typically considered to form as a metastable phase produced from graphite or other carbonaceous precursors. However, its existence has recently been called into question. Here we collected high-resolution synchrotron X-ray diffraction data for laboratory-shocked and natural impact diamonds that both show evidence for deviations from cubic symmetry, that would be consistent with the appearance of hexagonal stacking sequences. These results show that hexagonality can be achieved by shocking diamond as well as from graphite precursors. The diffraction results are analyzed in terms of a general model that describes intermediate stacking sequences between pure diamond (fully cubic) and "lonsdaleite" (fully hexagonal) phases, with provision made for ordered vs disordered stacking arrangements. This approach provides a "hexagonality index" that can be used to characterize and distinguish among samples that have experienced different degrees of shock or static high pressure-high temperature treatments. We have also examined the relative energetics of diamond and "lonsdaleite" structures using density functional theoretical (DFT) methods. The results set limits on the conditions under which a transformation between diamond and "lonsdaleite" structures can be achieved. Calculated Raman spectra provide an indicator for the presence of extended hexagonal stacking sequences within natural and laboratory-prepared samples. Our results show that comparable crystallographic structures may be developed by impact-generated shockwaves starting from ambient conditions using either of the two different allotropes of carbon (diamond, graphite). This broadens the scope for its occurrence in terrestrial and planetary systems.
DS201701-0016
2016
Prencipe, M.Jones, A.P., McMillan P.F., Salzmann, C.G., Alvaro, M., Nestola, F., Prencipe, M., Dobson, D., Hazael, R., Moore, M.Structual characterization of natural diamond shocked to 60 Gpa; implications for Earth and Planetary Systems.Lithos, In press availableTechnologyDiamond morphology

Abstract: The possible presence of the high-density carbon polymorph with hexagonal symmetry known as “lonsdaleite” provides an important marker for shock impact events. It is typically considered to form as a metastable phase produced from graphite or other carbonaceous precursors. However, its existence has recently been called into question. Here we collected high-resolution synchrotron X-ray diffraction data for laboratory-shocked and natural impact diamonds that both show evidence for deviations from cubic symmetry, that would be consistent with the appearance of hexagonal stacking sequences. These results show that hexagonality can be achieved by shocking diamond as well as from graphite precursors. The diffraction results are analyzed in terms of a general model that describes intermediate stacking sequences between pure diamond (fully cubic) and “lonsdaleite” (fully hexagonal) phases, with provision made for ordered vs disordered stacking arrangements. This approach provides a “hexagonality index” that can be used to characterize and distinguish among samples that have experienced different degrees of shock or static high pressure-high temperature treatments. We have also examined the relative energetics of diamond and “lonsdaleite” structures using density functional theoretical (DFT) methods. The results set limits on the conditions under which a transformation between diamond and “lonsdaleite” structures can be achieved. Calculated Raman spectra provide an indicator for the presence of extended hexagonal stacking sequences within natural and laboratory-prepared samples. Our results show that comparable crystallographic structures may be developed by impact-generated shockwaves starting from ambient conditions using either of the two different allotropes of carbon (diamond, graphite). This broadens the scope for its occurrence in terrestrial and planetary systems.
DS201802-0219
2018
Prencipe, M.Anzolini, C., Prencipe, M., Alvaro, M., Romano, C., Vona, A., Lorenzon, S., Smith, E.M., Brenker, F.E., Nestola, F.Depth of formation of super deep diamonds: Raman barometry of CaSiO3 walstromite inclusions.American Mineralogist, Vol. 103, pp. 69-74.Mantlegeobarometry

Abstract: “Super-deep” diamonds are thought to have a sub-lithospheric origin (i.e., below ~300 km depth) because some of the mineral phases entrapped within them as inclusions are considered to be the products of retrograde transformation from lower-mantle or transition-zone precursors. CaSiO3-walstromite, the most abundant Ca-bearing mineral inclusion found in super-deep diamonds, is believed to derive from CaSiO3-perovskite, which is stable only below ~600 km depth, although its real depth of origin is controversial. The remnant pressure (Pinc) retained by an inclusion, combined with the thermoelastic parameters of the mineral inclusion and the diamond host, allows calculation of the entrapment pressure of the diamond-inclusion pair. Raman spectroscopy, together with X-ray diffraction, is the most commonly used method for measuring the Pinc without damaging the diamond host. In the present study we provide, for the first time, a calibration curve to determine the Pinc of a CaSiO3-walstromite inclusion by means of Raman spectroscopy without breaking the diamond. To do so, we performed high-pressure micro-Raman investigations on a CaSiO3-walstromite crystal under hydrostatic stress conditions within a diamond-anvil cell. We additionally calculated the Raman spectrum of CaSiO3-walstromite by ab initio methods both under hydrostatic and non-hydrostatic stress conditions to avoid misinterpretation of the results caused by the possible presence of deviatoric stresses causing anomalous shift of CaSiO3-walstromite Raman peaks. Last, we applied single-inclusion elastic barometry to estimate the minimum entrapment pressure of a CaSiO3-walstromite inclusion trapped in a natural diamond, which is ~9 GPa (~260 km) at 1800 K. These results suggest that the diamond investigated is certainly sub-lithospheric and endorse the hypothesis that the presence of CaSiO3-walstromite is a strong indication of super-deep origin.
DS201811-2594
2018
Prencipe, M.Nestola, F., Prencipe, M., Nimis, P., Zaffiro, G.Toward a robust elastic geobarometry of kyanite inclusions in eclogitic diamonds. VoorspoedJournal of Geophysical Research: Solid Earth, doi: 10.1029/2018JB016012Africa, South Africadiamond inclusions

Abstract: Here we report the first results from elastic geobarometry applied to a kyanite inclusion entrapped within an eclogitic diamond (from Voorspoed mine, South Africa) using micro?Raman and Fourier transform infrared spectroscopy, electron microprobe analysis, ab initio calculations, and finite element modeling. Application of elastic geobarometry to very elastically anisotropic kyanite inclusions is challenging, as current models do not allow for elastic anisotropy. In order to minimize the effects of anisotropy, we have explored the effects of deviatoric stress on Raman modes via ab initio density functional theory. The results allowed us to select the Raman mode (at ca. 638 cm?1) that is the least sensitive to deviatoric stress. The shift of this band in the inclusion while still trapped within the diamond relative to the inclusion in air (once liberated) was used under hydrostatic approximation to determine a residual pressure on the inclusion of 0.184 ± 0.045 GPa and an entrapment pressure of 5.2 ± 0.3 GPa (~160 km depth) for an FTIR N?aggregation residence temperature of 1119 ± 50 °C. This is the first geothermobarometric determination for a diamond from the Voorspoed kimberlite. It overlaps with P-T estimates obtained by traditional chemical geobarometry for diamonds from other kimberlites from the Kaapvaal craton, suggesting that the hydrostatic approximation does not introduce significant errors in the geobarometric evaluation. Our protocol of Raman peak selection can be used for geobarometry of further kyanite?bearing diamonds and may provide a guide for more robust geobarometry of other types of mineral inclusions in diamonds, both eclogitic and peridotitic.
DS201812-2853
2018
Prencipe, M.Murri, M., Mazzucchelli, M.L., Campomenosi, N., Korsakov, A.V., Prencipe, M., Mihailova, B.D., Scambelluri, M., Angel, R.J., Alvaro, M.Raman elastic geobarometry for anisotropic mineral inclusions. MirAmerican Mineralogist, Vol. 103, pp. 1869-1872.Russiamineral inclusions

Abstract: Elastic geobarometry for host-inclusion systems can provide new constraints to assess the pressure and temperature conditions attained during metamorphism. Current experimental approaches and theory are developed only for crystals immersed in a hydrostatic stress field, whereas inclusions experience deviatoric stress. We have developed a method to determine the strains in quartz inclusions from Raman spectroscopy using the concept of the phonon-mode Grüneisen tensor. We used ab initio Hartree-Fock/Density Functional Theory to calculate the wavenumbers of the Raman-active modes as a function of different strain conditions. Least-squares fits of the phonon-wavenumber shifts against strains have been used to obtain the components of the mode Grüneisen tensor of quartz (??m1 and ?m3?) that can be used to calculate the strains in inclusions directly from the measured Raman shifts. The concept is demonstrated with the example of a natural quartz inclusion in eclogitic garnet from Mir kimberlite and has been validated against direct X-ray diffraction measurement of the strains in the same inclusion.
DS1995-0185
1995
Prendergast, M.D.Boudreau, A.E., Love, C., Prendergast, M.D.Halogen geochemistry of the Great Dyke, ZimbabweContributions to Mineralogy and Petrology, Vol. 122, No. 3, pp. 289-300Zimbabweplatinum group elements (PGE), Layered intrusion, Platinum, nickel, chromite, Deposit -Great Dyke
DS200412-1580
2004
Prendergast, M.D.Prendergast, M.D.The Buiawayan Supergroup: a late Archean passive margin related large igneous province in the Zimbabwe Craton.Journal of Geological Society of London, Vol. 161, 3, pp. 431-446.Africa, ZimbabweTectonics, igneous
DS1992-1233
1992
Prenn, N.B.Prenn, N.B.Reserve calculations: an adventure in geo-fantasy?American Institute of Mining, Metallurgical, and Petroleum Engineers (AIME) Preprint, Annual Meeting held Phoenix Arizona Feb. 24-27th. 1992, Preprint No. 92-196, 9pGlobalGeostatistics, ore reserves, Overview
DS1994-1464
1994
Prenn, N.B.Ristorcelli, S.J., Prenn, N.B.The use and misuse of geology in computer generated resource estimations:some case historiesAmerican Institute of Mining, Metallurgical, and Petroleum Engineers (AIME) Preprint, Meeting held Albuquerque Feb. 14-17th, No. 94-135, 12pNevadaOre reserves, geostatistics, Gold, epithermal
DS202203-0336
2022
Prent, A.Boone, S.C., Dalton, H., Prent, A., Kohlman, F., Theile, M., Greau, Y., Florin, G., Noble, W., Hodgekiss, S-A., Ware, B., Phillips, D., Kohn, B., O'Reilly, S., Gleadow, A., McInnes, B., Rawling, T.AusGeochem: an open platform for geochemical data preservation, dissemination and synthesis. Lithodat Pty *** not specific to diamonds but excellent concept/platformGeostandards and Geoanalysis Research, doi.org/10.1111/GGR.12419 34p. PdfAustraliageochemistry

Abstract: To promote a more efficient and transparent geochemistry data ecosystem, a consortium of Australian university research laboratories called the AuScope Geochemistry Network (AGN) assembled to build a collaborative platform for the express purpose of preserving, disseminating, and collating geochronology and isotopic data. In partnership with geoscience-data-solutions company Lithodat Pty Ltd, the open, cloud-based AusGeochem platform (https://ausgeochem.auscope.org.au) was developed to simultaneously serve as a geosample registry, a geochemical data repository, and a data analysis tool. Informed by method-specific groups of geochemistry experts and established international data reporting practices, community-agreed database schemas were developed for rock and mineral geosample metadata and secondary ion mass spectrometry U-Pb analysis, with additional models for laser ablation inductively-coupled mass spectrometry U-Pb and Lu-Hf, Ar-Ar, fission-track and (U-Th-Sm)/He under development. Collectively, the AusGeochem platform provides the geochemistry community with a new, dynamic resource to help facilitate FAIR (Findable, Accessible, Interoperable, Reusable) data management, streamline data dissemination and advanced quantitative investigations of Earth system processes. By systematically archiving detailed geochemical (meta-)data in structured schemas, intractably large datasets comprising thousands of analyses produced by numerous laboratories can be readily interrogated in novel and powerful ways. These include rapid derivation of inter-data relationships, facilitating on-the-fly data compilation, analysis, and visualisation.
DS200912-0599
2009
Prenzel, J.Prenzel, J., Abart, R., Keller, L.Complex chemical zoning in eclogite facies garnet reaction rims: the role of grain boundary diffusion.Mineralogy and Petrology, Vol. 95, 3-4, pp. 303-313.TechnologyMineral chemistry
DS2002-1281
2002
PreprintPreprintWorld wide exploration statisticsCanada International Government Statistics, 5p.GlobalEconomics - exploration spending charts
DS1999-0565
1999
Preprint news from S.A.Preprint news from S.A.Perth link to huge new South Africa diamond find... Majestic Res. reached agreement with Lutheran Church Pniel property.Preprint news from S.A., Sept. 2p.South AfricaNews item, Droogeveld Channel, Nooitgedacht
DS201312-0720
2014
Prescher, C.Prescher, C., Weigel, C., McCammon, C., Narygina, O., Potapkin, V., Kupenko, I., Sinmyo, R., Chumakov, A.I., Dubrovinsky, L.Iron spin state in silicate glass at high pressure: implications for melts in the Earth's lower mantle.Earth and Planetary Science Letters, Vol. 385, pp. 130-136.MantleUHP
DS201412-0711
2014
Prescher, C.Prescher, C., Langenhorst, F., Dubrovinsky, L.S., Prakapenka, V.B., Miyajima, N.The effect of Fe spin crossovers on its partitioning behavior and oxidation state in a pyrolitic Earth's lower mantle system.Earth and Planetary Science Letters, Vol. 399, pp. 86-91.MantleOxidation
DS201504-0213
2015
Prescher, C.Prescher, C., Dubrovinsky, L., Bykova, E., Kupenko, I., Glazyrin, K.High Poisson's ration of Earth's inner core explained by carbon alloying.Nature Geoscience, Vol. 8, 3, pp. 220-223.MantleCore, carbon
DS201710-2219
2017
Prescher, C.Cerantola, V., Bykova, E., Kupenko, I., Merlini, M., Ismailova, L., McCammon, C., Bykov, M., Chumakov, A.I., Petitgirard, S., Kantor, I., Svityk, V., Jacobs, J., Hanfland, M., Mezouar, M., Prescher, C., Ruffer, R., Prakapenka, V.B., Duvbovinsky, L.How iron carbonates help form diamonds.Nature Communications, July 18 #15960Mantlecarbonate inclusions
DS202006-0927
2020
Prescher, C.Ko, B., Prakapenka, V., Kunz, M., Prescher, C., Leinenweber, K., Shim, S-H.Mineralogy and density of Archean volcanic crust in the mantle transition zone.Physics of the Earth and Planetary Interiors, Vol. 305, 13p. PdfMantledensity

Abstract: The composition of Archean volcanic crust can be characterized by a higher Mg/Si ratio than modern mid-ocean ridge basalt (MORB), because of the higher degree melting from the warmer mantle in the Archean. Although modern MORB may become less dense than the surrounding mantle beneath the mantle transition zone (MTZ), the Mg-rich composition of Archean volcanic crust may result in the different density, and therefore different sinking behavior near the MTZ. In order to understand the compositional effect of Archean volcanic crust on the sinking behaviors and the scale of mantle mixing in the Archean, we investigated the mineralogy and density of Archean volcanic crust near the MTZ (470-910 km-depth). We conducted experiments at 19-34 GPa and 1400-2400 K using the laser-heated diamond anvil cell (LHDAC) combined with in-situ X-ray diffraction (XRD). The in-situ XRD and the chemical analysis revealed that Archean volcanic crust forms garnet and ringwoodite (84 and 16 vol%, respectively), which gradually transforms to Brg and CaPv (82 and 18 vol%, respectively) at 23-25 GPa and 1800 K. Our in-situ XRD experiments allowed us to measure the volumes of stable phases and to estimate their densities at high pressure and temperature. The results suggest that Archean volcanic crust maintains greater density than the pyrolitic mantle in the Archean regardless of temperature at 20-34 GPa (570-850 km-depth), promoting further sinking into the deeper mantle in the Archean. We also considered the density of the subducting slab in the Archean. The density model showed that the subducting slab is still denser or at least equally dense as the surrounding pyrolitic mantle in the Archean.
DS202008-1410
2020
Prescher, C.Ko, B., Prakapenka, V., Kunz, M., Prescher, C., Leinenweber, K., Shim, S-H.Mineralogy and density of Archean volcanic crust in the mantle transition zone.Physics of the Earth and Planetary Interiors, Vol. 305, 13p. PdfMantlesubduction

Abstract: The composition of Archean volcanic crust can be characterized by a higher Mg/Si ratio than modern mid-ocean ridge basalt (MORB), because of the higher degree melting from the warmer mantle in the Archean. Although modern MORB may become less dense than the surrounding mantle beneath the mantle transition zone (MTZ), the Mg-rich composition of Archean volcanic crust may result in the different density, and therefore different sinking behavior near the MTZ. In order to understand the compositional effect of Archean volcanic crust on the sinking behaviors and the scale of mantle mixing in the Archean, we investigated the mineralogy and density of Archean volcanic crust near the MTZ (470-910 km-depth). We conducted experiments at 19-34 GPa and 1400-2400 K using the laser-heated diamond anvil cell (LHDAC) combined with in-situ X-ray diffraction (XRD). The in-situ XRD and the chemical analysis revealed that Archean volcanic crust forms garnet and ringwoodite (84 and 16 vol%, respectively), which gradually transforms to Brg and CaPv (82 and 18 vol%, respectively) at 23-25 GPa and 1800 K. Our in-situ XRD experiments allowed us to measure the volumes of stable phases and to estimate their densities at high pressure and temperature. The results suggest that Archean volcanic crust maintains greater density than the pyrolitic mantle in the Archean regardless of temperature at 20-34 GPa (570-850 km-depth), promoting further sinking into the deeper mantle in the Archean. We also considered the density of the subducting slab in the Archean. The density model showed that the subducting slab is still denser or at least equally dense as the surrounding pyrolitic mantle in the Archean.
DS1993-1259
1993
Prescott, J.Prescott, J.The shape of things to come... address to AusIMM. Sleeping giants awaken...shift in geographic markets - China, India, Indonesia, energy demandsAustralian Institute of Mining Bulletin, No. 4, August pp. 60-63China, India, Indonesia, AustraliaEconomics, Legislation
DS1991-1379
1991
Preser, I.B.Preser, I.B.Characterization of lamproites from Paraguay (South America)Proceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 334-335GlobalGuaira-Paraguari Province, monchiquites, cocites, ijolites, Basanites, damkjernites, ouachitites, sannaites, carbonatit
DS200912-0272
2008
Presnall, D.Gudfinnsson, G., Keshav, S., Presnall, D.Water rich carbonatites at low pressures and kimberlites at high pressures.American Geological Union, Fall meeting Dec. 15-19, Eos Trans. Vol. 89, no. 53, meeting supplement, 1p. abstractMantleCarbonatite
DS1995-0056
1995
Presnall, D.C.Arima, M., Presnall, D.C.Melting experiments on the join diopside magnesite at 7 GPa and their bearing on the genesis of kimb. magmas.Proceedings of the Sixth International Kimberlite Conference Extended Abstracts, p. 11-13.GlobalPetrology -experimental, Kimberlite genesis
DS1995-0378
1995
Presnall, D.C.Dalton, J.A., Presnall, D.C.Phase relations in system Cao MgO Al2O3 SO2 CO2 from 4.0 to 6.0 GPa-application generation of kimberlitesEos, Vol. 76, No. 46, Nov. 7. p.F697. Abstract.GlobalKimberlites, Carbonatite, Petrogenesis
DS1997-0237
1997
Presnall, D.C.Dalton, J.A., Presnall, D.C.Phase relations in the system Cao MgO Al2O3 SiO2 Co2 from 3.0 to 7.0 GPa:carbonatites, kimberlites....Geological Association of Canada (GAC) Abstracts, GlobalCarbonatite, kimberlites, related rocks
DS1998-0300
1998
Presnall, D.C.Dalton, J.A., Presnall, D.C.Carbonatitic melts along the solidus of model lherzolite in the systemCaOMgOAl2O3 SiO2 CO2 (3-7 GPa)Contributions to Mineralogy and Petrology, Vol. 131, No. 2/3, pp. 123-135.GlobalCarbonatite, Petrology - experimental
DS1998-0301
1998
Presnall, D.C.Dalton, J.A., Presnall, D.C.The continuum of primary carbonatitic kimberlitic melt composition in equilibrium with lherzolite: dat a 6 GpaJournal of Petrology, Vol. 39, No. 11-12, Nov-Dec. pp. 1953-64.GreenlandCarbonatite, Lherzolite - kimberlite melt, petrology, Safartoq
DS1998-1185
1998
Presnall, D.C.Presnall, D.C., Walter, M.J.high pressure phase equilibrium constraints on the origin of eclogites7th. Kimberlite Conference abstract, pp. 705-7.MantleEclogites, Geochronology, petrology, mineral chemistry
DS1999-0785
1999
Presnall, D.C.Weng, Y.H., Presnall, D.C.Liquidus phase relations in the system forsterite diopside enstatite at 5GPa: a simplified model meltingGeological Association of Canada (GAC) Geological Association of Canada (GAC)/Mineralogical Association of Canada (MAC)., Vol. 24, p. 135. abstractMantlePetrology - experimental, Peridotite
DS2001-0423
2001
Presnall, D.C.Gudfinnson, G.H., Presnall, D.C.A pressure independent geothermometer for primitive mantle meltsJournal of Geophysical Research, Vol. 106, No. 8, pp. 16, 205-12.MantleGeothermometry
DS2001-1227
2001
Presnall, D.C.Weng, Y-Hua., Presnall, D.C.The system diopside forsterite enstatite at 5.1 GPa: a ternary model for melting of the mantle.Canadian Mineralogist, Vol. 39, No. 2, Apr. pp. 299-308.MantleMelting, phase relations, peridotite
DS2003-0517
2003
Presnall, D.C.Gudfinnsoon, G.H., Presnall, D.C.Continuous gradations among primary kimberlitic, carbonatitic, melititic and komatititic8 Ikc Www.venuewest.com/8ikc/program.htm, Session 7, AbstractSouth AfricaKimberlite petrogenesis
DS200412-0742
2003
Presnall, D.C.Gudfinnsoon, G.H., Presnall, D.C.Continuous gradations among primary kimberlitic, carbonatitic, melititic and komatititic melts in equilibrium with garnet lherzo8 IKC Program, Session 7, AbstractAfrica, South AfricaKimberlite petrogenesis
DS200512-0374
2005
Presnall, D.C.Gudfinnsson, G.H., Presnall, D.C.The implications of different geotherms for the generation of carbonatites, kimberlites and melilitites.Abstract 1p., Geothermometry
DS200512-0375
2005
Presnall, D.C.Gudfinnsson, G.H., Presnall, D.C.Continuous gradations among primary carbonatitic, kimberlitic, melilititic, basaltic, picritic and komatiitic melts in equilibrium with garnet lherzolite at 3-8 GPa.Journal of Petrology, Vol. 46, 8, pp. 1645-1659.MantlePetrology - kimberlite, carbonatite
DS200512-0873
2005
Presnall, D.C.Presnall, D.C., Gudfinnsson, G.H.Carbonate rich melts in the oceanic low-velocity zone and deep mantle.Plates, Plumes, and Paradigms, pp. 207-216. ( total book 861p. $ 144.00)MantleCarbonate melts
DS200512-0874
2005
Presnall, D.C.Presnall, D.C., Gudfinnsson, G.H.MORB major element systematics: implications for melting models and mantle temperatures.Chapman Conference held in Scotland August 28-Sept. 1 2005, 1p. abstractMantle, IcelandMantle plume, geothermometry
DS200712-0532
2007
Presnall, D.C.Keshav, S., Gudfinnsson, G.H., Presnall, D.C.Precipitous drop in the carbonated peridotite solidus between 14-16 GPa: calcic carbonatites in the Earth's transition zone.Plates, Plumes, and Paradigms, 1p. abstract p. A479.MantleCarbonatite
DS201112-0515
2011
Presnall, D.C.Keshav, S., Gudfinnsson, G.H., Presnall, D.C.Melting phase relations of simplified carbonated peridotite at 12-26 GPa in the system CaO-MgO-SiO2-CO2 and CaO-MgO-Al2O3-Sio2-CO2: highly calcic magmas EarthJournal of Petrology, Vol. 51, pp. 2265-2291.MantleTransition zone of the Earth
DS201112-0827
2011
Presnall, D.C.Presnall, D.C., Gudfinnsson, G.H.Oceanic volcanism from the low-velocity zone - without mantle plumes.Journal of Petrology, Vol. 52, 7-8, pp. 1533-1546.MantleVolcanism
DS200712-1119
2007
Presnyakov, S.L.Vetrin, V.R., Lepekhina, E.N., Larionov, A.N., Presnyakov, S.L., Serov, P.A.Initial subalkaline magmatism of the Neoarchean alkaline province of the Kola Peninsula.Doklady Earth Sciences, Vol. 415, No. 5, June-July pp. 714-717.Russia, Kola PeninsulaAlkalic
DS200912-0637
2009
Presnyakov, S.L.Rodonov, N.V., Belyatsky, B.V., Antonov, A.V., Presnyakov, S.L., Sergeev, S.A.Baddeleyite U Pb shrimp II age determination as a tool for carbonatite massifs dating.Doklady Earth Sciences, Vol. 428, 1, pp. 1166-1170.RussiaCarbonatite
DS201112-0971
2011
Presnyakov, S.L.Skublov, S.G., Astafev, B.Yu., Marin, Yu.B., Berezin, A.V., Melnik, A.E., Presnyakov, S.L.New dat a on the age of eclogites from the Belmorian mobile belt at Gridino settlement area.Doklady Earth Sciences, Vol. 439, 2, pp.1163-1170.RussiaEclogite
DS200412-1581
2004
Press ReleasePress ReleaseReceivers return 542 diamonds to U.S.: auction set. The gems were seized in 1999 from fugitive financier Martin Frankel ( schemeReuters, Oct. 21, 1p.United States, New YorkNews item - gem auction
DS2002-1282
2002
Pressacco, R.Pressacco, R.Geology of the Cargill Township carbonatite associated phosphate deposit, Kapuskasing Ontario.Exploration and Mining Geology, Vol. 10, 1-2, pp. 77-84.OntarioCarbonatite, Regional geology, geochemical analyses
DS201508-0372
2015
Presser, J.Presser, J.Kalahari Craton, Yakutia craton area - seismic tomography.[email protected], 3 images dvs inverted x-1 pdfs availableAfricaMap - kimberlites
DS201509-0421
2015
Presser, J.Presser, J.Mantle tomography - Cullinan[email protected], pdf fileAfrica, South AfricaDeposit - Cullinan
DS201509-0422
2015
Presser, J.Presser, J.Mantle tomography Itapoti diamond area [email protected], pdf fileSouth America, ParaguayGeophysics - seismics
DS201511-1868
2015
Presser, J.Presser, J.Orapa - example using seismics[email protected], 1p. AvailableAfrica, BotswanaGeophysics - Orapa
DS201511-1869
2015
Presser, J.Presser, J.International Mir - example using seismics[email protected], 1p. AvailableRussiaGeophysics - Mir
DS201512-1959
2015
Presser, J.Presser, J.Botswana showing pipe locations,[email protected], 1 pdf availableAfrica, BotswanaGeophysics - pipes
DS201603-0414
2016
Presser, J.Presser, J.Cataclastic deformation structures in sub-lithospheric diamonds.. Subduction origin? [email protected], 8p.MantleSubduction

Abstract: Forty-one diamonds sourced from the Juina-5 kimberlite pipe in Southern Brazil, which contain optically identifiable inclusions, have been studied using an integrated approach. The diamonds contain <20 ppm nitrogen (N) that is fully aggregated as B centres. Internal structures in several diamonds revealed using cathodoluminescence (CL) are unlike those normally observed in lithospheric samples. The majority of the diamonds are composed of isotopically light carbon, and the collection has a unimodal distribution heavily skewed towards ?13C ~ ?25 ‰. Individual diamonds can display large carbon isotope heterogeneity of up to ~15 ‰ and predominantly have isotopically lighter cores displaying blue CL, and heavier rims with green CL. The light carbon isotopic compositions are interpreted as evidence of diamond growth from abiotic organic carbon added to the oceanic crust during hydrothermal alteration. The bulk isotopic composition of the oceanic crust, carbonates plus organics, is equal to the composition of mantle carbon (?5 ‰), and we suggest that recycling/mixing of subducted material will replenish this reservoir over geological time. Several exposed, syngenetic inclusions have bulk compositions consistent with former eclogitic magnesium silicate perovskite, calcium silicate perovskite and NAL or CF phases that have re-equilibrated during their exhumation to the surface. There are multiple occurrences of majoritic garnet with pyroxene exsolution, coesite with and without kyanite exsolution, clinopyroxene, Fe or Fe-carbide and sulphide minerals alongside single occurrences of olivine and ferropericlase. As a group, the inclusions have eclogitic affinity and provide evidence for diamond formation at pressures extending to Earth’s deep transition zone and possibly the lower mantle. It is observed that the major element composition of inclusions and isotopic compositions of host Juina-5 diamonds are not correlated. The diamond and inclusion compositions are intimately related to subducted material and record a polybaric growth history across a depth interval stretching from the lower mantle to the base of the lithosphere. It is suggested that the interaction of slab-derived melts and mantle material combined with subsequent upward transport in channelised networks or a buoyant diapir explains the formation of Juina-5 diamonds. We conclude that these samples, despite originating at great mantle depths, do not provide direct information about the ambient mantle, instead, providing a snapshot of the Earth’s deep carbon cycle.
DS201603-0415
2016
Presser, J.Presser, J.Ultra-deep diamonds truly exist? Or are they lithospheric diamonds suffering from shock metamorphism? Slave Craton[email protected], 2p. PdfCanada, Northwest TerritoriesDeposit - Diavik arena
DS202105-0784
2021
Presser, J.Presser, J.Lampoites in Leucite HillsLinkedin, https://www.linkedin.com/ posts/jaime-l-b-presser -179a0415_and-the-paleo- volcanoes-of-lamproites -in-activity-6781902573 998759936-4fEnUnited States, Wyominglamproite
DS202102-0217
2021
Presser, J.B.Presser, J.B.Lamproites of the Kaapvaal type, two reference mines: Finch with 59.9 cpht and Dokolwayo with 30 cpht. Others …..https://www.linkedin.com/in/jaime-I-b-presser, Jan. 7, 8p. Africa, South Africa, Australia, South America, Paraguaylamproite
DS201908-1803
2019
Presser, J.B.L.Presser, J.B.L.The diamond bearing picritic lamprophyre Ymi-1. Researchgate, July 31p. PdfSouth America, Brazildeposit - Ymi-1

Abstract: In the central-northern portion of Archon lithospheric nucleus of the Rio de la Plata craton, the so-called rift/graben of Asunción was positioned; structure that would have formed thanks to a crustal thinning previously caused by the impact of a meteorite that forms the San Miguel impact cráter. The mega-impact structure is located immediately to the south of the Asunción rift/graben. Within the central segment E-W of the rift/graben and in association with other volcanic, sub-volcanic to plutonic rocks (potasic to ultra-potasic type Roman Province and lamproitic) of around 130-125 Ma., the picritic rock pipe with lamprofidic texture Ymi-1 occurs. Pipe that was positioned in the heavily depressed area (depths of up to -3000 meters) of the rift/graben. The Ymi-1 pipe would have been installed following faults, apparently very powerful, of the aforementioned distensive structure. Rocks of a plug and a dike exposed in the pipe Ymi-1 show that it is a strongly porphyritic rock with tendencies of lamprophidic texture formed by micro-feno-mega-crystals of forsteritic olivine (>10 to 30% modal); pheno-mega-crystals of titanium aluminosus diopside and chromite ((Mg-chromite poor in Ti and Mg-Ti chromite) micro-phenocrysts; they are supported by an inter-granular matrix formed by aluminosus diopside, Al-Ti-phlogopite-biotite, Mg-Ti-magnetite, amphiboles (Hornblends, eckernmanite together with some other potassium to sodic titaniferous amphiboles) accompanied by sanidine, analcime and traces of plagioclase (poor in An molecules). The mineral chemistry of spinels, phlogopites-biotites and diopsids are strongly compatible with mineral chemistry known in calc-alkaline lamprophyres. The rock chemistry of one available dyke is also compatible with the chemistry of calc-alkaline lamprophyres (SiO2 49.8%, with K2O/Na2O> 1, MgO 12%, Ni 298-ppm, Cr 904-ppm, La-76 ppm, Lu 0.15-ppm, TiO2 1.27%; CaO 8.59% and ratios of Sr87 / Sr86 = 0.707238 and 143Nd / 144Nd = 0.51196).Ymi-1 a calc-alkaline picritic lamprophyre pipe where the study of the chromite (50-57 % Cr2O3) type and frosting-tourmaline ("dravites"), obtained in rock and in heavy mineral concentrates (in vulcano-epi-clastic sediments and in stream sediments -collected in its bed) suggest that it would be a diamond-bearing lamprophyre. The presence of diamonds was confirmed (by X-rays and other methods) in the Ymi-1 pipe. 1D S-wave seismic profile of continental data, for the pipe Ymi-1 site, suggests a geothermal gradient between 38.5 to 39 mw/m2. Data that make the Ymi-1 calc-alkaline lamprophyre an attractive target for an eventual diamonds deposit.
DS201908-1804
2019
Presser, J.B.L.Presser, J.B.L., Alonso, R., Rocca, M.Malvinas Islands ( Falkland Islands): advances in the inferred buried marine impact mega-structure.Researchgate, July 27p. PdfFalkland Islandsimpact structure

Abstract: In 1992 Rampino noticed a large, almost circular negative gravity anomaly (~30 mGal) on the Falkland Plateau to the WNW of Malvinas Islands/Falklnad Islands using satellite data then available, and speculated that it might be associated with a large (~250 km wide?) buried impact structure. In some more recent compilations Rocca & Presser (2015) and Rocca et al. (2017) was attended the Malvinas Islands/Falklnad Islands “buried impact structure” with particular care; but also these works was harshly criticized. The present text, which is an advance to demonstrate the certain possibilities that this Malvinas Islands/Falklnad Islands It could really be a very probable mega impact structure, gathers shows and evaluates the existing and available indirect information; like gravimetry (Isostasy, Free-air and Bouguer); seismic reflection (Geco Prakla); and, even commenting aspects of its magnetic behavior and its local geology. In all gravimetric analyses from the Malvinas Islands/Falklnad Islands “buried impact structure” it can be shown that an annulus of positive gravity anomaly surrounding a circular oval depression of negative (isostasy and Free-air)/much lower (Bouguer) values gravity anomaly. The most relevant gravimetric information would be the near circular to oval Bouguer gravity low anomaly (with a minimum value of ~150 mGal) surrounded by at least circular ~255 kilometers wide circular ring of positive gravity anomaly (maximum ~225 mGal); a very high values of Bouguer anomaly that are highly compatible with what is expected to be found in mega impact structures. The Malvinas probable impact structure shows almost 100 mGal superior to the volcanic complex of Iceland; so it seems obvious that Malvinas probable impact structure moves away from a speculation by mega-paleo-volcano origin. When gravimetrically modeled, a probable peak ring of ~255 km is evidenced; as well as, the inferred the ~550 km probable rim-crest; configuration that reproduces an almost perfect and symmetrical modeling of a very probable giant impact structure with its clear visible the very probable elements: rim crest-annulus basin-peak ring-central basin-peak ring-annulus basin-rim crest. Four Geco Prakla seismic reflection lines on the area located to the SW of the potential peak ring show a vertical and disturbed crystalline basement (the “peak ring”); in three of them, the “central basin” what would it be filled with sediments after impact (probable ejecta). Using the empirical formula of Assumpçăo et al. (2013) calculation for crustal thickness could be found very clearly strong CT distortion along Malvinas very probable giant impact structure: around 3400-4000 meters; as is to be expected in terrestrial mega impact structure. Harness the EMAG2v3 a global Earth Magnetic Anomaly Grid compiled from satellite (Meyer et al., 2017) for the Malvinas very probable giant impact structure a well superior anomaly was found and better definition than observed, using the same information, to the one characterized by the impact crater Chicxulub. The geological map of the Falkland Islands Government that was placed on top of the modeling isostasy gravimetric map where the approximate circumference of the very probable peak-ring and the very probable rim-crest is highlighted. This information allows to see that the largest island (West Malvinas) would be part of the very probable peak-ring and the smaller island (East Malvinas) would be part of the very probable rim-crest; both separated by the depression that would correspond to the very probable annulus basin. Based on what was analyzed in the Malvinas Islands area, we concluded the Malvinas exhibited geophysics traits of a large ancient asteroid impact; i.e. Malvinas very probable giant impact structure. Very probable impact structure what could be among one of the world's largest impact crater.
DS201904-0767
2019
Presser, J.L.Presser, J.L.Diamond Occurrences in Paraguay.Diamond Development Exploration Event, 55 ppts. Pdf availableSouth America, Paraguaydiamond occurrences
DS2000-0776
2000
Presser, J.L.B.Presser, J.L.B.Lamproites of the Ybtyruzu field, Guaira department Eastern ParaguayIgc 30th. Brasil, Aug. abstract only 1p.GlobalLamproites
DS201212-0674
2012
Presser, J.L.B.Smith, C.B., Bulanova, G.P., Presser, J.L.B.Diamonds from Capibary, Paraguay10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractSouth America, ParaguayDeposit - Itapapoty
DS201412-0712
2014
Presser, J.L.B.Presser, J.L.B., Bulanova, G.P., Smith, C.B.Diamantes de Capiibary, DPTO. San Pedro, Paraguay.Boletin del Museo Nacional de Historia Narural del Paraguay, Vol. 17, 2, pp. 5-23.South America, ParaguayProject - Capiibary
DS201412-0951
2014
Presser, J.L.B.Vladykin, N.V., Btschene, P., Presser, J.L.B.Lamproitas de la porcion norte de la cordillera del Ybytytuzu, Paraguay oriental: YZU-6.6 Simposio Brasileiro de Geologia do Diamante, Aug. 3-7, 5p. AbstractSouth America, ParaguayLamproite
DS201702-0233
2016
Presser, J.L.B.Presser, J.L.B.Diamantes en Paraguay, Cincuenta an Os de occurrencia. ** PortBoletin del Museo Nacional de Historia Narural del Paraguay, Vol. 20, 2, pp. 154-187. pdf available in * PortSouth America, ParaguayLamproite

Abstract: Diamonds in Eastern-Paraguay began to be recognized in the 60s of last century near the town of Capiibary Dept. San Pedro; but it was only formalized the occurrence in 2008. In Capiibary and around, over 100 macro (1 ~ 3 mm) diamond (colorless, shades of brown and rare shades of pink, blue and green) were recovered from alluvial deposits. Micro-diamonds and small macro-diamonds were separated from sediment (conglomeratic/breccia´s/others; rich in indicators mineral: eclogitic garnets, rounded ilmenite, chromite, frosting-tourmaline, zircon, etc.) interpreted as reworked primary source. In the same locality 20 diamonds in its external morphology, internal structure, its mineral inclusions and the nitrogen content and state of aggregation were studied. The late 90s of last century diamonds were recovered from re-worked volcanic facies a probable pipe of Mesozoic picrític calc-alkaline lamprophyre, in the vicinity of the town of La Colmena in the Dept. Paraguari. Few later years (2003), some ten kilometers to the east, a mining company announced that it had found macro-diamond in a lamproite dyke (also Mesozoic) of 4 meters wide, along the Cordillera del Ybytyruzú, Dept. of Guaira. The same mining company notice that have found macro (~ 1 mm) diamonds in other departments of East Paraguay. It was also in late 2003 that were found in stream sediments, alluvium, soil and primary weathered rock /primary reworked -macro (millimeter) diamonds (colorless, yellow, pink, green, brown) accompanied by high concentration of indicator minerals (eclogitic garnets, rounded ilmenite, chromite, rutile, frosting-tourmaline, Fe-Ti-staurolite, zircon, etc.) around the town of Puentesińo (and adjacent areas), Dept. of Concepcion. More recently regional research work allowed locate macro (> 0.5 to 2 mm) diamonds in alluvial deposits and fine/coarse sediments (probable primary re-worked rock -also accompanied by high concentration of indicator minerals: rounded ilmenite, chromite, rutile, frosting-tourmaline, zircons, etc.) between the Department Concepción-Amambay -in the vicinity of Mesozoic carbonatitic alkaline complex. Officially between the 90s of last century to date have collected (Paraguay-East) around 5000 (for diamonds/indicator minerals) samples of stream sediment, soil, termite nest, weathered rock. Some samples (Puentesińo-around and Capiibary and vicinity) produced indicator minerals were analyzed in their chemical composition: eclogitic garnets (G-3 and G-4); picro-chromites (some with Zn and Mn); chromite-spinel; Mn-ilmenite, Ti-K-tourmaline (frosting-tourmaline); rutile and Fe-Ti-estaurolites. Eclogitic-garnets, picro-chromites and frosting-tourmaline reproduces compatible parameters with its association with diamonds (in the mantle and/or primary rocks). The composition of chromite-spinel, K-Ti-tourmaline, Mn-ilmenite and Zircons supported by the types of eclogitic-garnets and some forms of diamonds-corrosion suggest that the primary source for the diamonds try to lamproites. The tectonic environment, deduced from seismic tomography (Model TX2011 -dVs%) -supported by calculations of P in eclogitic garnets and in picro-chromites, correspond to a block Archon (Apa) of Rio de La Plata Craton. Archon- block that it would be deep (about 250-280 km deep) and thus ideal for the occurrence of primary productive sources of diamond.
DS201702-0234
2016
Presser, J.L.B.Presser, J.L.B., Farina-Dolsa, S., Larroza-Cristaldo, F.A., Rocca, M., Alonso, R.N., Acededo, R.D., Cabral-Antunez, N.D., Baller, L., Zarza-Lima, P.R., Sekatcheff, J.M.Modeled mega impact structures in Paraguay: II the eastern region. **PortBoletin del Museo Nacional de Historia Narural del Paraguay, Vol. 20, 2, pp. 205-213. pdf available in * PortSouth America, ParaguayImpact Crater

Abstract: We report here the discovery and study of several new modeled large impact craters in Eastern Paraguay, South America. They were studied by geophysical information (gravimetry, magnetism), field geology and also by microscopic petrography. Clear evidences of shock metamorphic effects were found (e.g., diaplectic glasses, PF, PDF in quartz and feldspar) at 4 of the modeled craters: 1) Negla: diameter:~80-81 km., 2) Yasuka Renda D:~96 km., 3) Tapyta, D: ~80 km. and 4) San Miguel, D: 130-136 km. 5) Curuguaty, D: ~110 km. was detected and studied only by geophysical information. Target-rocks range goes from the crystalline Archaic basement to Permian sediments. The modeled craters were in some cases cut by tholeiitic/alkaline rocks of Mesozoic age and partially covered by lavas of the basaltic Mesozoic flows (Negla, Yasuka Renda, Tapyta and Curuguaty). One of them was covered in part by sediments of Grupo Caacupé (age: Silurian/Devonian). Some of these modeled craters show gold, diamonds, uranium and REE mineral deposits associated. All new modeled large impact craters are partially to markedly eroded.
DS201707-1359
2017
Presser, J.L.B.Presser, J.L.B., Vladykin, N.V., Bitschene, P.R., Tondo, M.J., Acevedo, R.D., Alonso, R., Benitez, P.Olivine-lamproite from Ybtyruzu lamproite field, eastern Paraguay. *** In SpaPyroclastic Flow *** Spa, Vol. 7, 1, pp. 1-15.South America, Paraguaylamproite

Abstract: Numerous Mesozoic bodies of lamproite-like intrusions are located NE and E of the city of Villarrica, Guairá Department, in eastern Paraguay. This magmatic field, known as Ybytyruzú Field, lies immediately on the margin of the SW part of Paranapanemá cratonic-block, just of the Asunción rift backs-horst and so related to deep crustal/lithospheric fracture zones.Mostly of observed rocks are weathered, however fresh samples were collected in dykes from Acaty (=Yzu-2), Tacuarita (=Yzu-7); lava/breccias from Mbocayaty (=Yzu-3); and sill from Salto Boni (=Yzu-6). They intrude, both, the sediments (Independencia Group and Misiones Formation) and the tholeiitic basalts of the Paraná Basin. In the present study we have performed petrographic and mineral chemistry data to show that all of the study rocks, from the Ybytyruzú Field, are lamproites (leucite lamproite from Yzu-2/Yzu-3/Yzu-7 and sanidine lamproite from Yzu-6).With respect to Yzu-2, Yzu-3 and Yzu-6, the following analyzes show the lamproite character: -phenocrysts/microphenocrysts of: olivine (mg# (Mg/(Mg+Fe)) 0.80-0.85), Al-poor diopside (Al2O3 0.53-2.09% and TiO2 0.65-1.61%), phlogopite/Al-poor-Ti phlogopite (mg# 0.76-0.85, TiO2 5.8-10.2% and Al2O3 12.7-13.9%), Mg-Ti magnetites and leucite (pseudomorphs). -and matrix phases of: Al-poor diopside (Al2O3 0.39-2.46% and TiO2 0.43-1.55%), Al-poor-Ti phlogopite/biotite (mg# 0.57-0.80, TiO2 5.6-10.2% and Al2O3 8.9-12.8%), Mg-Ti magnetites/Ti-magnetites; sanidine (0-4.0% Fe2O3, 0-2.6% BaO and 0-2.5% Na2O). And as accessory phases, ilmenite (0.2-5.7% MgO and 0.3-6.6% MnO), K and Ti-rich Feeckermanite/richterite (1.32-3.6% K2O and 4.7-9.0% TiO2), K-rich Fe-Mg-Mn amphiboles, apatite and quartz (Yzu-6). And so, Ybytyruzú lamproite-like intrusions authenticates the true lamproitic province in Paraguay. III; INTERNATIONAL, 2000 BRAZIL 2000; 3 1ST INTERNATIONAL GEOLOGICAL CONGRESS; ABSTRACTS VOLUME
DS201710-2257
2017
Presser, J.L.B.Presser, J.L.B., Tondo, M.J., Dolsa, S.F., Rocca, M.C.L., Alonso, R.N., Benetiz, P., Larroza, F.A., Duarte, B.J.R., Cabral-Antunez, N.D.Brief comments on the impact metamorphism in Cerro Leon quartzites, western Paraguay. English abstract ** in PORTPyroclastic Flow, Vol. 7, 1,pp. 16-24.South America, Paraguayimpact diamonds

Abstract: The petrographic study of two samples (quartzite and impactite) of Cerro León, a mountain range located in the middle of very probable impact basins (Cerro Leon-1, 2, 3 and 4-department of Alto Paraguay, Western-Paraguay) indicated evidences of impact metamorphism: PDFs (Not decorated and decorated) and diaplectic glass. Associated with diaplectic glass, impact diamonds or diamond/lonsdaleite crystals (micro and small macros) were observed with a range of morphologies including isolated and mostly agglutinated crystal varieties. Impact diamonds estimated to have formed by carbonate impact metamorphism present in the sedimentary target-rock of the Silurian/Devonian age. The identification of elements that reveal the impact metamorphism, in the analyzed samples of the Cerro León, evidences that the area of occurrence that would have been indicated as Very Probable Impact Basin, would be more of an Impact Basin.
DS201802-0259
2017
Presser, J.L.B.Presser, J.L.B., Alonso, R.N., Farina Dolsa, S., Larroza, F.A., Rocca, M.C.L., Hornes, K., Baller, L.Impact metamorphism evidence of Negla and Yasuka Renda large impact crater. ***PORT only abstract in eng Boletin Museum History Natural Paraguay ***IN PORT, Vol. 21, no. 2, pp. 69-82. pdfSouth America, Paraguayimpact craters
DS201803-0471
2018
Presser, J.L.B.Presser, J.L.B.An approach to geoethics in Paraguay. Diamonds mentionedAcededo, R.G., Frias, J.M. eds Geoethics in Latin America, Springer Publisher, Chapter 12, 11p. PdfSouth America, Paraguaydiamond mining
DS201908-1805
2019
Presser, J.L.B.Presser, J.L.B., Kumar, S.With the eyes in Bunder lamproites cluster.Researchgate, July 16p. pdfIndia, Madhya Pradeshdeposit - Bunder
DS201909-2079
2019
Presser, J.L.B.Presser, J.L.B.Olie-2 diamond bearing pipe anomaly in Boshof district, S.A.Linkedin, 1p. AbstractAfrica, South Africadeposit - Olie-2
DS201911-2554
2019
Presser, J.L.B.Presser, J.L.B., Alonso, R., Rocca, M.Malvinas Islands ( Falkland Islands): advances in the inferred buried marine impact mega-structure.Pyroclastic Flow Journal of Geology, Vol. 9, no. 1, pp. 1-14. pdf.Antarcticaimpact structure

Abstract: In 1992 Rampino noticed a large, almost circular negative gravity anomaly (~30 mGal) on the Falkland Plateau to the WNW of Malvinas Islands/Falkland Islands using satellite data then available, and speculated that it might be associated with a large (~250 km wide?) buried impact structure. In some more recent compilations Rocca & Presser (2015) and Rocca et al. (2017) was attended the Malvinas Islands/Falkland Islands “buried impact structure” with particular care; but also these works was harshly criticized. The present text, which is an advance to demonstrate the certain possibilities that this Malvinas Islands/Falklnad Islands It could really be a very probable mega impact structure, gathers shows and evaluates the existing and available indirect information; like gravimetry (Isostasy, Free-air and Bouguer); seismic reflection (Geco Prakla); and, even commenting aspects of its magnetic behavior and its local geology. In all gravimetric analyses from the Malvinas Islands/Falklnad Islands “buried impact structure” it can be shown that an annulus of positive gravity anomaly surrounding a circular oval depression of negative (isostasy and Free-air)/much lower (Bouguer) values gravity anomaly. The most relevant gravimetric information would be the near circular to oval Bouguer gravity low anomaly (with a minimum value of ~150 mGal) surrounded by at least circular ~255 kilometers wide circular ring of positive gravity anomaly (maximum ~225 mGal); a very high values of Bouguer anomaly that are highly compatible with what is expected to be found in mega impact structures. The Malvinas probable impact structure shows almost 100 mGal superior to the volcanic complex of Iceland; so it seems obvious that Malvinas probable impact structure moves away from a speculation by mega-paleo-volcano origin. When gravimetrically modeled, a probable peak ring of ~255 km is evidenced; as well as, the inferred the ~550 km probable rim-crest; configuration that reproduces an almost perfect and symmetrical modeling of a very probable giant impact structure with its clear visible the very probable elements: rim crest-annulus basin-peak ring-central basin-peak ring-annulus basin-rim crest. Four Geco Prakla seismic reflection lines on the area located to the SW of the potential peak ring show a vertical and disturbed crystalline basement (the “peak ring”); in three of them, the “central basin” what would it be filled with sediments after impact (probable ejecta). Using the empirical formula of Assumpçăo et al. (2013) calculation for crustal thickness could be found very clearly strong CT distortion along Malvinas very probable giant impact structure: around 3400-4000 meters; as is to be expected in terrestrial mega impact structure. Harness the EMAG2v3 a global Earth Magnetic Anomaly Grid compiled from satellite (Meyer et al., 2017) for the Malvinas very probable giant impact structure a well superior anomaly was found and better definition than observed, using the same information, to the one characterized by the impact crater Chicxulub. The geological map of the Falkland Islands Government that was placed ontop of the modeling isostasy gravimetric map where the approximate circumference of the very probable peak-ring and the very probable rim-crest is highlighted. This information allows to see that the largest island (West Malvinas) would be part of the very probable peak-ring and the smaller island (East Malvinas) would be part of the very probable rim-crest; both separated by the depression that would correspond to the very probable annulus basin. Based on what was analyzed in the Malvinas Islands area, we concluded the Malvinas exhibited geophysics traits of a large ancient asteroid impact; i.e. Malvinas very probable giant impact structure. Very probable impact structure what could be among one of the world's largest impact crater.
DS202001-0033
2019
Presser, J.L.B.Presser, J.L.B.The diamonds-bearing picritic lamprophyre Ymi-1. ** PORTPyroclastic Flow, Vol. 9, 1, pp. 23-34.South America, Paraguaydeposit - Ymi-1

Abstract: The so-called rift/graben of Asunción was formed in the central-northern portion of the Archon lithospheric nucleus of the Rio de la Plata craton. This structure, related to a crustal thinning, likely resulted from an extraterrestrial impact which produced the San Miguel impact crater. The impact structure is located immediately to the south of the Asunción rift/graben. Within the central E-W segment of the rift/graben and in association with other igneous rocks (potasic to ultra-potasic) of around 130-125 Ma, the picritic rock pipe with lamprofidic texture Ymi-1 occurs. This pipe is found in the lower region of this rift/graben through faults (depths of up to -3000 m). Rocks of a plug and a dike exposed in the pipe Ymi-1 show that it is a strongly porphyritic rock with tendencies of lamprophiric texture formed by micro-feno crystals and mega-crystals of forsteritic olivine (>10 to 30% modal); mega-phenocrysts of Ti-Al diopside and micro-phenocrysts of chromite (Mg-chromite poor in Ti and Mg-Ti chromite); they are supported by an inter-granular matrix formed by aluminosus diopside, Al-Ti-phlogopite/biotite, Mg-Ti-magnetite, amphiboles (hornblends, eckernmanite together with some other potassium to sodic titaniferous amphiboles) accompanied by sanidine, analcime and traces of plagioclase (poor in An molecules). The mineral chemistry of spinels, phlogopites/biotites and diopsids are strongly compatible with mineral chemistry known in calc-alkaline lamprophyres. The rock chemistry of one available dyke is also compatible with the chemistry of calc-alkaline lamprophyres.Ymi-1 is a calc-alkaline picritic lamprophyre pipe where the study of the chromite (50-57 % Cr2O3) type and frosting-tourmaline ("dravites"), obtained in rock and in heavy mineral concentrates (in volcano-epiclastic sediments and in stream sediments -collected in its bed) suggest that it would be a diamond-bearing lamprophyre. The presence of diamonds was confirmed (by X-rays and other methods) in the Ymi-1 pipe. 1D S-wave seismic profile of continental data, for the pipe Ymi-1 site, suggests a geothermal gradient between 38.5 to 39 mW/m2, thus the Ymi-1 calc-alkaline lamprophyre an attractive target for an eventual diamond deposit. Supplementary materials S1 - PDF (Figuras suplementarias) S2 - PDF (Geoquímica mineral) https://pyflow.net/joomla30/index.php/9-all-issues/38-el-lamprofido-picritico-con-diamantes-ymi-1.
DS202006-0947
2020
Presser, J.L.B.Presser, J.L.B., Kumar, S.K. The Bunder lamproites cluster ( India): tectonics, lithospheric mantle and environment - a review.Pyroclastic Flow, Vol. 10, 1, pp. 1-9. pdfIndia, Madhya Pradeshlamproite

Abstract: Bunder diamond-bearing lamproite cluster, located in Madhya Pradesh, India, was discovered in 2004. The Precambrian lamproites are intruding Paleoproterozoic and Mesoproterozoic intracratonic sedimentary rocks covering the Archean Bundelkhand craton. The study of Bundelkhand craton through global dVs% TX2011 model (1D and 2D) led us to recognize that it is underlain by Archean lithospheric mantle as is observed in other locations, in mines with medium to very high diamond-grade (greater than 100 cpht). The Bunder Archean lithospheric mantle has 35 mW/m2 surface heat flow, typical of Archons with pipes with a very high degree of diamonds such as the Argyle lamproite and the kimberlites Internationalnaya, Mir, Ekati, among others. In the Bunder lamproite cluster, the Rio Tinto Exploration estimates for the pipes diamond-grade are below 100 cpht. To understand why Bunder lamproite pipes are low grade in diamonds, we combined comparative gravimetric studies to study the structural architecture model of the crystalline basement. In fact, very-rich diamond pipes develop in different crystalline basement architecture when compared to the pipes discovered in the Bunder cluster; for example the pipe Atri. The pipes next to the Argyle lamproite, the kimberlites pipes International, Mir, Diavik and others were located in the most depressed center of graben/micro graben structures; while the pipe Atri would have positioned on the edges of a graben. It is expected that additional exploration focused on the structural configuration of Bundelkhand craton basement may help to discover new lamproite pipes with a much greater diamond degree than the Bunder cluster.
DS202010-1867
2020
Presser, J.L.B.Presser, J.L.B., Benitez, P.Eclogitic geotherms of the Rio de la Plata craton archon-core: Estancia Trementina and Puentesino, Dpto. Of Concepccion-Paraguay. Compared to two large diamond deposits Argyle ( lamproitic ) and Orapa ( kimberlitic.[email protected], 13p. Pdf 330360071South America, Paraguaygeothermometry
DS202010-1868
2020
Presser, J.L.B.Presser, J.L.B., Monteiro, M., Maldonado, A.Impact diamonds in an extravagant metal piece found in Paraguay. *** PORTHistoria Natural *** english abstract, Vol. 10, 2, 12p. PdfSouth America, Paraguaymeteorite

Abstract: Around 70 km SSE of Chovoreca Hill (Paraguay), a pitcher-like metal piece weighing approximately 303 kg was found. Several studies have been carried out on this piece. Metallographic examination resembles cast iron that presents eutectoid microtextures, but the metal showed Neumann lines. Small fragments of the piece were diluted in concentrated HCl and with this it was possible to obtain colorless crystals, with size ranging from 10 ?m to 1 mm, approximately; SEM/EDS studies showed that major element present is carbon which suggests the presence of diamonds. Raman spectroscopy proved that crystals are diamonds, that showing bands in the “lonsdaleite/diamond zone”, further, the results also showed bands that accuse that the carbon of the diamonds are of meteoritic origin. From the calculus of the FWHM with values around to 42-373 cm-1 centered on 1282 cm-1 peak could be an indication of a very powerful impact that would have formed the diamonds.
DS202101-0029
2020
Presser, J.L.B.Presser, J.L.B.Peridotite geotherms of the Rio de la Plata craton-archon core. *** in EngHistoria Natural , Vol. 10, 3, pp. 5-10. pdfSouth Americageothermometry

Abstract: At the Rio de la Plata Craton archon-core environment were inferred, based on 1D Vs profiles (on 208 numbers of points), of the peridotitic geotherms. Values for the archon-core environment, it was estimated 38.5 to 40 mW/m2 in its central northern portion and southern portion and in its edges/southern portion 40 to 42 mW/m2. Geotherm values that allowed estimate LAB between 243 to 237 km depth (northern portion) and 225 to 213 km depth (southern portion). The same 1D Vs information allowed recognizing for this geothermal environment the depth of the graphite-to-diamond phase transition, finding that it is located at ~135 km. depth. So, projecting 70-90 Km. (southern portion) to 102-108 km. (northern portion) thickness of the “diamond window” for the Rio de la Plata craton archon-core. "Diamond window" thickness very close to those of the Kalahari archon craton where the highest grade of diamond deposit is the Kimberley with 200 cpht. Thus, it is estimated for eventual diamond deposit, in the Río de la Plata craton core, are quite similar to Kimberley diamond deposits could be also expected in the archon-core of Río de la Plata craton.
DS202101-0030
2020
Presser, J.L.B.Presser, J.L.B., Benitez, P.Eclogitic geotherms of the Rio de la Plata craton archon-core: Estancia Trementina and Puentesino, Dpto. Of Concepion - Paraguay. Compared to two large diamond deposits Argyle ( lamproitic) and Orapa ( Kimberlitic).Linked in, 20p. PdfSouth America, Paraguaygeothermometry
DS202107-1124
2021
Presser, J.L.B.Presser, J.L.B.Olie-2 ( Olivevenput) diamond-bearing pipe anomaly in Boshof district, South Africa. ( lamproites)Journal of Gems & Precious Metals, Vol. 1, 1 pp. 1-11. pdfAfrica, South Africadeposit - Loxtondal

Abstract: At the end of 2014, around the so called Loxtondal Orangeitic (now called Kaapval type lamproites) cluster, in Boshof district, two circular a nomalies (~540 to ~1100 meters in diameter) were identified by Landsat Satellite Images and interpreted as being of "kimberlites" pipes; probable anomaly which were referred to as Olie 1 and Olie 2. Subsequently, 100 kg of soil samples (horizon A/B) were taken for each of these anomalies. From them there was a high concentration of indicator minerals (IM): olivine, garnets (violets, reds and oranges), chromites, ilmenites, rutile, frosting tourmaline, zircon and among them some crystals of micro and macro diamonds. The high concentration of IM on Olie 2 led to focus the work on it . IM of Olie 2 was burned in HFl and by caustic fusion what contributed about 86 macro (<1 mm) and micro diamonds. The previus works contributed to raising the interest of some diamond geology groups that took new samples that provided electron microprobe analysis of hundreds of chromites and hundreds of garnets: chromites; picro-cromites, and G-9-G-10 garnets. The calculated pressure of the formation of chromites and garnets of Oli e 2 released in the information of seismic Vs-1D and tomography (Model TX2011). It would allow more adequately to reproduce these two minerals generated in the facies of diamonds and separate them from those generated in facies of graphite. A task that would allow a better approach to the diamond potential of this anomaly studied. It was found that in Olie 2 chromites of diamond facies and garnets (G 9 and G 10) are very representative. For this time the study of the lithospheric cratonic mantle (Archon), through of the commented seismic Vs-1D and tomography (Model TX2011) on the Loxtondal cluster (Olie-2)/Kimberley-area setting allowed to estimate the surface heat flow as being approximately 37.5 mW/m2 = 280 km depth of cratonic root (or LAB). Environment in which the highest reference diamond grade is the Kimberley pipe with 200 cpht; and so, for this reason, a similar diamonds-grade could be expected on the Olie-2/potential associated pipes-area.
DS202108-1305
2021
Presser, J.L.B.Presser, J.L.B., Benitez, P.Geophysical constraints of the Rio de la Plata archon craton.Historia Natural, Vol. 11, 2, pp. 17-37. pdfSouth America, Paraguaygeophysics
DS202108-1306
2021
Presser, J.L.B.Presser, J.L.B., Benitez, P.Eclogitic geotherms of the Rio de la Plata craton archon-core. Estancia Trementina and Puentesino, DPTO. Of Concepcion - Parauay. Compared of two large diamond deposits Argyle ( lamproitic ) and Orapa ( kimberlitic).Historia Natural, Vol. 11, 2, pp. 5-16. pdfSouth America, Paraguay, Australia, Africa, Botswanadeposit - Argyle, Orapa
DS201712-2720
2017
Presser Baez, J.L.Presser Baez, J.L.Presser states this is a series of short essays, a task that during this time helped to understand and improve the definition of the craton (Lito-Archon) Rio de la plata. It is intended to be published at the 7th. Brazilian Symposium of Diamond Geology injaimeleonardobp@ gmail.com, Nov. 16, 25p. Lito-archon-Jaime.pdfSouth America, Brazil, Paraguay, globalcraton - Rio de la plata
DS1984-0597
1984
Pressler, J.W.Pressler, J.W.Gem Stones; Usbm Yearbook 1984Usbm Yearbook 1984, Preprint, 14pGlobalOverview
DS1987-0172
1987
Prest, V.K.Dyke, A.S., Prest, V.K.The Late Wisconsi nan and Holocene history of the Laurentide ice sheetGeograph. Phys. Quaternaire, Vol. 41, pp. 237-63.Northwest TerritoriesGeomorphology
DS1986-0268
1986
Presti, A.A.Garcia, M.O., Presti, A.A.Mantle metasomatism of pyroxenite xenoliths from Kaula Island, HawaiiProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, pp. 241-243HawaiiBlank
DS1998-1495
1998
PrestonTyler, I.M., Pirajno, F., Bagas, L., Meyers, PrestonThe geology and mineral deposits of the Proterozoic in western AustraliaAgso, Vol. 17, No. 3, pp. 223-244.Australia, Western AustraliaTectonics, orogeny, Halls Creek, King Leopold, Diamonds mentioned p. 237
DS2003-1103
2003
PrestonPrestonSlab earthquakes: to dehydrate or to transformScience, p. 1197.MantleSubduction
DS200412-1582
2003
PrestonPrestonSlab earthquakes: to dehydrate or to transform.Science, p. 1197.MantleSubduction
DS1994-1409
1994
Preston, P.G.Preston, P.G., Novak, V.Exploration in Western Australia... brief mention of diamond activitiesAustralian Institute of Mining and Metallurgy (AusIMM) Bulletin., No. 3, May, pp. 54-56AustraliaNews item, Exploration activity
DS201212-0339
2012
Preston, R.Jelsma, H.,Krishnan, S.U., Perritt, S.,Kumar, M., Preston, R., Winter, F., Lemotlo, L., Costa, J., Van der Linde, G., Facatino, M., Posser, A., Wallace, C., Henning, A., Joy, S., Chinn, I., Armstrong, R., Phillips, D.Kimberlites from central Angola: a case stidy of exploration findings.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractAfrica, AngolaOverview of kimberlites
DS201312-0559
2013
Preston, R.Lynn, M., Joy, S., Preston, R.The geology and geochemistry of the Wadagera kimberlite and the characteristics of the underlying subcontinental lithospheric mantle, Dharwar craton, India.Proceedings of the 10th. International Kimberlite Conference, Vol. 1, Special Issue of the Journal of the Geological Society of India,, Vol. 1, pp. 167-181.IndiaDeposit - Wadagera
DS201412-0427
2013
Preston, R.Jelsma, H., Krishnan, U., Perritt, S., Preston, R., Winter, F., Lemotlo, L., van der Linde, G., Armstrong, R., Phillips, D., Joy, S., Costa, J., Facatino, M., Posser, A., Kumar, M., Wallace, C., Chinn, I., Henning, A.Kimberlites from central Angola: a case study of exploration findings.Proceedings of the 10th. International Kimberlite Conference, Vol. 2, pp. 173-190.Africa, AngolaExploration - kimberlites
DS201601-0038
2015
Preston, R.Perritt, S., Preston, R., Viljoen, F., Van Der Linde, G.Morphology, micro-structure and chemistry of a deformed garnet megacryst suite from Montelo kimberlite, Free State Province, South Africa.South African Journal of Geology, Vol. 118, 4, pp. 439-454.Africa, South AfricaDeposit - Montelo
DS202008-1427
2020
Preston, R.Nimis, P., Preston, R., Perritt, S., Chinn, I.Is diamond depth distribution systematic?Goldschmidt 2020, 1p. AbstractAfrica, South Africageobarometry

Abstract: The thermobarometric analysis of inclusions in lithospheric diamonds indicates that they originated from a wide range of depths, with a global mode at ca. 170±15 km [1]. Studies based on diamond depth distribution at global scale, however, cannot clarify if this mode reflects a real concentration of diamonds, preferential sampling of materials from this level by rising kimberlites, or even a statistical distribution within the hard limits imposed by diamond stability, lithosphere thickness, and mantle adiabat under typical cratonic thermal regimes. We addressed this problem by comparing depth distributions for peridotitic diamonds from the three localities that have been the most prolific for diamond geobarometry (Cullinan, Kimberley and Voorspoed, South Africa) with those of mantle xenocrysts from the same kimberlite sources. P-T estimates indicate that the diamonds were formed at T higher, equal or lower than the ambient geotherm. They may record old mantle thermal regimes or local thermal perturbations related to infiltration of parent fluids or melts. Nonetheless, the diamonds show similar depth distributions for different localities, with a distinct mode at ?175 ?? 10 km. The similarity of these distributions with that calculated for peridotitic diamonds worldwide, as well as the lack of systematic correlation with kimberlite sampling efficiency as recorded by mantle xenocrysts, suggests that this mode has genetic significance. Based on observed depth distributions at both local and global scale and on thermodynamic modeling of COH fluids, diamond-forming processes are predicted to become less efficient with decreasing depth from at least ?160 km. In addition, diamond endowment near the base of the lithosphere may be negatively affected by infiltration of carbon-undersaturated melts. Considering the poor correlation between diamond and xenocryst depth distributions in single kimberlites or kimberlite clusters, even limited xenocryst records from diamond favorable depths (especially the 160-190 km interval) may correspond to significant diamond potential.
DS202009-1647
2020
Preston, R.Nimis, P., Preston, R., Perritt, S.H., Chinn, I.L.Diamond's depth distribution systematics. ( geotherm)Lithos, 10.1016/j.lithos. 2020.105729 15p. PdfAfrica, South Africadeposit - Cullinan, Kimberley, Voorspoed

Abstract: The thermobarometric analysis of inclusions in lithospheric diamonds has shown that these diamonds may originate from a wide range of depths, with a global mode at ~175 ± 15 km. Studies based on diamond depth distribution at global scale, however, cannot clarify if this mode reflects a real concentration of diamonds, preferential sampling of materials from this level by ascending kimberlites, or simply a statistical distribution within the hard limits imposed by diamond stability, lithosphere thickness and mantle adiabat under typical cratonic thermal regimes. We addressed this problem by comparing depth distributions for peridotitic diamonds from the three localities that have been the most prolific for diamond geobarometry (Cullinan, Kimberley and Voorspoed, South Africa) with those of mantle xenocrysts from the same kimberlite sources. The revised P-T estimates indicate that the diamonds were formed at T higher, equal or lower than the ambient geotherm recorded by the xenocrysts. These conditions may represent old mantle thermal regimes or local thermal perturbations related to infiltration of parental fluids or melts. Nonetheless, the studied diamonds show similar depth distributions for the different localities, with a distinct mode at ?180 ± 10 km. The similarity of these distributions with that calculated for peridotitic diamonds worldwide, as well as the lack of systematic correlation with kimberlite sampling efficiency as recorded by mantle xenocrysts, suggests that this mode has genetic significance. Based on observed depth distributions and thermodynamic modeling of COH fluids, diamond-forming processes are predicted to become less efficient with decreasing depth from at least ?165 km. In addition, diamond endowment near the base of the lithosphere may be negatively affected by infiltration of carbon-undersaturated melts or fluids after diamond formation. Considering the poor correlation between diamond and xenocryst depth distributions in single kimberlites or kimberlite clusters, even limited xenocryst records from diamond favorable depths (especially from the 160-190 km interval) may correspond to significant diamond potential.
DS2003-1104
2003
Preston, R.F.Preston, R.F., Sweeney, R.J.A comparison of clinopyroxene thermobarometric techniques: applied to Jwaneng8 Ikc Www.venuewest.com/8ikc/program.htm, Session 6, POSTER abstractBotswanaDeposit - Jwaneng, Orapa
DS200412-1583
2003
Preston, R.F.Preston, R.F., Sweeney, R.J.A comparison of clinopyroxene thermobarometric techniques: applied to Jwaneng, Orapa and Markt kimberlites.8 IKC Program, Session 6, POSTER abstractAfrica, BotswanaMantle petrology Deposit - Jwaneng, Orapa
DS201212-0343
2012
Preston, R.F.Joy, S., Jelsma, H.A., Preston, R.F., Kota, S.Geology and diamond provenance of the Proterozoic Banganapalle conglomerates, Kurnool Group, India.Geological Society of London Special Publication, No. 365, pp. 197-218.IndiaDeposit - Banganapalle
DS201212-0573
2012
Preston, R.F.Preston, R.F., Wyatt, B., Perrit, S.Lithospheric structure beneath the Cretaceous Orapa kimberlite field, Botswana: 4D lithosphere imaging using garnet indicator mineral chemistry.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractAfrica, BotswanaDeposit - Orapa
DS1999-0165
1999
Preston, R.J.Dempster, T.J., Preston, R.J., Bell, B.R.The origin of Proterozoic massif type anorthosites: evidence from interactions between crustal xenoliths...Journal of Geological Society of London, Vol. 156, No. 1, Jan. pp. 41-46.Mantle, CrustBasaltic magma, Xenoliths
DS1999-0566
1999
Preston, R.J.Preston, R.J., Dempster, T.J., Rogers, G.The petrology of melilite bearing peraluminous xenoliths: implications for contamination processes..Journal of Petrology, Vol. 40, No. 4, Apr. 1, pp. 549-574.GlobalMagma - basalts, Xenolith
DS1998-0624
1998
Preston, W.A.Hocking, R.M., Preston, W.A.Western Australia: Phanerozoic geology and mineral resourcesAgso, Vol. 17, No. 3, pp. 245-260.Australia, Western AustraliaBasin development, Paleozoic history, Diamonds mentioned pp. 254-6.
DS2001-0047
2001
Preston, Y.Armstrong, J.P., Preston, Y.Kimberlite anomaly diamond drill hole compilation - a GIS compatible compilation locations and logs ...29th. Yellowknife Geoscience Forum, Nov. 21-23, abstract p.2-3.Northwest Territories, NunavutKimberlite anomalies - drill logs, GIS - database
DS1997-0922
1997
Prestud Anderson, S.Prestud Anderson, S., Drever, J.I., Humphrey, N.F.Chemical weathering in glacial environmentsGeology, Vol. 25, No. 5, May pp. 399-402Canada, IndiaWeathering - glacial geomorphology, Geochemistry
DS1990-1197
1990
Prestvik, T.Prestvik, T., Barnes, C.G., Sunbdvoll, B., Duncan, R.A.Petrology of Peter I-OY (Peter-I Island), west AntarcticaJournal of Volcanology, Vol. 44, No. 3-4, December pp. 315-338AntarcticaPetrology, Related rocks
DS1990-1198
1990
Prestvik, T.Prestvik, T., Sundvoll, B.Geochemistry of early Tertiary olivine-nephelinite and basanite from the Norwegian continental shelfGeological Society of America (GSA) Annual Meeting, Abstracts, Vol. 22, No. 7, p. A344NorwayBasanite, Geochemistry
DS1992-1234
1992
Prestvik, T.Prestvik, T., et al.Petrology of early Tertiary olivine melanephelinites off Mid-NorwayEos, Transactions, Annual Fall Meeting Abstracts, Vol. 73, No. 43, October 27, abstracts p. 604.NorwayNephelinite, Basanite
DS1999-0567
1999
Prestvik, T.Prestvik, T., Torske, T., Sundvoll, B., Karlsson, H.Petrology of early Tertiary nephelinites off mid-Norway: additional evidence for an enriched ...Lithos, Vol. 46, No. 2, Feb. pp. 317-330.GlobalMantle plume - endmember of the ancestral Iceland plume
DS200412-1513
2004
Prestvik, T.Peate, D.W., Baker, J.A., Breddam, K., Waight, T.E., Skovgaard, A.C., Stecher, O., Prestvik, T., JonassonPb isotope heterogeneity of the mantle beneath Iceland.Geochimica et Cosmochimica Acta, 13th Goldschmidt Conference held Copenhagen Denmark, Vol. 68, 11 Supp. July, ABSTRACT p.A569.Europe, IcelandGeochronology
DS200612-0085
2006
Prestvik, T.Barnes, C.G., Li, Y., Barnes, M., McCullock, L., Frost, C., Prestvik, T., Allen, C.Carbonate assimilation in the alkaline Hortavaer igneous complex, Norway.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 1. abstract only.Europe, NorwayCarbonatite
DS201312-0515
2013
Presyakov, S.L.Krasnobaev, A.A., Valizer, P.M., Cherednichenko, S.V., Busharina, S.V., Medvedeva, E.V., Presyakov, S.L.Zirconology of carbonate rocks ( marbles-carbonatites) of the Ilmeno-Visnevogorskii complex, southern Urals.Doklady Earth Sciences, Vol. 450, 1, pp. 504-508.Russia, UralsCarbonatite
DS200412-0514
2004
Presz, A.Ekimov, E.A., Sidorov, V.A., Melnik, N.N., Gierlotka, S., Presz, A.Synthesis of polycrystalline diamond in the boron carbide graphite and boron graphite systems under high pressure and temperaturJournal of Materials Research, Vol. 39, 15, pp. 4957-4960.TechnologyDiamond synthesis
DS1994-1073
1994
Pretes, M.Luzin, G.P., Pretes, M., Vasiliev, V.V.The Kola Peninsula: geography, history and resourcesArctic, Vol. 47, No. 1, March pp. 1-15.Russia, Kola PeninsulaHistory, Resources
DS1998-0905
1998
Pretorius, C.C.Lutjen, H., Blume, J., Pretorius, C.C.Geophysical survey over the Elizabeth Bay mine, Namibia. ( aeoliandeposits).7th International Kimberlite Conference Abstract, pp. 518-20.NamibiaGeophysics - seismics, resistivity, borehole, Deposit - Elizabeth Bay
DS1998-1186
1998
Pretorius, C.C.Pretorius, C.C., Blume, J., Lutjen, TrofimczykResults of geophysical trials to profile the kimberlite/host rock contacts at Venetia and BK-9 pipe.7th. Kimberlite Conference abstract, pp. 708-9.South Africa, BotswanaGeophysics - resistivity imaging, Deposit - Venetia, BK-9
DS1975-0835
1978
Pretorius, D.A.Pretorius, D.A.The Contribution of the Aeromagnetic Interpretation to an Assessment of the Mineral Potential of Botswana.In: Reeves, C.v., Reconnaissance Aeromagnetic Survey of Bots, PP. A1-A63.BotswanaRegional Tectonics
DS1975-1185
1979
Pretorius, D.A.Pretorius, D.A.The Aeromagnetic Delineation of the Distribution Patterns Of Karroo Volcanic in Botswana and Consequent Implications For the Tectonics of the Sub Continent.Botswana Geological Survey, Bulletin. No. 22, PP. 93-140.BotswanaGeophysics, Tectonics
DS1975-1186
1979
Pretorius, D.A.Pretorius, D.A.Seminar on Geophysics and its Role in the Geologic Exploration of the Kalahari in Southern Africa. Resume and Review.Botswana Geological Survey, Bulletin. No. 22, PP. 413-418.Botswana, South AfricaRegional Tectonics
DS1981-0341
1981
Pretorius, D.A.Pretorius, D.A.Comments on a Report on the Gravity Survey of LesothoJohannesburg: Economic Geol. Res. University University Witwatersrand., INTERNAL REPORT, 6P.LesothoRegional Tectonics, Geophysics
DS1984-0598
1984
Pretorius, D.A.Pretorius, D.A.The Kalahari Foreland, its Marginal Troughs and Over thrust Belts, and the Regional Structure of Botswana.Economic Geology Research Unit., INF. Circular No. 169, 24P.Botswana, South Africa, Southwest Africa, NamibiaRegional Geology, Geotectonics
DS1985-0415
1985
Pretorius, D.A.Marshall, T.R., Pretorius, D.A.The Alluvial Diamond Fields of the Western Transvaal, Southafrica.Fourth International Kimberlite Conference, 2P. (abstract.) SUBMITTED.South Africa, TransvaalGeotectonics, Structure, Alluvial Placer Deposits
DS1985-0543
1985
Pretorius, D.A.Pretorius, D.A.The Structural Setting of Pipe and Alluvial Diamond Fields In Southern Africa.6th. International Conference Basement Tectonics, Held Sante Fe, Septem, P. 31. (abstract.).South Africa, Botswana, ZimbabweGeotectonics
DS1985-0544
1985
Pretorius, D.A.Pretorius, D.A.The Influence of the Regional Structure of the Rhodesian Craton on the Distribution of Kimberlites in Botswana and Zimbabwe.Fourth International Kimberlite Conference., 2P. (abstract.) SUBMITTED.Southern Africa, Botswana, ZimbabweGeotectonics, Geophysics
DS1986-0650
1986
Pretorius, D.A.Pretorius, D.A.The influence of the regional structure of the Rhodesian craton on the distribution of kimberlites in Botswana and ZimabaweProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, pp. 139-141GlobalTectonics, Structure
DS1986-0651
1986
Pretorius, D.A.Pretorius, D.A.The structural setting of pipe and alluvial diamond fields in SouthernAfricaSixth International Basement Tectonics Conf, p. 203. abstractSouth AfricaStructure, diamond
DS1994-1410
1994
Pretorius, W.Pretorius, W., Barton, J.M. Jr.Crustal and upper mantle xenoliths from the Venetia pipes, Limpopobelt, relationship lithospheric structureInternational Symposium Upper Mantle, Aug. 14-19, 1994, Extended abstracts pp. 11-13.South AfricaXenoliths, Deposit -Venetia
DS1995-1519
1995
Pretorius, W.Pretorius, W., Barton, J.M.Lithospheric structure and geothermal gradient at 53- Ma beneath a Portion of central zone Limpopo-VenetiaCentennial Geocongress (1995) Extended abstracts, Vol. 1, p. 335-338. abstractSouth AfricaXenoliths, kimberlites, Deposit -Venetia
DS1996-1140
1996
Pretorius, W.Pretorius, W.A geochemical and geophysical investigation of a suite of crustal and Upper mantle nodules from Venetia pipes.Msc Thesis Rand Afrikaans University, Please note notice onlySouth AfricaGeochemistry, mantle, Limpopo Belt, Deposit - Venetia
DS1997-0081
1997
Pretorius, W.Barton, J.M. Jr., Pretorius, W.The lower unconformity-bounded sequence of the South pansberg Group and its correlatives - remnants....South African Journal of Geology, Vol. 100, 4, Dec. pp. 335-339.South AfricaProterozoic igneous province, Deposit - Venetia
DS1998-1187
1998
Pretorius, W.Pretorius, W., Barton, J.M.The use of amphibolite melting experiments in constraining conditions Of melting in natural nodules..7th. Kimberlite Conference abstract, pp. 710-12.South AfricaAmphibolite nodules, Deposit - Venetia
DS1998-1188
1998
Pretorius, W.Pretorius, W., Leahy, K.Implications for diamond prospectivity from comparisons of diamond bearing lithosphere in two Proterozoic belts7th. Kimberlite Conference abstract, pp. 713-15.South Africa, Manitoba, northwest Territories, WyomingOrogeny - Limpopo, Glennie, Trans Hudson, Lithospheric composition, comparison
DS1999-0046
1999
Pretorius, W.Barton, J.M., Pretorius, W.Crustal xenoliths in Venetia kimberlite pipes indicate a decollement at similar to 10 km beneath Central ZoneSouth African Journal of Geology, Vol. 101, No. 4, Dec. 1, pp. 323-28.South AfricaTectonics - Central Zone, Limpopo Belt, Deposit - Venetia
DS2003-1105
2003
Pretorius, W.Pretorius, W., Helmstaedt, H.H., Kyser, K.Platinum group element geochemistry of kimberlitic rocks - a window into the nature of8 Ikc Www.venuewest.com/8ikc/program.htm, Session 7, POSTER abstractUnited States, Canada, Greenland, Somerset Island, ChinaBlank
DS2003-1106
2003
Pretorius, W.Pretorius, W., Barton, J.M.Petrology and geochemistry of a crustal and upper mantle xenoliths from the VenetiaSouth African Journal of Geology, Special Volume, No. 106, pp. 213-230.South AfricaGeochemistry - Venetia
DS2003-1107
2003
Pretorius, W.Pretorius, W., Barton, J.M.Measured and calculated compressional wave velocities of crustal and upper mantleSouth African Journal of Geology, Special Volume, No. 106, pp. 205-212.South AfricaGeophysics - seismics
DS2003-1108
2003
Pretorius, W.Pretorius, W., Chipley, D., Keyser, K., Helmstaedt, H.Direct determination of Os Ir Ru Pt and Re in kimberlites and other geologicalJournal of Analytical Atomic Spectrometry, Vol. 18, 4, pp. 302-9.GlobalGeochemistry
DS2003-1109
2003
Pretorius, W.Pretorius, W., Chipley, D., Kyser, K., Helmstaedt, H.Direct determination of trace levels of Os Ir Ru Pt and Re in kimberlite and otherJournal of Analytical Atomic Spectrometry, Vol. 18, 4, pp. 302-9.GlobalSpectrometry - trace elements
DS200412-1584
2003
Pretorius, W.Pretorius, W.,Helmstaedt, H.H., Kyser, K.Platinum group element geochemistry of kimberlitic rocks - a window into the nature of the Diamondiferous mantle.8 IKC Program, Session 7, POSTER abstractUnited States, Canada, Nunavut, Somerset IslandKimberlite petrogenesis
DS200412-1585
2003
Pretorius, W.Pretorius, W., Barton, J.M.Petrology and geochemistry of a crustal and upper mantle xenoliths from the Venetia diamond mine: evidence for Archean crustal gSouth African Journal of Geology, No. 106, pp. 213-230.Africa, South AfricaGeochemistry - Venetia
DS200412-1586
2003
Pretorius, W.Pretorius, W., Barton, J.M.Measured and calculated compressional wave velocities of crustal and upper mantle rocks in the Central Zone of the Limpopo belt,South African Journal of Geology, No. 106, pp. 205-212.Africa, South AfricaGeophysics - seismics
DS200412-1587
2003
Pretorius, W.Pretorius, W., Chipley, D., Kyser, K., Helmstaedt, H.Direct determination of trace levels of Os Ir Ru Pt and Re in kimberlite and other geological materials using HR ICP Ms.Journal of Analytical Atomic Spectrometry, Vol. 18, 4, pp. 302-9.TechnologySpectrometry - trace elements
DS2002-1154
2002
Prevec, L.Norris, B., LeBlanc, G., Prevec, L.An alternative simple procedure to identify magnetic and other geophysical anomaliesSociety of Exploration Geophysicists, program abstracts, Vol. 72, pp. 712-715.AlbertaGeophysics - magnetics
DS200412-1444
2002
Prevec, L.Norris, B., LeBlanc, G., Prevec, L.An alternative simple procedure to identify magnetic and other geophysical anomalies due to kimberlite pipes.Society of Exploration Geophysicis, Vol. 72, pp. 712-715.Canada, AlbertaGeophysics - magnetics
DS1994-1411
1994
Prevec, S.A.Prevec, S.A., Stevenson, R.K., Emslie, R.F., Hamilton, M.A.Evolution of the mid-Proterozoic Flowers River peralkaline granite, Labrador: geochemical and samarium-neodymium (Sm-Nd) isotopic evidence.Geological Association of Canada (GAC) Abstract Volume, Vol. 19, p. posterLabradorAlkaline rocks, Flowers River
DS2003-1110
2003
Prevec, S.A.Prevec, S.A.Tectono geochemical controls on PGE sulphide and chromite mineralization inEconomic Research Unit, University of Witwatersrand, No. 371, October, 18p.Finland, Russia, FennoscandiaMagmatism - not specific to diamonds
DS200412-1588
2003
Prevec, S.A.Prevec, S.A.Tectono geochemical controls on PGE sulphide and chromite mineralization in Fennoscandian mafic rocks.Economic Geology Research Institute Information Circular, No. 371, October, 18p.Europe, Finland, Russia, Kola PeninsulaMagmatism - not specific to diamonds
DS200412-1589
2004
Prevec, S.A.Prevec, S.A., Anhaeusser, C.R., Poujol, M.Origin and evolution of late mafic dykes in an Archean gneissic assemblage, Kaapvaal Craton, South Africa.Economic Geology Research Institute Information Circular, Information Circular 380, 11p.Africa, South AfricaEcologitic lithosphere, lamprophyres
DS200512-0875
2004
Prevec, S.A.Prevec, S.A., Anhaeusser, C.R., Poujot, M.Evidence for Archean lamprophyres from the Kaapvaal Craton, South Africa.South African Journal of Science, Vol. 100, 11/12, pp. 549-555.Africa, South AfricaLamprophyre
DS201112-0453
2011
Prevec, S.A.Howarth, G.H., Skinner, E.M.W., Prevec, S.A.Petrology of the hypapbyssal kimberlite of the Kroonstad group II kimberlite (orangeite) cluster, South Africa: evolution of the magma within the clusterLithos, Vol. 125, pp. 795-808.Africa, South AfricaContamination - Kroonstad
DS201112-0328
2011
Prevelic, D.Foley, S.F., Prevelic, D., Link, K.Mantle migmatites and alkaline rock genesis.Peralk-Carb 2011... workshop June 16-18, Tubingen, Germany, Abstract p.45-47.Africa, TanzaniaMelt production
DS201112-0329
2011
Prevelic, D.Foley, S.F., Prevelic, D., Link, K.Mantle migmatites and alkaline rock genesis.Peralk-Carb 2011... workshop June 16-18, Tubingen, Germany, Abstract p.45-47.Africa, TanzaniaMelt production
DS200712-0211
2007
Prevelvi, D.Cvetkovi, V., Lazarov, M., Downes, H., Prevelvi, D.Modification of the subcontinental mantle beneath East Serbia: evidence from orthopyroxene rich xenoliths.Lithos, Vol. 92, 1-4, pp. 90-110.EuropeXenoliths - not specific to diamonds
DS2000-0777
2000
PreviewPreview, Australian Society of Exploration Geophysicists (ASEG)Advances in seismic interpretation 1990-2000Preview ( ASEG), No. 88, Oct. pp. 20-23.GlobalGeophysics - seismics
DS1988-0540
1988
Prevot, M.Perrin, M., Prevot, M.Uncertainties about the Proterozoic and Paleozoic polar wanderpath Of the West African craton and Gondwana: evidence for successive remagnetizationeventsEarth and Planetary Science Letters, Vol. 88, No. 3-4, May pp. 337-347West AfricaBlank
DS1996-1141
1996
Prevot, R.Prevot, R., Chatelain, J-L., Guillier, B., Yepes, H.Tomographie des Andes equatoriennes evidence d'une continuite des AndesCentralesC.r. Academy Of Science Paris, Vol. 323, 11a, pp. 833-840Bolivia, Ecuador, AndesTomography, Geophysics - seismics
DS1983-0556
1983
Prewitt, C.T.Sasaki, S., Prewitt, C.T., Liebermann, R.C.The Crystal Structure of Cageo3 Perovskite and the Crystal Chemistry of the Gdfeo3 Type Perovskites.American Mineralogist., Vol. 68, PP. 1189-1198.GlobalMineralogy
DS1986-0264
1986
Prewitt, C.T.Garanin, V.K., Kudryavtseva, G.P., Prewitt, C.T.Mineralogy of ilmenite from Yakutia kimberlites14th. International Meeting I.m.a., P. 109. (abstract.)RussiaKimberlite mineralogy, Ilmenite
DS1990-1199
1990
Prewitt, C.T.Prewitt, C.T., Carlson, R., Hemley, R.J.Chemical evolution of the mantleAmerican Geophysical Union (AGU)/MSA Meeting to be held May 29-June 1, Session MO2-GlobalMantle, Tectonics
DS1993-1810
1993
Prewitt, C.T.Zhang, J., Ko, J., Hazen, C.T., Prewitt, C.T.high pressure crystal chemistry of KAlSi3O8 hollanditeAmerican Mineralogist, Vol. 78, pp. 493-9.GlobalPetrology, ultra high pressure (UHP)
DS1997-0923
1997
Prewitt, C.T.Prewitt, C.T.Understanding the earth at high pressureCarnegie Institute Yearbook 96-97, pp. 65-71.MantleDiamond synthesis - experimental, Overview of CI activities
DS1998-1189
1998
Prewitt, C.T.Prewitt, C.T., Downs, R.T.high pressure crystal chemistryReviews in Mineralogy, Vol. 37, pp. 284-318.MantleMineralogy, Petrology - experimental
DS202004-0507
2020
Prezzi, C.Demarco, P.N., Masquelin, H., Prezzi, C., Muzio, R., Loureiro, J., Peel, E., Campal, N., Sanchez Bettucci, L. Aeromagnetic patterns in southern Uruguay: Precambrian- Mesozoic dyke swarms and Mesozoic rifting structural and tectonic evolution.Tectonophysics, in press available 40p. PdfSouth America, Uruguaygeophysics

Abstract: New high-resolution airborne magnetic data of Uruguay allowed constructing new maps concerning the spatial distribution of dyke swarms, main faults and other magnetic bodies, which compose the Uruguayan Shield. We combined geophysical analyses (vertical derivatives, upward continuation, Euler deconvolution), structural analyses of the magnetic maps and previous geological data in order to discriminate the main structural features of the Uruguayan Shield and contribute to a better understanding of its tectonic evolution. The magnetic maps revealed several outstanding features in the Uruguayan Shield. The Paleoproterozoic dyke swarm is larger, denser, more widespread and complex than originally thought, suggesting a possible plume origin. In addition, a new Mesozoic dyke swarm, as complex as the previous one, was identified crosscutting the Paleoproterozoic dyke swarm and the Neoproterozoic orogenic structures. Moreover, this swarm is connected to volcanic calderas in the Merín basin, and shows displacements along Neoproterozoic shear zones, in the magnetic maps, revealing its brittle reactivation during Mesozoic times. The new observations clarify how Proterozoic basement structures controlled the development of the Mesozoic rift. Paleoproterozoic dyke swarms were reactivated as normal faults and Neoproterozoic structures hindered the rift growth, deflecting the deformation in transcurrent movements. Meanwhile, the Mesozoic dyke swarm was developed in a perpendicular direction to the Neoproterozoic structures. Moreover, these findings contradict the current rift model for Uruguay and rise a new model in which the Mesozoic rift developed as two rift basins connected by a central transfer zone, generated by the reactivation of Dom Feliciano Belt structures, between the Sierra Ballena and Sarandí del Yí Shear Zones.
DS200612-1109
2006
Pribavkin, S.V.Pribavkin, S.V., Nedosekova, I.L.Carbonatite sources of the Ilmeny Vishnevogorsk complex: evidence from Sr and Nd isotope dat a on carbonates.Doklady Earth Sciences, Vol. 408, 4, pp. 627-630.RussiaCarbonatite
DS200712-0857
2007
Pribavkin, S.V.Pribavkin, S.V., Ronkiv, Yu.L., Travin, A.V., Ponomarenko, V.A.New dat a on the age of lamproite-lamprophyre magmatism in the Urals.Doklady Earth Sciences, Vol. 413, 2, pp. 213-215..Russia, UralsLamproite
DS200912-0533
2009
Pribavkin, S.V.Nedosekova, I.L., Vladykin, N.V., Pribavkin, S.V., Bayanova, T.B.The Ilmensky Vishnevogorsky miaskite carbonatite complex, the Urals, Russia: origin, ore resource potential, and sources.Geology of Ore Deposits, Vol. 51, 2, pp. 139-161.Russia, UralsCarbonatite
DS2000-0197
2000
PriceDa Silva, C.R.S., Wentzcovitch, Patel, Price, KaratoThe composition and geotherm of the lower mantle: constraints from eleasticity of silicate perovskite.Physical Earth and Planetary Interiors, Vol. 118, No.1-2, pp. 103-9.MantleGeothermometry
DS200412-0954
2003
PriceKarlstrom, K.E., Sears, J.W., Holm, D.K., Williams, M.L., Wooden, Hatcher, Finn, Price, Miller, BerquistSouthern Laurentia in Rodinia: collaborative compilation of a tectonic map for IGCP 440.Geological Society of America, Annual Meeting Nov. 2-5, Abstracts p.342.Gondwana, RodiniaTectonics
DS1975-0836
1978
Price, B.J.Price, B.J.Geological Report, Spaniel 1-9 Claims, Mackenzie Mining District, Northwest Territories.Report Submitted For Assessment., Canada, Northwest TerritoriesGeology
DS1985-0237
1985
Price, B.J.Godwin, C.I., Price, B.J.Geology of the Mountain Diatreme Kimberlite, North Central Mackenzie Mountains, District of Mackenzie, Northwest Territories.The Canadian Institute of Mining, Metallurgy and Petroleum (CIM) SPECIAL VOLUME., IN PRESS, REPRINT 28P. 8 TABLES, 25 FIGS.Canada, Northwest TerritoriesSayunei Range, Geology, Petrography, Lithology, Geochemistry
DS1987-0252
1987
Price, B.J.Godwin, C.I., Price, B.J.Geology of the Mountain diatreme kimberlite, north central MackenzieMountains, District of Mackenzie, Northwest TerritoriesMineral Deposits of Northern Cordillera, The Canadian Institute of Mining, Metallurgy and Petroleum (CIM), Special Paper Vol No. 37, pp.. 298-310Northwest TerritoriesCanada, Diatreme
DS201705-0838
2017
Price, D.Jones, A., Alvaro, M., McMillan, P., Price, D., Milledge, J.Lonsdaleite signatures and shock remnants in mantle diamond?European Geosciences Union General Assembly 2017, Vienna April 23-28, 1p. 16597 AbstractChinaDeposit - Liaoning
DS1975-0824
1978
Price, D.C.Newman, D.J., Price, D.C., Runciman, W.A.Superposition Model Analysis of the Near Infrared Spectrum Of Iron 2+ in Pyrope-almandine Garnets.American Mineralogist., Vol. 63, No. 11-12, PP. 1278-1281.AustraliaAnalyses, Pyrope, Garnets, Classification
DS1995-1520
1995
Price, D.G.Price, D.G.Weathering and weathering processesQuart. Journal of Engineering Geology, Vol. 28, No. 3, August pp. 243-252GlobalWeathering, Laterites
DS201906-1338
2019
Price, D.L.Price, D.L., Butler, I.B., Ngwenya, B.T., Kirstein, L.A.Crystallisation pathways of mixed La and Nd carbonates.3rd International Critical Metals Meeting held Edinburgh, 1p. Abstract p. 64.Chinadeposit - Bayan Obo
DS1986-0652
1986
Price, G.D.Price, G.D.Perovskites and plate tectonicsNature, Vol. 319, Jan. 16. p. 175GlobalMantle genesis
DS1991-1077
1991
Price, G.D.Matsui, M., Price, G.D.Simulation of the pre-melting behaviour of MgSiO3 perovskite at high pressures and temperaturesNature, Vol. 351, June 27, pp. 735-737GlobalMantle, Silicate perovskite
DS1992-1235
1992
Price, G.D.Price, G.D., Poirier, J.P.Dislocation melting of mantle mineralsEos, Transactions, Annual Fall Meeting Abstracts, Vol. 73, No. 43, October 27, abstracts p. 599.MantleMineralogy, Enstatite melting point
DS1993-1771
1993
Price, G.D.Wright, K., Price, G.D.Computer simulation of defects and diffusion in perovskitesJournal of Geophysical Research, Vol. 98, No. B12, December 10, pp. 22, 245-22, 253.MantlePerovskites
DS1995-0614
1995
Price, G.D.Genge, M.J., Jones, A.P., Price, G.D.An infrared and Raman study of carbonate glasses: implications for the structure of carbonatite magmas.Geochimica et Cosmochimica Acta, Vol. 59, No. 5, pp. 927-937.GlobalMagma -carbonatite, Mantle metasomatism, Melt, structure
DS1995-0615
1995
Price, G.D.Genge, M.J., Price, G.D., Jones, A.P.Molecular dynamics simulations of CaCO3 melts -mantle pressure/temperatures: implications for carbonatite.Earth and Planetary Science Letters, Vol. 131, No. 3-4, April pp. 225-238.GlobalCarbonatite
DS1995-2005
1995
Price, G.D.Vocadlo, L., Patel, A., Price, G.D.Molecular dynamics: some recent change developments in classical and quantum mechanical simulation of mineralsMineralogical Magazine, Vol. 59, Dec. pp. 597-605GlobalMineralogy, Geodynamics
DS1995-2007
1995
Price, G.D.Volcado, L., Patel, A., Price, G.D.Molecular dynamics: some recent developments in classical and quantum mechanical simulation of mineralsMineralogical Magazine, Vol. 59, Dec. pp. 597-605.GlobalPetrology -experimental, Pyrovskite
DS1995-2050
1995
Price, G.D.Wentzcovitch, R.M., Ross, N.L., Price, G.D.Ab initio study of MgSiO3 and CaSiO3 perovskites at lower mantlepressures.Physics of Earth Plan. International, Vol. 90, pp. 101-112.MantlePerovskites
DS1996-1142
1996
Price, G.D.Price, G.D., Vocadlo, L.Computational mineralogy...quantitative means of determining mineralstructures, properties and processC.r. Academy Of Science Paris, Vol. 323, 11a, pp. 357-371GlobalMineralogy - lattice dynamics, Computers
DS1998-0234
1998
Price, G.D.Chaplin, T., Price, G.D., Ross, N.L.Computer simulation of the infrared and Raman activity of pyrope garnet, and assignment of calculated modes..American Mineralogist, Vol. 83, pp. 841-7.GlobalGarnet - computer - specific atomic motions
DS2002-0020
2002
Price, G.D.Alfe, D., Gillan, M.J., Price, G.D.Composition and temperature of the Earth's core constrained by combining ab initio calculations/seismicEarth and Planetary Science Letters, Vol. 195, No. 1-2, pp. 91-8.MantleGeophysics - seismics, Geochemistry
DS2002-0789
2002
Price, G.D.Jones, A.P., Price, G.D., rice, N.J., DeCarli, P.S., Clegg, R.A.Impact induced melting and the development of large igneous provincesEarth and Planetary Science Letters, Vol. 202, 3-4, pp. 551-61.GlobalMagmatism - not specific to diamonds
DS2002-1171
2002
Price, G.D.Oganov, A.R., Price, G.D., Brodholt, J.P.Theory of MgSiO3 perovskite: towards a thermal and mineralogical model of the Earth's mantle.18th. International Mineralogical Association Sept. 1-6, Edinburgh, abstract p.70.MantleUHP - mineralogy
DS2003-0007
2003
Price, G.D.Alfe, D., Gillan, M.J., Price, G.D.Thermodynamics from first principles: temperature and composition of the Earth's coreMineralogical Magazine, Vol. 67, 1, pp. 113-24.MantleGeothermometry
DS2003-0008
2003
Price, G.D.Alfe, D., Gillan, M.J., Price, G.D.Thermodynamics from first principles: temperature and composition of the Earth's coreMineralogical Magazine, Vol. 67, 1, Feb. pp. 113-124.MantleGeothermometry
DS2003-0169
2003
Price, G.D.Brodholt, J.P., Oganov, A.R., Price, G.D.Computational mineral physics and the physical properties of perovskitePhilosophical Transactions of the Royal Society of London, Vol. 360, 1800, pp. 2507-20.GlobalMineralogy, mantle, perovskite
DS200412-0216
2003
Price, G.D.Brodholt, J.P., Oganov, A.R., Price, G.D.Computational mineral physics and the physical properties of perovskite.Philosophical Transactions of the Royal Society of London Series A Mathematical Physical and Engineering Sciences, Vol. 360, 1800, pp. 2507-20.TechnologyMineralogy, mantle, perovskite
DS200412-0741
2004
Price, G.D.Gubbins, D., Alfe, D., Masters, G., Price, G.D., Gillan, M.Gross thermodynamics of two component core convection.Geophysical Journal International, Vol. 157, 3, pp. 1407-1414.MantleConvection
DS200412-1435
2004
Price, G.D.Nimmo, F., Price, G.D., Brodholt, J., Gubbins, D.The influence of potassium on core and geodynamo evolution.Geophysical Journal International, Vol. 156, 2, pp. 363-376.MantleMineralogy
DS200612-1543
2005
Price, G.D.Wookey, J., Stackhouse, S., Kendall, J.M., Brodholt, J., Price, G.D.Efficacy of the post perovskite phase as an explanation for lowermost mantle seismic properties.Nature, No. 7070, Dec. 15, pp. 1004-1007.MantlePetrology
DS1995-1521
1995
Price, J.C.Price, J.C.Examples of high resolution visible to near infrared reflectance spectraand a standardized collection -dataInternational Journal of Remote Sensing, Vol. 16, No. 6, April pp. 993-1000GlobalRemote sensing
DS1998-0630
1998
Price, J.D.Hogan, J.P., Price, J.D., Gilbert, M.C.Magma traps and driving pressure: consequences for pluton shape and emplacement in an extensional regime.Journal of Structural Geology, Vol. 20, No. 9/10, Sept. pp. 1155-68.GlobalTectonics, structure, Not specific to diamonds
DS1986-0358
1986
Price, J.G.Henry, C.D., McDowell, F.W., Price, J.G., Smyth, R.C.Compilation of potassium argon ages of Tertiary igneous rocks,Trans PecosTexasTexas Bur. Econ. Geol, Geol. Circular, No. 86-2, 20pGlobalGeochronology
DS1986-0653
1986
Price, J.G.Price, J.G., Henry, C.D., Parker, D.F., Barker, D.S.Igneous geology of Trans Pecos TexasTexas Bur. of Economic Geology, Guidebook, No. 23, 100pGlobalBlank
DS1987-0595
1987
Price, J.G.Price, J.G., Henry, C.D., Barker, D.S., Parker, D.F.Alkalic rocks of contrasting tectonic settings in Trans Pecos TexasMantle metasomatism and alkaline magmatism, edited E. Mullen Morris and, No. 215, pp. 335-346GlobalAnalyses p. 340
DS1993-1341
1993
Price, J.G.Rubin, J.N., Henry, C.D., Price, J.G.The mobility of zirconium and other immobile elements during hydrothermalalterationChemical Geology, Vol. 110, No. 1/3, November 25, pp. 29-48GlobalAlteration -hydrothermal, Zircon
DS1997-0924
1997
Price, M.Price, M.Mountain environments and Geographical Information SystemsEarth Observation Magazine books, $ 100.00GlobalBook - ad, GIS - Mountains
DS1999-0284
1999
Price, M.C.Hamilton, W.N., Price, M.C., Langenberg, C.W.Geological map of AlbertaAlberta Geological Survey, 1:1, 000, 000AlbertaMap - not specific to diamonds
DS1975-0589
1977
Price, N.J.Norman, J.W., Price, N.J., Peters, E.R.Photo geological Fracture Trace Study of Controls of Kimberlite Intrusion in Lesotho Basalts.Institute of Mining and Metallurgy. Transactions, Vol. 86, PP. B78-90.LesothoTectonics, Photogeology
DS1990-1200
1990
Price, N.J.Price, N.J., Cosgrove, J.W.Analysis of geological structuresCambridge University Press, 511p. Paperback approx. $50.00GlobalStructure, Book -ad
DS1993-1147
1993
Price, R.Nutman, A.P., Bennett, V.C., Kinny, P.D., Price, R.Large scale crustal structure of the northwestern Yilgarn craton, westernAustralia: evidence from neodymium isotopic dat a and zircon geochronologyTectonics, Vol. 12, No. 4, August pp. 971-981AustraliaGeochronology, Structure, tectonics
DS2001-0743
2001
Price, R.McBride, J.S., Lambert, D.D., Nicholls, I.A., Price, R.Osmium isotopic evidence for crust mantle interaction in the genesis of continental intraplate basalts ...Journal of Petrology, Vol. 42, No. 6, pp. 1197-1218.Australia, southeastNewer Volcanic Province, Geochronology
DS1988-0554
1988
Price, R.A.Price, R.A.The mechanical paradox of large overthrustsGeological Society of America (GSA) Bulletin, Vol. 100, No. 12, December pp. 1898-1908GlobalStructure, Thrust-overview
DS1995-0340
1995
Price, R.A.Colpron, M., Price, R.A.Tectonic significance of the Kootenay terrane, southeastern CanadianCordillera: an alternative modelGeology, Vol. 23, No. 1, Jan. pp. 25-28British ColumbiaTectonics, Terrane
DS1998-0362
1998
Price, R.A.Doughty, P.T., Price, R.A., Parrish, R.R.Geology and uranium-lead (U-Pb) geochronology of Archean basement and Proterozoic cover...Cordilleran structure...Canadian Journal of Earth Sciences, Vol. 35, No. 1, Jan. pp. 39-54.British Columbia, Alberta, MontanaTectonics - Precambrian, Basement provinces
DS1998-1104
1998
Price, R.A.Osadetz, K.G., Kohn, B.P., Feinstein, S., Price, R.A.Aspects of foreland belt thermal and geological history fission track data: age Lewis thrust, Flathead fault..Reservoir, Vol. 25, No. 1.p.9 abstract.AlbertaGeochronology
DS2002-1438
2002
Price, R.A.Searsm J.W., Price, R.A.Break up and dispersal of the Early Neoproterozoic Siberia - Laurentia Australia troika.Geological Society of America Annual Meeting Oct. 27-30, Abstract p. 559.Australia, Russia, Canada, OntarioTectonics, Gondwana
DS2003-1245
2003
Price, R.A.Sears, J.W., Price, R.A.Tightening the Siberian connection to western LaurentiaGeological Society of America Bulletin, Vol. 115, 8, August pp. 943-53.Russia, Australia, CanadaCordillera, Rodinia, plate reconstruction, Proterozoic
DS200412-1780
2003
Price, R.A.Sears, J.W., Price, R.A.Tightening the Siberian connection to western Laurentia.Geological Society of America Bulletin, Vol. 115, 8, August pp. 943-53.Russia, Australia, CanadaCordillera, Rodinia, plate reconstruction, Proterozoic
DS1981-0221
1981
Price, R.C.Irving, A.J., Price, R.C.Geochemistry and Evolution of Lherzolite Bearing Phonolitic lavas from Nigeria, Australia, East Germany, and New Zealand.Geochimica Et Cosmochimica Acta, Vol. 45, No. 8, PP. 1309-L320.GlobalPhonolite, Xenolith
DS1985-0545
1985
Price, R.C.Price, R.C., Johnson, R.W., Gray, C.M., Frey, F.A.Geochemistry of Phonolites and Trachytes from the Summit Region of Mt. Kenya.Contributions to Mineralogy and Petrology, Vol. 89, No. 4, PP. 394-409.East Africa, KenyaGeochemistry
DS1991-1380
1991
Price, R.C.Price, R.C., Gray, C.M., Wilson, R.E., Frey, F.A.The effects of weathering on rare earth element, Yttrium and Barium abundances in Tertiary basalts from southeastern AustraliaChemical Geology, Vol. 93, No. 3/4, December 5, pp. 245-266AustraliaWeathering, Yttrium, Barium, Rare earths, basalts
DS1991-1381
1991
Price, R.C.Price, R.C., Gray, C.M., Wilson, R.E., Frey, F.A., Taylor, S.R.The effects of weathering on rare-earth element Yttrium and Barium abundances in Tertiary basalts from southeastern AustraliaChemical Geology, Vol. 93, No. 3/4, December 5, pp. 245-266AustraliaTholeiitic basalts, Geochemistry, rare earths, weathering
DS1993-1128
1993
Price, R.C.Nicholls, I.A., Greig, A.G., Gray, C.M., Price, R.C.Newer volcanics province- basalts, xenoliths and megacrystsAustralia Geological Survey AGSO, Record No. 1993/58, $ 16.95AustraliaNewer Volcanics, Xenoliths
DS201510-1785
2015
Price, R.C.Martin, A.P., Price, R.C., Cooper, A.F., McCammon, C.A.Petrogenesis of the rifted southern Victoria Land lithospheric mantle, Antarctica, inferred from petrography, geochemistry, thermobarometry and oxybarometry of peridotite and pyroxenite xenoliths from the Mount Morning eruptive centre.Journal of Petrology, Vol. 56, 1, pp. 193-226.AntarcticaMelting, subduction

Abstract: The lithospheric mantle beneath West Antarctica has been characterized using petrology, whole-rock and mineral major element geochemistry, whole-rock trace element chemistry and Mössbauer spectroscopy data obtained on a suite of peridotite (lherzolite and harzburgite) and pyroxenite xenoliths from the Mount Morning eruptive centre, Southern Victoria Land. The timing of pyroxenite formation in Victoria Land overlaps with subduction of the Palaeo-Pacific plate beneath the Gondwana margin and pyroxenite is likely to have formed when fluids derived from, or modified by, melting of the subducting, eclogitic, oceanic crustal plate percolated through peridotite of the lithospheric mantle. Subsequent melting of lithospheric pyroxenite veins similar to those represented in the Mount Morning xenolith suite has contributed to the enriched trace element (and isotope) signatures seen in Cenozoic volcanic rocks from Mount Morning, elsewhere in Victoria Land and Zealandia. In general, the harzburgite xenoliths reflect between 20 and 30% melt depletion. Their depleted element budgets are consistent with Archaean cratonization ages and they have mantle-normalized trace element patterns comparable with typical subcontinental lithospheric mantle. The spinel lherzolite mineral data suggest a similar amount of depletion to that recorded in the harzburgites (20-30%), whereas plagioclase lherzolite mineral data suggest <15% melt depletion. The lherzolite (spinel and plagioclase) xenolith whole-rocks have compositions indicating <20% melt depletion, consistent with Proterozoic to Phanerozoic cratonization ages, and have mantle-normalized trace element patterns comparable with typical depleted mid-ocean ridge mantle. All peridotite xenoliths have undergone a number of melt-rock reaction events. Melting took place mainly in the spinel peridotite stability field, but one plagioclase peridotite group containing high-sodium clinopyroxenes is best modelled by melting in the garnet field. Median oxygen fugacity estimates based on Mössbauer spectroscopy measurements of spinel and pyroxene for spinel-facies conditions in the rifted Antarctic lithosphere are -0·6 ?log fO2 at Mount Morning and –1·0 ± 0·1 (1?) ?log fO2 for all of Victoria Land, relative to the fayalite-magnetite-quartz buffer. These values are in good agreement with a calculated global median value of -0·9 ± 0·1 (1?) ?log fO2 for mantle spinel-facies rocks from continental rift systems.
DS1998-1190
1998
Price, S.E.Price, S.E., Kopylova, M.G.Primitive kimberlite magmas from the Jericho pipe, northwest Territories: constraints on primary magma chemistry.Geological Society of America (GSA) Annual Meeting, abstract. only, p.A245.Northwest TerritoriesMagma - geochemistry, Deposit - Jericho
DS1999-0568
1999
Price, S.E.Price, S.E., Russell, J.K., Kopylova, M.G.Aphanitic kimberlite samples from Jericho, northwest Territories Canada: a step towards aprimary kimberlite magma?Assocation of Exploration Geologists (AEG) 19th. Diamond Exploration Methods Case Histories, pp. 56-65.Northwest TerritoriesKimberlite melts - aphanitic, Deposit - Jericho
DS2000-0778
2000
Price, S.E.Price, S.E., Russell, J.K., Kopylova, M.G.Primitive magma from Jericho pipe: constraints on primary kimberlite melt chemistry.Journal of Petrology, Vol. 41, No. 6, June pp.789-808.Northwest Territories, NunavutGeochemistry - mineral chemistry, aphanitic, Deposit - Jericho
DS201112-0828
2009
Price, S.E.Price, S.E.Primitive kimberlite magmas from Jericho, N.W.T. Canada: constraints on primary magma chemistry.University of British Columbia, Thesis,Canada, NunavutDeposit - Jericho
DS1999-0735
1999
Price, S.P.Thomson, K., Green, P.F., Whithm, A.G., Price, S.P.New constraints on the thermal history of southeast Greenland from apatite fission track analysis.Geological Society of America (GSA) Bulletin., Vol. 111, No. 7, July pp. 1054-68.GreenlandGeothermometry
DS2003-1111
2003
Price, T.M.Price, T.M.The Kimberley Process: conflict diamonds, WTO obligations and the universalityMinnesota Journal of Global Trade, Vol. 12, 1, pp. 1-70. Ingenta 1030399837GlobalKimberley process
DS200512-0876
2005
Price Waterhouse CoopersPrice Waterhouse CoopersMine* enter the dragon. Review of global trends in the mining industry in 2004.PWC, June 2005, 52p.GlobalMining industry review
DS1997-0925
1997
Price. R.C.Price. R.C., Gray, C.M., Frey, F.A.Strontium isotopic and trace element heterogeneity in the plains basalts of Newer Volcanic Province, VictoriaGeochimica et Cosmochimica Acta, Vol. 61, No. 1, pp. 171-92.AustraliaGeochronology, Alkaline rocks
DS1993-1260
1993
Prichard, H.M.Prichard, H.M., et al.Magmatic processes and plate tectonicsGeological Society of London, No. 76, 526pGlobalMagmatism, Book -ad
DS2002-1681
2002
Prichard. H.M.Walker, R.J., Prichard. H.M., Ishiwatari, A., PimentelThe osmium isotopic composition of convecting upper mantle deduced from ophiolite chromites.Geochimica et Cosmochimica Acta, Vol. 66, No. 2, pp. 329-45.MantleGeochronology, Chromites
DS202006-0942
2020
Prichodko, V.S.Nikitina, L.P., Goncharov, A.G., Bogomolov, E.S., Beliatsky, B.V., Krimsky, R.Sh., Prichodko, V.S., Babushkina, M.S., Karaman, A.A.HFSE and REE geochemistry and Nd-Sr-Os systematics of peridotites in the subcontinental lithospheric mantle of the Siberian craton and central Asian fold belt junction area: data on mantle xenoliths.Petrology, Vol. 28, 2, pp. 207-219.RussiaREE

Abstract: Mantle xenoliths were found in alkaline basalts of Tokinsky Stanovik (TSt) in the Dzhugdzhur-Stanovoy superterrane (DS) and Vitim plateau (VP) in the Barguzin-Vitim superterrane (BV) (Stanovoy suture area) at junction of the Central Asian Orogenic Belt (CAOB) and the Siberian craton (SC). Xenoliths from TSt basalts are represented by spinel lherzolites, harzburgites, wehrlites; while VP basalts frequently contain spinel-garnet and garnet peridotites lherzolites, and pyroxenites. Xenoliths in kimberlites of the Siberian craton are mainly represented by garnet-bearing lherzolites with abundant eclogite xenoliths (age of 2.7-3.1 Ga), which were not found in mantle of superterranes. The Re-Os determinations point to the Early Archean age of peridotites and eclogites from mantle beneath the Siberian craton. The major and trace (rare-earth and high-filed strength) elements and Nd-Sr-Os composition were analyzed in the peridotites (predominant rocks) of lithospheric mantle at junction of the Central Asian Orogenic Belt and Siberian Craton. The degree of rock depletion in CaO and Al2O3 and enrichment in MgO relative to the primitive mantle in the peridotites of the Dzhugdzhur-Stanovoy superterrane is close to that of the Siberian craton. The peridotites of the Barguzin-Vitim superterrane are characterized by much lower degree of depletion and have mainly a primitive composition. Mantle melting degree reaches up to 45-50% in the Siberian Craton and Dzhugdzhur-Stanovoy superterrane, and is less than 25% in the Barguzin-Vitim terrane. The mantle peridotites of the craton as compared to those of adjacent superterranes are enriched in Ba, Rb, Th, Nb, and Ta and depleted in Y and REE from Sm to Lu. However, all studied peridotites are characterized by mainly superchondritic values of Nb/Ta (>17.4), Zr/Hf (>36.1), Nb/Y (>0.158), and Zr/Y (>2.474). The Nb/Y ratio is predominantly >1.0 in SC peridotites and < 1.0 in the superterrane peridotites. The Nd and Sr isotopic compositions in the latter correspond to those of oceanic basalts. The 187Os/188Os ratio is low (0.108-0.115) in the peridotites of the Siberian Craton and > 0.115 but usually lower than 0.1296 (primitive upper mantle value) in the peridotites of the Dzhugdzhur-Stanovoy and Barguzin-Vitim superterranes. Thus, the geochemical and isotopic composition of peridotites indicates different compositions and types of mantle beneath the Siberian craton and adjacent superterranes of the Central Asian Orogenic Belt in the Early Archean, prior to the formation of 2.7-3.1 Ga eclogites in the cratonic mantle.
DS1993-1018
1993
Pride, D.E.Memmi, J.M., Pride, D.E.An integrated approach to diamond exploration in the north-central UnitedStates.Preprint from Poster session, Denver SEG Integrated Exploration Meeting, 2p.WisconsinBrief overview, DEGIS
DS1994-1166
1994
Pride, D.E.Memi, J.M., Pride, D.E.Local sources for historic diamond finds in WisconsinGeological Society of America Abstracts, Vol. 26, No. 5, April p. 54. Abstract.WisconsinHistory, Diamonds
DS1997-0763
1997
Pride, D.E.Memi, J.M., Pride, D.E.The application of diamond exploration geoscientific information system(DEGRIS) technology.....International Journal of Remote Sensing, Vol. 18, No. 7, May 10, pp. 1439-64.MidcontinentRemote sensing
DS1997-0926
1997
Pride, D.E.Pride, D.E., Memmi, J.M., Loomis, J., Yagel, R.SEARCHMAP - interactive map interpretation system for mineral explorationExplore., No. 95, April pp. 1, 3-10MidcontinentComputer - GIS, Remote sensing, GIS datasets
DS1997-0927
1997
Pride, D.E.Pride, D.E., Memmi, J.M., Loomis, J., Yagel, R.SEARCHMAP - interactive map exploration system for mineral exploration.Specific application for diamonds.Explore, No. 95, April pp. 1, 3-10.MidcontinentGIS, Map information data
DS1986-0654
1986
Pride, K.R.Pride, K.R., LeCouteur, P.C., Mawer, A.B.Geology and mineralogy of the Aley carbonatite, Ospika Riverarea, BritishColumbiaThe Canadian Mining and Metallurgical Bulletin (CIM Bulletin), Vol. 79, No. 891, July p. 32. (abstract.)British ColumbiaCarbonatite
DS1930-0287
1938
Prider, R.T.Wade, A., Prider, R.T.The Geology and Petrology of the Kimberley District, Western Australia.British Association Advanced Science Report of The 108th. Meeting Held In, P. 419.Australia, Western AustraliaLeucite, Lamproite
DS1940-0015
1940
Prider, R.T.Prider, R.T.Some Minerals from the Leucite Rich Rocks of the West Kimberley Area, Western Australia.Mineralogical Magazine., Vol. 25, No. 166, PP. 373-387.AustraliaLeucite, Lamproite, Fitzroy Valley, Magnophorite, Wadeite
DS1940-0019
1940
Prider, R.T.Wade, A., Prider, R.T.The Leucite Bearing Rocks of the West Kimberley Area, Western Australia.Quarterly Journal of Geological Society (London), Vol. 96, PT. 1, PP. 39-98.Australia, Western AustraliaLeucite, Lamproite, Fitzroyite, Wolgidite, Cedricite, Mamilite
DS1940-0056
1942
Prider, R.T.Prider, R.T., Cole, W.F.The Alteration Products of Olivine and Leucite in the Leucite Lamproites from the West Kimberley Area, Western Australia.American Mineralogist., Vol. 27, PP. 496-501.AustraliaLeucite, Lamproite
DS1960-0084
1960
Prider, R.T.Prider, R.T.The Leucite Lamproites of the Fitzroy Basin, Western Australia. P.Geological Society AUST. Journal, Vol. 6, PT. 2, PP. 71-118.AustraliaLeucite, Lamproite, Whole Rock Analyses (12)
DS1960-0590
1965
Prider, R.T.Prider, R.T.Noonkanbahite, a Potassic Batisite from the Lamproites of Western Australia.Mineralogical Magazine., Vol. 34, PP. 403-405.AustraliaLeucite, Lamproite, Shcherbakovite
DS1960-1191
1969
Prider, R.T.Prider, R.T.The Probability of Finding Diamonds in the West Kimberley Area, Western australia.In: Prospectus For Stellar Mining N.l., PP. 6-8.Australia, Western Australia, Kimberley RegionFitzroy Valley, Lennard Shelf, Leucite, Lamproites, Mt. Abbott
DS1975-0837
1978
Prider, R.T.Prider, R.T.The Diamond Prospects of the Nullagine AreaIn: Prospectus For Samantha Exploration N.l. Exploration Rep, PP. 19-21.Australia, PilbaraNullagine
DS1975-0838
1978
Prider, R.T.Prider, R.T.The Diamond Prospects of the Mt. Percy AreaIn: Prospectus For Samantha Exploration N.l., PP. 16-19.Australia, Western Australia, Kimberley RegionLennard Shelf, Lamproite
DS1975-1187
1979
Prider, R.T.Prider, R.T.The Geology of Western Australia in Relation to its Mineralresources. In: Mining in Western Australia.Perth: University of Western Australia Press, CHAPT. 2, PP. 24-38.AustraliaKimberlite, Regional Geology, Kimberley
DS1982-0508
1982
Prider, R.T.Prider, R.T.A Glassy Lamproite from the West Kimberley Area Western Australia.Mineralogical Magazine., Vol. 45, PP. 279-282.AustraliaLamproite
DS1989-1241
1989
Prider, R.T.Prider, R.T.Introduction to the Fourth International Kimberlite ConferenceGeological Society of Australia Inc. Blackwell Scientific Publishing, Special, No. 14, Vol. 1, pp. 1-6GlobalKimberlite conference overview
DS1990-0381
1990
Pridmore, D.F.Cunneen, J.P., Pridmore, D.F.The use of aeromagnetics and vector magnetics in gold and diamond search with examples from Botswana and AustraliaModern Exploration Techniques, editors L.S. Beck, C.T. Harper, Saskatchewan, p. 149GlobalGeophysics -magnetics, Diamonds
DS1990-1380
1990
Pridmore, D.F.Smith, R.J., Pridmore, D.F.Exploration in weathered terrains 1989 perspectiveExploration Geophysics, Vol. 20, No. 4, December pp. 411-434AustraliaGeophysics, Argyle deposit area menti
DS1990-1381
1990
Pridmore, D.F.Smith, R.J., Pridmore, D.F.Exploration in weathered terrains 1989 perpectiveExploration Geophysics, Vol. 20, No. 4, December pp. 411-434AustraliaReview -geophysics, Weathered terrains
DS1989-1242
1989
Priem, H.N.A.Priem, H.N.A., Bon, E.H. , Verdurmen, E.A.Th., Bettencourt, J.S.rubidium-strontium (Rb-Sr) chronology of Precambrian crustal evolution in Rondonia (western margin of the Amazonian craton),BrasilJournal of South American Earth Sciences, Vol. 2, No. 2, pp. 162-170BrazilGeochronology, Amazonian craton
DS1990-1201
1990
Priem, H.N.A.Priem, H.N.A.Strange relatives - Earth and her sibling neighboursGeol. en Mijnbou, Vol. 69, pp. 391-406.MantleEarth - planetology
DS1995-1522
1995
Pries, R.A.Pries, R.A.A system for large scale image mapping and GIS dat a collectionPhotogrammetric Engineering and Remote Sensing, Vol. LXI, No. 5, May pp. 503-512.GlobalRemote sensing, GIS
DS1991-1382
1991
Priester, M.Priester, M., Hentschel, T.Technology and problems of small scale mining in South AmericaRaw Materials Alert, Vol. 8, No. 1, pp. 40-49Bolivia, ColumbiaMining -general, Economics
DS1993-1261
1993
Priester, M.Priester, M., Wiemer, H-J.Diamond mining in the Central African Republic. (in German)Erzmetall., (in German), Vol. April pp. 226-239.Central African RepublicMining
DS2000-0606
2000
Priestley, K.Maggi, A., Jackson, J.A., McKenszie, D., Priestley, K.Earthquake focal depths, effective elastic thickness and the strength of the continental lithosphere.Geology, Vol. 28, No. 6, June pp. 495-8.MantleEarthquakes - crustal thickness, Seismogenic crust
DS2002-1233
2002
Priestley, K.Pavlenkova, G.A., Priestley, K., Cipar, J.2D model of the crust and uppermost mantle along rift profile, Siberian cratonTectonophysics, Vol. 355, 1-4, pp.171-86.Russia, SiberiaGeophysics - seismics, Tectonics
DS200512-0705
2005
Priestley, K.McKenzie, D., Jackson, J., Priestley, K.Thermal structure of oceanic and continental lithosphere.Earth and Planetary Science Letters, Vol. 233, 3-4, May 15, pp. 337-349.Mantle, CanadaGeothermometry, mantle rheology, heat flow
DS200512-0860
2004
Priestley, K.Pilidou, SA., Priestley, K., Gudmundsson, O., Debayle, E.Upper mantle S-wave speed heterogeneity and anisotropy beneath the North Atlantic from regional surface wave tomography: the Iceland and Azores plumes.Geophysical Journal International, Vol. 159, 3, pp. 1057-1076.Europe, IcelandGeophysics - seismics
DS200612-1110
2006
Priestley, K.Priestley, K., Debayle, E., McKenzie, D., Pilidou, S.Upper mantle structure of eastern Asia from multimode surface waveform tomography.Journal of Geophysical Research, Vol. 111, B 10, B 10304.AsiaGeophysics - seismics
DS200612-1111
2006
Priestley, K.Priestley, K., McKenzie, D.The thermal structure of the lithosphere from shear wave velocities.Earth and Planetary Science Letters, Vol. 244, 1-2, Apr. 15, pp. 285-301.MantleGeothermometry, diamond
DS200712-0292
2006
Priestley, K.Emmerson, B., Jackson, J., McKensie, D., Priestley, K.Seismicity, structure and rheology of the lithosphere in the Lake Baikal region.Geophysical Journal International, Vol. 167, 3, Dec. 1, pp. 1233-1272.RussiaGeophysics - seismics
DS200712-0707
2007
Priestley, K.McKenzie, D., Priestley, K.A seismological view of the continental lithosphere.Frontiers in Mineral Sciences 2007, Joint Meeting of Mineralogical societies Held June 26-28, Cambridge, Abstract Volume p.186.MantleGeophysics - seismics
DS200712-0708
2007
Priestley, K.McKenzie, D., Priestley, K.A seismological view of the continental lithosphere.Frontiers in Mineral Sciences 2007, Joint Meeting of Mineralogical societies Held June 26-28, Cambridge, Abstract Volume p.186.MantleGeophysics - seismics
DS200812-0513
2008
Priestley, K.Jackson, J., McKenzie, D., Priestley, K., Emmerson, B.New views on the structure and rheology of the lithosphere.Journal Geological Society of London, Vol. 165, 2, pp. 453-466.MantleTectonics
DS200812-0733
2008
Priestley, K.McKenzie, D., Priestley, K.The influence of lithospheric thickness variations on continental evolution.Lithos, Vol. 102, 3-4, pp.1-11.MantlePetrology
DS200912-0600
2009
Priestley, K.Priestley, K., Tilmann, F.Relationship between the upper mantle high velocity seismic lid and the continental lithosphere.Lithos, Vol. 109, 1-2, pp. 112-124.MantleGeophysics - seismics
DS201112-0219
2011
Priestley, K.Craig, T.J., Jackson, J.A., Priestley, K., McKenzie, D.Earthquake distribution patterns in Africa: their relationship to variations in lithospheric and geological structure, and their rheological implicationGeophysical Journal International, Vol. 185, 1, pp. 403-404.AfricaGeophysics - seismics
DS201112-0654
2011
Priestley, K.Mather, K.A., Pearson, D.G., McKenzie, D., Kjarsgaard, B.A., Priestley, K.Constraints on the depth and thermal history of cratonic lithosphere from peridotite xenoliths, xenocrysts and seismology.Lithos, Vol. 125, pp. 729-742.Africa, South Africa, Canada, Somerset IslandGeothermometry, geophysics - seismics
DS201312-0721
2013
Priestley, K.Priestley, K., McKenzie, D.The relationship between shear wave velocity, temperature, attenuation and viscosity in the shallow part of the mantle.Earth and Planetary Science Letters, Vol. 381, pp. 78-91.MantleGeophysics - seismics
DS201509-0416
2015
Priestley, K.McKenzie, D., Daly, M.C., Priestley, K.The lithospheric structure of Pangea.Geology, Vol. 43, 9, pp. 783-786.MantlePangea

Abstract: Lithospheric thickness of continents, obtained from Rayleigh wave tomography, is used to make maps of the lithospheric thickness of Pangea by reconstructing the continental arrangement in the Permian. This approach assumes that lithosphere moves with the overlying continents, and therefore that the arrangement of both can be obtained using the poles of rotation obtained from magnetic anomalies and fracture zones. The resulting reconstruction shows that a contiguous arc of thick lithosphere underlay most of eastern Pangea. Beneath the western convex side of this arc, there is a wide belt of thinner lithosphere underlying what is believed to have been the active margin of Pangea, here named the Pangeides. On the inner side of this arc is another large area of thin lithosphere beneath the Pan-African belts of North Africa and Arabia. The arc of thick lithosphere is crossed by bands of slightly thinner lithosphere that lie beneath the Pan-African and Brasiliano mobile belts of South America, Africa, India, Madagascar, and Antarctica. This geometry suggests that lithospheric thickness has an important influence on continental deformation and accretion.
DS202103-0401
2021
Priestley, K.Priestley, K., Ho, T., McKenzie, D.The formation of continental roots.Geology, Vol. 49, pp. 190-194. pdfMantlegeophysics, seismics, tomography

Abstract: New evidence from seismic tomography reveals a unique mineral fabric restricted to the thick mantle lithosphere beneath ancient continental cratons, providing an important clue to the formation of these prominent and influential features in Earth’s geological history. Olivine, the dominant mineral of Earth’s upper mantle, has elastic properties that differ along its three crystallographic axes, and preferential alignment of individual olivine grains during plastic deformation can affect the bulk nature of seismic-wave propagation. Surface-wave tomography has shown that over most of Earth, deformation of the mantle lithosphere has oriented olivine crystals with the fast axis in the horizontal plane, but at depths centered at ?150 km within cratonic continental-lithosphere roots, the fast crystallographic axis is preferentially aligned vertically. Because of the high viscosity of the cratonic roots, this fabric is likely to be a vestige from craton formation. Geochemical and petrological studies of upper-mantle garnet-peridotite nodules demonstrate that the cratonic mantle roots are stabilized by their reduced density, which was caused by melt removal at much shallower depths than those from which the nodules were subsequently extracted. The mineral fabric inferred from surface-wave tomography suggests that horizontal shortening carried the depleted zone downward after the melt-depletion event to form the thick continental roots, stretching the depleted material in the vertical dimension by pure shear and causing the fast crystallographic axis to be aligned vertically. This seismological fabric at ?150 km is evidence of the shortening event that created the cratonic roots.
DS1999-0569
1999
Priestly, K.Priestly, K.Velocity structure of the continental upper mantle: evidence from southernAfrica.Lithos, Vol. 48, No. 1-4, Sept. pp. 45-56.South Africa, southern Africa, BotswanaGeophysics - seismics, Tectonics
DS2001-0831
2001
Priestly, K.Neves, F.A., Singh, S.C., Priestly, K.Velocity structure of the upper mantle discontinuities beneath North America from waveform inversion.. seismicJournal of Geophysical Research, Vol. 106, No. 10, pp.21,883-96.North AmericaTectonics, seismics, stress, Modeling
DS2002-1283
2002
Priestly, K.Priestly, K., McKenzie, D.The structure of the upper mantle beneath southern AfricaGeological Society of London Special Publication, No. 199, pp. 45-64.South AfricaGeophysics - seismics, Tectonics
DS2003-0523
2003
Priestly, K.Gupta, S., Rai, S.S., Prakasam, K.S., Sringesh, D., Chadha, R.K., Priestly, K.First evidence for anomalous thick crust beneath mid Archean western Dharwar cratonCurrent Science, Vol. 84, 9, pp. 1219-26.IndiaCraton
DS2003-1112
2003
Priestly, K.Priestly, K., De Bayle, E.Seismic evidence for a moderately thick lithosphere beneath the Siberian PlatformGeophysical Research Letters, Vol. 30, 3, Feb. 1, p. 18.RussiaGeophysics - seismics
DS200412-0750
2003
Priestly, K.Gupta, S., Rai, S.S., Prakasam, K.S., Srinagesh, D., Basal, B.K., Chadha, R.K., Priestly, K., Gaur, V.K.The nature of the crust in southern India: implications for Precambrian crustal evolution.Geophysical Research Letters, Vol. 30, 8, 10.1029/2002 GLO16770IndiaTectonics
DS200412-0751
2003
Priestly, K.Gupta, S., Rai, S.S., Prakasam, K.S., Sringesh, D., Chadha, R.K., Priestly, K., Gaur, V.K.First evidence for anomalous thick crust beneath mid Archean western Dharwar craton.Current Science, Vol. 84, 9, pp. 1219-26.IndiaCraton
DS200412-1590
2003
Priestly, K.Priestly, K., De Bayle, E.Seismic evidence for a moderately thick lithosphere beneath the Siberian Platform.Geophysical Research Letters, Vol. 30, 3, Feb. 1, p. 18.RussiaGeophysics - seismics
DS200512-0859
2005
Priestly, K.Pilidou, S., Priestly, K., Debayle, E., Gudmundson, O.Rayleigh wave tomography in the North Atlantic: high resolution images of the Iceland, Azores and Eifel mantle plumes.Lithos, Vol. 79, 3-4, pp. 453-474.Europe, IcelandTomography
DS200612-1112
2006
Priestly, K.Priestly, K., McKenzie, D., Debayle, E.The state of the upper mantle beneath southern Africa.Tectonophysics, Vol. 416, 1-4, April 5, pp. 101-112.Africa, South Africa, BotswanaGeophysics - seismics
DS200812-0923
2008
Priestly, K.Priestly, K., Jackson, J., McKenzie, D.Lithospheric structure and deep earthquakes beneath India, the Himalaya and southern Tibet.Geophysical Journal International, Vol. 172, 1, pp. 345-362.IndiaGeophysics - seismics
DS200812-0924
2008
Priestly, K.Priestly, K., McKenzie, D., Debayle,E., Pilldou, S.The African upper mantle and its relationship to tectonics and surface geology.Geophysical Journal International, Vol. 175, 3, pp. 1108-1125.AfricaTectonics
DS200912-0292
2009
Priestly, K.Heintz, M., Kumar, V.P., Gaur, V.K., Priestly, K., Rai, S.S., Prakasam, K.S.Anisotropy of the Indian continental lithospheric mantle.Geophysical Journal International, Vol. 179, 3, pp. 1341-1360.IndiaGeodynamics
DS2000-0206
2000
Priestly, K.F.Darbyshire, F.A., White, R.S., Priestly, K.F.Structure of the crust and uppermost mantle of Iceland from a combined seismic and gravity study.Earth and Planetary Science Letters, Vol.181, No.3, Sept.15, pp.409-28.GlobalMantle - structure, Geophysics - seismics
DS201112-0570
2011
Prieto, G.A.Lawrence, J.F., Prieto, G.A.Attenuation tomography of the western United States from ambient seismic noise.Journal of Geophysical Research, Vol. 116, B6, B06302.United StatesGeophysics - seismic
DS202104-0596
2021
Prieto, G.A.Nieto, I.E.M., Prieto, G.A.Structural signatures of the Amazonian Craton in eastern Columbia from gravity and magnetometry data interpretation.Tectonophysics, Vol. 800, 228705, 15p. PdfSouth America, Colombiageophyics - magnetics, gravity

Abstract: Geophysical interpretation of potential field data plays an important role in the integration of geological data. Estimation of density and magnetic susceptibility variations within the upper crust helps evaluating the continuity of geological structures in the field. In the present study we use gravity and magnetic data in NW Amazonian Craton in Colombia. Total horizontal gradient of the reduction to magnetic pole were used to delineate magnetic lineaments and domains showing four zones, each with its own features. Multiscale edge detection (worming) of the data help delineate upper crustal structures that we interpret as tectonic boundaries that correlate with the four zones identified. 3D density and magnetic susceptibility inversion showed high density and/or high magnetic susceptibility sources correlated with these crustal structures. Zone (1) is located south of the Guaviare River, with predominant NW-SE and NE-SW magnetic lineaments; zone (2), located from south of the Guaviare River to the north, present nearly E-W magnetic lineaments and a deep E-W edge interpreted as a possible shear zone parallel to Guaviare, Orinoco and Ventuari rivers; zone (3) from south of the Vichada River to the north, with NE-SW and NW-SE lineaments; N-S zone (4) cuts the zones (2) and (3), characterized by high density/magnetic susceptibility source bounded by N-S deep edges. A more complete tectonic evolution interpretation requires further work, but we speculate that the zone (4) could indicate an aborted rift/collision suture and that the zone (2) is indicative of a younger deformation event. Shear direction at (2) is not clear: geological maps show NEE-SWW right-lateral faulting, but geophysical anomalies suggest left-lateral displacement, highlighted by left dislocation of the Orinoco River. We also speculate that a N-S edge located at the SE of the area can be related with the Atabapo Belt and the limit of Ventuari-Tapajós and Rionegro geochronological provinces.
DS1993-1262
1993
Prijosoesilo, P.Prijosoesilo, P., Sunarya, Y., Wahab, A.Recent progress of geological investigations in IndonesiaJournal of Southeast Asian Earth Sciences, Vol. 8, No. 104, pp. 5-23.IndonesiaMining, Mineral resources -0verview
DS2002-1757
2002
PrikhodkoYamamoto, J., Kagi, H., Kaneoka, Lai, Prikhodko,AraiFossil pressures of fluid inclusions in mantle xenoliths exhibiting rheology of mantle minerals...Earth and Planetary Science Letters, Vol.198,3-4,pp.511-19., Vol.198,3-4,pp.511-19.MantleSpectroscopy, Geobarometry - mantle minerals
DS2002-1758
2002
PrikhodkoYamamoto, J., Kagi, H., Kaneoka, Lai, Prikhodko,AraiFossil pressures of fluid inclusions in mantle xenoliths exhibiting rheology of mantle minerals...Earth and Planetary Science Letters, Vol.198,3-4,pp.511-19., Vol.198,3-4,pp.511-19.MantleSpectroscopy, Geobarometry - mantle minerals
DS200612-0623
2006
PrikhodkoIonov, D.A., Hofmann, A.W., Merlet, C., Gurenko, A.A., Hellebrand, E., Montagnac, G., Gillet, P., PrikhodkoDiscovery of whitlockite in mantle xenoliths: inferences for water and halogen poor fluid and trace element residence in the terrestrial upper mantle.Earth and Planetary Science Letters, Vol. 244, 1-2, Apr. 15, pp. 201-207.MantleXenolith - mineralogy
DS201807-1478
2018
Prikhodko, A.Bournas, N., Prikhodko, A., Plastow, G., Legault, J., Polianichko, V., Treshchev, S.Exploring for kimberlite pipes in the Cuango area, Angola using helicopter-borne EM survey.AEM2018/7th International Workshop on Airborne electromagnetics, Held June 17-20, 4p.Africa, Angolageophysics - TEM
DS202004-0504
2020
Prikhodko, D.D.Chernykh, S.V., Chernykh, A.V., Tarelkin, S., Didenko, S. ,Kondakov, M.N., Shcherbachev, K.D., Trifonova, E.V., Drozdova, T.E., Troschiev, S.Y., Prikhodko, D.D., Glybin, Y.N., Chubenko, A.P., Britvich, G.I., Kiselev, D.A., Polushin, N.I., Rabinovich, O.IHPHT single crystal diamond type IIa characterization for particle detectors.Physicsa Status Solidi , doi:10.1002/pssa.201900888GlobalHPHT

Abstract: Various samples of multisectoral high?pressure high?temperature (HPHT) single?crystal diamond plate (IIa type) (4?×?4?×?0.53?mm) are tested for particle detection applications. The samples are investigated by X?ray diffractometry, photoluminescence spectroscopy, Raman spectroscopy, Fourier?transform infrared, and visible/ultraviolet (UV) absorption spectroscopy. High crystalline perfection and low impurity concentration (in the {100} growth sector) are observed. To investigate detector parameters, circular 1.0 and 1.5?mm diameter Pt Schottky barrier contacts are created on {111} and {100} growth sectors. On the backside, a Pt contact (3.5?×?3.5?mm) is produced. The {100} growth sector is proved to be a high?quality detector: the full width at half maximum energy resolution is 0.94% for the 5.489?MeV 226Ra ??line at an operational bias of +500?V. Therefore, it is concluded that the HPHT material {100} growth sector is used for radiation detector production, whose quality is not worse than the chemical vapor deposition method or specially selected natural diamond detectors.
DS2002-0108
2002
Prikhodko, V.Barron, L.M., Kepezhinskas, P., Barron, B.J., Prikhodko, V.Arc ultramafic rocks at Phanerozooic age in New South Wales and Siberia and theirNew South Wales Quarterly Notes, No. 112, pp. 9-16.Australia, New South Wales, Russia, SiberiaBlank
DS200412-0102
2002
Prikhodko, V.Barron, L.M., Kepezhinskas, P., Barron, B.J., Prikhodko, V.Arc ultramafic rocks at Phanerozooic age in New South Wales and Siberia and their relation to occurrence of diamond: possible neNew South Wales Quarterly Notes, No. 112, pp. 9-16.Australia, New South Wales, Russia, SiberiaLachlan Fold Belt, shoshonite, indicators
DS201508-0379
2015
Prikhodko, V.Wang, K-L., Prikhodko, V., O'Reilly, S.Y., Griffin, W.L., Pearson, N.J., Kovach, V., Lizuka, Y., Chien, Y-H.Ancient mantle lithosphere beneath the Khanka Massif in Russian Far-East: in situ Re-Os evidence.Terra Nova, Vol. 27, 4, pp. 277-284.RussiaGeochronology
DS1995-0854
1995
Prikhodko, V.S.Ionov, D.A., Prikhodko, V.S., O'Reilly, S.Y.Peridotite xenoliths in alkali basalts from the Sikhote-Alin southeasternSiberia: trace elementsChemical Geology, Vol. 120, No. 3-4, March 1, pp. 275-294.Russia, SiberiaXenoliths, mantle signatures, Priorie, margin
DS1995-1523
1995
Prikhodko, V.S.Prikhodko, V.S.Composition and structure of lithospheric mantle in the Pacific margin ofAsia.Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 455-456.GlobalMantle, Peridotite xenoliths
DS1996-0440
1996
Prikhodko, V.S.Esin, S.V., Prikhodko, V.S., et al.Petrogenesis of Mesozoic alkaline picrite melaleucite association in the central Sikhote Alin.Russian Geology and Geophysics, Vol. 37, No. 10, pp. 15-25.Russia, AlinPetrology, Alkaline rocks
DS1996-1143
1996
Prikhodko, V.S.Prikhodko, V.S., et al.Major element composition of the upper mantle beneath the southern Russian far east (East Asia) xenolithsInternational Geological Congress 30th Session Beijing, Abstracts, Vol. 1, p. 119.Russia, AsiaXenoliths
DS1998-1191
1998
Prikhodko, V.S.Prikhodko, V.S., Zemlyanukhin, V.N.Petrology of spinel peridotite xenoliths from Cenozoic basaltoids in the Khanka Craton terrain.7th. Kimberlite Conference abstract, pp. 716.Russia, Central AsiaGeochemistry, Craton - Khankaisk. Bureinsk
DS1998-1553
1998
Prikhodko, V.S.Voinova, I.P., Prikhodko, V.S.Post accretionary stage in the evolution of ultramafic magmatism inaccretionary prisms: rock types -7th International Kimberlite Conference Abstract, p. 949.Russia, East, Sikhote AlinStructure, Petrogeochemical mafic rocks
DS1999-0325
1999
Prikhodko, V.S.Ionov, D.A., Gregoire, M., Prikhodko, V.S.Feldspar Ti Oxide metasomatism in off cratonic continental and oceanic upper mantle.Earth and Planetary Science Letters, Vol.165, No.1, Jan.15, pp.37-44.MantleMetasomatism
DS2000-0989
2000
Prikhodko, V.S.Voinova, I.P., Prikhodko, V.S.Magmatic rocks in accretionary prisms and their diamond bearing potential ( Central Sikhote Alin).Igc 30th. Brasil, Aug. abstract only 1p.RussiaBasaltoids, xenoliths
DS200412-1436
2004
Prikhodko, V.S.Nishio, Y., Nakai, S., Yamamoto, J., Sumino, H., Matsumoto, T., Prikhodko, V.S., Arai, S.Lithium isotopic systematics of the mantle derived ultramafic xenoliths: implications for EMI origin.Earth and Planetary Science Letters, Vol. 217, 3, Jan. 15, pp. 245-261.MantleGeochronology
DS200412-2165
2004
Prikhodko, V.S.Yamamoto, J., Kaneoka, I., Nakai, S., Kagi, H., Prikhodko, V.S., Arai, S.Evidence for subduction related components in the subcontinental mantle from low 3He/4He and 40Ar/36Ar ratio in mantle xenolithsChemical Geology, Vol. 207, 3-4, July 16, pp. 237-259.RussiaGeochemistry - noble gases, subduction, lherzolite
DS200512-0461
2005
Prikhodko, V.S.Ionov, D., Prikhodko, V.S., Bodinier, J.L., Sobolev, A.V., Weis, D.Lithospheric mantle beneath the south eastern Siberian Craton: petrology of peridotite xenoliths in basalts from the Tokinsky Stanovik.Contributions to Mineralogy and Petrology, Vol. 149, no. 6, pp. 647-665.Russia, SiberiaXenoliths
DS200512-0463
2005
Prikhodko, V.S.Ionov, D.A., Prikhodko, V.S., Bodinier, J-L.et.al.Lithospheric mantle beneath the south eastern Siberian Craton: petrology of peridotite xenoliths in basalts from the Tokinsky Stanovik.'Contributions to Mineralogy and Petrology, Online AccessRussiaXenoliths, Aldan Shield, Siberian Craton, metasomatism
DS200512-0877
2004
Prikhodko, V.S.Prikhodko, V.S., Petukhova, L.L., Chubarov, V.M.Pecularities of compositional variations in xenoliths of mantle spinel peridotite possible mechanisms of their formation in fold and stable areas.Deep seated magmatism, its sources and their relation to plume processes., pp. 293-301.MantleXenoliths
DS200612-1087
2005
Prikhodko, V.S.Petukhova, L.I., Voinova, I.P., Prikhodko, V.S.Pecularities of alkaline basaltoid mineralogy in Central Sikhote Alin terrigeneous volcanogenic siliceous complexes.Problems of Sources of deep magmatism and plumes., pp. 282-RussiaAlkalic
DS200912-0585
2009
Prikhodko, V.S.Petukkova, L.I., Prikhodko, V.S.Micaeous picrites of the Sikhote Alin ridge.alkaline09.narod.ru ENGLISH, May 10, 2p. abstractRussiaDiamond potential
DS200912-0831
2009
Prikhodko, V.S.Yamamoto, J.,Nakai, S., Nishimura, K., Kaneoka, I., Sato, K., Okumura, T., Prikhodko,V.S., Arai, S.Intergranular trace elements in mantle xenoliths from Russian Far East: example for mantle metasomatism by hydrous melt.Island Arc, Vol. 18, 1, pp. 225-241.RussiaMetasomatism
DS201012-0714
2010
Prikhodko, V.S.Simonov, V.A., Prikhodko, V.S., Kovyazin, S.V., Tarnavsky, A.V.Crystallization conditions of dunites in the Konder platiniferous alkaline ultramafic massif of the southeastern Aldan Shield.Russian Journal of Pacific Geology, Vol. 4, 5, pp. 429-440.Russia, Aldan ShieldAlkalic
DS201112-0792
2010
Prikhodko, V.S.Petukhova, L.L., Prikhodko, V.S.Lamprophyres of south Sikhote-Alin.Vladykin, N.V., Deep Seated Magmatism: its sources and plumes, pp. 200-RussiaLamprophyre
DS201501-0032
2014
Prikhodko, V.S.Simonov, V.A., Prikhodko, V.S., Kovyazin, S.V., Kotlyarov, A.V.Petrogenesis of meymechites of Sikhote Alin inferred from melt inclusions.Russian Journal of Pacific Geology, Vol. 8, 6, pp. 423-442.RussiaMeymechites
DS201804-0737
2017
Prikhodko, V.S.Simonov, V.A., Prikhodko, V.S., Vasiliev, Yu.R., Kotlyarov, A.V.Physicochemical conditions of the crystallization of rocks from ultrabasic massifs of the Siberian platform. Konder, Inagli, Chad) Cr-spinelsRussian Journal of Pacific Geology, Vol. 11, 6, pp. 447-468.Russiapicrites

Abstract: A great volume of original information on the formation of the ultrabasic rocks of the Siberian Platform has been accumulated owing to the study of melt inclusions in Cr-spinels. The inclusions show the general tendencies in the behavior of the magmatic systems during the formation of the ultrabasic massifs of the Siberian Platform, tracing the main evolution trend of decreasing Mg number with SiO2 increase in the melts with subsequent transition from picrites through picrobasalts to basalts. The compositions of the melt inclusions indicate that the crystallization conditions of the rocks of the concentrically zoned massifs (Konder, Inagli, Chad) sharply differ from those of the Guli massif. Numerical modeling using the PETROLOG and PLUTON softwares and data on the composition of inclusions in Cr-spinels yielded maximum crystallization temperatures of the olivines from the dunites of the Konder (1545-1430°C), Inagli (1530-1430°C), Chad (1460-1420°C), and Guli (1520-1420°C) massifs, and those of Cr-spinels from the Konder (1420-1380°C), Inagli (up to 1430°C), Chad (1430-1330°C), and Guli (1410-1370°C) massifs. Modeling of the Guli massif with the PLUTON software using the compositions of the melt inclusions revealed the possible formation of the alkaline rocks at the final reverse stage of the evolution of the picritic magmas (with decrease of SiO2 and alkali accumulation) after termination of olivine crystallization with temperature decrease from 1240-1230°C to 1200-1090°C. Modeling with the PLUTON software showed that the dunites of the Guli massif coexisted with Fe-rich (with moderate TiO2 contents) melts, the crystallization of which led (beginning from 1210°C) to the formation of pyroxenes between cumulate olivine. Further temperature decrease (from 1125°C) with decreasing FeO and TiO2 contents provided the formation of clinopyroxenes of pyroxenites. For the Konder massif, modeling with the PLUTON software indicates the possible formation of kosvites from picrobasaltic magmas beginning from 1350°C and the formation of clinopyroxenites and olivine-diopside rocks from olivine basaltic melts from 1250°C.
DS201512-1984
2015
Prikhodo, V.Wang, K-L., Prikhodo, V., O'Reilly, S.Y., Griffin, W.L., Pearson, N.J., Kovach, V., Iizuka, Y., Chien, Y-H.Ancient mantle lithosphere beneath the Khanka massif in the Russian Far East: in situ Re-Os evidence.Terra Nova, Vol. 27, 4, pp. 277-284.RussiaGeochronology

Abstract: The Os-isotope compositions of sulphides in mantle xenoliths hosted by Late Miocene alkali basalts from the Sviyaginsky volcano, Russian Far East, reveal the presence of Archaean-Proterozoic subcontinental lithospheric mantle beneath the Khanka massif. Their TMA and TRD model ages reveal similar peaks at 1.1 and 0.8 Ga suggesting later thermotectonic events in the subcontinental lithospheric mantle, whereas TRD model ages range back to 2.8 ± 0.5 (2?) Ga. The events recognized in the subcontinental lithospheric mantle are consistent with those recorded in the crust of the Khanka massif. The sulphide Os-isotope data show that the subcontinental lithospheric mantle beneath the Khanka massif had formed at least by the Mesoproterozoic, and was subsequently metasomatized by juvenile crustal-growth events related to the evolution of the Altaids. The Khanka massif is further proposed to have tectonic affinity to the Siberia Craton and should originate from it accordingly.
DS201901-0058
2018
Prikryl, J.Prikryl, J., Stefansson, A., Pearce, C.R.Tracing olivine carbonation and serpentinization in CO2 rich fluids via magnesium exchange and isotopic fractionation.Geochimica et Cosmochimica Acta, Vol. 243, pp. 133-148.Mantleolivine

Abstract: Chemical exchange between seawater and the oceanic crust is thought to play a significant role in the regulation of the global magnesium (Mg) cycle, yet relatively little is known about the rates and mechanisms of Mg exchange in these crustal environments. In this study we experimentally characterize the extent, and nature, of Mg isotope fractionation during the carbonation and serpentinization of olivine (one of the principal minerals found in ultramafic rocks) under hydrothermal conditions. Olivine alteration was found to be incongruent, with the reactant fluid composition varying according to the extent of olivine dissolution and the precipitation of secondary minerals. In mildly acid water (pH???6.5), olivine dissolved to form Mg-Fe carbonate solid solutions and minor chrysotile. Upon carbonation and a decrease of CO2 in the water, the pH increased to >8, with chrysotile and brucite becoming the dominant alteration minerals. The Mg-rich carbonates preferentially incorporated lighter Mg isotopes, resulting in a ?0.5‰ increase of the ?26Mg composition of the fluid relative to olivine during the initial carbonation and serpentinization reactions. This was followed by a decrease in ?26Mg under higher pH conditions associated with the formation of brucite. Our experimental and modeling results therefore demonstrate that the ?26Mg composition of fluids involved in olivine alteration reflect the type and quantity of secondary Mg minerals formed, which in turn depend on the pH and CO2 concentration of the water. Comparison of these results with natural groundwaters and geothermal waters from basaltic terrains indicate that the ?26Mg composition of natural waters are likely to also be controlled by mafic rock dissolution and the preferential incorporation of isotopically light Mg into carbonates and isotopically heavy Mg into Mg-Si minerals. Together, these findings improve our understanding of Mg isotope systematics during water-rock interaction, and suggest that ?26Mg may be a useful tool for tracing reactions that are critical to geological CO2 sequestration.
DS1993-1263
1993
Prime EquitiesPrime EquitiesNorthern Alberta diamond play mapPromotional Brochure, Handout From Two Day Seminar Held Vancouver, B.c. May, 2p.AlbertaPromotional brochure, Company information
DS2003-1113
2003
Prime-TassPrime-TassPutin signs bill declassifying PGM, gem output, reserve dataPrime-Tass, Nov. 20, 1/8p.RussiaNews item - legal, diamonds
DS200412-1591
2003
Prime-TassPrime-TassPutin signs bill declassifying PGM, gem output, reserve data.Prime-Tass, Nov. 20, 1/8p.RussiaNews item - legal, diamonds
DS2000-0779
2000
Prince, C.I.Prince, C.I., Kosler, J., Vance, D., Gunther, D.Comparison of laser ablation ICP MS and isotope dilution rare earth elements (REE) analyses - Smneodymium garnet geochronology.Chemical Geology, Vol. 168, No. 3-4, Aug. 1, pp. 255-74.GlobalGarnet chronology - crystal, Age determination, dating, light rare earth element (LREE) enriched minerals
DS1991-1383
1991
Prince, C.M.Prince, C.M.DECODE and DFOUR: 2-D Fourier processing of petrographic imagesComputers and Geosciences, Vol. 17, No. 4, pp. 505-526GlobalComputers, Program -DECODE AND DFOUR petrography
DS1991-1384
1991
Prince, C.M.Prince, C.M.DECODE and DFOUR - 2 D Fourier processing of petrographic imagesComputers and Geosciences, Vol. 17, No. 4, pp. 505-526GlobalComputers, Program -DECODE, DEFOUR.
DS1993-1192
1993
Prince, D.Parry, S., Prince, D.The Save our North Campaign.CRSCrs Perspectives, No. 43, March pp. 11-14OntarioEconomics, Philosophy -mining
DS1994-1412
1994
Prince, D.Prince, D.Canadians accept exploration in parksPda Digest, Vol. 7, No. 31, Winter pp. 1, 2, 3CanadaEnvironmental, Parks -access
DS1993-1264
1993
Prince Albert Daily HeraldPrince Albert Daily HeraldDiamond jackpot excites companies....fancies make find more attractivePrince Albert Daily Herald, November 18, 1p.SaskatchewanNews item, Rhonda Mining
DS1992-0082
1992
Principe, C.Barberi, F., Bertagnini, A., Landi, P., Principe, C.A review on phreatic eruptions and their precursorsJournal of Volcanology and Geothermal Research, Vol. 52, pp. 231-246GlobalVolcanics, Phreatomagmatics
DS1985-0546
1985
Princivalle, F.Princivalle, F., Secco, L.Crystal Structure Refinement of 13 Olivines in the Forsterite-fayalite Series from Volcanic Rocks and Ultramafic Nodules.Tschermaks Mineralogische und Petrographische Mitteilungen MITTEILUNGEN., Vol. 34, No. 2, PP. 105-116.GlobalMineralogy
DS1992-1323
1992
Princivalle, F.Salviulo, G., Princivalle, F., Demarchi, G., Fabro, C.Effects of Ca-magnesium substitution in C2/c pyroxene structure on natural clinopy roxenes from spinel peridotite nodules (Pico Cabugi, Brasil).Phys. Chem. Minerals, Vol. 19, pp. 213-219.BrazilNodules, Peridotite
DS1994-1413
1994
Princivalle, F.Princivalle, F., Salviulo, G., Fabro, C., Demarchi, G.Inter and intra crystalline temperature and pressure estimates on pyroxenes from northeast Brasil mantle xenoliths.Contr. Mineralogy and Petrology, Vol. 116, No. 1/2, pp. 1-6.BrazilXenoliths
DS2000-0780
2000
Princivalle, F.Princivalle, F., Salviulo, G., Marzoli, PiccirilloClinopyroxene of spinel peridotite mantle xenoliths from Lake Nji: crystal chemistry and petrological....Contributions to Mineralogy and Petrology, Vol. 139, No. 5, pp. 503-8.GlobalMantle xenoliths
DS2000-0781
2000
Princivalle, F.Princivalle, F., Tirone, M., Comin-Chiaramonti, P.Clinopyroxenes from metasomatized spinel peridotite mantle xenoliths from Nemby: crystal chemistry, petrol.Min. Petrol., Vol. 70, No. 1-2, pp. 25-36.ParaguayPetrology, mineral chemistry, Xenoliths
DS2003-0162
2003
Princivalle, F.Brizi, E., Nazzareni, S., Princivalle, F., et al.Clinopyroxene from mantle related xenocrysts in alkaline basalts from Hannuoba (Contribution to Mineralogy and Petrology, Vol. 145, 5, August, pp. 578-584.ChinaGeothermometry, alkaline rocks
DS200412-0211
2003
Princivalle, F.Brizi, E., Nazzareni, S., Princivalle, F., et al.Clinopyroxene from mantle related xenocrysts in alkaline basalts from Hannuoba ( China): augite pigeonite exsolutions and theirContributions to Mineralogy and Petrology, Vol. 145, 5, August, pp. 578-584.ChinaGeothermometry Alkaline rocks
DS200712-1212
2007
Princivalle, F.Zaccarini, F., Thalhammer, O.A.R., Princivalle, F., Lenaz, D., Stanley, C.J., Garuti, G.Djerfisherite in the Guli dunite complex, Polar Siberia: a primary or metasomatic phase?Canadian Mineralogist, Vol. 45, 5, Oct. pp. 1201-1211.RussiaMetasomatism
DS200812-0790
2008
Princivalle, F.Nedii, Z., Princivalle, F., Lenaz, D., Toth, T.M.Crystal chemistry of clinopyroxene and spinel from mantle xenoliths hosted in late Mesozoic lamprophyres ( Villany Mts, S. Hungary).Neues Jahrbuch fur Mineralogie, Vol. 185, 1, pp. 1-10.Europe, HungaryLamprophyre
DS200912-0434
2009
Princivalle, F.Lenaz, D., Logvinova, A.M., Princivalle, F., Sobolev, N.V.Structural parameters of chromite included in diamond and kimberlites from Siberia: a new tool for discriminating ultramafic source.American Mineralogist, Vol. 94, 7, pp. 1067-1070.Russia, SiberiaDiamond inclusions
DS200912-0534
2009
Princivalle, F.Nestola, F., Smyth, J.R., Parisatto, M., Secco, L., Princivalle, F., Bruno, M., Prencipe, M., Dal Negro, A.Effects of non-stochiometry on the spinel structure at high pressure: implications for Earth's mantle mineralogy.Geochimica et Cosmochimica Acta, Vol. 73, 2, pp. 489-492.MantleUHP
DS201012-0433
2010
Princivalle, F.Lenaz, D., Skogby, H., Logvinova, A.M., Princivalle, F., Sobolev, N.V.Fe3+ Fe tot ratio in the mantle: a micro-Mossbauer study of chromites included in diamond and kimberlites.International Mineralogical Association meeting August Budapest, abstract p. 431.Russia, YakutiaOxidation state
DS201212-0574
2012
Princivalle, F.Princivalle, F., Martignago, F., Nestola, F., Dal Negro, A.Kinetics of cation ordering in synthetic Mg(Al,Fe3+2O4 spinels.European Journal of Mineralogy, Vol. 24, 4, pp. 633-643.TechnologySpinel
DS201312-0531
2013
Princivalle, F.Lenaz, D., Skogby, H., Logvinova, A.M., Sobolev, N.V., Princivalle, F.A micro-Mossbauer study of chromites included in diamond and other mantle related rocks.Physics and Chemistry of Minerals, Vol. 40, 9, pp. 671-679.Russia, SiberiaSpectroscopy - diamond
DS201412-0504
2013
Princivalle, F.Lenaz, D., Skogby, H., Logvinova, A., Sobolev, N., Princivalle, F.A micro-mossbauer study of chromites included in diamond and other mantle related rocks.Physics and Chemistry of Minerals, Vol. 40, 9, pp. 671-679.Russia, SiberiaDiamond inclusions
DS201910-2288
2019
Princivalle, F.Nestola, F., Zaffiro, G., Mazzucchelli, M.L., Nimis, P., Andreozzi, G.B., Periotto, B., Princivalle, F., Lenaz, D., Secco, L., Pasqualetto, L., Logvinova, A.M., Sobolev, N.V., Lorenzetti, A., Harris, J.W.Diamond inclusion system recording old deep lithosphere conditions at Udachnaya ( Siberia).Nature Research, Vol. 9, 12586 8p. PdfRussia, Siberiadeposit - Udachnaya

Abstract: Diamonds and their inclusions are unique fragments of deep Earth, which provide rare samples from inaccessible portions of our planet. Inclusion-free diamonds cannot provide information on depth of formation, which could be crucial to understand how the carbon cycle operated in the past. Inclusions in diamonds, which remain uncorrupted over geological times, may instead provide direct records of deep Earth’s evolution. Here, we applied elastic geothermobarometry to a diamond-magnesiochromite (mchr) host-inclusion pair from the Udachnaya kimberlite (Siberia, Russia), one of the most important sources of natural diamonds. By combining X-ray diffraction and Fourier-transform infrared spectroscopy data with a new elastic model, we obtained entrapment conditions, Ptrap?=?6.5(2) GPa and Ttrap?=?1125(32)-1140(33) °C, for the mchr inclusion. These conditions fall on a ca. 35?mW/m2 geotherm and are colder than the great majority of mantle xenoliths from similar depth in the same kimberlite. Our results indicate that cold cratonic conditions persisted for billions of years to at least 200?km in the local lithosphere. The composition of the mchr also indicates that at this depth the lithosphere was, at least locally, ultra-depleted at the time of diamond formation, as opposed to the melt-metasomatized, enriched composition of most xenoliths.
DS1999-0454
1999
PringleMcClenaghan, B., Kjarsgaard, Stirling, Pringle, BergerMineralogy and chemistry of the A4 kimberlite and associated glacialsediments, Kirkland Lake, Ontario.Geological Survey of Canada (GSC) Open file, No. 3769, 162p. plus Disc $ 65.00Ontario, Kirkland LakeGeochemistry - indictor minerals, Deposit - A4
DS1989-1243
1989
Pringle, G.Pringle, G.EDDI: a Fortran computer program to produce corrected microprobe analysis of minerals using an energy dispersive X-ray spectrometerG.s.c. Open File, No. 2127, 210p. $ 25.00GlobalComputer Program, Microprobe spectrometer -
DS1989-1244
1989
Pringle, G.Pringle, G.EDDI: a Fortran computer program to produce corrected microprobe analyses of minerals using an energy dispersive X-ray spectrometerG.s.c. Open File, No. 2127, 210p. $ 25.00GlobalComputer, Program -EDDI
DS1993-0991
1993
Pringle, G.McClenaghan, M.B., Kjarsgaard, B.M., Stirling, J.A.R., Pringle, G.Chemistry of kimberlitic indicator minerals in drift from the Kirkland Lakearea, northeastern OntarioGeological Survey of Canada, $ 57.00 and $ 15.00 and 15.00, Open File, No. 2761, 375p. 1 disc. 1 map 1: 200, 000OntarioGeochemistry, Indicator minerals
DS1994-1161
1994
Pringle, G.McMartin, I., Pringle, G.Regional kimberlite indicator mineral dat a and till geochemistry from the Wekusko Lake area (63J) north central Manitoba.Geological Survey of Canada Open File, No. 2844, 78p. 1 disc. $ 13.00ManitobaGeochemistry, Wekusko Lake area
DS1995-1524
1995
Pringle, G.J.Pringle, G.J.MINREP - a FORTRAN computer program to produce tables of mineral analyses with formulae and end membersGeological Survey of Canada Open File, No. 2596, 113p. $ 20.00 and disc $ 20.00GlobalComputer -Program, Program -MINREP
DS1996-1375
1996
Pringle, G.J.Stirling, J.A.R., Pringle, G.J.Tools of investigation: the electron microprobe and scanning electronmicroscope.Geological Survey of Canada, LeCheminant ed, OF 3228, pp. 47-54.CanadaTechniques, Microprobe
DS1991-0492
1991
Pringle, M.Floyd, P.A., Castillo, P.R., Pringle, M.Tholeiitic and alkalic basalts of the oldest Pacific Ocean crustTerra Nova, Vol. 3, No. 3, pp. 257-265Pacific OceanBasalt, Lava
DS1998-0735
1998
Pringle, M.S.Kent, R.W., Kelley, S.P., Pringle, M.S.Mineralogy and 40 Ar-39 Ar geochronology of orangeites (Group IIkimberlites) from the Damodar Valley.Mineralogical Magazine, Vol. 62, No. 3, June pp. 313-24.India, EasternGeochronology, Argon, Orangeites
DS2003-0077
2003
Pringle, M.S.Barry, T.L., Saunders, A.D., Kempton, P.D., Windley, B.F., Pringle, M.S.Petrogenesis of Cenozoic basalts from Mongolia: evidence for the role ofJournal of Petrology, Vol. 44, 1, pp. 55-92.MongoliaMantle - metasomatism
DS200612-0400
2006
Pringle, M.S.Flowers, R.M., Mahan, K.H., Bowring, S.A., Williams, M.L., Pringle, M.S., Hodges, K.V.Multistage exhumation and juxaposition of lower continental crust in the western Canadian Shield: linking high resolution U Pb and 40 Ar / 39 Ar thermochronometry with pressure temperature deformation paths.Tectonics, Vol. 25, 4, TC4003, 20p.Canada, Alberta, Saskatchewan, Northwest TerritoriesGeothermometry, thermocrhonmetry, deformation P T
DS201212-0756
2012
Prins, C.Verster, A., De Waal, D., Schall, R., Prins, C.A truncated Pareto model to estimate the under recoveru of large diamonds.Mathematical Geosciences, Vol. 44, 1, pp. 91-100TechnologyRecovery
DS201412-0418
2014
Prins, C.Jacob, J., Prins, C., Oelofsen, A.Determination of sampling configuration for near shore Diamondiferous gravel occurrence using geostatistical methods. Mining area no. 1 - linear beach NamdebJournal of South African Institute of Mining and Metallurgy, Vol. 114, Jan. pp. 31-38.Africa, NamibiaSampling - geostatistics
DS201606-1126
2012
Prins, C.Verster, A., de Waal, D., Schall, R., Prins, C.A truncated Pareto model to estimate the under recovery of large diamonds. Bayesian approach.Mathematical Geosciences, Vol. 44, 1, pp. 91-100.TechnologyMetallurgy process

Abstract: The metallurgical recovery processes in diamond mining may, under certain circumstances, cause an under-recovery of large diamonds. In order to predict high quantiles or tail probabilities we use a Bayesian approach to fit a truncated Generalized Pareto Type distribution to the tail of the data consisting of the weights of individual diamonds. Based on the estimated tail probability, the expected number of diamonds larger than a specified weight can be estimated. The difference between the expected and observed frequencies of diamond weights above an upper threshold provides an estimate of the number of diamonds lost during the recovery process.
DS201612-2307
2016
Prins, C.Jacob, J., Prins, C.Construction of an expert opinion based virtual orebody for a Diamondiferous linear beach deposit.Journal of South African Institute of Mining and Metallurgy, Vol. 116, July pp. 629-635.Africa, NamibiaDeposit - marine placers

Abstract: During early-stage diamond exploration projects, hard data underpinning spatial continuity is often very limited. An extreme example of this is a submerged diamondiferous marine placer target area alongside a current onshore mining area in southwestern Namibia. Although an abundance of geological and grade data exists for the adjacent onshore mining area, the target area itself contains no such information. Despite this apparent abundance of data, it is extremely difficult to obtain a variogram (Prins and Jacob, 2014) for use in this study area. The use of traditional simulation techniques is further hindered by the fact that diamond entrapment within the highly gullied footwall is non-stationary. An alternative approach for creating a simulated virtual orebody (VOB) is thus required in order to enable the assessment of sampling strategies. This paper demonstrates how expert opinion is used to generate a composite probability map for diamond concentration using a greyscale hand-sketching technique. The probability map is subsequently calibrated and populated using the diamond distribution for different raised beaches obtained from analog data based on sample results adjacent to the target area. The resultant grade simulation is used to test different sample scenarios and is a first step towards determining an appropriate sampling strategy for the target area. The VOB is used to analyse and rank the efficiency of different sampling strategies for grade determination of submerged diamondiferous linear beach exploration targets.
DS201709-2004
2016
Prins, C.Jacob, J., Prins, C.Construction of an expert opinion based virtual orebody for a Diamondiferous linear beach deposit. South African Institute of Mining and Metallurgy, Vol. 116, 7, pp. 629-336.Africa, Namibiatechnology, alluvials
DS201709-2005
2016
Prins, C.Jacob, J., Prins, C.Using the proportion of barren samples as a proxy for minimum grade in a Diamondiferous linear beach deposit - an application of the Nachman model.South African Institute of Mining and Metallurgy, Vol. 116, 8, pp. 731-737.Africa, Namibiadeposit - Orange River

Abstract: Over the past 80 years, the Namibian diamondiferous marine placer has been studied extensively to develop solutions for mining and sampling challenges. The types of studies include the statistical modelling of the distributions of the stone counts per sample; investigating the relationship between geology and the grade distribution; assessing the quality potential of the entrapment of the available diamond pulse; using predetermined acceptability of barren samples (zero proportion (Zp) samples) to model distributions; optimal sample sizes; and more. During early-stage project evaluation it is more important to find out if a particular area is likely to be above a specific cut-off grade than to focus on sampling for the purpose of accurate resource estimation. Previous work using mixed Poisson and Sichel distributions to model the abundant onshore diamond data has been very successful in modelling the long-tailed nature of these linear beach deposits. The means of these distributions are, however, sensitive to extreme values. Technical and cost constraints prevent a similar scale of sample collection in an adjacent, geologically equivalent, submerged beach environment. A method not sensitive to extreme values is thus required to make early-stage assessments of the likelihood that the grade of a particular target is above a minimum cut-off grade. The Nachman model describes the functional relationship between the mean population density and proportion of barren patches ( Zp) in a patchy environment. A prerequisite for using the Nachman model is that the underlying data must be modelled using a negative binomial distribution (NBD). The case study data is from an analogous area adjacent to the exploration target and meets the NBD requirement. It is thus appropriate to apply the Nachman model. The Nachman model provides an opportunity to use the observed Zpto predict the mean grade for an area at the very early stage of an exploration project. In future, early-stage exploration data from a homogenous geological zone exhibiting characteristics of the Nachman model assumptions can thus be used to rank and target those areas that show potential to be above the minimum required grade cut-off for follow-up sampling and inclusion in the mine planning cycle.
DS1983-0523
1983
Prins, J.F.Prins, J.F.Electrical Resistance of Diamond Implanted at Liquid Nitrogen Temperature with Carbon Ions.Radiation Effects, Vol. 76, No. 3, PP. 79-82.GlobalExperimental Studies, Mineralogy
DS1975-0839
1978
Prins, P.Prins, P.Geochemical Aspects of the Alkaline Carbonatite Complexes Of Damaraland, Southwest Africa.I Symposio International De Carbonatitos, PP. 179-188.Southwest Africa, NamibiaPetrology, Fenitization
DS1981-0342
1981
Prins, P.Prins, P.The Geochemical Evolution of the Alkaline and Carbonatite Complexes of the Damaral and Igneous Province, Southwest Africa.Annale Universiteit Van Stellenbosch, Serie A, Thesis, No. 3, PP. 145-278.Southwest Africa, NamibiaGeochemistry
DS2000-0981
2000
Prins, P.Verwoerd, W.J., Retief, E.A., Prins, P.The Etanenberg alkaline complex, NamibiaJournal of African Earth Sciences, p. 86. abstract.NamibiaAlkaline rocks
DS1988-0555
1988
Prins. J.F.Prins. J.F.Improved activation of boron Dopant atoms imprinted into diamondNucl. Instrum. Methods Phys. Res. Sect. B., Vol. B35, No. 3-4, 12(II) pp. 484-487GlobalDiamond synthesis
DS1860-0949
1896
PrinsepPrinsepDiamond NullagineWestern Australia Geological Survey Report For 1895, P. 6; P. 27, P. 29.Australia, Western AustraliaDiamond Occurrence
DS1975-0549
1977
Printzlau, I.Kresten, P., Printzlau, I., Rex, D., Vartiainen, H., Woolley, A.New Ages of Carbonatite and Alkaline Ultramafic Rock from Southwest eden and Finland.Geol. Foren. Forhandl., Vol. 99, PP. 62-65.Sweden, Finland, ScandinaviaCarbonatite, Alnoite, Geochronology
DS1975-0165
1975
Prinz, M.Prinz, M., Manson, D.V., Hlava, P.F., Keil, K.Inclusions in Diamonds: Garnet Lherzolite and Eclogite Assemblages.Physics and Chemistry of the Earth., Vol. 9, PP. 797-815.South AfricaMineral Chemistry
DS1988-0556
1988
Prinz, M.Prinz, M.Evolution of ureilitesNature, Vol. 331, January 28, pp. 299-300GlobalMeteorite
DS1985-0547
1985
Prinzhofer, A.Prinzhofer, A., Allegre, C.J.Residual Peridotites and the Mechanism of Partial MeltingEarth and Planetary Science Letters, Vol. 74, pp. 251-265GlobalMantle
DS1992-1013
1992
Prior, D.Matthews, M., Harte, B., Prior, D.Mantle garnets - a cracking yarnGeochimica et Cosmochimica Acta, Vol. 56, No. 7, July pp. 2633-2642Lesotho, Southern AfricaMantle geochemistry, Garnets
DS1990-0846
1990
Prior, D.J.Knipe, R.J., Ritter, E.H., Agar, S.M., Prior, D.J., Law, R.D.Deformation mechanisms, rheology and tectonicsGeological Society of London Special Publication, No. 54, 520pGlobalRock deformation, fracture, faulting, flow mechanisms, Flow laws, rock fabrics, tectonics
DS1991-1005
1991
Prior, D.J.Lloyd, G.E., Schmidt, N.H., Mainprice, D., Prior, D.J.Crystallographic texturesMineralogical Magazine, Vol. 55, pp. 331-345GlobalTextures, Crystallography -review not specific to diamonds
DS2000-0782
2000
Prior, D.J.Prior, D.J., Wheeler, J., Brenker, F. Harte, MatthewsCrystal plasticity of natural garnet: new microstructural evidenceGeology, Vol. 28, No. 1, Nov. pp. 1003-6.MantleGarnets, xenoliths, kelphite, Microscopy
DS200612-1383
2005
Prior, D.J.Storey, C.D., Prior, D.J.Plastic deformation and recrystallization of garnet: a mechanism to facilitate diffusion creep.Journal of Petrology, Vol. 46, 12, pp. 2593-2613.MantleMetasomatism
DS201809-2001
2018
Prior, D.J.Brenker, F.E., Koch, T.E., Prior, D.J., Lilly, K., Krot, A.N., Bizzarro, M., Frost, D.Fe rich Ferropericlase in super deep diamonds and the stability of high FeO wadsleyite. Implications on the composition and temperature of the Earth's transition zone.Goldschmidt Conference, 1p. AbstractMantlediamond inclusions

Abstract: The high amount of Fe-rich ferropericlase inclusions found in diamonds of a potential super-deep origin questions the bulk chemical model of the Earth [e.g., 1]. Although this might be due to a biased sampling of the lower mantle, it is worth to further address this discrepancy. A limiting factor of the Fe-content of the Earth´s deep mantle (TZ and lower mantle) is a correlation of the depths of the observed main mantle discontinuities with the (Fe,Mg)SiO4 phase diagram. In particular, the 520 kmdiscontinuity is related to the phase transformation of wadsleyite (assuming Fa10) to ringwoodite. The existing phase diagrams suggest a stability limit of wadsleyite ?Fa40 [e.g., 2,3], which limits the Fe-content of the Earth´s transition zone. Here we report on a discovery of Fe-rich wadsleyite grains (up to Fa56) in the high-pressure silicate melt droplets within Fe,Ni-metal in shock veins of the CB (Bencubbin-like) metal-rich carbonaceous chondrite QC 001 [4], which were identified using HR-EDX, nano-EBSD and TEM. Although the existence of such Fe-rich wadsleyite in shock veins may be due to the kinetic reasons, new theoretical and experimental studies of the stability of (Fe,Mg)SiO4 at high temperature (> 1800 K) are clearly needed. This may have significant impact on the temperature and chemical estimates of the Earth´s transition zone.
DS200612-1362
2006
Prior, G.Stachel, T., Paulen, R., Prior, G., Micea, C., Cubbing, M., McConnell, GlennDiamond exploration in western sedimentary basin ( glacial processes, till sampling, geophysics)Calgary Mining Forum, April 28 Short Course # 3, NOTICE only meg.calgary.ab.caCanada, AlbertaExploration - program
DS2003-0404
2003
Prior, G.J.Fenton, M.M., Pawlowicz, J.G., Paulen, R.C., Prior, G.J., Olsen, R.A.Quaternary geology of northern Alberta: implications for kimberlite exploration8 Ikc Www.venuewest.com/8ikc/program.htm, Session 8, POSTER abstractAlbertaBlank
DS200412-0547
2003
Prior, G.J.Fenton, M.M., Pawlowicz, J.G., Paulen, R.C., Prior, G.J., Olsen, R.A.Quaternary geology of northern Alberta: implications for kimberlite exploration.8 IKC Program, Session 8, POSTER abstractCanada, AlbertaDiamond exploration
DS200612-1113
2006
Prior, G.J.Prior, G.J., McCurdy, M.W., Friske, P.W.B., Pawlowicz, S.J.A.,Day, R.J.Mc.Preliminary release of kimberlite indicator mineral dat a from National geochemical Reconnaissance stream sediment samples in the Jackpine Lake area Buffalo Head HillsGeological Survey of Canada Open File, 5267, 23p. 1 CD $ 26.00Canada, AlbertaGeochemistry
DS200712-0705
2006
Prior, G.J.McCurdy, M.W., Prior, G.J., Friske, P.W.B., McNeil, R.J., Day, S.J.A., Nicholl, T.J.Geochemical, mineralogical and kimberlite indicator mineral electron microprobe dat a from sills, heavy mineral concentrates and waters Buffalo Head Hills.Geological Survey of Canada Open File, No. 5057, 16p.Canada, AlbertaGeochemistry
DS201012-0600
2009
Prior, G.J.Prior, G.J., McCurdy, M.W., Friske, P.W.B.Stream sediment sampling for kimberlite indicator minerals in the western Canada sedimentary basin: the Buffalo Head Hills Survey, north central Alberta.Geological Association of Canada Short Course, No. 18, pp. 111-124.Canada, AlbertaGeochemistry, technology
DS1910-0084
1910
Prior, P.Prior, P.Die Diamanten D.s.w.aSenk. Naturf. Ges. (frankfurt) Abh., Vol. 41, PP. 133-141.Southwest Africa, NamibiaGeology, Marine Diamond Placers
DS1985-0548
1985
Pripachkin, V.A.Pripachkin, V.A., Pavlova, M.A., Galakhova, T.N., et al.Bitumens of Khibini CarbonatitesDoklady Academy of Sciences Nauk SSSR., Vol. 281, No. 6, PP. 1424-1426.RussiaBlank
DS1986-0655
1986
Pripachkin, V.A.Pripachkin, V.A., Pavlova, N.A., Galakhova, T.N., VolokhovaBitumens in carbonatites of the KhibinyDoklady Academy of Science USSR, Earth Science Section, Vol. 281, No. 1-6, November pp. 137-140RussiaCarbonatite
DS1994-0094
1994
Pripachkin, V.A.Balaganskaya, Ye.G., Pripachkin, V.A.Petrological and geochemical features of breccias at the Khibiny apatite-nepheline deposits.Geochemistry International, Vol. 31, No. 3, pp. 124-142.RussiaAlkaline rocks
DS1982-0070
1982
Prishchepa, V.I.Argunov, K.P., Zuyev, V.M., Nikiforova, T.M., Prishchepa, V.I.Sculptures of Corrosion of Crystal Regeneration in DiamondsMineral. Zhurnal, Vol. 4, No. 3, PP. 66-70.RussiaMineralogy, Surface Defects
DS202007-1172
2020
Prissel, K.B.Prissel, K.B., Krawcznski, M.J., Van Orman, J.A.Fe-Mg and Fe-Mn interdiffusion in ilmenite with implications for geospeedometry using oxides. ( mentions kimberlites)Contributions to Mineralogy and Petrology, Vol. 175, 62 17p. PdfMantleilmenite

Abstract: The Fe-Mg and Fe-Mn interdiffusion coefficients for ilmenite have been determined as a function of temperature and crystallographic orientation. Diffusion annealing experiments were conducted at 1.5 GPa between 800 and 1100 ?C. For Fe-Mg interdiffusion, each diffusion couple consisted of an ilmenite polycrystal and an oriented single crystal of geikielite. The activation energy (Q) and pre-exponential factor (D0) for Fe-Mg diffusion in the ilmenite polycrystal were found to be Q = 188±15 kJ mol?1 and logD0 = ?6.0±0.6 m2 s?1. For the geikielite single crystal, Fe-Mg interdiffusion has Q=220±16 kJ mol?1 and logD0=?4.6±0.7 m2 s?1. Our results indicate that crystallographic orientation did not significantly affect diffusion rates. For Fe-Mn interdiffusion, each diffusion couple consisted of one ilmenite polycrystal and one Mn-bearing ilmenite polycrystal. For Fe-Mn interdiffusion, Q = 264±30 kJ mol?1 and logD0 = ?2.9±1.3 m2 s?1 in the ilmenite. We did not find a significant concentration dependence for the Fe-Mg and Fe-Mn interdiffusion coefficients. In comparing our experimental results for cation diffusion in ilmenite with those previously reported for hematite, we have determined that cation diffusion is faster in ilmenite than in hematite at temperatures <1100 ?C. At oxygen fugacities near the wüstite-magnetite buffer, Fe and Mn diffusion rates are similar for ilmenite and titanomagnetite. We apply these experimentally determined cation diffusion rates to disequilibrium observed in ilmenites from natural volcanic samples to estimate the time between perturbation and eruption for the Bishop Tuff, Fish Canyon Tuff, Mt. Unzen, Mt. St. Helens, and kimberlites. When integrated with natural observations of chemically zoned ilmenite and constraints on pre-eruptive temperature and grain size, our experimentally determined diffusivities for ilmenite can be used to estimate a minimum time between magmatic perturbation and eruption on the timescale of hours to months.
DS1860-1043
1898
Prister, A.Prister, A.Note on Dr. Molengraaff's Paper of 1898 on Diamonds at Rietfontein. PremierGeological Society of South Africa Transactions, Vol. 3, PT. 2, P. 150.Africa, South Africa, TransvaalAlluvial Placers
DS1860-1097
1899
Prister, A.Prister, A.Notes on the Paper by Alison Entitled Origin and Formation Of Pans #1Geological Society of South Africa Transactions, Vol. 4, PP. 167-168.Africa, South AfricaGeomorphology
DS1993-1265
1993
Pritchar, P.C.Pritchar, P.C.Undiscovered diamonds for the crown jewelsOceanus, Vol. 36, No. 3, Fall, pp. 3-6. # MH627GlobalHistory
DS201605-0885
2016
Pritchard, M.E.Pritchard, M.E., Gregg, P.M.Enigmatic relationship between silicic and volcanic and plutonic rocks: geophysical evidence for silicic crustal melt in the continents: where. What kind, and how much?Elements, Vol. 12, pp. 121-127.TechnologyGeophysics
DS1995-0063
1995
Pritchard, R.A.Ash, W.M., Pritchard, R.A., Walker, R.T.Metallic and industrial mineral assessment report on the Pinhorn and Black Butte diamond/gold prop. Milk R.Alberta Geological Survey, MIN 19950022AlbertaExploration - assessment, Marum Resources
DS200512-1152
2002
Prithodko, V.S.Voltnova, I.P., Prithodko, V.S.Meymechites in central Sikhote Alin.Deep Seated Magmatism, magmatism sources and the problem of plumes., pp. 223-229.RussiaMeymechites
DS201312-0520
2013
Priya, R.Kumar, A., Ahmed, S., Priya, R., Sridhar, M.Discovery of lamproites near Vattikod area, nw margin of the Cuddapah basin, eastern Dharwar craton, southern India.Journal of the Geological Society of India, Vol. 82, 4, pp. 307-312.IndiaLamproite
DS201412-0714
2014
Priyatkina, N.Priyatkina, N., Khudoley, A.K., Ustinov, V.N., Kullerud, K.1.92 Ga kimberlitic rocks from Kimozero, NW Russia: their geochemistry tectonic setting and unusual field occurrence.Precambrian Research, Vol. 249, pp. 162-179.RussiaDeposit - Kimozero
DS1960-0288
1962
Prizhimova, L.P.Prizhimova, L.P.Geological and Petrographical Characteristics of Paleozoic Carbonate rocks in Thwe Muna Kimberlite Pipe Region.Trudy Iafan Sssr Transactions Geol. Series, No. 8, PP. 90-111.RussiaKimberlite
DS201312-0371
2013
Prmentier, E.M.Havlin, C., Prmentier, E.M., Hirth, G.Mineral associations in diamonds from the lowermost upper mantle and uppermost lower mantle.Earth and Planetary Science Letters, Vol. 376, pp. 20-28.MantleMelting
DS200812-0925
2007
Prno, J.Prno, J.Have IBA's worked ( impact and benefit agreements).Canadian Diamonds, Fall, pp. 33-36, 38,40.CanadaLegal - IBA
DS1994-1414
1994
Proceedings of the Indian Academy of SciencesProceedings of the Indian Academy of SciencesSecond symposium on the structure and properties of diamondProceedings Indian Acad. Sciences, Vol 24, No. A, No. 1, July ppIndiaBackground reference missed, Diamond morphology
DS1982-0509
1982
Proctor, P.D.Proctor, P.D., Koenig, J.W.Selected Structural Basins of the Midcontinent, United States (us)U.m.r. Journal, No. 3, University MISSOURI, ROLLA, 120P.GlobalMid-continent
DS1993-1146
1993
Proctor, R.J.Nuhfer, E.B., Proctor, R.J., Moser, P.H.The citizen's guide to geologic hazardsAmerican Institute of Professional Geologists, 134p. $ 20.00United StatesBook review, Geological hazards
DS2002-1284
2002
Proctor, R.N.Proctor, R.N.Anti-agate: the great diamond hoax and the semi precious stone scamConfigurations, Vol.9,3,pp. 381-412. Ingenta 1017050146GlobalHistory
DS200512-0503
2005
ProdehlKeller, G.R., Karlstrom, K.E., Williams, M.L., Miller, K.C., Andronicos, C., Levander, A.R., Snelson, ProdehlThe dynamic nature of the continental crust-mantle boundary: crustal evolution in the southern Rocky Mountain region as an example.American Geophysical Union, Geophysical Monograph, No. 154, pp. 403-420.United States,Wyoming, Colorado PlateauTectonics
DS1995-0196
1995
Prodehl, C.Braile, L.W., Keller, G.R., Mueller, S., Prodehl, C.Methods of investigation: seismic techniquesContinental Rifts: evolution, structure, tectonics, No. 25, pp. 61-92North AmericaSeismics -reflection, refraction
DS1995-0197
1995
Prodehl, C.Braile, L.W., Keller, G.R., Mueller, S., Prodehl, C.Methods of investigation: seismic techniquesContinental Rifts: evolution, structure, tectonics, No. 25, pp. 61-92.North AmericaSeismics -reflection, refraction
DS1995-1525
1995
Prodehl, C.Prodehl, C.The lithosphere beneath the Afro-Arabian rift systemGeological Society Africa 10th. Conference Oct. Nairobi, pp. 140-1. Abstract.KenyaTectonics, East African Rift
DS1995-1526
1995
Prodehl, C.Prodehl, C., Mueller, St., Haak, V.The European Cenozoic rift systemContinental Rifts: evolution, structure, tectonics, No. 25, pp. 133-212.EuropeGeophysics -seismics, magnetics, gravity, Heat flow, structure
DS1997-0928
1997
Prodehl, C.Prodehl, C., Fuchs, K., Mechie, J.Seismic-refraction studies of the Afri-Arabian rift system - a briefreview.Tectonophysics, Vol. 278, No. 1-4, Sept. 15, pp. 1-14.AfricaTectonics, Rifting
DS2000-0783
2000
Prodehl, C.Prodehl, C.The lithospheric structure of the Kenya rift from wide angle seismic measurements (KRISP).Journal of African Earth Sciences, p. 71. abstract.KenyaTectonics - rifting
DS200512-1011
2005
Prodehl, C.Snelson, C.M., Keller, G.R., Miller, K.C., Rumpel, H.M., Prodehl, C.Regional crustal structure derived from the CD-ROM 99 Seismic Refraction/Wide Angle Reflection Profile: the lower crust and upper mantle.American Geophysical Union, Geophysical Monograph, No. 154, pp. 271-292.United States,Wyoming, Colorado PlateauGeophysics - seismics, tectonics
DS201312-0322
2013
Proenza, J.A.Gonzalez-Jimienez, J.M., Griffin, W.L., Gervilla, F., Proenza, J.A., O'Reilly, S.Y., Pearson, N.J.Chromitites in ophiolites: how, where, when, why? Part 1. A review of new ideas on the origin and significance of platinum-group minerals.Lithos, Vol. 189, pp. 127-139.MantleGeodynamics
DS201711-2514
2017
Proenza, J.A.Gonzalez-Jimenez, J.M., Camprubi, A., Colas, V., Griffin, W.L., Proenza, J.A., O'Reilly, S.Y., Centeno-Garcia, El., Garcia-Casco, A., Belousova, E., Talavera, C., Farre-de-Pablo, J., Satsukawa, T.The recycling of chromitites in ophiolites from southwestern North America. ( Baja)Lithos, in press available, 52p.United States, Californiachromitites

Abstract: Podiform chromitites occur in mantle peridotites of the Late Triassic Puerto Nuevo Ophiolite, Baja California Sur State, Mexico. These are high-Cr chromitites [Cr# (Cr/Cr + Al atomic ratio = 0.61-0.69)] that contain a range of minor- and trace-elements and show whole-rock enrichment in IPGE (Os, Ir, Ru). That are similar to those of high-Cr ophiolitic chromitites crystallised from melts similar to high-Mg island-arc tholeiites (IAT) and boninites in supra-subduction-zone mantle wedges. Crystallisation of these chromitites from S-undersaturated melts is consistent with the presence of abundant inclusions of platinum-group minerals (PGM) such as laurite (RuS2)-erlichmanite (OsS2), osmium and irarsite (IrAsS) in chromite, that yield TMA ? TRD model ages peaking at ~ 325 Ma. Thirty-three xenocrystic zircons recovered from mineral concentrates of these chromitites yield ages (2263 ± 44 Ma to 278 ± 4 Ma) and Hf-O compositions [?Hf(t) = ? 18.7 to + 9.1 and 18O values < 12.4‰] that broadly match those of zircons reported in nearby exposed crustal blocks of southwestern North America. We interpret these chromitite zircons as remnants of partly digested continental crust or continent-derived sediments on oceanic crust delivered into the mantle via subduction. They were captured by the parental melts of the chromitites when the latter formed in a supra-subduction zone mantle wedge polluted with crustal material. In addition, the Puerto Nuevo chromites have clinopyroxene lamellae with preferred crystallographic orientation, which we interpret as evidence that chromitites have experienced high-temperature and ultra high-pressure conditions (< 12 GPa and ~ 1600 °C). We propose a tectonic scenario that involves the formation of chromitite in the supra-subduction zone mantle wedge underlying the Vizcaino intra-oceanic arc ca. 250 Ma ago, deep-mantle recycling, and subsequent diapiric exhumation in the intra-oceanic basin (the San Hipólito marginal sea) generated during an extensional stage of the Vizcaino intra-oceanic arc ca. 221 Ma ago. The TRD ages at ~ 325 Ma record a partial melting event in the mantle prior to the construction of the Vizcaino intra-oceanic arc, which is probably related to the Permian continental subduction, dated at ~ 311 Ma.
DS201902-0270
2018
Proenza, J.A.Farre-de-Pablo, J., Proenza, J.A., Gonzales-Jimenez, J.M., Garcia-Casco, A., Colas, V., Roque-Rossell, J., Camprubi, A., Sanchez-Navas, A.A shallow origin for diamonds in ophiolitic chromitites.Geology, Vol. 46, pp. 75-78.Mexico, Pueblaophiolite

Abstract: Recent findings of diamonds in ophiolitic peridotites and chromitites challenge our traditional notion of Earth mantle dynamics. Models attempting to explain these findings involve incorporation of diamonds into chromite near the mantle transition zone. However, the occurrence of metastable diamonds in this context has not been considered. Here, we report for the first time in situ microdiamonds in chromite from ophiolitic chromitite pods hosted in the Tehuitzingo serpentinite (southern Mexico). Here, diamonds occur as fracture-filling inclusions along with quartz, clinochlore, serpentine, and amorphous carbon, thus indicating a secondary origin during the shallow hydration of chromitite. Chromite chemical variations across the diamond-bearing healed fractures indicate formation during the retrograde evolution of chromitite at temperatures between 670 °C and 515 °C. During this stage, diamond precipitated metastably at low pressure from reduced C-O-H fluids that infiltrated from the host peridotite at the onset of serpentinization processes. Diamond was preserved as a result of fracture healing at the same temperature interval in which the chromite alteration began. These mechanisms of diamond formation challenge the idea that the occurrence of diamond in ophiolitic rocks constitutes an unequivocal indicator of ultrahigh-pressure conditions.
DS201909-2038
2019
Proenza, J.A.Farre-de-Pblo, J., Proenza, J.A., Gonzalez-Jiminez, J.M., Garcia-Casco, A., Colas, V., Roque-Rosell, J., Camprubi, A., Sanchez-Navas, A.A shallow origin for diamonds in ophiolitic chromitites. Geology, Vol. 47, pp. e477-478.North America, Mexicomicrodiamonds

Abstract: Recent findings of diamonds in ophiolitic peridotites and chromitites challenge our traditional notion of Earth mantle dynamics. Models attempting to explain these findings involve incorporation of diamonds into chromite near the mantle transition zone. However, the occurrence of metastable diamonds in this context has not been considered. Here, we report for the first time in situ microdiamonds in chromite from ophiolitic chromitite pods hosted in the Tehuitzingo serpentinite (southern Mexico). Here, diamonds occur as fracture-filling inclusions along with quartz, clinochlore, serpentine, and amorphous carbon, thus indicating a secondary origin during the shallow hydration of chromitite. Chromite chemical variations across the diamond-bearing healed fractures indicate formation during the retrograde evolution of chromitite at temperatures between 670 °C and 515 °C. During this stage, diamond precipitated metastably at low pressure from reduced C-O-H fluids that infiltrated from the host peridotite at the onset of serpentinization processes. Diamond was preserved as a result of fracture healing at the same temperature interval in which the chromite alteration began. These mechanisms of diamond formation challenge the idea that the occurrence of diamond in ophiolitic rocks constitutes an unequivocal indicator of ultrahigh-pressure conditions.
DS202008-1396
2020
Proenza, J.A.Gonzales-Jiminez, J.M., Tassara, S., Schettino, E., Roque-Rosell, J., Farre-de-Pablo, J., Saunders, J.E., Deditius, A.P., Colas, V., Rovira-Medina, J.J., Guadalupe Davalos, M., Schilling, M., Jiminez-Franco, A., Marchesi, C., Nieto, F., Proenza, J.A., GerMineralogy of the HSE in the subcontinental lithospheric mantle - an interpretive review.Lithos, in press available, 44p. PdfMantleHSE

Abstract: The highly siderophile elements (HSE: Os, Ir, Ru, Rh, Pt, Pd, Re, Au) exist in solid solution in accessory base-metal sulfides (BMS) as well as nano-to-micron scale minerals in rocks of the subcontinental lithospheric mantle (SCLM). The latter include platinum-group minerals (PGM) and gold minerals, which may vary widely in morphology, composition and distribution. The PGM form isolated grains often associated with larger BMS hosted in residual olivine, located at interstices in between peridotite-forming minerals or more commonly in association with metasomatic minerals (pyroxenes, carbonates, phosphates) and silicate glasses in some peridotite xenoliths. The PGM found inside residual olivine are mainly Os-, Ir- and Ru-rich sulfides and alloys. In contrast, those associated with metasomatic minerals or silicate glasses of peridotite xenoliths consist of Pt, Pd, and Rh bonded with semimetals like As, Te, Bi, and Sn. Nanoscale observations on natural samples along with the results of recent experiments indicate that nucleation of PGM is mainly related with the uptake of HSE by nanoparticles, nanominerals or nanomelts at high temperature (> 900?°C) in both silicate and/or sulfide melts, regardless of the residual or metasomatic origin of their host minerals. A similar interpretation can be assumed for gold minerals. Our observations highlight that nanoscale processes play an important role on the ore-forming potential of primitive mantle-derived magmas parental to magmatic-hydrothermal deposits enriched in noble metals. The metal inventory in these magmas could be related with the physical incorporation of HSE-bearing nanoparticles or nanomelts during processes of partial melting of mantle peridotite and melt migration from the mantle to overlying continental crust.
DS202010-1869
2020
Proenza, J.A.Pujol-Sola, N., Garcia-Casco, A., Proenza, J.A., Gonzalez-Jiminez, J.M., del Camp, A., Colas, V., Canals, A., Sanchez-Navas, A., Roque-Rosell, J.Diamond forms during low pressure serpentinisation of oceanic lithosphere.Geochemical Perspectives Letters, 7p. PdfCentral America, Cubadiamond genesis

Abstract: Diamond is commonly regarded as an indicator of ultra-high pressure conditions in Earth System Science. This canonical view is challenged by recent data and interpretations that suggest metastable growth of diamond in low pressure environments. One such environment is serpentinisation of oceanic lithosphere, which produces highly reduced CH4-bearing fluids after olivine alteration by reaction with infiltrating fluids. Here we report the first ever observed in situ diamond within olivine-hosted, CH4-rich fluid inclusions from low pressure oceanic gabbro and chromitite samples from the Moa-Baracoa ophiolitic massif, eastern Cuba. Diamond is encapsulated in voids below the polished mineral surface forming a typical serpentinisation array, with methane, serpentine and magnetite, providing definitive evidence for its metastable growth upon low temperature and low pressure alteration of oceanic lithosphere and super-reduction of infiltrated fluids. Thermodynamic modelling of the observed solid and fluid assemblage at a reference P-T point appropriate for serpentinisation (350 °C and 100 MPa) is consistent with extreme reduction of the fluid to logfO2 (MPa) = ?45.3 (?logfO2[Iron-Magnetite] = ?6.5). These findings imply that the formation of metastable diamond at low pressure in serpentinised olivine is a widespread process in modern and ancient oceanic lithosphere, questioning a generalised ultra-high pressure origin for ophiolitic diamond.
DS202106-0965
2021
Proenza, J.A.Pujol-Sola, N., Dominguez-Carretero, D., Proenza, J.A., Haissen, F., Ikenne, M., Gonzales-Jiminez, J.M., Colas, V., Maacha, L., Garcia-Casco, A.The chromitites of the Neoproterozoic Bou Azzer ophiolite ( central Anti-Atlas, Morocco) revisited.Ore Geology Reviews, Vol. 134, 104166, 24p. PdfAfrica, Moroccomoissanite

Abstract: The Neoproterozoic Bou Azzer ophiolite in the Moroccan Anti-Atlas Panafrican belt hosts numerous chromitite orebodies within the peridotite section of the oceanic mantle. The chromitites are strongly affected by serpentinization and metamorphism, although they still preserve igneous relicts amenable for petrogenetic interpretation. The major, minor and trace element composition of unaltered chromite cores reveal two compositional groups: intermediate-Cr (Cr# = 0.60 - 0.74) and high-Cr (Cr# = 0.79 - 0.84) and estimates of parental melt compositions suggest crystallization from pulses of fore-arc basalts (FAB) and boninitic melts, respectively, that infiltrated the oceanic supra-subduction zone (SSZ) mantle. A platinum group elements (PGE) mineralization dominated by Ir-Ru-Os is recognized in the chromitites, which has its mineralogical expression in abundant inclusions of Os-Ir alloys and coexisting magmatic laurite (RuS2) and their products of metamorphic alteration. Unusual mineral phases in chromite, not previously reported in this ophiolite, include super-reduced and/or nominally ultra-high pressure minerals moissanite (SiC), native Cu and silicates (oriented clinopyroxene lamellae), but “exotic” zircon and diaspore have also been identified. We interpret that clinopyroxene lamellae have a magmatic origin, whereas super-reduced phases originated during serpentinization processes and diaspore is linked to late circulation of low-silica fluids related to rodingitization. Zircon grains, on the other hand, with apatite and serpentine inclusions, could either have formed after the interaction of chromitite with mantle-derived melts or could represent subducted detrital sediments later incorporated into the chromitites. We offer a comparison of the Bou Azzer chromitites with other Precambrian ophiolitic chromitites worldwide, which are rather scarce in the geological record. The studied chromitites are very similar to the Neoproterozoic chromitites reported in the Arabian-Nubian shield, which are also related to the Panafrican orogeny. Thus, we conclude that the Bou Azzer chromitites formed in a subduction-initiation geodynamic setting with two-stages of evolution, with formation of FAB-derived intermediate-Cr chromitites in the early stage and formation of boninite-derived high-Cr chromitites in the late stage.
DS201012-0209
2010
Proenza, Y.Francis, D., Minarik, W., Proenza, Y., Shi, L.An overview of the Canadian Cordilleran lithospheric mantle.Canadian Journal of Earth Sciences, Vol. 47, 4, pp. 353-368.Canada, British ColumbiaGeophysics - seismic
DS201112-0829
2010
Professional Jeweller.comProfessional Jeweller.comThe unedited Wikileaks diamond cable ... Regime elites looting deadly diamond field. ChiadzwaProfessional Jeweller.com, Dec. 15, 5p.Africa, ZimbabweNews item - legal
DS2000-0235
2000
ProfetDilles, J.H., Barton, Johnson, Profet, EinaudiContrasting styles of intrusion associated hydrothermal systemsSociety of Economic Geologists Guidebook, Vol. 32, 160p.NevadaBook - table of contents, Deposit - Tin Creeks, Getchell, Pinson
DS2002-1315
2002
ProkofevRazvozzhaeva, E.A., Prokofev, Spiridonov, MartikhaevPrecious metals and carbonaceous substance in ores of the Sukhoi Log deposit, Eastern Siberia, Russia.Geology of Ore Deposits, Vol.44,2,pp. 103-110.RussiaGold, carbon, metallogeny, Deposit - Sukhoi Log
DS201412-0490
2014
Prokofev, A.Kuskov, O., Kronrod, V., Prokofev, A., Pavlenkova, N.Petrological -geophysical models of the internal structure of the lithospheric mantle of the Siberian craton.Petrology, Vol. 22, 1, pp. 17-44.RussiaGeophysics - geodynamics
DS200512-0878
2005
Prokofev, V.Y.Prokofev, V.Y., Seredkin, M.V., Zotov, I.A., Anoshechkina, V.A.Genesis of magnetite apatite and phlogopite deposits in the Kovdor Massif, Kola Peninsula: evidence from melt and fluid inclusions.Doklady Earth Sciences, Vol. 403, 5, pp. 727-731.Russia, Kola PeninsulaAlkalic
DS201112-0830
2011
Prokofev, V.Yu.Prokofev, V.Yu., Smirnov, S.Z.Research in fluid inclusions in minerals: current state and future outlook. Third biennial conference on fluid inclusions held Sept. 2010. discussion of papers...Geology of Ore Deposits, Vol. 53, 2, pp. 171-176.GlobalDiamond inclusions mentioned
DS201412-0491
2014
Prokofyev, A.A.Kuskov, O.L., Kronrod, V.A., Prokofyev, A.A., Pavlenkova, N.I.Thermo-chemical structure of the lithospheric mantle underneath the Siberian craton inferred from long-range seismic profiles.Tectonophysics, Vol. 615-616, pp. 154-166.Russia, SiberiaGeothermometry
DS1992-1236
1992
Prokofyev, V.Yu.Prokofyev, V.Yu., Vorobyev, Ye.I.P-T formation conditions for Sr-Ba carbonatites, charoite rocks and torgolites in the Murun Alkali intrusion, East Siberia.Geochemistry International, Vol. 29, No. 5, pp. 83-92.Russia, SiberiaCarbonatite, Charoite
DS1981-0343
1981
Prokopchuk, B.Prokopchuk, B., Melelkina, M.P., et al.Two Types of Initial Sources of Precambrian DiamondsIzd. Nauka Kaz. Sssr, Alma-ata, Litologiya I Osadochnaya Geo, PP. 25-26.RussiaDiamond Genesis
DS1960-0265
1962
Prokopchuk, B.I.Leonov, B.N., Prokopchuk, B.I.Problem of the Age of the Kimberlites in Northeastern Siberian PlatformIn: Data of Regional Geology of The Siberian Platform And It, TRUDY VSES AEROGEOL. TRESTA, No. 8, PP. 80-84.RussiaBlank
DS1960-0397
1963
Prokopchuk, B.I.Sibirtzev, YU. M., Prokopchuk, B.I.New Dat a on the Age of the Kimberlites of the Northeastern Part of the Siberian Platform (kuoyko Ri Basin).French Geological Survey (BRGM) TRANSLATION., RussiaBlank
DS1960-0488
1964
Prokopchuk, B.I.Prokopchuk, B.I.The First Diamond Find in the Callovian Deposits of the Northeastern Siberian PlatformAkad. Nauk. Ussr Izv. Ser. Geol., No. 9.RussiaKimberlite
DS1960-0698
1966
Prokopchuk, B.I.Leonov, B.N., Prokopchuk, B.I., Orlov, I.L.Almazy-prilenskoy OblastiMoscow: Nauka., 278P.RussiaDiamonds, Kimberley
DS1960-0948
1968
Prokopchuk, B.I.Frantsesson, YE. V., Prokopchuk, B.I.Kimberlites, a Tectonomagmatic Facies of the Alkaline Ultramafic Associations of the Platforms Based on a Study of the Siberian PlatformIn: Volcanism And Tectogenesis. International Geological Congress 23rd., PP. 159-163.RussiaBlank
DS1960-1192
1969
Prokopchuk, B.I.Prokopchuk, B.I.Conditions Necssary for the Formation of Rich Alluvial Diamond Placers in Western Yakutia As Illustrated by the Ebelyakh Channel Placer.Doklady Academy of Science USSR, Earth Science Section., Vol. 189, No. 1-6, PP. 201-203.RussiaKimberlite
DS1970-0806
1973
Prokopchuk, B.I.Prokopchuk, B.I.Zoning in the Distribution of Diamond Placers on Old PlatformsDoklady Academy of Sciences, Vol. 212, pp. 100-2.RussiaAlluvials, Placers, Syungyude Uplift
DS1970-0807
1973
Prokopchuk, B.I.Prokopchuk, B.I., Frantsesson, YE.V., Kaminskiy, F.V.Conference on the Principles and Methodology of Prospecting for Diamonds.Soviet Geology, No. 5, PP. 153-154.Russia, YakutiaKimberlite, Geophysics
DS1975-0386
1976
Prokopchuk, B.I.Prokopchuk, B.I., Trofimov, V.S., Levin, V.I.The Main Types of Diamond Deposits of Foreign CountriesSovetskaya Geologiya., No. 6, PP. 134-143.Russia, GlobalClassification
DS1983-0524
1983
Prokopchuk, B.I.Prokopchuk, B.I., Shofman, I.L., Bereza, V.P.An Attempt at Using the Quantitative Characteristics of The dynamics of Alluvium Accumulation in the Study of Placers.Soviet Geology and GEOPHYSICS, Vol. 24, No. 9, PP. 49-54.Russia, SiberiaDiamonds
DS1983-0525
1983
Prokopchuk, B.I.Prokopchuk, B.I., Shumilov, YU.V., Vazhenin, B.P.Experimental Dat a on Weathering of Kimberlite and its Behavior in Streams.Doklady Academy of Sciences ACAD. NAUK USSR EARTH SCI. SECTION., Vol. 261, No. 1-6, PP. 113-115.RussiaGeochemistry
DS1983-0593
1983
Prokopchuk, B.I.Taranenko, V.I., Prokopchuk, B.I., Yanygin, YU.T., Shapovalova.Paleogeomorphological Environment of Diamond Placer Genesis at the Southeastern Slope of the Tunguska Syneclise During The Late Paleozoic.Geomorfologiya., 1983 (2), PP. 48-53.RussiaGeomorphology, Alluvial Placers
DS1985-0508
1985
Prokopchuk, B.I.Ostrovskii, E.J., Prokopchuk, B.I., Ursov, A.A.Forecasting by Objectives in Search for KimberlitesDoklady Academy of Sciences AKAD. NAUK SSSR., Vol. 280, No. 3, PP. 705-707.RussiaProspecting
DS1985-0549
1985
Prokopchuk, B.I.Prokopchuk, B.I., Argunov, K.P., Boris, Y.I., Zazhardova, V.R.Seperation of Diamonds in Placer Deposits. (russian)Soviet Geology, (Russian), No. 3, pp. 43-57RussiaPlacers
DS1986-0624
1986
Prokopchuk, B.I.Ostrovskiy, E.J., Prokopchuk, B.I., Kantarov, R.S.Objective forecast based on differentiation of kimberlitepromisingareas. (Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 288, No. 6, pp. 958-961RussiaBlank
DS1986-0625
1986
Prokopchuk, B.I.Ostrovskiy, E.Ya., Prokopchuk, B.I., Ursov, A.A.Target forecasting in prospecting for kimberlite depositsDokl. Academy of Science Ussr Earth Science Section, Vol. 280, No. 3, pp. 72-73RussiaProspecting
DS1986-0656
1986
Prokopchuk, B.I.Prokopchuk, B.I., Tarasov, V.S., et al.Pyrope and chromium diopside in terrigenous formations of the Onega RiverBasin.(Russian)Zap. Vses. Mineral. Obsch.(Russian), Vol. 115, No. 1, pp. 83-86RussiaGarnet, Mineralogy
DS1986-0657
1986
Prokopchuk, B.I.Prokopchuk, B.I., Vagahov, V.I.From uncut diamonds to cut diamonds.(Russian)Nedra Moscow, (Russian), 126pRussiaDiamond cutting
DS1987-0559
1987
Prokopchuk, B.I.Ostrovskiy, E.Ya., Prokopchuk, B.I., Kontarovich, R.S.Zoning of kimberlite bearing areas by target forecastingDoklady Academy of Science USSR, Earth Science Section, Vol. 288, No. 1-6, pp. 78-81RussiaBlank
DS1987-0596
1987
Prokopchuk, B.I.Prokopchuk, B.I., Levin, V.I., Kolodko, A.A.Detrital quartz from kimberlitic rocks. (Russian)Litol. Polezn. Iskop., (Russian), No. 3, pp. 141-144RussiaBlank
DS1987-0597
1987
Prokopchuk, B.I.Prokopchuk, B.I., Levin, V.I., Metelkina, M.P., Shofman, I.L.Prospecting for sources of diamond placers based onunconventionalindicators.(Russian)Soviet Geology, (Russian), No. 6, pp. 41-49RussiaBlank
DS1987-0598
1987
Prokopchuk, B.I.Prokopchuk, B.I., Levin, V.I., Metelkina, M.P., Shofman, I.L.Prediction of diamond placers through the use of unconventionalindicators.(Russian)Soviet.Geol., (Russian), No. 6, pp. 41-49RussiaBlank
DS1989-0769
1989
Prokopchuk, B.I.Kharkiv, A.D., Prokopchuk, B.I.First find of titanoclinohumite in kimberlites of AfricaInternational Geology Review, Vol. 31, No. 2, pp. 180-185GlobalMineralogy
DS1997-0619
1997
Prokopchuk, S.I.Korbeinikov, A.F., Kravchenko, V.M., Prokopchuk, S.I.Geochemical background and anomalies of noble metals in Upper Archean volcanic Terrigenous formations...Geochemistry International, Vol. 34, No. 12, pp. 1032-40Russia, UkraineGreenstone belts, Aldan, Ukrainian shields
DS200612-0332
2005
Prokopenko, A.Didenko, A., Zverev, B., Prokopenko, A.Microwave fracturing and grinding of solid rocks by example of kimberlite.Doklady Physical Chemistry, Vol. 50, 7, pp. 349-350.TechnologyMining
DS201312-0731
2013
Prokoph, A.Rampino, M.R., Prokoph, A.Are mantle plumes periodic?EOS Transaction of AGU, Vol. 94, 12, March 19, pp. 113-120.MantlePlume cycles
DS2002-0487
2002
Prokopiev, A.V.Friodvsky, V.Y., Prokopiev, A.V.Tectonics, geodynamics and mineralization of the eastern margin of the North Asia Craton.Geological Society of London Special Publication, No. 204, pp. 299-318.AsiaTectonics - not specific to diamonds
DS200812-0926
2008
Prokopiev, A.V.Prokopiev, A.V., Toro, J., Miller, E.L., Gehrels, G.E.The paleo-Lena River - 200 m.y. of transcontinental zircon transport in Siberia.Geology, Vol. 36, 9, Sept. pp. 699-702.RussiaVerkhoyansk area
DS201312-0605
2013
Prokopiev, A.V.Miller, E.L., Solovev, A.V., Prokopiev, A.V., Toro, J., Harris, D., Kuzmichev, A.B., Gehrels, G.E.Triassic river systems and the paleo-Pacific margin of northwestern Pangea. Lena River systemGondwana Research, Vol. 23, 4, pp. 1631-1645.RussiaSource areas
DS201412-0021
2014
Prokopiev, S.A.Ashchepkov, I.V., Alymova, N.V., Lognova, A.M., Vladykin, N.V., Kuligin, S.S., Lityukhin, S.I., Downes, H., Stegnitsky, Yu.B., Prokopiev, S.A., Salikhov, R.F., Palessky, V.S., Khmelnikova, O.S.Picroilmenites in Yakutian kimberlites: variations and genetic models.Solid Earth, Vol. 5, pp. 915-938.Russia, YakutiaKimberlite genesis
DS201412-0022
2014
Prokopiev, S.A.Ashchepkov, I.V., Vladykin, N.N., Ntaflos, T., Kostrovitsky, S.I., Prokopiev, S.A., Downes, H., Smelov, A.P., Agashev, A.M., Logvinova, A.M., Kuligin, S.S., Tychkov, N.S., Salikhov, R.F., Stegnitsky, Yu.B., Alymova, N.V., Vavilov, M.A., Minin, V.A., BabusLayering of the lithospheric mantle beneath the Siberian Craton: modeling using thermobarometry of mantle xenolith and xenocrysts. Tectonophysics, Vol. 634, 5, pp. 55-75.Russia, YakutiaDaldyn, Alakit, Malo-Botuobinsky fields
DS202010-1829
2013
Prokopiev, S.A.Ashchepkov, I.V., Alymova, N.V., Loginova, A.M., Vladykin, N.V., Kuligin, S.S., Mityukhin, S.I., Stegnitsky, Y.B., Prokopiev, S.A., Salikhov, R.F., Palessky, V.S., Khmelnikova, O.S.Picroilmenites in Yakutian kimberlites: variations and genetic models. Solid Earth Discussions, Vol. 5, pp. 1-75. pdf * note dateRussia, Yakutiapicroilmenites

Abstract: Major and trace element variations in picroilmenites from Late Devonian kimberlite pipes in Siberia reveal similarities within the region in general, but show individual features for ilmenites from different fields and pipes. Empirical ilmenite thermobarometry (Ashchepkov et al., 2010), as well as common methods of mantle thermobarometry and trace element geochemical modeling, shows long compositional trends for the ilmenites. These are a result of complex processes of polybaric fractionation of protokimberlite melts, accompanied by the interaction with mantle wall rocks and dissolution of previous wall rock and metasomatic associations. Evolution of the parental magmas for the picroilmenites was determined for the three distinct phases of kimberlite activity from Yubileynaya and nearby Aprelskaya pipes, showing heating and an increase of Fe# (Fe# = Fe / (Fe + Mg) a.u.) of mantle peridotite minerals from stage to stage and splitting of the magmatic system in the final stages. High-pressure (5.5-7.0 GPa) Cr-bearing Mg-rich ilmenites (group 1) reflect the conditions of high-temperature metasomatic rocks at the base of the mantle lithosphere. Trace element patterns are enriched to 0.1-10/relative to primitive mantle (PM) and have flattened, spoon-like or S- or W-shaped rare earth element (REE) patterns with Pb > 1. These result from melting and crystallization in melt-feeding channels in the base of the lithosphere, where high-temperature dunites, harzburgites and pyroxenites were formed. Cr-poor ilmenite megacrysts (group 2) trace the high-temperature path of protokimberlites developed as result of fractional crystallization and wall rock assimilation during the creation of the feeder systems prior to the main kimberlite eruption. Inflections in ilmenite compositional trends probably reflect the mantle layering and pulsing melt intrusion during melt migration within the channels. Group 2 ilmenites have inclined REE enriched patterns (10-100)/PM with La / Ybn ~ 10-25, similar to those derived from kimberlites, with high-field-strength elements (HFSE) peaks (typical megacrysts). A series of similar patterns results from polybaric Assimilation + fractional crystallization (AFC) crystallization of protokimberlite melts which also precipitated sulfides (Pb < 1) and mixed with partial melts from garnet peridotites. Relatively low-Ti ilmenites with high-Cr content (group 3) probably crystallized in the metasomatic front under the rising protokimberlite source and represent the product of crystallization of segregated partial melts from metasomatic rocks. Cr-rich ilmenites are typical of veins and veinlets in peridotites crystallized from highly contaminated magma intruded into wall rocks in different levels within the mantle columns. Ilmenites which have the highest trace element contents (1000/PM) have REE patterns similar to those of perovskites. Low Cr contents suggest relatively closed system fractionation which occurred from the base of the lithosphere up to the garnet-spinel transition, according to monomineral thermobarometry for Mir and Dachnaya pipes. Restricted trends were detected for ilmenites from Udachnaya and most other pipes from the Daldyn-Alakit fields and other regions (Nakyn, Upper Muna and Prianabarie), where ilmenite trends extend from the base of the lithosphere mainly up to 4.0 GPa. Interaction of the megacryst forming melts with the mantle lithosphere caused heating and HFSE metasomatism prior to kimberlite eruption.
DS202112-1919
2021
Prokopiev, S.A.Ashchepkov, I.V., Alymova, N.V., Loginova, A.M., Vladykin, N.V.. Kuligin, S.S., Mityukhin, S.I., Stegnitsky, Y.B., Prokopiev, S.A.Picroilmenites in Yakutian kimberlites: variations and genetic models.Lithos, Vol. 406-407. doi: 10.1016/j.lithos.2021.106499 77p. PdfRussiakimberlite genesis

Abstract: Major and trace element variations in picroilmenites from Late Devonian kimberlite pipes in Siberia reveal similarities within the region in general, but show individual features for ilmenites from different fields and pipes. Empirical ilmenite thermobarometry (Ashchepkov et al., 2010), as well as common methods of mantle thermobarometry and trace element geochemical modeling, shows long compositional trends for the ilmenites. These are a result of complex processes of polybaric fractionation of protokimberlite melts, accompanied by the interaction with mantle wall rocks and dissolution of previous wall rock and metasomatic associations. Evolution of the parental magmas for the picroilmenites was determined for the three distinct phases of kimberlite activity from Yubileynaya and nearby Aprelskaya pipes, showing heating and an increase of Fe# (Fe# = Fe / (Fe + Mg) a.u.) of mantle peridotite minerals from stage to stage and splitting of the magmatic system in the final stages. High-pressure (5.5–7.0 GPa) Cr-bearing Mg-rich ilmenites (group 1) reflect the conditions of high-temperature metasomatic rocks at the base of the mantle lithosphere. Trace element patterns are enriched to 0.1–10/relative to primitive mantle (PM) and have flattened, spoon-like or S- or W-shaped rare earth element (REE) patterns with Pb > 1. These result from melting and crystallization in melt-feeding channels in the base of the lithosphere, where high-temperature dunites, harzburgites and pyroxenites were formed. Cr-poor ilmenite megacrysts (group 2) trace the high-temperature path of protokimberlites developed as result of fractional crystallization and wall rock assimilation during the creation of the feeder systems prior to the main kimberlite eruption. Inflections in ilmenite compositional trends probably reflect the mantle layering and pulsing melt intrusion during melt migration within the channels. Group 2 ilmenites have inclined REE enriched patterns (10–100)/PM with La / Ybn ~ 10–25, similar to those derived from kimberlites, with high-field-strength elements (HFSE) peaks (typical megacrysts). A series of similar patterns results from polybaric Assimilation + fractional crystallization (AFC) crystallization of protokimberlite melts which also precipitated sulfides (Pb < 1) and mixed with partial melts from garnet peridotites. Relatively low-Ti ilmenites with high-Cr content (group 3) probably crystallized in the metasomatic front under the rising protokimberlite source and represent the product of crystallization of segregated partial melts from metasomatic rocks. Cr-rich ilmenites are typical of veins and veinlets in peridotites crystallized from highly contaminated magma intruded into wall rocks in different levels within the mantle columns. Ilmenites which have the highest trace element contents (1000/PM) have REE patterns similar to those of perovskites. Low Cr contents suggest relatively closed system fractionation which occurred from the base of the lithosphere up to the garnet–spinel transition, according to monomineral thermobarometry for Mir and Dachnaya pipes. Restricted trends were detected for ilmenites from Udachnaya and most other pipes from the Daldyn–Alakit fields and other regions (Nakyn, Upper Muna and Prianabarie), where ilmenite trends extend from the base of the lithosphere mainly up to 4.0 GPa. Interaction of the megacryst forming melts with the mantle lithosphere caused heating and HFSE metasomatism prior to kimberlite eruption.
DS201610-1901
2016
Prokopyev, I.R.Prokopyev, I.R., Borisenko, A.S., Borovikov, A.A., Pavlova, G.G.Origin of REE rich ferrocarbonatites in southern Siberia ( Russia): implications based on melt and fluid inclusions.Mineralogy and Petrology, in press available 15p.Russia, Kola PeninsulaDeposit - Tuva

Abstract: Fe-rich carbonatites with a mineral assemblage of ankerite-calcite or siderite are widespread in southern Siberia, Russia. The siderite carbonatites are associated with F-Ba-Sr-REE mineralization and have a 40Ar/39Ar age of 117.2 ± 1.3 Ma. Melt and fluid inclusions suggest that the carbonatites formed from volatile-rich alkali- and chloride-bearing carbonate melts. Ankerite-calcite carbonatites formed from carbonatite melt at a temperature of more than 790 °C. The ferrocarbonatites (the second phase of carbonatite intrusion) formed from a sulfate-carbonate-chloride fluid phase (brine-melt) at >650 °C and ?360 MPa. The brine-melt fluid phase had high concentrations of Fe and LREEs. A subsequent hydrothermal overprint contributed to the formation of economically important barite-Sr-fluorite-REE mineralization in polymict siderite breccia.
DS201701-0028
2016
Prokopyev, I.R.Prokopyev, I.R., Borisenko, A.S., Borovikov, A.A., Pavlova, G.G.Origin of REE rich ferrocarbonatites in southern Siberia ( Russia): implications based on melt and fluid inclusions.Mineralogy and Petrology, Vol. 110, pp. 845-859.Russia, SiberiaCarbonatite

Abstract: Fe-rich carbonatites with a mineral assemblage of ankerite-calcite or siderite are widespread in southern Siberia, Russia. The siderite carbonatites are associated with F-Ba-Sr-REE mineralization and have a 40Ar/39Ar age of 117.2 ± 1.3 Ma. Melt and fluid inclusions suggest that the carbonatites formed from volatile-rich alkali- and chloride-bearing carbonate melts. Ankerite-calcite carbonatites formed from carbonatite melt at a temperature of more than 790 °C. The ferrocarbonatites (the second phase of carbonatite intrusion) formed from a sulfate-carbonate-chloride fluid phase (brine-melt) at >650 °C and ?360 MPa. The brine-melt fluid phase had high concentrations of Fe and LREEs. A subsequent hydrothermal overprint contributed to the formation of economically important barite-Sr-fluorite-REE mineralization in polymict siderite breccia.
DS201710-2258
2017
Prokopyev, I.R.Prokopyev, I.R., Doroshkevich, A.G., Redina, A.A.Magnetite apatite dolomitic rocks of Ust-Chulman ( Aldan Shield, Russia): Seligdar type carbonatites?Mineralogy and Petrology, in press available 10p.Russiacarbonatite

Abstract: The Ust-Chulman apatite ore body is situated within the Nimnyrskaya apatite zone at the Aldan shield in Russia. The latest data confirm the carbonatitic origin of the Seligdar apatite deposit (Prokopyev et al. in Ore Geol Rev 81:296-308, 2017). The results of our investigations demonstrate that the magnetite-apatite-dolomitic rocks of the Ust-Chulman are highly similar to Seligdar-type dolomitic carbonatites in terms of the mineralogy and the fluid regime of formation. The ilmenite and spinel mineral phases occur as solid solutions with magnetite, and support the magmatic origin of the Ust-Chulman ores. The chemical composition of REE- and SO3-bearing apatite crystals and, specifically, monazite-(Ce) mineralisation and the formation of Nb-rutile, late hydrothermal sulphate minerals (barite, anhydrite) and haematite are typical for carbonatite complexes. The fluid inclusions study revealed similarities to the evolutionary trend of the Seligdar carbonatites that included changes of the hydrothermal solutions from highly concentrated chloride to medium-low concentrated chloride-sulphate and oxidized carbonate-ferrous.
DS201802-0260
2018
Prokopyev, I.R.Prokopyev, I.R., Doroshkevich, A.G., Redina, A.A., Obukhov, A.V.Magnetite apatite dolomitic rocks of Ust Chulman ( Aldan Shield, Russia): Seligdar type carbonatites?Mineralogy and Petrology, in press available, 10p.Russia, Aldan shieldcarbonatites

Abstract: The Ust-Chulman apatite ore body is situated within the Nimnyrskaya apatite zone at the Aldan shield in Russia. The latest data confirm the carbonatitic origin of the Seligdar apatite deposit (Prokopyev et al. in Ore Geol Rev 81:296-308, 2017). The results of our investigations demonstrate that the magnetite-apatite-dolomitic rocks of the Ust-Chulman are highly similar to Seligdar-type dolomitic carbonatites in terms of the mineralogy and the fluid regime of formation. The ilmenite and spinel mineral phases occur as solid solutions with magnetite, and support the magmatic origin of the Ust-Chulman ores. The chemical composition of REE- and SO3-bearing apatite crystals and, specifically, monazite-(Ce) mineralisation and the formation of Nb-rutile, late hydrothermal sulphate minerals (barite, anhydrite) and haematite are typical for carbonatite complexes. The fluid inclusions study revealed similarities to the evolutionary trend of the Seligdar carbonatites that included changes of the hydrothermal solutions from highly concentrated chloride to medium-low concentrated chloride-sulphate and oxidized carbonate-ferrous.
DS201803-0443
2018
Prokopyev, I.R.Doroshkevich< A.G., Prokopyev, I.R., Izokh, A.E., Klemd, R., Ponomarchuk, A.V., Nikolaeva, I.V., Vladykin, N.V.Isotopic and trace element geochemistry of the Seligdar magnesiocarbonatites ( South Yakutia, Russia): insights regarding the mantle evolution beneath the Aldan Stanovoy shield.Journal of Asian Earth Sciences, Vol. 154, pp. 354-368.Russia, Yakutiacarbonatite -Seligdar

Abstract: The Paleoproterozoic Seligdar magnesiocarbonatite intrusion of the Aldan-Stanovoy shield in Russia underwent extensive postmagmatic hydrothermal alteration and metamorphic events. This study comprises new isotopic (Sr, Nd, C and O) data, whole-rock major and trace element compositions and trace element characteristics of the major minerals to gain a better understanding of the source and the formation process of the carbonatites. The Seligdar carbonatites have high concentrations of P2O5 (up to 18?wt%) and low concentrations of Na, K, Sr and Ba. The chondrite-normalized REE patterns of these carbonatites display significant enrichments of LREE relative to HREE with an average La/Ybcn ratio of 95. Hydrothermal and metamorphic overprints changed the trace element characteristics of the carbonatites and their minerals. These alteration processes were responsible for Sr loss and the shifting of the Sr isotopic compositions towards more radiogenic values. The altered carbonatites are further characterized by distinct 18O- and 13C-enrichments compared to the primary igneous carbonatites. The alteration most likely resulted from both the percolation of crustal-derived hydrothermal fluids and subsequent metamorphic processes accompanied by interaction with limestone-derived CO2. The narrow range of negative ?Nd(T) values indicates that the Seligdar carbonatites are dominated by a homogenous enriched mantle source component that was separated from the depleted mantle during the Archean.
DS201905-1068
2019
Prokopyev, I.R.Prokopyev, I.R., Doroshkevich, A.G., Sergeev, S.A., Ernst, R.E., Ponomarev, J.D., Redina, A.A., Chebotarev, D.A., Nikolenko, A.M., Dultsev, V.F., Moroz, T.N., Minakov, A.V.Petrography, mineralogy and SIMS U-Pb geochronology of 1.0 - 1.8 Ga carbonatites and associated alkaline rocks of the Central Aldan magnesiocarbonatite province ( South Yakutia, Russia).Mineralogy and Petrology, Doi.org/a0.1007/ s00710-019-00661-3 24p.Russiacarbonatites
DS201906-1289
2019
Prokopyev, I.R.Doroshkevich, A.G., Chebotarev, D.A., Sharygin, V.V., Prokopyev, I.R., Nikolenko, A.M.Petrology of alkaline silicate rocks and carbonatites of the Chuktukon massif, Chadobets upland, Russia: sources, evolution and relation to the Triassic Siberian LIP.Lithos, Vol. 332-333, pp. 245-260.Russiacarbonatites

Abstract: The petrogenesis of temporally and spatially associated carbonatitic and deeply derived carbonated alkaline silicate magmas provides an opportunity to gain insights into the nature of the deepest lithospheric mantle. The Chuktukon massif, which is part of the Chadobets alkaline ultramafic carbonatite complex (Chadobets upland, Siberian craton) is a carbonatite-melilitite-damtjernite intrusion, whose emplacement was coeval with the Siberian Traps large igneous province (LIP). In this study, the sources of the primary melts are examined, the petrogenetic evolution of the complex is reconstructed and the relationship with the Siberian LIP is also discussed. Isotopic and geochemical information indicate that the source for the Chuktukon primary melts was isotopically moderately depleted and the primary melts were formed by low degree partial melting of garnet carbonated peridotite. Hydrothermal processes caused 18 O- and 13 C- enrichment. The weathering process was accompanied by trace element re-distribution and enrichment of the weathering crust in Zn, Th, U, Nb, Pb and REE, relative to the Chuktukon rocks and a change in radiogenic (Sr, Nd) isotope compositions.
DS201906-1339
2019
Prokopyev, I.R.Prokopyev, I.R., Doroshkevich, A.G., Sergeev, S.A., Ernst, R.E., Ponomarev, J.D., Redina, A.A., Chebotarev, D.A., Nikolenko, A.M., Dultsev, V.F., Moroz, T.N., Minakov, A.V.Petrography, mineralogy and SIMS U-Pb geochronology of 1.9-1.8 Ha carbonatites and associated alkaline rocks of the Central-Aldan magnesiocarbonatite province ( South Yakutia, Russia).Mineralogy and Petrology, Vol. 113, pp. 329-352.Russia, Yakutiacarbonatites
DS202008-1426
2020
Prokopyev, I.R.Nikolenko, A.M., Doroshkevich, A.G., Ponomarchuk, A.V., Redina, A.A., Prokopyev, I.R., Vladykin, N.V., Nikolaeva, I.V.Ar-Ar geochronology and petrogenesis of the Mushgai-Khudag alkaline-carbonatite complex 9 southern Mongolia).Lithos, Vol. 372-372, 105675 15p. PdfAsia, Mongoliacarbonatite

Abstract: The Mushgai-Khudag alkaline?carbonatite complex, located in southern Mongolia within the Central Asian Orogenic Belt (CAOB), comprises a broad range of volcanic and subvolcanic alkaline silicate rocks (melanephelinite-trachyte and shonkinite-alkaline syenite, respectively). Magnetite-apatite rocks, carbonatites, and fluorite mineralization are also manifested in this area. The complex formed between 145 and 133 Ma and is contemporaneous with late Mesozoic alkaline-carbonatite magmatism within the CAOB. Major and trace element characteristics of silicate rocks in the Mushgai-Khudag complex imply that these rocks were formed by the fractional crystallization of alkaline ultramafic parental magma. Magnetite-apatite rocks may be a product of silicate-Ca-Fe-P liquid immiscibility that took place during the alkaline syenite crystallization stage. The Mushgai-Khudag rocks have variable and moderately radiogenic Sr (87Sr/86Sr(i) = 0.70532-0.70614), ?Nd(t) = ?1.23 to 1.25) isotopic compositions. LILE/HFSE values and SrNd isotope compositions indicate that the parental melts of Mushgai-Khudag were derived from a lithospheric mantle source that was affected by a metasomatic agent in the form a mixture of subducted oceanic crust and its sedimentary components. The ?18OSMOW and ?18CPDB values for calcites in carbonatites range from 16.8‰ to 19.2‰ and from ?3.9‰ to 2.0‰, respectively. CO covariations in calcites of the Mushgai-Khudag carbonatites can be explained by the slight host limestone assimilation.
DS202008-1436
2020
Prokopyev, I.R.Prokopyev, I.R., Kozlov, E., Fomina,E., Doroshkevich, A.Mineralogy and fluid regime of formation of the REE-Late-Stage hydrothermal mineralization of Petyayan-Vara carbonatites ( Vuoriyarvi, Kola region, NW Russia.Minerals, 19p. PdfRussia, Kola Peninsulacarbonatite

Abstract: The Vuoriyarvi Devonian alkaline-ultramafic complex (northwest Russia) contains magnesiocarbonatites with rare earth mineralization localized in the Petyayan-Vara area. High concentrations of rare earth elements are found in two types of these rocks: (a) ancylite-dominant magnesiocarbonatites with ancylite-baryte-strontianite-calcite-quartz (±late Ca-Fe-Mg carbonates) ore assemblage, i.e., “ancylite ores”; (b) breccias of magnesiocarbonatites with a quartz-bastnäsite matrix (±late Ca-Fe-Mg carbonates), i.e., “bastnäsite ores.” We studied fluid inclusions in quartz and late-stage Ca-Fe-Mg carbonates from these ore assemblages. Fluid inclusion data show that ore-related mineralization was formed in several stages. We propose the following TX evolution scheme for ore-related processes: (1) the formation of ancylite ores began under the influence of highly concentrated (>50 wt.%) sulphate fluids (with thenardite and anhydrite predominant in the daughter phases of inclusions) at a temperature above300-350 °C; (2) the completion of the formation of ancylite ores and their auto-metasomatic alteration occurred under the influence of concentrated (40-45 wt.%) carbonate fluids (shortite and synchysite-Ce in fluid inclusions) at a temperature above 250-275 °C; (3) bastnäsite ores deposited from low-concentrated (20-30 wt.%) hydrocarbonate-chloride fluids (halite, nahcolite, and/or gaylussite in fluid inclusions) at a temperature of 190-250 °C or higher. Later hydrothermal mineralization was related to the low-concentration hydrocarbonate-chloride fluids (<15 wt.% NaCl-equ.) at 150-200 °C. The presented data show the specific features of the mineral and fluid evolution of ore-related late-stage hydrothermal rare earth element (REE) mineralization of the Vuoriyarvi alkaline-ultramafic complex.
DS202102-0178
2020
Prokopyev, I.R.Chayka, I., Kamenetsky, V.S., Vasilyev, Y., Prokopyev, I.R.Spinel-group minerals in peridotites of the Guli and Bor-Uryakh intrusions ( Meimecha-Kotuy Province, northern Siberia).SGEM Conference 20th., doi:10.5593/ sgem2020/1.1. /s01.038Russia, Siberiaperidotites

Abstract: The Guli and Bor-Uryakh massifs, a part of the Siberian Large igneous province (LIP) are mafic-ultramafic intrusive complexes, withstrongalkaline affinity. They contain deposits of apatite and arealsoknown to be source rocks ofOs-Ir-Ruplacers.These massifs are of great interest for petrologists worldwide, as they are composed of an unusual variety of rocks (dunites/olivinites, shonkinites, melilitites, alkali syenites and carbonatites) and being coeval with Siberian trap volcanic rocks, includingdiamondiferous kimberlites. Since mineralogical approaches based on spinel-group minerals have been proved to be efficient in constraining origin of the ultramafics, we present the first descriptive study of chromite and magnetite mineralization, observed in olivine-dominated rocks of the Guli and Bor-Uryakh intrusions. In dunites of Guli massif spinel-group minerals are dominated by Mg-poor chromite (FeMg)Cr2O4and Cr-Ti-rich magnetiteFeFe2O4, while in Bor-Uryakh massif spinel-group minerals are predominantly magnetite with only minor Mg-poor chromite.These minerals form either small euhedral inclusions in olivine or largesubhedral to anhedral grains in serpentinized fractures and interstitial space. The lattertype of grainscan have intricated irregular shapeand contain inclusions. We also observed abundant Cr-magnetite lamellae in olivine and chromite/magnetite micro-grains within olivine-hosted multiphase inclusions.Spinel (MgAl2O4) is occasionally found in intergrowths with chromite and magnetite.The obtained data show that spinel-group minerals in the massifsdo not correspond to primary-magmatic varieties and suggestextensive alteration during post-magmatic processes. Textural and chemical evidenceof substantial modification of initially-cumulative lithologies of Guli and Bor-Uryakh massifsfavorsmeta-magmatic origin for these massifs.
DS202104-0601
2021
Prokopyev, I.R.Prokopyev, I.R., Doroshkevich, A.G., Zhumadilova, D.V., Starikova, A.E., Nugumanova, Ya.N., Vladykin, N.V.Petrogenesis of Zr-Nb ( REE) carbonatites from the Arbarastakh complex ( Aldan Shield, Russia): mineralogy and inclusion data.Ore Geology Reviews, Vol. 131, 104042, 15p. Pdf.Russiadeposit - Arbarastakh

Abstract: The Arbarastakh Neoproterozoic ultramafic carbonatite complex is located in the southwestern part of the Siberian Craton (Aldan Shield) and contains ore-bearing Zr-Nb (REE) carbonatites and phoscorites. Carbonatites are mainly represented by calcite and silicocarbonatite varieties. The primary minerals composing the carbonatites are calcite and dolomite, as well as phlogopite, clinopyroxene, fluorapatite, amphibole, fluorite, K-feldspar and feldspathoids. Olivine (forsterite), Ti-magnetite, apatite, phlogopite, calcite, dolomite and the minor spinel group minerals form the primary phoscorites. The ore-bearing Zr-Nb mineral assemblages of the phoscorites and carbonatites include accessory zircon, zirconolite, perovskite, pyrochlore and baddeleyite. The Ba-Sr-REE hydrothermal mineralisation consists of ancylite-(Ce), bastnaesite-(Ce) and burbankite, as well as barite-celestite, strontianite, barytocalcite, and rare Cu-Fe sulphides. The silicocarbonatites and carbonatites formed in multiple stages from a single alkaline Ca-Na-K-silicocarbonatite melt, while the phoscorites are products of differentiation of the carbonatitic melt and were crystallised from an Fe-rich phosphate-carbonate melt at temperatures of more than 720 °C. The silicate-phosphate-carbonate melts were responsible for the Zr-Nb mineralisation of the carbonatites at temperatures of more than 540-575 °C; the hydrothermal REE-bearing mineral assemblages crystallised from saline (60-70 wt%) carbonatitic fluids of Na-Ca-Mg-F-carbonate composition at a minimum temperature range of 350-300 °C. The Ca-Sr-carbonate as well as the Na-hydro-carbonate fluids were responsible for the Ba-Sr-REE mineralisation of the phoscorites at ~500-480 and 450-430 °C.
DS202107-1109
2021
Prokopyev, I.R.Kruk, M.N., Doroshkevich, A.G., Prokopyev, I.R., Izbrodin, I.A.Mineralogy of phoscorites of the Arbarastakh complex, Republic of Sakha, Yakutia, Russia).Minerals MDPI, Vol. 11, 556 24p. PdfRussia, Yakutiacarbonatite

Abstract: The Arbarastakh ultramafic carbonatite complex is located in the southwestern part of the Siberian Craton and contains ore-bearing carbonatites and phoscorites with Zr-Nb-REE mineralization. Based on the modal composition, textural features, and chemical compositions of minerals, the phoscorites from Arbarastakh can be subdivided into two groups: FOS 1 and FOS 2. FOS 1 contains the primary minerals olivine, magnetite with isomorphic Ti impurities, phlogopite replaced by tetraferriphlogopite along the rims, and apatite poorly enriched in REE. Baddeleyite predominates among the accessory minerals in FOS 1. Zirconolite enriched with REE and Nb and pyrochlore are found in smaller quantities. FOS 2 has a similar mineral composition but contains much less olivine, magnetite is enriched in Mg, and the phlogopite is enriched in Ba and Al. Of the accessory minerals, pyrochlore predominates and is enriched in Ta, Th, and U; baddeleyite is subordinate and enriched in Nb. Chemical and textural differences suggest that the phoscorites were formed by the sequential introduction of different portions of the melt. The melt that formed the FOS 1 was enriched in Zr and REE relative to the FOS 2 melt; the melt that formed the FOS 2 was enriched in Al, Ba, Nb, Ta, Th, U, and, to a lesser extent, Sr.
DS201312-0032
2013
Prokopyev, S.A.Ashchepkov, I.V., Alymova, N.V., Logvinova, A.M., Vladykin, N.V., Kuligin, S.S., Mityukhin, S.I., Stegnitsky, Y.B., Prokopyev, S.A., Salikhov, R.F., Palessky, V.S., Khmelnikova, O.S.Picroilmenites in Yakutian kimberlites: variations and genetic models.Solid Earth, Vol. 5, pp. 1259-1334.Russia, YakutiaDeposits
DS201612-2274
2016
Prokopyev, S.A.Ashchepkov, I.V., Logvinova, A.M., Ntaflos, T., Vladykin, N.V., Kostrovitsky, S.I., Spetsius, Z., Mityukhin, S.I., Prokopyev, S.A., Medvedev, N.S., Downe, H.Alakit and Daldyn kimberlite fields, Siberia, Russia: two types of mantle sub-terranes beneath central Yakutia?Geoscience Frontiers, in press availableRussia, SiberiaDeposit - Alakit, Daldyn

Abstract: Mineral data from Yakutian kimberlites allow reconstruction of the history of lithospheric mantle. Differences occur in compositions of mantle pyropes and clinopyroxenes from large kimberlite pipes in the Alakit and Daldyn fields. In the Alakit field, Cr-diopsides are alkaline, and Stykanskaya and some other pipes contain more sub-calcic pyropes and dunitic-type diamond inclusions, while in the Daldyn field harzburgitic pyropes are frequent. The eclogitic diamond inclusions in the Alakit field are sharply divided in types and conditions, while in the Daldyn field they show varying compositions and often continuous Pressure-Temperature (P-T) ranges with increasing Fe# with decreasing pressures. In Alakit, Cr-pargasites to richterites were found in all pipes, while in Daldyn, pargasites are rare Dalnyaya and Zarnitsa pipes. Cr-diopsides from the Alakit region show higher levels of light Rare Earth Elements (LREE) and stronger REE-slopes, and enrichment in light Rare Earth Elements (LREE), sometimes Th-U, and small troughs in Nb-Ta-Zr. In the Daldyn field, the High Field Strength Elements HFSE troughs are more common in clinopyroxenes with low REE abundances, while those from sheared and refertilized peridotites have smooth patterns. Garnets from Alakit show HREE minima, but those from Daldyn often have a trough at Y and high U and Pb. PTXfO2 diagrams from both regions show similarities, suggesting similar layering and structures. The degree of metasomatism is often higher for pipes which show dispersion in P-Fe# trends for garnets. In the mantle beneath Udachnaya and Aykhal, pipes show 6-7 linear arrays of P-Fe# in the lower part of the mantle section at 7.5-3.0 GPa, probably reflecting primary subduction horizons. Beneath the Sytykanskaya pipe, there are several horizons with opposite inclinations which reflect metasomatic processes. The high dispersion of the P-Fe# trend indicating widespread metasomatism is associated with decreased diamond grades. Possible explanation of the differences in mineralogy and geochemistry of the mantle sections may relate to their tectonic positions during growth of the lithospheric keel. Enrichment in volatiles and alkalis possibly corresponds to interaction with subduction-related fluids and melts in the craton margins. Incorporation of island arc peridotites from an eroded arc is a possible scenario.
DS1960-0875
1967
Prokupchuk, B.I.Rozhkov, I.S., Mikhalev, G.P., Prokupchuk, B.I., Shamshina, E.A.Alluvial Diamond Deposits of Western YakutiaMoscow: Izdat Nauka., 280P.Russia, YakutiaKimberlite, Diamond, Kimberley
DS1994-1078
1994
Prol-Ledesma, R-M.Macfarlane, A.W., Prol-Ledesma, R-M., Conrad, M.E.Isotope and fluid inclusion studies of geological and hydrothermal processes northern PeruInternational Geology Review, Vol. 36, No. 7, July pp. 645-677PeruGeochronology, Metallogeny
DS1993-1266
1993
Promprated, P.Promprated, P., Taylor, L.A., Neal, C.R.Petrochemistry of mafic granulite xenoliths from the Chantaburi basaltic field:International Geology Review, Vol. 45, 5, pp. 383-406.ThailandXenoliths - not specific to diamonds
DS1999-0570
1999
Promprated, P.Promprated, P., Taylor, L. A., Snyder, G.A.Petrochemistry of the mantle beneath Thailand: evidence from peridotitexenoliths.International Geology Review, Vol. 41, No. 6, June pp. 506-30.GlobalPeridotite, Xenoliths - not specific to diamonds
DS2003-1114
2003
Promprated, P.Promprated, P., Taylor, L.A., Floss, C., Malkovets, V.G., Anand, M., GriffinDiamond inclusions from Snap Lake, NWT, Canada8ikc, Www.venuewest.com/8ikc/program.htm, Session 3, POSTER abstractNorthwest TerritoriesDiamonds - inclusions, Deposit - Snap Lake
DS2003-1363
2003
Promprated, P.Taylor, L.A., Anand, M., Promprated, P.Diamonds and their inclusions: are the criteria for syngenesis valid?8 Ikc Www.venuewest.com/8ikc/program.htm, Session 2, AbstractGlobalDiamonds - inclusions, Genesis
DS2003-1364
2003
Promprated, P.Taylor, L.A., Anand, M., Promprated, P., Floss, C., Sobolev, N.V.The significance of mineral inclusions in large diamonds from Yakutia, RussiaAmerican Mineralogist, Vol. 88, 5/6, pp. 912-928.Russia, YakutiaDiamond - inclusions, protogenetic, Deposit - Udachnaya, Mir, Aikhal
DS2003-1366
2003
Promprated, P.Taylor, L.A., Spetsius, Z.A., Wiesli, R., Anand, M., Promprated, P., Valley, J.The origin of mantle peridotites: crustal signatures from Yakutian kimberlites8ikc, Www.venuewest.com/8ikc/program.htm, Session 4, POSTER abstractRussia, YakutiaMantle geochemistry
DS200412-1592
2004
Promprated, P.Promprated, P., Taylor, L.A., Anand, M., Floss, C., Sobolev, N.V., Pokhilenko, N.P.Multiple mineral inclusions in diamonds from the Snap Lake/King Lake kimberlite dike, Slave Craton: a trace element perspective.Lithos, Vol. 77, 1-4, Sept. pp. 69-81.Canada, Northwest TerritoriesDiamond inclusions, trace element, REE, in situ analysi
DS200412-1593
1993
Promprated, P.Promprated, P., Taylor, L.A., Neal, C.R.Petrochemistry of mafic granulite xenoliths from the Chantaburi basaltic field: implications for the nature of the lower crust bInternational Geology Review, Vol. 45, 5, pp. 383-406.Asia, ThailandXenoliths - not specific to diamonds
DS200412-1972
2003
Promprated, P.Taylor, L.A., Anand, M., Promprated, P.Diamonds and their inclusions: are the criteria for syngenesis valid?8 IKC Program, Session 2, AbstractTechnologyDiamonds - inclusions Genesis
DS200412-1973
2003
Promprated, P.Taylor, L.A., Anand, M., Promprated, P., Floss, C., Sobolev, N.V.The significance of mineral inclusions in large diamonds from Yakutia, Russia.American Mineralogist, Vol. 88, 5/6, pp. 912-928.Russia, YakutiaDiamond - inclusions, protogenetic Deposit - Udachnaya, Mir, Aikhal
DS1984-0685
1984
Pronyagin, N.I.Snyatkova, O.L., Pronyagin, N.I., et al.The carbonatite complex of the Khibiny massif and the discovery perspectives of economically important accumulations of natural soda.(Russian)Izves. Akad. Nauk SSSR (Russian), No. 11, pp.124-128RussiaCarbonatite
DS1990-1340
1990
Proshenkin, I.E.Sharygin, V.V., Proshenkin, I.E.Garnets of alkaline rocks of the Sakun massifSoviet Geology and Geophysics, Vol. 31, No. 4, pp. 54-61RussiaAlkaline rocks, Garnet mineralogy
DS1991-1292
1991
Proshenkin, I.E.Panina, L.I., Sharygin, V.V., Proshenkin, I.E.Apatite contents of potassium alkaline massifsSoviet Geology and Geophysics, Vol. 32, No. 1, pp. 107-114RussiaAlkaline rocks, Apatite
DS1992-1376
1992
Proshenkin, I.E.Sharygin, V.V., Proshenkin, I.E., Panina, L.I., Bazarova, T.Yu.Modal leucite in melanocratic rocks of synnritiferous massifs as An indicator of their genesis.Russian Geology and Geophysics, Vol. 33, No. 5, pp. 56-61.GlobalMineralogy, Leucite
DS202110-1634
2021
Proskumin, V.F.Proskumin, V.F., Grakhanov, S.A., Petrov, O.V., Vasiliev, E.A., Berzon, E.I., Antonov, A.V., Sobolev, N.V.Forecast of the diamond potential of Taimyr.Doklady Earth Sciences, Vol. 499, 2, pp. 611-615.Russiadeposit - Taimyr

Abstract: Although irrefutable evidence for the presence of signs of diamondiferous kimberlite on the Taimyr Peninsula were obtained in the 1930s, it was only in 2020 that a macrodiamond (>1 mm) was first discovered in Eastern Taimyr. This was a colorless laminar crystal of a transitional shape from an octahedron to a rhombododecahedron. According to the set of features, the crystal is rare and atypical of the known primary and alluvial deposits of the Siberian Diamond Province. The find of this diamond indicates the presence of primary sources and the need for medium-scale geological survey and exploration over a large area from Anabar Bay (Pronchishchev Ridge) to the west to the Kiryaka-Tas and Tulai-Kiryaka highlands and to the northeast to Tsvetkov Cape.
DS201112-0788
2010
Proskurin, V.F.Petrov, O.V., Proskurin, V.F.Early Mesozoic carbonatites in folded formations of the Taimyr Peninsula.Doklady Earth Sciences, Vol. 435, 2, pp. 1592-1595.RussiaCarbonatite
DS201112-0831
2010
Proskurnin, V.F.Proskurnin, V.F., Petrov, Bagdasarov, Rozinov, Tolmacheva, Larionov, Bilskaya, Gavrish, Mozoleva, PetrushkovOrigin of carbonatites of eastern Taimyr deduced from an isotopic and geochemical study of zircons.Geology of Ore Deposits, Vol. 52, 8, pp. 711-724.RussiaPetrology - carbonatites
DS1992-1237
1992
Proskuryakov, V.V.Proskuryakov, V.V., Uvadyev, L.I.Lamproites of the eastern part of the Baltic shield.(Russian)Izvest. Akad. Nauk (Russian), No. 8, August pp. 65-75.Russia, Baltic shieldLamproite, Geochemistry
DS1992-1238
1992
Proskuryakov, V.V.Proskuryakov, V.V., Uvad'yev, L.I., Voinova, O.A.Lamproites of the Karelia-Kola regionDoklady Academy of Sciences USSR, Earth Science Section, Vol. 314, No. 1-6, July 1992, pp. 152-156.Russia, Karelia, KolaLamproites, Petrology
DS200712-0858
2006
Prospectors & Developers Association of CanadaProspectors & Developers Association of CanadaA strategy to ensure the long-term competitiveness of the Canadian mineral industry. Submission to the 63rd Mines Ministers' Conference August 27-29th.WhitehorseProspectors and Developers Association of Canada, August 27-29, 13p.CanadaEconomics
DS1993-1267
1993
Prospectors and Developers Association CanadaProspectors and Developers Association CanadaDiamond shortcourse manualDiamonds: exploration, sampling and evaluation proceedings of a short, 379p. approx. $ 55.00 plus shipping/handlingUnited States, CanadaPractical techniques, Practical applications, case studies
DS1994-1415
1994
Prospectors and Developers Association CanadaProspectors and Developers Association CanadaProspecting in tropical and arid terrainsProspectors and Developers Association of Canada (PDAC) Meeting, Shortcourse notes, 325pGlobalBook -table of contents, Prospecting in tropical and arid terrains
DS1995-1527
1995
Prospectors and Developers Association CanadaProspectors and Developers Association CanadaNew Mines, development and advanced exploration projects for 1994.. listing by provinceProspectors and Developers Association of Canada (PDAC) Annual Publishing Exploration and Dev. Highlights, March pp. 24, 25, 44CanadaMining, exploration activities
DS1995-1528
1995
Prospectors and Developers Association CanadaProspectors and Developers Association CanadaProject evaluation and due diligenceProspectors and Developers Association of Canada (PDAC) Short Course Notes, 181p. $ 45.00CanadaOre reserves, geostatistics, Economics -due diligence
DS1997-0929
1997
Prospectors and Developers Association CanadaProspectors and Developers Association CanadaGuidelines to regulatory requirements and procedures affecting exploration development and mining in CanadaProspectors and Developers Association of Canada (PDAC)., $ 65.00CanadaBook - ad, Legal - guidelines revised edition
DS1997-0930
1997
Prospectors and Developers Association CanadaProspectors and Developers Association CanadaSecurities law reporting requirements for ore reservesProspectors and Developers Association of Canada (PDAC) Short Course, 120p. approx. 15.00CanadaLegal, Reserves
DS1997-0931
1997
Prospectors and Developers Association CanadaProspectors and Developers Association CanadaExploration and mining fundamentals - a short course for representatives from developing countriesProspectors and Developers Association of Canada (PDAC) Short Course, 180p. approx. 25.00GlobalMining laws, terminology, model, financial, Economics
DS1997-0932
1997
Prospectors and Developers Association CanadaProspectors and Developers Association CanadaAfter the discoveryProspectors and Developers Association of Canada (PDAC) Short Course, 101p. approx. 25.00GlobalResources, assays, bioleaching, environment, Economics
DS1998-1192
1998
Prospectors and Developers Association CanadaProspectors and Developers Association CanadaCanadian junior resource companies exploration expendituresProspectors and Developers Association of Canada (PDAC) Communique, March, 8pCanadaEconomics, Companies - activities, discoveries
DS2001-0950
2001
Prospectors and Developers Association CanadaProspectors and Developers Association CanadaWhat you should know about "super" flow through sharesProspectors and Developers Association of Canada (PDAC) Brochure, March, 6p.CanadaEconomics - flow through, discoveries, exploration, Not specific to diamonds
DS2002-1285
2002
Prospectors and Developers Association CanadaProspectors and Developers Association CanadaVideo cassette order formProspectors and Developers Association of Canada (PDAC) 2002, March 10-13TorontoConference - videos
DS1998-1193
1998
Prospectors and Developers Association MeetingProspectors and Developers Association MeetingThe fundamentals of exploration and MiningProspectors and Developers Association of Canada (PDAC) Short course notes, 180p. approx. $40.00GlobalBook - table of contents, Exploration and mining - laws, regulations, terminology
DS200412-1594
2004
Prospectors and Developers Association of CanadaProspectors and Developers Association of CanadaE3 Environmental Excellence in Exploration *** compilation of available practical methods and best practices to ensure exploE3mining.com , FREEGlobalEnvironment - best practices guidelines
DS200412-1595
2004
Prospectors and Developers Association of CanadaProspectors and Developers Association of CanadaAll presentations - PDAC 2004 Audio and power points on CD Rom - where avaliable by permission of author.softconference.com also dorad @cmcgc.com, CD complete package $295.00TechnologyInformation - PDAC conference
DS200512-0879
2005
Prospectors and Developers Association of CanadaProspectors and Developers Association of CanadaA brief submitted to the 62nd Annual Energy & Mines Ministers' Conference ... held St. Andrews, New Brunswick Sept. 18-20th. 2005.PDAC, Aug. 23, 28p.CanadaOverview - mineral industry, exploration, legal
DS2000-0784
2000
Prospectors and Developers Association of Canada (PDAC) CommuniqueProspectors and Developers Association of Canada (PDAC) CommuniqueThe new federal exploration investment tax creditProspectors and Developers Association of Canada (PDAC)., November 4p.CanadaEconomics, legal - EITC.
DS2000-0785
2000
Prospectors and Developers Association of Canada (PDAC) in BriefProspectors and Developers Association of Canada (PDAC) in BriefFlow through premium returnsProspectors and Developers Association of Canada (PDAC)., No. 22, Winter, p.1.GlobalEconomics, legal - flow through
DS2003-1115
2003
Prospectors and Developers Association of Canada 2003 ConventionProspectors and Developers Association of Canada 2003 ConventionDiamond, Diamonds everywhere! Which ones to mine? Diamond session - 2Audio Archives @ Duplicators Inc. [email protected], set 2 tapes $ 49.00 plus shippingGlobalSee abstracts cited
DS201812-2842
2018
Prosperi, L.Lorenzi, R., Zullino, A., Prosperi, L., Paleari, A.Visible light excited red-emitting vacancies at carbon interstitials as indicators of irradiated and annealed Type Ia diamonds.Diamond & Related Materials, Vol. 90, pp. 188-193.Europe, Italydiamond radiation

Abstract: During the last decades many studies have been carried out to investigate how point defects and aggregates respond and evolve in natural Type Ia diamonds as a result of treatments, and a number of underlying mechanisms have been identified and interpreted. However, the analysis of radiation-induced creation/ionization of defects, as well as their migration and aggregation in secondary defect structures, often requires experimental approaches which can hardly constitute a simple-to-use diagnostic tool for the identification of artificially treated diamonds. Here we disclose a novel simple indicator of artificial exposure of Type Ia diamonds to ionizing radiations and subsequent annealing. This indicator consists in narrow photoluminescence lines in the red region, between 681 and 725?nm, we recently found to result from vacancies trapped by interstitial carbon aggregates and platelets. Our results demonstrate that interstitial structures become sites of vacancy trapping - by thermal migration of radiation-induced vacancies - only when diamond undergoes treatments. We give the rigorous validation of the new spectroscopic probe of artificial treatments analysing photoluminescence and infrared absorption spectra of well-known H1b and H1c centres in a hundred samples. Importantly, the method is based on emission lines which do not require neither high photon-energy excitation nor cryogenic temperatures.
DS1993-1143
1993
Prosser, D.J.North, C.P., Prosser, D.J.Characterization of fluvial and aeolian reservoirsGeological Society of London Special Publication, No. 73, 450pGlobalTable of contents, Sedimentology -aeolian characterizations, Paleosols, geomorphology
DS1997-0933
1997
Prost, G.Prost, G.English - Spanish and Spanish -English glossary of geoscience termsGordon and Breach Publ, 340p. approx. $ 100.00GlobalBook - ad, Glossary - Spanish
DS1995-1529
1995
Prost, G.L.Prost, G.L.Remote sensing for geologists: guide to image interpretationGordon and Breach Publ, 358p. approx. $ 115.00 United StatesGlobalBook -ad, Remote sensing
DS2003-1480
2003
Proud, W.G.Wilmott, G.R., Proud, W.G., Field, J.E.Shock properties of diamond and kimberliteJournal de Physique 4, Vol. 110, pp. 833-838. Ingenta 1033872008GlobalGeophysics
DS200412-2121
2003
Proud, W.G.Wilmott, G.R., Proud, W.G., Field, J.E.Shock properties of diamond and kimberlite.Journal de Physique 4, Vol. 110, pp. 833-838. Ingenta 1033872008TechnologyGeophysics
DS200512-1184
2004
Proud, W.G.Willmott, G.R., Proud, W.G., Field, J.E.Shock properties of kimberlite.AIP Conference Proceedings, American Institute of Physics, Vol.706, 2, pp. 1492-1495.Geophysics - kimberlite
DS200712-1161
2007
Proud, W.G.Wilmott, G.R., Proud, W.G.The shock Hugoniot of tuffisitic breccia.International Journal of Rock Mechanics and Mining Sciences, Vol. 44, 2, pp. 228237.TechnologyMineral processing
DS2002-1286
2002
Prouse, D.Prouse, D.Exploration spending up despite difficult year.. diamonds mentionedProspectors and Developers Association of Canada (PDAC) Exploration and Development Highlights, pp. 16-8.ManitobaNews item - brief review
DS2002-1381
2002
Proussevitch, A.Sahagian, D., Proussevitch, A., Carlson, W.Timing of Colorado Plateau uplift: initial constraints from vesicular basalt derived paleoelevations.Geology, Vol. 30,9,Sept. pp. 807-10.Colorado PlateauBasalts - uplift - not specific to diamonds
DS2001-0951
2001
Prouteau, C.Prouteau, C., Scaillet, B., Maury, R.Evidence for mantle metasomatism by hydrous silicate melts derived from subducted oceanic crust.Nature, Vol. 410, No. 6825, Mar. 8, pp. 197-9.MantleMetasomatism, Subduction
DS2001-1021
2001
Prouteau, G.Scaillet, B., Prouteau, G.Oceanic slab melting and mantle metasomatismScience Progress, Vol. 84, No. 4, pp. 335-54.MantleMetasomatism
DS201412-0151
2014
Prouteau, G.Crepisson, C., Morard, G., Bureau, H., Prouteau, G., Morizet, Y., Petitgirard, S., Sanloup, C.Magmas trapped at the continental lithosphere-asthenosphere boundary.Earth and Planetary Science Letters, Vol. 393, pp. 105-112.MantleBoundary, magmatism
DS201703-0430
2016
Prouty, M.Prouty, M.Miniature magnetometrers for small UAVS.Society of Exploration Geophysics, Dallas annual meeting, Geometrics, 22ppt.TechnologyGeophysics
DS201112-0904
2010
Provenzano, C.Sander, A., Provenzano, C., Valdir Silveira, F., Castro, J.H., Bottari, L.Um novo corpo kimberlitico no escudo sul rio Grandense: petrografia preliminar.5th Brasilian Symposium on Diamond Geology, Nov. 6-12, abstract p. 75.South America, BrazilGeobank
DS201112-0201
2011
Provenzano, C.A.S.Conceicao, R.V., Lenz, C., Provenzano, C.A.S., Sander, A., Silveira, F.V.U Pb perovskite ages of kimberlites from the Rosario do Sul cluster Southern Brazil.Goldschmidt Conference 2011, abstract p.691.South America, Brazil, Rio Grande do SulGeochronology
DS202003-0352
2020
Prover, A.Moore, A.,Yudovskaya, M., Prover, A., Blenkinsop, T.Evidence for olivine deformation in kimberlites and other mantle derived magmas during crustal emplacement. LemphaneContributions to Mineralogy and Petrology, Vol. 175, 9p. PdfAfrica, Lesothoolivine

Abstract: This paper highlights published and new field and petrographic observations for late-stage (crustal level) deformation associated with the emplacement of kimberlites and other mantle-derived magmas. Thus, radial and tangential joint sets in the competent 183 Ma Karoo basalt wall rocks to the 5 ha. Lemphane kimberlite blow in northern Lesotho have been ascribed to stresses linked to eruption of the kimberlite magma. Further examples of emplacement-related stresses in kimberlites are brittle fractures and close-spaced parallel shears which disrupt olivine macrocrysts. In each of these examples, there is no evidence of post-kimberlite regional tectonism which might explain these features, indicating that they reflect auto-deformation in the kimberlite during or immediately post-emplacement. On a microscopic scale, these inferred late-stage stresses are reflected by fractures and domains of undulose extinction which traverse core and margins of some euhedral and anhedral olivines in kimberlites and olivine melilitites. Undulose extinction and kink bands have also been documented in olivines in cumulates from layered igneous intrusions. Our observations thus indicate that these deformation features can form at shallow levels (crustal pressures), which is supported by experimental evidence. Undulose extinction and kink bands have previously been presented as conclusive evidence for a mantle provenance of the olivines—i.e. that they are xenocrysts. The observation that these deformation textures can form in both mantle and crustal environments implies that they do not provide reliable constraints on the provenance of the olivines. An understanding of the processes responsible for crustal deformation of kimberlites could potentially refine our understanding of kimberlite emplacement processes.
DS1860-0964
1897
Providence BulletinProvidence BulletinThe Origin of Diamonds (1897)Providence Bulletin., MAY 7TH.GlobalDiamond Genesis
DS1990-1202
1990
Provincial Geologists Journal for 1989Provincial Geologists Journal for 1989Brief mention in Saskatchewan section of diamond activities -no companies just government projectsProvincial Geologists Journal, Vol. 7, p. 42-43SaskatchewanNews item, Brief mention of kimberlite projects
DS200512-0880
2004
Provins, D.A.Provins, D.A.Earth synthesis: determining Earth's structure from geopotential fields.University of Calgary, Phd. thesisMantleGeodynamics, density
DS2001-0037
2001
Provost, A.Annen, C., Lanat, J-F., Provost, A.The long term growth of volcanic edifices: numerical modelling of the roleof dike intrusion and lava flow..Journal of Volcan. Geotherm Res., Vol. 105, pp. 263-89.GlobalDyke intrusions - not specific to diamond
DS200712-0947
2006
Provost, A.Schiano, P., Provost, A., Clocchiatti, R., Faure, F.Transcrystalline melt migration and Earth's mantle.Science, Vol. 314, Nov. 10, pp. 970-974.MantleTectonics, volcanism, geothermometry, melting
DS201212-0126
2012
Provost, A.Chen, Y., Provost, A., Schiano, P., Cluzel, N.Magma ascent rate and initial water concentration inferred from diffusive water loss from olivine hosted melt inclusions.Contributions to Mineralogy and Petrology, in press available 17p.MantleMelting
DS201212-0394
2012
Provost, A.Lambart, S., Laporte, D., Provost, A., Schinao, P.Fate of pyroxenite derived melts in the periodotitic mantle: thermodynamic and experimental constraints.Journal of Petrology, Vol 53, 3, pp. 451-476.MantlePeridotite
DS201912-2798
2019
Provost, A.Laumonier, M., Laporte, D., Faure, F., Provost, A., Schiano, P., Ito, K.An experimental study of dissolution and precipitation of forsterite in a thermal gradient: implications for cellular growth of olivine phenocrysts in basalt and melt inclusion formation.Contributions to Mineralogy and Petrology, Vol. 174, 21p. PdfMantlebasanite

Abstract: The morphology of crystals in magmas strongly depends on the temperature regime of the system, in particular the degree of undercooling and the cooling rate. To simulate low degrees of undercooling, we developed a new experimental setup based on thermal migration, in which large cylinders of forsterite (single crystals) immersed in haplobasaltic melt were subjected to a temperature gradient. As forsterite solubility is sensitive to temperature, the forsterite on the high-temperature side undergoes dissolution and the dissolved components are transported toward the low-temperature side where a layer of newly grown forsterite forms (up to 340 ?m thick after 101 h). A striking feature is that the precipitation process does not produce a planar front of forsterite advancing at the expense of liquid: the growth front shows a fingered outline in planar section, with solid lobes separated by glass tubes that are perpendicular to the growth front. We ascribe this texture to cellular growth, a type of growth that had not been experimentally produced so far in silicate systems. We find that the development of cellular growth requires low degrees of undercooling (a few °C) and large crystal-liquid interfaces (~?1 mm across or more), and that it occurs at a growth rate of the order of 10?9 m/s. We found natural occurrences of cellular growth on the rims of olivines from basanites, but otherwise cellular textures are poorly documented in natural volcanic rocks. Melt inclusions were produced in our experiments, showing that they can form in olivine at relatively slow rates of growth (10?9 m/s or lower).
DS200712-0859
2006
Prowatke, S.Prowatke, S., Klemme, S.Rare earth element partitioning between titanite and silicate melts: Henry's law revisited.Geochimica et Cosmochimica Acta, In press availableTechnologyREE - melting
DS201412-0154
2014
Prowse, N.Cummings, D.I., Prowse, N.Till in Arctic Canada is not till.2014 Yellowknife Geoscience Forum Poster, p. 84, abstractCanada, Northwest TerritoriesDiamicton
DS201512-1923
2015
Prowse, N.D.Haiblen, A.M., Ward, B.C., Normandeau, P.X., Prowse, N.D.Glacial history and landform genesis in the Lac de Gras area and implications for kimberlite drift prospecting.43rd Annual Yellowknife Geoscience Forum Abstracts, abstract p. 43.Canada, Northwest TerritoriesGeomorphology

Abstract: During the last glaciation, bedrock was eroded, transported and deposited by the Laurentide Ice Sheet across much of Canada. The complex ice and meltwater processes that resulted in sediment deposition are not completely understood. In the central Slave Craton, Northwest Territories, glacial sediments overly many diamond-bearing kimberlites. Diamond deposits in the Lac de Gras area were discovered in the early 1990s by drift prospecting. To better interpret drift prospecting datasets a more thorough understanding of the detailed glacial history of the area is required. We spent six weeks in the Lac de Gras area in summer 2015. Field mapping was complimented by a number of other techniques to elucidate the glacial history of the area. Enigmatic landforms were examined in detail and pits were dug to examine their sedimentology. Samples of matrix material were collected to compare grain size distribution between different sediment types. Pebble counts were done to consider sediment provenance. We also collected ground-penetrating radar profiles to look for stratified sediments within enigmatic mounds. High-resolution orthophotos and a one metre LiDAR digital elevation model of the area, obtained by Dominion Diamond Ekati Corporation, have also been used to investigate landform genesis and the glacial history of the area. In the Lac de Gras area many meltwater corridors can be identified in the high-resolution imagery. These corridors are typically 300-1500 m wide and form dendritic networks. Between the corridors, sandy till of varying thickness overlies bedrock. Within corridors, glaciofluvial landforms and scoured bedrock are common. Also associated with corridors are many mounds of enigmatic origin. These mounds commonly occur in groups and are typically 20-100 m wide and rise 5-15 m above the surrounding area. They are usually composed of an unstratified to poorly-stratified sandy diamicton containing no clay and minor silt. Matrix grain size distribution and pebble lithology results from some mounds are similar to those of nearby regional till. However, patches of well-stratified sediments, exhibiting laminated silts as well as climbing ripples in sand, do exist on parts of some mounds. GPR data suggests that these patches are discontinuous, and that the majority of mounds are composed largely of sandy diamicton. Variation in the sedimentology of the mounds does not appear to be related to variations in mound morphology. It is likely that the majority of the glaciofluvial sediments in the Lac de Gras area were deposited during the final stages of ice retreat across the area when meltwater volumes were high. We suggest that the corridors were formed by subglacial meltwater flow. This is because glaciofluvial deposition almost exclusively occurs within corridors, very little till is found within corridors and the corridors have an undulating elevation profile in the direction of ice flow. Water must have played a role in the deposition of the well-stratified patches of sediment found on some mounds, however, the mounds may not be solely the product of subglacial meltwater flow. A thorough understanding of sediment transport and depositional processes is critical if kimberlite indicator mineral data is to be accurately interpreted.
DS1990-1203
1990
Proy, C.Proy, C., Tanre, D., Deschamps, P.Y.Evaluation of topographic effects in remotely sensed dataRemote Sensing of the Environment, Vol. 30, pp. 21-32Europe, PyreneesRemote sensing, Topography
DS2003-1116
2003
Proyer, A.Proyer, A.Metamorphism of pelites in NKFMASH - a new petrogenetic grid with implications forJournal of Metamorphic Geology, Vol. 21, 5, June pp. 493-510.GlobalUHP - not specific to diamonds
DS200412-1596
2003
Proyer, A.Proyer, A.Metamorphism of pelites in NKFMASH - a new petrogenetic grid with implications for the preservation of high pressure mineral assJournal of Metamorphic Geology, Vol. 21, 5, June pp. 493-510.TechnologyUHP - not specific to diamonds
DS200412-1597
2004
Proyer, A.Proyer, A., Dachs, E., McCamon, C.pit falls in geothermobarometry of eclogites: Fe 3+ and changes in the mineral chemistry of omphacite at ultrahigh pressures.Contributions to Mineralogy and Petrology, Vol. 147, 3, pp. 305-329.TechnologyEclogite - geochemistry
DS200612-1076
2006
Proyer, A.Perraki, M., Proyer, A., Mposkos, E., Kaindl, R., Hoinkes, G.Raman micro spectroscopy on diamond, graphite and other carbon polymorphs from the ultrahigh pressure metamorphic Kimi Complex of the Rhodope metamorphic province.Earth and Planetary Science Letters, Vol. 241, 3-4, pp. 672-685.Europe, GreeceUHP
DS201012-0601
2010
Proyer, A.Proyer,A., Krenn, K., Hoinkes, G.Open system precipitation - a new way to explain crystallographically oriented precipitates/exsolutions in mineral from high-T/high-P rocks.International Mineralogical Association meeting August Budapest, abstract p. 211.Europe, Greece, BulgariaUHP Rhodope Mountains
DS201607-1371
2016
Proyer, A.Proyer, A.Redox reactions caused by exsolution: a potential factor influencing mantle redox state and diamond formation.IGC 35th., Session The Deep Earth 1 p. abstractMantleDiamond formation
DS201607-1372
2016
Proyer, A.Proyer, A.Reducing environment in chromitites: possible causes for PGE and diamond formation.IGC 35th., Session The Deep Earth 1 p. abstractMantleDiamond formation
DS202109-1483
2021
Proyer, A.Moore, A., Costin, G., Proyer, A.Cognate versus xenocrystic olivines in kimberlites - a review.Earth Science Reviews , 103771 75p. PdfAfrica, South Africadeposit - Monastery

Abstract: Models for a xenocryst origin for kimberlite olivines emphasise the similarity between their core compositions and those in mantle peridotites. While this permits a xenocryst origin, it does not provide proof, as magmas generated in equilibrium with mantle olivines could, in principle, crystallize initial olivines matching those in the source region. Further, in several kimberlites, there is a striking disparity between the compositional range of olivine cores and that in associated mantle peridotite xenoliths from the same locality. Olivine-liquid Mg-Fe exchange coefficients and Ni partition coefficients permit equilibrium between Mg-rich mantle olivines (Mg#?~?94-93) and magmas matching kimberlite bulk rock compositions. Glass inclusions in olivine megacrysts from the Monastery kimberlite, with compositions which overlap the range of archetypal Group I kimberlites, were interpreted to represent original liquids trapped at pressures of 4.5-6?GPa. These glass inclusions provide direct petrographic support for primitive melts matching kimberlite bulk chemistry in the lower SCLM. A majority of kimberlitic olivines show normal (decreasing Mg#) core to rim zonation. Cores of normal-zoned kimberlitic olivines are typically homogeneous, but collectively define a field with a range in Mg # and invariant or slightly decreasing Ni towards more Fe-rich compositions. The most Mg-rich cores of normal-zoned olivines typically have Mg# in the range 94-93, but there are marked differences in the Fe-rich extreme of the normal-zoned population between different kimberlite clusters. Olivine rims typically define a field characterized by steeply decreasing Ni, coupled with invariant or slightly increasing or decreasing Mg#, which invariably overlaps the Fe-extreme of core compositions of the relatively Mg-rich, normal-zoned olivines. Consequently, while there is a sharp inflection in chemical gradient between the respective fields of cores and rims, they nevertheless define a continuous compositional field. Trace element modelling demonstrates that these zonation patterns can be explained in terms of a Raleigh crystallization model. Most, if not all kimberlites are characterized by a subordinate group of olivine macrocrysts with cores that are Fe-rich relative to the field for rims, and thus show reverse zonation, which are interpreted to be linked to the Cr-poor megacryst suite. Rare Mg-rich olivines (relative to rims), have high-pressure inclusions of garnet, clinopyroxene and orthopyroxene. When present, such inclusions often show disequilibrium features such as internal chemical zonation. This points to a very short mantle residence time prior to entrainment by the host kimberlite, indicating a link to the Cr-rich megacryst suite rather than mantle peridotites. In addition to a variable, but generally subordinate proportion of olivines derived from Cr-poor and Cr-rich megacrysts, xenocrysts derived from disaggregated mantle peridotites will undoubtedly be present. While their proportions are difficult to quantify, the collective evidence points to a cognate origin for a majority of kimberlitic olivines. A kimberlite magma ascent model is proposed which provides a framework for understanding both olivine compositional variation and apparently enigmatic internal and external olivine morphology.
DS2002-0345
2002
Proyer, D.Dachs, E., Proyer, D.Constraints on the duration of high pressure metamorphism in the Tauarn Window from diffusion modelling of discontinuous zones in eclogite garnet.Journal of Metamorphic Geology, Vol. 20, 8, pp. 769-80.GlobalUHP - eclogite
DS1994-1732
1994
Prozesky, V.Sweeney, R.J., Prozesky, V., Przybylowiez, W.Trace element partitioning between silicate minerals and carbonatite and silicate melts at 18kb and 46kbMineralogical Magazine, Vol. 58A, pp. 885-886. AbstractMantleCarbonatite
DS1995-1862
1995
Prozesky, V.Sweeney, R.J.,Prozesky, V., Przybylowicz, W.Selected trace and minor element partioning between peridotite minerals and carbonatite melts at 18-46Kb.Geochimica et Cosmochimica Acta, Vol. 59, No. 18, Sept. pp. 3671-3684.GlobalCarbonatite, Geochemistry
DS1998-1433
1998
Prozesky, V.M.Sweeney, R.J., Konzett, J., Prozesky, V.M.The determination of hydrogen in peridotite minerals by nuclear methods7th International Kimberlite Conference Abstract, pp. 874-6.South Africa, Russia, SiberiaElastic recoil method, Oxide phases
DS1988-0557
1988
Prudden, J.M.Prudden, J.M.Physical evaluation of placer depositsAlaska Placer Mining, 10th. Annual Conference proceedings, pp. 27-30AlaskaPlacer -alluvials, Application for gold
DS200712-0860
2006
Prudden, J.M.Prudden, J.M.Geology of placer gem deposits.Gems & Gemology, 4th International Symposium abstracts, Fall 2006, p.149. abstract onlyGlobalDiamond alluvials
DS1992-1239
1992
Prudhomme, N.Prudhomme, N.Caracterisation petrographique et geochimique de la carbonatite de la syenite de la mine Lac Shortt.University of du Quebec a Chicoutimi, MSc., 64p.QuebecCarbonatite
DS1999-0522
1999
Pruess, K.Oldenburg, C.M., Pruess, K.Plume separation by transient thermohaline convection in porous mediaGeophysical Research Letters, Vol. 26, No. 19, Oct. 1, pp. 2997-GlobalGeophysics, Plume - convection
DS1994-1416
1994
Pruett, L.M.Pruett, L.M.Developments in mined land reclamation legislation in ArizonaAmerican Institute of Mining, Metallurgical, and Petroleum Engineers (AIME) Preprint, Meeting held Albuquerque Feb. 14-17th, No. 94-220, 4pArizonaLegal environmental, Reclamation laws
DS1982-0510
1982
Prugger, A.F.Prugger, A.F.Conductive Studies in the Vicinity of the Mid-continent Gravity High.Eos, Vol. 63, No. 45, P. 909, (abstract.).GlobalMid-continent
DS1982-0511
1982
Prugger, A.F.Prugger, A.F., Woods, D.V.Conductive Structures in the Vicinity of the Mid-continent Gravity High.Eos, Vol. 63, No. 45, P. 909. (abstract.).GlobalMid-continent
DS1984-0599
1984
Prugger, A.F.Prugger, A.F., Woods, D.V.The Pattern of Anomalous Geomagnetic Variation Fields Over The Midcontinent Gravity High.Journal of Geophysical Research, Vol. 89, No. B9, PP. 7773-7782.GlobalMid Continent
DS201707-1363
2017
Pruseth, K.L.Shaikh, A.M., Patel, S.C., Ravi, S., Behera, D., Pruseth, K.L.Mineralogy of the TK1 and TK4 'kimberlites' in the Timmasamudram cluster, Wajrakur kimberlite field, India: implications for lamproite magmatism in a field of kimberlites and ultramafic lamprophyres.Chemical Geology, Vol. 455, pp. 208-230.Indiadeposit - Wajrakur

Abstract: A mineralogical study of the hypabyssal facies, late Cretaceous macrocrystic pulse of TK1 intrusion and the Mesoproterozoic aphanitic pulse of TK4 intrusion in the Wajrakarur Kimberlite Field of southern India shows that the rocks contain macrocrysts of forsteritic olivine, phenocrysts and microphenocrysts of Al–Na-poor diopside and phlogopite set in a groundmass mainly of Al–Na-poor diopside and phlogopite. Other groundmass minerals are spinel, perovskite and fluorapatite in TK1, and spinel, titanite, chlorite, calcite and gittinsite in TK4. K-richterite and perovskite occur only as inclusions in phlogopite and titanite, respectively in TK4. Late-stage deuteric phases include pyrite and barite in TK1, and strontianite, chalcopyrite, galena and pentlandite in TK4. Diopside microphenocrysts in TK4 exhibit oscillatory zoning with characteristics of diffusion controlled magmatic growth. TK1 spinels show magmatic trend 2 that evolves from magnesiochromite and culminates in titaniferous magnetite, whereas TK4 spinels are less evolved with magnesiochromite composition only. TK1 phlogopites show a simple compositional trend that is typical of lamproite micas, while four distinct growth zones are observed in TK4 phlogopites with the following compositional characteristics: zone I: high Cr2O3 and TiO2 and low BaO; zone II: low Cr2O3; zone III: low TiO2 and high BaO; zone IV: low BaO. Forsterite contents and trace element concentrations reveal two xenocrystic core populations and one magmatic rim population for TK1 olivines. Mineralogically, both TK1 and TK4 are classified as diopside–phlogopite lamproites rather than archetypal kimberlites. The two lamproites are considered to have formed from the same parent magma but crystallised under distinct oxygen fugacity conditions. With elevated content of Fe3 + in phlogopite, spinel and perovskite, TK1 appears to have crystallised in a relatively high oxygen fugacity environment. Multiple growth generations of phlogopite, spinel and fluorapatite in TK4 indicate a complex evolutionary history of the magma. Close spatial and temporal associations of Mesoproterozoic kimberlites and lamproites in southern India can possibly be explained by a unifying model which accounts for the generation of diverse magmas from a range of geochemical resevoirs in a continental rift setting.
DS201709-2067
2017
Pruseth, K.L.Upadhyay, D., Ranjan, S., Abhinay, K., Pruseth, K.L., Nanda, J.K.India-Antarica connection: constraints from deformed alkaline rocks and carbonatites.Goldschmidt Conference, abstract 1p.Indiacarbonatites

Abstract: Deformed Alkaline Rocks and Carbonatites (DARCs) are markers of suture zones where continents have rifted apart and later amalgamated [1]. Petrological and geochronological data indicates that parts of India and East Antarctica may have been involved in several episodes of collision and breakup during the assembly of past supercontinents [2]. DARCs at the eastern margin of the Eastern Ghats Province (EGP) in India preserve the record of these amalgamation and breakup events. It is thought that the Napier Complex of East Antarctica collided with the Dharwar Craton of India at ca. 1.60 Ga forming the central and eastern Indian shield [3]. New zircon U-Pb ages from DARCs at the EGP margin show that the alkaline complexes (Kamakhyanagar: 1350±14 Ma Rairakhol: 1379±6 Ma; Khariar: 1478±5 Ma; Koraput: 1387±34 Ma; Kunavaram: 1360±5 Ma; Jojuru: 1352±6 Ma) were emplaced in a narrow time interval. The alkaline magmatism marks an episode of rifting in the Indo-Antarctic continental fragment, correlatable with breakup of the Columbia supercontinent. Metamorphic zircon from the alkaline rocks furnish age populations at 917-950 Ma, 792- 806 Ma and 562-569 Ma. The 917-950 Ma ages are correlated with the closure of an oceanic basin between the Ruker Terrane of East Antarctica and the Indian Shield during the assembly of the Rodinia supercontinent. This led to the collision of the Ruker Terrane with the combined India-Napier Complex producing the Grenville-age EGPRayner Complex orogen [2, 3]. The 792-806 Ma ages record the disintegration of Rodinia when Greater India started to break away from East Antarctica [4]. In the early Paleozoic, India reconverged towards Antarctica and Australia during Gondwanaland assembly. The 562-569 Ma zircon ages date the resulting collisions during Pan-African orogenesis.
DS201710-2272
2017
Pruseth, K.L.Upadhyay, D., Ranjan, S., Abhinay, K., Pruseth, K.L., Nanda, J.K.India-Antarctica connection: constraints from deformed alkaline rocks and carbonatites.Goldschmidt Conference, 1p. AbstractIndiacarbonatites

Abstract: Re-Os and platinum group element analyses are reported for peridotite xenoliths from the 533 Ma Venetia kimberlite cluster situated in the Limpopo Mobile Belt, the Neoarchaean collision zone between the Kaapvaal and Zimbabwe Cratons. The Venetian xenoliths provide a rare opportunity to examine the state of the cratonic lithosphere prior to major regional metasomatic disturbance of Re-Os systematics throughout the Phanerozoic. The 32 studied xenoliths record Si-enrichment that is characteristic of the Kaapvaal lithospheric mantle and can be subdivided into five groups based on Re-Os analyses. The most pristine group I samples (n = 13) display an approximately isochronous relationship and fall on a 3.28 ± 0.17 Ga (95 % conf. int.) reference line that is based on their mean TMA age. This age overlaps with the formation age of the Limpopo crust at 3.35-3.28 Ga. The group I samples derive from ?50 to ?170 km depth, suggesting coeval melt depletion of the majority of the Venetia lithospheric mantle column. Group II and III samples have elevated Re/Os due to Re addition during kimberlite magmatism. Group II has otherwise undergone a similar evolution as the group I samples with overlapping 187Os/188Os at eruption age: 187Os/188OsEA, while group III samples have low Os concentrations, unradiogenic 187Os/188OsEA and were effectively Re-free prior to kimberlite magmatism. The other sample groups (IV and V) have disturbed Re-Os systematics and provide no reliable age information. A strong positive correlation is recorded between Os and Re concentrations for group I samples, which is extended to groups II and III after correction for kimberlite addition. This positive correlation precludes a single stage melt depletion history and indicates coupled remobilisation of Re and Os. The combination of Re-Os mobility, preservation of the isochronous relationship, correlation of 187Os/188Os with degree of melt depletion and lack of radiogenic Os addition puts tight constraints on the formation and subsequent evolution of Venetia lithosphere. First, melt depletion and remobilisation of Re and Os must have occurred within error of the 3.28 Ga mean TMA age. Second, the refractory peridotites contain significant Re despite recording >40 % melt extraction. Third, assuming that Si-enrichment and Re-Os mobility in the Venetia lithospheric mantle were linked, this process must have occurred within ?100 Myr of initial melt depletion in order to preserve the isochronous relationship. Based on the regional geological evolution, we propose a rapid recycling model with initial melt depletion at ?3.35 Ga to form a tholeiitic mafic crust that is recycled at ?3.28 Ga, resulting in the intrusion of a TTG suite and Si-enrichment of the lithospheric mantle. The non-zero primary Re contents of the Venetia xenoliths imply that TRD model ages significantly underestimate the true depletion age even for highly depleted peridotites. The overlap of the ?2.6 Ga TRD ages with the time of the Kaapvaal-Limpopo collision is purely fortuitous and has no geological significance. Hence, this study underlines the importance of scrutiny if age information is to be derived from whole rock Re-Os analyses.
DS201809-2052
2017
Pruseth, K.L.Kumar, S.P., Patel, S.C., Ravi, S., Pruseth, K.L.Mineralogy of the Banganapalle lamproite, India, and spinel zonation as a record of chemical evolution during crystallization.Geophysical Research Abstracts EGU , Vol. 19, EGU2017-12945-2 1p. AbstractIndialamproites

Abstract: The Mesoproterozoic Banganapalle Lamproite Field of southern India comprises four lamproite dykes which have intruded the Tadpatri Shale of the Cuddapah platformal sedimentary sequence. Mineralogical study of the dyke no. 551/110/4 shows that the rock has an inequigranular texture with megacrysts and macrocrysts of possibly olivine which are completely pseudomorphed by calcite and quartz due to pervasive hydrothermal and/or duteric alteration. Phenocrysts and microphenocrysts of phlogopite are highly chloritised with occasional preservation of relicts. The groundmass is dominated by calcite with subordinate amounts of phlogopite (completely chloritised), diopside, apatite, rutile and spinel. Other minor phases in the groundmass include titanite, allanite, monazite, zircon, barite, carboceranite, pyrite, pyrrhotite, chalcopyrite, galena, sphalerite, heazlewoodite, and pentlandite. Spinel occurs in three textural types: (i) xenocrysts showing homogeneous composition; (ii) phenocrysts and microphenocrysts with continuous compositional zoning from the core to the rim; and (iii) groundmass crystals with distinct growth zones marked by discontinuous compositional zoning from the core to the rim. Four growth zones (zones I-IV) of spinel are recognized. Phenocrysts and microphenocrysts are designated as zone I spinels which have 55.0-65.7 wt% Cr2O3, 2.7-7.2 wt% Al2O3, <0.4 wt% TiO2, and record a decrease in Al/(Al+Cr) from the core to the rim. Zone II spinels either occur as overgrowth rims on xenocrystal and zone I spinels or form cores to zone III rims in discrete grains, and have higher TiO2 (1.2-3.6 wt%), lower Al2O3 (1.2-2.9 wt%) and similar Cr2O3 (55.0-63.8 wt%) contents compared to zone I spinels. Zone III spinels either occur as overgrowth rims on xenocrystal and zone II spinels or form cores to zone IV rims in discrete grains, and contain higher Al2O3 (5.7-10.2 wt%), lower Cr2O3 (45.9-56.0 wt%) and similar TiO2 (1.6-3.4 wt%) compared to zone II spinels. Overgrowth rims of zone II and zone III spinels locally exhibit oscillatory zoning with characteristics of diffusion controlled magmatic growth. Zone IV spinels are marked by low Cr2O3 (17.4-25.5 wt%) and Al2O3 (1.6-2.0 wt%), and high Fe2O3 (28.8-35.4 wt%) and TiO2 (4.0-7.1 wt%) contents. Xenocrystal spinels are distinguished from magmatic spinels by high Al2O3 content (11.3-22.4 wt%) and uniform composition of individual grains. The wide range of composition and the zonation pattern of magmatic spinels suggest that the mineral was on the liquidus through most part of the lamproite crystallisation. The abrupt changes in composition between the zones indicate hiatus in crystallisation and/or sudden changes in the environmental conditions, resulting from crystallisation of associated minerals and periodic emplacement of certain elements into the magma. Diopside occurs in groundmass segregations and has low contents of Na2O (<0.77 wt%), Al2O3 (<1.2 wt%), Cr2O3 (<0.25 wt%) and TiO2 (<1.7 wt%), although higher values of TiO2 (up to 3.0 wt%) are locally encountered. Phenocrystal phlogopite has Mg/(Mg+Fe2+) ratios in the range of 0.76-0.83, and a Cr-rich composition (3.2-3.6 wt% Cr2O3) that indicates its crystallisation at mantle pressures. Co-precipitation of this phlogopite with phencocrystal spinel can explain the observed Al-Cr zoning in the latter.
DS201902-0264
2019
Pruseth, K.L.Chakraborty, T., Upadhyay, D., Ranjan, S., Pruseth, K.L., Nanda, J.K.The geological evolution of the Gangpur schist belt, eastern India: constraints on the formation of the greater Indian landmass of the Proterozoic.Journal of Metamorphic Geology, Vol. 37, 1, pp. 113-151.Indiageology

Abstract: The Central Indian Tectonic Zone (CITZ) is a Proterozoic suture along which the Northern and Southern Indian Blocks are inferred to have amalgamated forming the Greater Indian Landmass. In this study, we use the metamorphic and geochronological evolution of the Gangpur Schist Belt (GSB) and neighbouring crustal units to constrain crustal accretion processes associated with the amalgamation of the Northern and Southern Indian Blocks. The GSB sandwiched between the Bonai Granite pluton of the Singhbhum craton and granite gneisses of the Chhotanagpur Gneiss Complex (CGC) links the CITZ and the North Singhbhum Mobile Belt. New zircon age data constrain the emplacement of the Bonai Granite at 3,370 ± 10 Ma, while the magmatic protoliths of the Chhotanagpur gneisses were emplaced at c. 1.65 Ga. The sediments in the southern part of the Gangpur basin were derived from the Singhbhum craton, whereas those in the northern part were derived dominantly from the CGC. Sedimentation is estimated to have taken place between c. 1.65 and c. 1.45 Ga. The Upper Bonai/Darjing Group rocks of the basin underwent major metamorphic episodes at c. 1.56 and c. 1.45 Ga, while the Gangpur Group of rocks were metamorphosed at c. 1.45 and c. 0.97 Ga. Based on thermobarometric studies and zircon-monazite geochronology, we infer that the geological history of the GSB is similar to that of the North Singhbhum Mobile Belt with the Upper Bonai/Darjing and the Gangpur Groups being the westward extensions of the southern and northern domains of the North Singhbhum Mobile Belt respectively. We propose a three?stage model of crustal accretion across the Singhbhum craton - GSB/North Singhbhum Mobile Belt - GC contact. The magmatic protoliths of the Chhotanagpur Gneisses were emplaced at c. 1.65 Ga in an arc setting. The earliest accretion event at c. 1.56 Ga involved northward subduction and amalgamation of the Upper Bonai Group with the Singhbhum craton followed by accretion of the Gangpur Group with the Singhbhum craton-Upper Bonai Group composite at c. 1.45 Ga. Finally, continent-continent collision at c. 0.96 Ga led to the accretion of the CGC with the Singhbhum craton-Upper Bonai Group-Gangpur Group crustal units, synchronous with emplacement of pegmatitic granites. The geological events recorded in the GSB and other units of the CITZ only partially overlap with those in the Trans North China Orogen and the Capricorn Orogen of Western Australia, indicating that these suture zones are not correlatable.
DS202010-1853
2020
Pruseth, K.L.Kumar, S.P., Shaikh, A.M., Patel, S.C., Sheikh, J.M., Behera, D., Pruseth, K.L., Ravi, S.,Tappe, S.Multi-stage magmatic evidence of olivine-leucite lamproite dykes from Banganapalle, Dharwar craton, India: evidence from compositional zoning of spinel.Mineralogy and Petrology, doi.org/10.1007/s00710-020-00722-y 26p. PdfIndialamproite

Abstract: Mesoproterozoic lamproite dykes occurring in the Banganapalle Lamproite Field of southern India show extensive hydrothermal alteration, but preserve fresh spinel, apatite and rutile in the groundmass. Spinels belong to three genetic populations. Spinels of the first population, which form crystal cores with overgrowth rims of later spinels, are Al-rich chromites derived from disaggregated mantle peridotite. Spinels of the second population include spongy-textured grains and alteration rims of titanian magnesian aluminous chromites that formed by metasomatic interactions between mantle wall-rocks and precursor lamproite melts before their entrainment into the erupting lamproite magma. Spinels that crystallised directly from the lamproite magma constitute the third population and show five distinct compositional subtypes (spinel-IIIa to IIIe), which represent discrete stages of crystal growth. First stage magmatic spinel (spinel-IIIa) includes continuously zoned macrocrysts of magnesian aluminous chromite, which formed together with Al-Cr-rich phlogopite macrocrysts from an earlier pulse of lamproite magma at mantle depth. Crystallisation of spinel during the other four identified stages occurred during magma emplacement at crustal levels. Titanian magnesian chromites (spinel-IIIb) form either discrete crystals or overgrowth rims on spinel-IIIa cores. Further generations of overgrowth rims comprise titanian magnesian aluminous chromite (spinel-IIIc), magnetite with ulvöspinel component (spinel-IIId) and lastly pure magnetite (spinel-IIIe). Abrupt changes of the compositions between successive zones of magmatic spinel indicate either a hiatus in the crystallisation history or co-crystallisation of other groundmass phases, or possibly magma mixing. This study highlights how different textural and compositional populations of spinel provide important insights into the complex evolution of lamproite magmas including clues to elusive precursor metasomatic events that affect cratonic mantle lithosphere.
DS202103-0390
2021
Pruseth, K.L.Kumar, S.P., Shaikh, A.M., Patel, S.C., Sheikh, J.M., Behera, D., Pruseth, K.L., Ravi, S., Tappe, S.Multi-stage magmatic history of olivine-leucite lamproite dykes from Banganapalle, Dharwar craton, India: evidence from compositional zoning of spinel.Mineralogy and Petrology, Vol. 115, pp. 87-112. pdfIndialamproite

Abstract: Mesoproterozoic lamproite dykes occurring in the Banganapalle Lamproite Field of southern India show extensive hydrothermal alteration, but preserve fresh spinel, apatite and rutile in the groundmass. Spinels belong to three genetic populations. Spinels of the first population, which form crystal cores with overgrowth rims of later spinels, are Al-rich chromites derived from disaggregated mantle peridotite. Spinels of the second population include spongy-textured grains and alteration rims of titanian magnesian aluminous chromites that formed by metasomatic interactions between mantle wall-rocks and precursor lamproite melts before their entrainment into the erupting lamproite magma. Spinels that crystallised directly from the lamproite magma constitute the third population and show five distinct compositional subtypes (spinel-IIIa to IIIe), which represent discrete stages of crystal growth. First stage magmatic spinel (spinel-IIIa) includes continuously zoned macrocrysts of magnesian aluminous chromite, which formed together with Al-Cr-rich phlogopite macrocrysts from an earlier pulse of lamproite magma at mantle depth. Crystallisation of spinel during the other four identified stages occurred during magma emplacement at crustal levels. Titanian magnesian chromites (spinel-IIIb) form either discrete crystals or overgrowth rims on spinel-IIIa cores. Further generations of overgrowth rims comprise titanian magnesian aluminous chromite (spinel-IIIc), magnetite with ulvöspinel component (spinel-IIId) and lastly pure magnetite (spinel-IIIe). Abrupt changes of the compositions between successive zones of magmatic spinel indicate either a hiatus in the crystallisation history or co-crystallisation of other groundmass phases, or possibly magma mixing. This study highlights how different textural and compositional populations of spinel provide important insights into the complex evolution of lamproite magmas including clues to elusive precursor metasomatic events that affect cratonic mantle lithosphere.
DS202203-0361
2022
Pruseth, K.L.Patel, A., Mishra, B., Upadhyay, D., Pruseth, K.L.Mineralogical and geochemical evidence of dissolution-reprecipitation controlled hydrothermal rare earth mineralization in the Amba Dongar carbonatite complex, Gujarat, western India.Economic Geology, Vol. 117, pp. 683-702.Indiadeposit - Amba Dongar

Abstract: The Amba Dongar carbonatite complex in western India comprises an inner ring of carbonatite breccia surrounded by a sövite ring dike. The various carbonatite units in the body include calcite carbonatite, alvikite, dolomite carbonatite, and ankerite carbonatite. The carbonate phases (calcite and ankerite) occur as phenocrysts, groundmass phases, fresh primary grains, and partially altered grains and/or pseudomorphs when hydrothermally overprinted. Rare earth element (REE) enrichment in the groundmass/altered calcite grains compared to the magmatic ones is ascribed to the presence of micron-sized REE phases. Fluorapatite and pyrochlore constitute important accessory phases that are altered to variable extents. Higher concentrations of Sr, Si, and REEs in fluorapatite are suggestive of a magmatic origin. Fresh pyrochlore preserves its magmatic composition, characterized by low A-site vacancy and high F in the Y-site, which on alteration becomes poorer in Na, Ca, and F and displays an increase in vacancy. The C-O isotope compositions of the carbonates also corroborate the extensive low-temperature hydrothermal alteration of the carbonatites. The REE mineralization is the result of interaction of the carbonatite with a sulfur-bearing, F-rich hydrothermal fluid that exsolved from late-stage carbonatitic magmas. The hydrothermal fluids caused dissolution of the primary carbonates and simultaneous precipitation of REEs and other high field strength element (HFSE)-bearing minerals. Complex spatial associations of the magmatic minerals with the REE fluorocarbonates, [synchysite-(Ce), parisite-(Ce), bastnäsite-(Ce)] and florencite-(Ce) point to the formation of these REE phases as a consequence of postmagmatic hydrothermal dissolution of the REEs from fluorapatite, pyrochlore, and carbonates. Ubiquitous association of fluorite and barite with REE minerals indicates transport of REEs as sulfate complexes in F-rich fluids. Precipitation of REE fluorocarbonates/florencite resulted from fluid-carbonate interaction, concomitant increase in pH, and decrease in temperature. Additionally, REE precipitation was aided and abetted by the removal of sulfur from the fluid by the precipitation of barite, which destabilized the REE sulfate complexes.
DS202109-1472
2021
Pruss, S.B.Hoffman, P.F., Halverson, G.P., Schrag, D.P., Higgins, J.A., Domack, E.W., Macdonald, F.A., Pruss, S.B., Blattler, C.L., Crockford, P.W., Hodgin, E.B., Bellefroid, E.J., Johnson, B.W., Hodgskiss, M.S.W., Lamothe, K.G., LoBianco, S.J.C., Busch, J.F., HowesSnowballs in Africa: sectioning a long-lived Neoproterozoic carbonate platform and its bathyal foreslope ( NW Namibia). (Octavi Group)Earth Science Reviews , Vol. 219, 103616 231p. PdfAfrica, NamibiaCraton - Congo

Abstract: Otavi Group is a 1.5-3.5-km-thick epicontinental marine carbonate succession of Neoproterozoic age, exposed in an 800-km-long Ediacaran?Cambrian fold belt that rims the SW cape of Congo craton in northern Namibia. Along its southern margin, a contiguous distally tapered foreslope carbonate wedge of the same age is called Swakop Group. Swakop Group also occurs on the western cratonic margin, where a crustal-scale thrust cuts out the facies transition to the platformal Otavi Group. Subsidence accommodating Otavi Group resulted from S?N crustal stretching (770-655?Ma), followed by post-rift thermal subsidence (655-600?Ma). Rifting under southern Swakop Group continued until 650-635?Ma, culminating with breakup and a S-facing continental margin. No hint of a western margin is evident in Otavi Group, suggesting a transform margin to the west, kinematically consistent with S?N plate divergence. Rift-related peralkaline igneous activity in southern Swakop Group occurred around 760 and 746?Ma, with several rift-related igneous centres undated. By comparison, western Swakop Group is impoverished in rift-related igneous rocks. Despite low paleoelevation and paleolatitude, Otavi and Swakop groups are everywhere imprinted by early and late Cryogenian glaciations, enabling unequivocal stratigraphic division into five epochs (period divisions): (1) non-glacial late Tonian, 770-717?Ma; (2) glacial early Cryogenian/Sturtian, 717-661?Ma; (3) non-glacial middle Cryogenian, 661-646?±?5?Ma; (4) glacial late Cryogenian/Marinoan, 646?±?5-635?Ma; and (5) non-glacial early Ediacaran, 635-600?±?5?Ma. Odd numbered epochs lack evident glacioeustatic fluctuation; even numbered ones were the Sturtian and Marinoan snowball Earths. This study aimed to deconstruct the carbonate succession for insights on the nature of Cryogenian glaciations. It focuses on the well-exposed southwestern apex of the arcuate fold belt, incorporating 585?measured sections (totaling >190?km of strata) and?>?8764 pairs of ?13C/?18Ocarb analyses (tabulated in Supplementary On-line Information). Each glaciation began and ended abruptly, and each was followed by anomalously thick ‘catch-up’ depositional sequences that filled accommodation space created by synglacial tectonic subsidence accompanied by very low average rates of sediment accumulation. Net subsidence was 38% larger on average for the younger glaciation, despite its 3.5-9.3-times shorter duration. Average accumulation rates were subequal, 4.0 vs 3.3-8.8?m Myr?1, despite syn-rift tectonics and topography during Sturtian glaciation, versus passive-margin subsidence during Marinoan. Sturtian deposits everywhere overlie an erosional disconformity or unconformity, with depocenters ?1.6?km thick localized in subglacial rift basins, glacially carved bedrock troughs and moraine-like buildups. Sturtian deposits are dominated by massive diamictite, and the associated fine-grained laminated sediments appear to be local subglacial meltwater deposits, including a deep subglacial rift basin. No marine ice-grounding line is required in the 110 Sturtian measured sections in our survey. In contrast, the newly-opened southern foreslope was occupied by a Marinoan marine ice grounding zone, which became the dominant repository for glacial debris eroded from the upper foreslope and broad shallow troughs on the Otavi Group platform, which was glaciated but left nearly devoid of glacial deposits. On the distal foreslope, a distinct glacioeustatic falling-stand carbonate wedge is truncated upslope by a glacial disconformity that underlies the main lowstand grounding-zone wedge, which includes a proximal 0.60-km-high grounding-line moraine. Marinoan deposits are recessional overall, since all but the most distal overlie a glacial disconformity. The Marinoan glacial record is that of an early ice maximum and subsequent slow recession and aggradation, due to tectonic subsidence. Terminal deglaciation is recorded by a ferruginous drape of stratified diamictite, choked with ice-rafted debris, abruptly followed by a syndeglacial-postglacial cap-carbonate depositional sequence. Unlike its Sturtian counterpart, the post-Marinoan sequence has a well-developed basal transgressive (i.e., deepening-upward) cap dolomite (16.9?m regional average thickness, n?=?140) with idiosyncratic sedimentary features including sheet-crack marine cements, tubestone stromatolites and giant wave ripples. The overlying deeper-water calci-rhythmite includes crystal-fans of former aragonite benthic cement ?90?m thick, localized in areas of steep sea-floor topography. Marinoan sequence stratigraphy is laid out over ?0.6?km of paleobathymetric relief. Late Tonian shallow-neritic ?13Ccarb records were obtained from the 0.4-km-thick Devede Fm (~770-760?Ma) in Otavi Group and the 0.7-km-thick Ugab Subgroup (~737-717?Ma) in Swakop Group. Devede Fm is isotopically heavy, +4-8‰ VPDB, and could be correlative with Backlundtoppen Fm (NE Svalbard). Ugab Subgroup post-dates 746?Ma volcanics and shows two negative excursions bridged by heavy ?13C values. The negative excursions could be correlative with Russřya and Garvellach CIEs (carbon isotope excursions) in NE Laurentia. Middle Cryogenian neritic ?13C records from Otavi Group inner platform feature two heavy plateaus bracketed by three negative excursions, correlated with Twitya (NW Canada), Taishir (Mongolia) and Trezona (South Australia) CIEs. The same pattern is observed in carbonate turbidites in distal Swakop Group, with the sub-Marinoan falling-stand wedge hosting the Trezona CIE recovery. Proximal Swakop Group strata equivalent to Taishir CIE and its subsequent heavy plateau are shifted bidirectionally to uniform values of +3.0-3.5‰. Early Ediacaran neritic ?13C records from Otavi Group inner platform display a deep negative excursion associated with the post-Marinoan depositional sequence and heavy values (??+?11‰) with extreme point-to-point variability (?10‰) in the youngest Otavi Group formation. Distal Swakop Group mimics older parts of the early Ediacaran inner platform ?13C records, but after the post-Marinoan negative excursion, proximal Swakop Group values are shifted bidirectionally to +0.9?±?1.5‰. Destruction of positive and negative CIEs in proximal Swakop Group is tentatively attributed to early seawater-buffered diagenesis (dolomitization), driven by geothermal porewater convection that sucks seawater into the proximal foreslope of the platform. This hypothesis provocatively implies that CIEs originating in epi-platform waters and shed far downslope as turbidites are decoupled from open-ocean DIC (dissolved inorganic carbon), which is recorded by the altered proximal Swakop Group values closer to DIC of modern seawater. Carbonate sedimentation ended when the cratonic margins collided with and were overridden by the Atlantic coast-normal Northern Damara and coast-parallel Kaoko orogens at 0.60-0.58?Ga. A forebulge disconformity separates Otavi/Swakop Group from overlying foredeep clastics. In the cratonic cusp, where the orogens meet at a right angle, the forebulge disconformity has an astounding ?1.85?km of megakarstic relief, and km-thick mass slides were displaced gravitationally toward both trenches, prior to orogenic shortening responsible for the craton-rimming fold belt.
DS200712-1111
2007
Prusskaya, S.N.Vasilev, Y.R., Prusskaya, S.N., Mazurov, M.P.A new type of large scale manifestation of within plate intrusive trap magmatism.Doklady Earth Sciences, Vol. 413, 2, pp. 187-191.RussiaMagmatism
DS200812-0927
2008
Prutkin, L.Prutkin, L.Gravitational and magnetic models of the core-mantle boundary and their correlation.Journal of Geodyanmics, Vol. 45, 2-3, March pp. 146-153.MantleCore, mantle boundary, gravity
DS1998-1194
1998
Pryde, R.Pryde, R.Seismic investigation of the Buffalo Hills kimberlite ProvinceAbstract only, 1/4pg.AlbertaGeophysics - seismics
DS1998-0216
1998
Pryde, R.P.Carlson, S.M., Hillier, W.D., Hood, C.T., Pryde, R.P.The Buffalo Hills kimberlite province, north central Alberta, Canada7th International Kimberlite Conference Abstract, pp. 138-140.AlbertaKimberlites, Petrography
DS200512-0384
2005
Pryhodko, V.L.Gursky, D.S., Metalidi, V.S., Pryhodko, V.L., Geiko, Y.V.Prospects of diamond bearing ability in Ukraine and trends of geological prospecting works.Gems & Gemology, abstracts Mineralogical Journal (Ukraine) Vol. 26, 1, pp. 7-17. *** in English, Vol. 41, 2, Summer p. 194. abstract onlyEurope, UkraineStructure, occurrences
DS1993-1419
1993
Prysbylo.., W.J.Sellschop, J.P., Connell, S.H., Prysbylo.., W.J., Meyer, H.O.A.Comparison of proton and electron microbeam studies of mineral inclusions in diamond.Nucl. Institute B., Vol. 77, No. 1-4, May pp. 144-150.GlobalSpectrometry, Mineral inclusions
DS201810-2364
2018
Prytulak, J.Perrin, A., Goes, S., Prytulak, J., Rondenay, S., Davies, D.R.Mantle wedge temperatures and their potential relation to volcanic arc location.Earth and Planetary Science Letters, Vol. 501, pp. 67-77.Mantlesubduction

Abstract: The mechanisms underpinning the formation of a focused volcanic arc above subduction zones are debated. Suggestions include controls by: (i) where the subducting plate releases water, lowering the solidus in the overlying mantle wedge; (ii) the location where the mantle wedge melts to the highest degree; and (iii) a limit on melt formation and migration imposed by the cool shallow corner of the wedge. Here, we evaluate these three proposed mechanisms using a set of kinematically-driven 2D thermo-mechanical mantle-wedge models in which subduction velocity, slab dip and age, overriding-plate thickness and the depth of decoupling between the two plates are systematically varied. All mechanisms predict, on the basis of model geometry, that the arc-trench distance, D, decreases strongly with increasing dip, consistent with the negative D-dip correlations found in global subduction data. Model trends of sub-arc slab depth, H, with dip are positive if H is wedge-temperature controlled and overriding-plate thickness does not exceed the decoupling depth by more than 50 km, and negative if H is slab-temperature controlled. Observed global H-dip trends are overall positive. With increasing overriding plate thickness, the position of maximum melting shifts to smaller H and D, while the position of the trenchward limit of the melt zone, controlled by the wedge's cold corner, shifts to larger H and D, similar to the trend in the data for oceanic subduction zones. Thus, the limit imposed by the wedge corner on melting and melt migration seems to exert the first-order control on arc position.
DS201912-2779
2020
Prytulak, J.Fitzpayne, A., Prytulak, J., Giuliani, A., Hergt, J.Thallium isotope composition of phlogopite in kimberlite hosted MARID and PIC mantle xenoliths.Chemical Geology, Vol. 531, 14p. PdfMantlemetasomatism

Abstract: MARID (Mica-Amphibole-Rutile-Ilmenite-Diopside) and PIC (Phlogopite-Ilmenite-Clinopyroxene) rocks are rare mantle xenoliths entrained by kimberlites. Their high phlogopite modes (15 to ?100 vol.%) and consequent enrichments in alkali metals and H2O suggest a metasomatic origin. Phlogopite also has high concentrations (>0.2 ?g/g) of thallium (Tl) relative to mantle abundances (<3 ng/g). Thallium isotope ratios have proven useful in tracing the input of Tl-rich materials, such as pelagic sediments and altered oceanic crust, to mantle sources because of their distinct isotopic compositions compared to the peridotitic mantle. This study presents the first Tl isotopic compositions of well-characterised phlogopite separates from MARID and PIC samples to further our understanding of their genesis. The PIC rocks in this study were previously interpreted as the products of kimberlite melt metasomatism, whereas the radiogenic and stable N-O isotope systematics of MARID rocks suggest a parental metasomatic agent containing a recycled component. The ?205Tl values of phlogopite in both PIC (-2.7 ± 0.8; 2 s.d., n = 4) and MARID samples (-2.5 ± 1.3; 2 s.d., n = 21) overlap with the estimated mantle composition (-2.0 ± 1.0). PIC phlogopite Tl contents (?0.4 ?g/g) are suggestive of equilibrium with kimberlite melts (0.1-0.6 ?g/g Tl), based on partitioning experiments in other silica-undersaturated melts. Kimberlite Tl-?205Tl systematics suggest their genesis does not require a recycled contribution: however, high temperature-altered oceanic crust cannot be ruled out as a component of the Kimberley kimberlites’ source. Mantle-like ?205Tl values in MARID samples also seem to contradict previous suggestions of a recycled contribution towards their genesis. Recycled components with isotopic compositions close to mantle values (e.g., high temperature-altered oceanic crust) are still permitted. Moreover, mass balance mixing models indicate that incorporation into the primitive mantle of 1-30% of a low temperature-altered oceanic crust + continental crust recycled component or 1-50% of continental crust alone could be accommodated by the Tl-?205Tl systematics of the MARID parental melt. This scenario is consistent with experimental evidence and existing isotopic data. One PIC phlogopite separate has an extremely light Tl isotopic composition of -9.9, interpreted to result from kinetic isotopic fractionation. Overall, phlogopite is the main host mineral for Tl in metasomatised mantle and shows a very restricted range in Tl isotopic composition, which overlaps with estimates of the mantle composition. These results strongly suggest that negligible high temperature equilibrium Tl isotopic fractionation occurs during metasomatism and reinforces previous estimates of the mantle’s Tl isotopic composition.
DS202007-1141
2020
Prytulak, J.Fitzpayne, A., Prytulak, J., Giuliani, A., Hergt, J.Thallium content and isotopic composition of phlogopite in mantle derived MARID and PIC rocks.Chemical Geology, Vol. 531, 119347Mantlegeochronology
DS1900-0696
1908
PrzyborskiPrzyborskiDie Diamant gruben der Gesell. von Beers in der KapkolonieAnnual Mines (PARIS), Vol. 5, ALSO: ZEITSCHR. BERG. HUTTEN, PP. 277-280.Africa, South AfricaMining
DS1995-1862
1995
Przybylowicz, W.Sweeney, R.J.,Prozesky, V., Przybylowicz, W.Selected trace and minor element partioning between peridotite minerals and carbonatite melts at 18-46Kb.Geochimica et Cosmochimica Acta, Vol. 59, No. 18, Sept. pp. 3671-3684.GlobalCarbonatite, Geochemistry
DS1994-1732
1994
Przybylowiez, W.Sweeney, R.J., Prozesky, V., Przybylowiez, W.Trace element partitioning between silicate minerals and carbonatite and silicate melts at 18kb and 46kbMineralogical Magazine, Vol. 58A, pp. 885-886. AbstractMantleCarbonatite
DS200712-0261
2007
Psakhe, S.G.Dobtresov, V.Y., Psakhe, S.G., Popov, V.L., Shilko, E.V., Granin, Timofeev,Astafurov, Dimaki, StarchevichIce cover of Lake Baikal as a model for studying tectonic processes in the Earth's crust.Doklady Earth Sciences, Vol. 413, 2, pp. 155-159.RussiaGeomorphology
DS200812-0763
2008
Ptacek, C.J.Moore, M.L., Blowes, D.W., Ptacek, C.J., Gould, W.D., Smith, L.,Sego, D.Humidity cell analysis of waste rock from the Diavik diamond mine NWT, Canada.Goldschmidt Conference 2008, Abstract p.A647.Canada, Northwest TerritoriesDeposit - Diavik
DS201012-0031
2010
Ptacek, C.J.Bailey, B.L., Smith, L.J.D., Blowes, D.W., Ptacek, C.J., Smith, L., Sego, D.C.Diavik waste rock project: blasting residuals in waste rock piles.38th. Geoscience Forum Northwest Territories, Abstract p. 30.Canada, Northwest TerritoriesDiavik
DS201212-0046
2012
Ptacek, C.J.Bailey, B.L., Smith, L.J.D., Blowes, D.W.,Ptacek, C.J., Smith, L., Sego, D.C.The Diavik waste rock project: persistence of contaminants from blasting agents in waste rock effluent.Applied Geochemistry, in press availableCanada, Northwest TerritoriesDeposit - Diavik mining
DS201312-0850
2013
Ptacek, C.J.Bailey, B.L., Smith, L.J.D., Blowes, D.W., Ptacek, C.J., Smith, L., Sego, D.C.The Diavik waste rock project: persistence of contaminants from blasting agents in waste rock effluent.Applied Geochemistry, Vol. 36, pp. 256-270.Canada, Northwest TerritoriesMining - Diavik
DS201510-1804
2015
Ptacek, C.J.Smith, L.j.D., Ptacek, C.J., Blowes, D.W., Groza, L.G., Moncur, M.C.Perchlorate in lake water from an operating mine. DiavikEnvironmental Science and Technology, Vol. 49, 13, pp. 7589-7596.Canada, Northwest TerritoriesDeposit - Diavik

Abstract: Mining-related perchlorate [ClO4(-)] in the receiving environment was investigated at the operating open-pit and underground Diavik diamond mine, Northwest Territories, Canada. Samples were collected over four years and ClO4(-) was measured in various mine waters, the 560 km(2) ultraoligotrophic receiving lake, background lake water and snow distal from the mine. Groundwaters from the underground mine had variable ClO4(-) concentrations, up to 157 ?g L(-1), and were typically an order of magnitude higher than concentrations in combined mine waters prior to treatment and discharge to the lake. Snow core samples had a mean ClO4(-) concentration of 0.021 ?g L(-1) (n=16). Snow and lake water Cl(-)/ClO4(-) ratios suggest evapoconcentration was not an important process affecting lake ClO4(-) concentrations. The multiyear mean ClO4(-) concentrations in the lake were 0.30 ?g L(-1) (n = 114) in open water and 0.24 ?g L(-1) (n = 107) under ice, much below the Canadian drinking water guideline of 6 ?g L(-1). Receiving lake concentrations of ClO4(-) generally decreased year over year and ClO4(-) was not likely [biogeo]chemically attenuated within the receiving lake. The discharge of treated mine water was shown to contribute mining-related ClO4(-) to the lake and the low concentrations after 12 years of mining were attributed to the large volume of the receiving lake.
DS201801-0081
2018
Ptacek, C.J.Wilson, D., Amos, R.T., Blowes, D.W., Langman, J.B., Ptacek, C.J., Smith, L., Sego, D.C.Diavik waste rock project: a conceptual model for temperature and sulfide content dependent geochemical evolution of waste rock - Laboratory scale.Applied Geochemistry, Vol. 89, pp. 160-172.Canada, Northwest Territoriesdeposit - Diavik

Abstract: The Diavik Waste Rock Project consists of laboratory and field experiments developed for the investigation and scale-up of the geochemical evolution of sulfidic mine wastes. As part of this project, humidity cell experiments were conducted to assess the long-term geochemical evolution of a low-sulfide waste rock. Reactive transport modelling was used to assess the significant geochemical processes controlling oxidation of sulfide minerals and their dependence on temperature and sulfide mineral content. The geochemical evolution of effluent from waste rock with a sulfide content of 0.16 wt.% and 0.02 wt.% in humidity cells was simulated with the reactive transport model MIN3P, based on a conceptual model that included constant water flow, sulfide mineral content, sulfide oxidation controlled by the availability of oxidants, and subsequent neutralization reactions with carbonate and aluminosilicate minerals. Concentrations of Ni, Co, Cu, Zn, and SO4 in the humidity cell effluent were simulated using the shrinking core model, which represented the control of oxidant diffusion to the unreacted particle surface in the sulfide oxidation process. The influence of temperature was accounted for using the Arrhenius relation and appropriate activation energy values. Comparison of the experiment results, consisting of waste rock differentiated by sulfide mineral content and temperature, indicated surface area and temperature play important roles in rates of sulfide oxidation and release of sulfate and metals. After the model was calibrated to fit the effluent data from the higher sulfide content cells, subsequent simulations were conducted by adjusting only measured parameters, including sulfide mineral content and surface area.
DS1996-0086
1996
Ptersen, S.W.Barnes, C.G., Ptersen, S.W., Kays, M.A.Source and tectonic implications of tonalite trondhjemite magmatism in the Klamath Mountains.Contributions to Mineralogy and Petrology, Vol. 123, No. 2, pp. 40-60.CaliforniaTectonics
DS201809-2077
2018
Pu, Y.Pu, Y., Derek, A., Huawei, X.A principal component analysis/fuzzy comprehensive evaluation for rockburst potential in kimberlite.Pure and Applied Physics, Vol. 175, 6, pp. 2141-2151.Canada, Northwest Territoriesmining

Abstract: Kimberlite is an igneous rock which sometimes bears diamonds. Most of the diamonds mined in the world today are found in kimberlite ores. Burst potential in kimberlite has not been investigated, because kimberlite is mostly mined using open-pit mining, which poses very little threat of rock bursting. However, as the mining depth keeps increasing, the mines convert to underground mining methods, which can pose a threat of rock bursting in kimberlite. This paper focuses on the burst potential of kimberlite at a diamond mine in northern Canada. A combined model with the methods of principal component analysis (PCA) and fuzzy comprehensive evaluation (FCE) is developed to process data from 12 different locations in kimberlite pipes. Based on calculated 12 fuzzy evaluation vectors, 8 locations show a moderate burst potential, 2 locations show no burst potential, and 2 locations show strong and violent burst potential, respectively. Using statistical principles, a Mahalanobis distance is adopted to build a comprehensive fuzzy evaluation vector for the whole mine and the final evaluation for burst potential is moderate, which is verified by a practical rockbursting situation at mine site.
DS1989-1212
1989
Publoule, M.Picard, C., Publoule, M.The Ungava trough Proterozoic basalts, Quebec- a very well preserved example of abyssal lava. (in French)Bulletin. de la Soc. Geologique de France, (in French), Vol. 5, No. 4, July-August pp. 723-736Quebec, Labrador, UngavaProterozoic basalts
DS202202-0210
2021
Pucharovsky, D.Pucharovsky, D., Balitsky, D.V., Bindi, L.The importance of crystals and crystallography in Space research programs.Crystallography Reports, Vol. 66, 6, pp. 934-939. 10.1134/S1063774521060298CosmosCrystallography

Abstract: The Mars exploration rovers have used various remote-sensing instruments over the last two and a half decades. The Chemistry and Camera tool uses laser-induced breakdown spectroscopy to obtain semi-quantitative elemental abundances. The SuperCam instrument is a response to the requirement for remote mineralogy and is also adapted for Raman spectroscopy studies. Both analyzers contain pulsed laser units with Nd:YAG rods and Pockels cells with crystals of rubidium titanyl phosphate, potassium titanyl phosphate and lithium triborate. The specific features of their structure, chemistry, and crystal growth are discussed.
DS2001-0135
2001
PuchkovBrown, D., Alvarez-Marron, J., Perez-Estaun, PuchkovStructure and evolution of the Magnitogorsk forearc basin: identifying upper crustal processes during arcTectonics, Vol. 20, No. 3, June pp. 364-75.Russia, UralsTectonics, arc terranes, subduction zone
DS202111-1793
2021
Puchkov, A.Yakovlev, E., Puchkov, A.Radon over kimberlite pipes: estimation of the emanation properties of rocks ( Lomonosov diamond deposit, NW Russia).MDPI Applied Sciences, Vol. 11, 6065, 22p. PdfRussia, Arkangelskdeposit - Lomonosov

Abstract: In this paper, using the example of the Lomonosov diamond deposit, experimental studies of rocks were carried out to assess the main radiation and physical factors affecting the formation of the radon field over the kimberlite pipes of the Arkhangelsk diamondiferous province. For various types of rocks, represented by vent kimberlites, tuffaceous-sedimentary rocks of the crater and enclosing and overlying sediments, the following were studied: porosity, density, activity of radium-226, activity of radon in a free state, level of radon production, and emanation coefficient. The research results showed that the greatest amount of radon in a free state is produced by rocks of the near-pipe space, represented by the enclosing Vendian V2 deposits and characterized by high values of the emanation coefficient, radium activity, radon production level and porosity. This fact is associated with the structural and geological features of the near-pipe space, which was exposed to the impact of kimberlite magma on the host rocks. The lowest values of these parameters are characteristic of the kimberlites of the vent facies, which limits the formation of free radon in the body of the pipe. The results of the experimental studies create prospects for the development of emanation methods for searching for kimberlite pipes in the conditions of the Arkhangelsk diamondiferous province.
DS2002-0211
2002
Puchkov, V.Brown, D., Juhlin, C., Puchkov, V.Mountain building in the Uralides ... Pangea to the presentAmerican Geophysical Union, Geophysical Monograph, No. 132, 300p.Russia, Europe, UralsBook - Tectonics, arc collision, crustal, orogenesis, Geochronology
DS200412-0223
2002
Puchkov, V.Brown, D., Juhlin, C., Puchkov, V.Mountain building in the Uralides ... Pangea to the present.American Geophysical Union, Geophysical Monograph, No. 132, 300p.Russia, Europe, UralsBook - Tectonics, arc collision, crustal, orogenesis Geochronology
DS200612-0177
2006
Puchkov, V.Brown, D., Juhlin, C., Tryggvason, A., Friberg, M., Rybalka, A., Puchkov, V.Structural architecture of the southern and middle Urals foreland from reflection seismicsTectonics, Vol. 25, 1, Jan. TC1002RussiaTectonics
DS200712-0115
2006
Puchkov, V.Brown, D., Puchkov, V., Alvarez Marron, J., Bea, F., Perez Estaun, A.Tectonic processes in the southern and middle Urals: an overview.Geological Society of London Memoir, No. 32, pp. 407-420.Russia, Europe, UralsTectonics
DS200712-0116
2006
Puchkov, V.Brown, D., Spadea, P., Puchkov, V., Alvarez-Marron, J., Herrington, R., Willner, A.P., Hetzel, R., Gorozhanina, Y., Juhlin, C.Arc continent collision in the southern Urals.Earth Science Reviews, in press availableRussia, UralsBaltica tectonics, UHP, geochemistry
DS200612-0574
2005
Puchkov, V.N.Herrington, R.J., Puchkov, V.N., Yakubchuk, A.S.A reassessment of the tectonic zonation of the Uralides: implications for metallogeny.Geological Society of London Special Paper, No. 248, pp. 153-166.RussiaTectonics
DS201012-0602
2009
Puchkov, V.N.Puchkov, V.N.The evolution of the Uralian orogen.Ancient Orogens and Modern Analogues, Geological Society of London Special Publication, No. 327, pp. 161-195.RussiaTectonics
DS201609-1738
2016
Puchkov, V.N.Puchkov, V.N.Relationship between plume and plate tectonics.Geotectonics, Vol. 50, 4, pp. 425-438.MantleGeothermometry

Abstract: The relationship between plate- and plume-tectonics is considered in view of the growth and breakdown of supercontinents, active rifting, the formation of passive volcanic-type continental margins, and the origin of time-progressive volcanic chains on oceanic and continental plates. The mantle wind phenomenon is described, as well as its effect on plume morphology and anisotropy of the ambient mantle. The interaction of plumes and mid-ocean ridges is discussed. The principles and problems of plume activity analysis in subduction- and collision-related foldbelts are considered and illustrated with examples.
DS201711-2527
2017
Puchkov, V.N.Saveliev, D.E., Puchkov, V.N., Sergeev, S.N., Misabirov, I.I.Deformation induced decomposition of enstatite in mantle peridotite and its role in partial melting and chromite ore formation.Doklady Earth Sciences, Vol. 476, 1, pp. 1058-1061.Mantleperidotite

Abstract: Deformed orthopyroxene grains are studied in detail in mantle peridotite. It is shown that deformation of enstatite is accompanied by its decomposition with the formation of low-temperature phases (pargasite, Fe-rich olivine) and restite represented by depleted enstatite, forsterite, and small newly formed chrome spinellide grains. The role of plastic deformation in initiation of partial melting of peridotite and in the formation new chrome spinellide grains is discussed.
DS201905-1053
2019
Puchkov, V.N.Kovalev, S.G., Puchkov, V.N., Kovalev, S.S., Vysotsky, S.I.Rare Th-Sc minerals in picrites of the southern Urals and their genetic value.Doklady Earth Sciences, Vol. 484, 2, pp. 138-141.Russia, Uralspicrites

Abstract: The first data on the discovery of Th-Sc mineralization in the pyritic complexes of the Southern Urals are presented. The minerals of Th (thorite) and Sc-containing thorium minerals are described. The conclusion is made that the Th-Sc mineralization formed due to crystallization of a residual melt in the local volume.
DS200712-0347
2007
PuchtelGao, S., Rudnick, R.L., Xu, W-L., Yuan, Liu, Puchtel, Liu, Huang, WangRecycling deep cratonic lithosphere and generation of intraplate magmatism.Plates, Plumes, and Paradigms, 1p. abstract p. A307.ChinaAlkaline rocks, picrites
DS200812-0385
2008
PuchtelGao, S., Rudnick, R.L., Xu, Yuan, Liu, Walker, Puchtel, Liu, Huang, Wang, WangRecycling deep cratonic lithosphere and generation of intraplate magmatism in the North Chin a Craton.Earth and Planetary Science Letters, Vol. 270, 1-2, June 15, pp. 41-53.ChinaTectonics - delamination, picrites
DS1995-1530
1995
Puchtel, I.S.Puchtel, I.S., Bogadikov, O.A., et al.The role of crustal and mantle sources in the petrogenesis of continentalmagmatism: picrites OnegaPetrology, Vol. 3, No. 4, July-August, pp. 357-378Russia, Baltic shield, Karelia, KolaGeochemistry, Proterozoic
DS1997-0934
1997
Puchtel, I.S.Puchtel, I.S., Haase, K.M., Nemchin, A.A., et al.Petrology and geochemistry of kimberlite Pipe II of Chigicherla area, Anantapur District, Andhra Pradesh.Geochimica et Cosmochimica Acta, Vol. 61, No. 6, March 1, pp. 1205-Baltic shieldPetrology, Proterozoic mantle plume, Archean continent lithosphere, Tectonics, rifting, Mantle
DS1998-1195
1998
Puchtel, I.S.Puchtel, I.S., Arndt, N.T., Nemchin, A.A.Petrology of mafic lavas within the Onega Plateau, central Karelia:evidence for 2.0 Ga plume related ...Contributions to Mineralogy and Petrology, Vol. 130, No. 2, pp. 134-153.Russia, Karelia, Baltic shieldContinental crustal growth
DS1999-0571
1999
Puchtel, I.S.Puchtel, I.S., Brugmann, G.E., Hofmann, A.W.Precise Re Os mineral isochron and lead neodymium Os isotope systematics of a mafic ultramafic sill in 2.0 Ga OnegaEarth and Planetary Science Letters, Vol. 170, No. 4, July 30, pp. 447-62.Baltic shieldGeochronology, Onega plateau
DS1999-0572
1999
Puchtel, I.S.Puchtel, I.S., Brugmann, G.E., Hofmann, A.W.Precise Re Os mineral isochron and lead neodymium Os isotope systematics of mafic ultramafic sill in 2.0 Ga OnegaEarth and Planetary Science Letters, Vol. 170, No. 4, July 30, pp. 447-62.Baltic ShieldGeochronology, Onega Plateau
DS2001-0952
2001
Puchtel, I.S.Puchtel, I.S., Brugmann, G.E., Hofman, A.W.1870's enriched domain in an Archean mantle plume: evidence from 2.8 Ga komatiites of the Kostomuksha GSEarth and Planetary Science Letters, Vol. 186, No. 3-4, Apr. 15, pp. 513-26.Baltic ShieldPlume - geochronology - not specific to diamonds
DS2001-0953
2001
Puchtel, I.S.Puchtel, I.S., Brugmann, G.E., Kulikova, V.V.Os isotope systematics of komatiitic basalts from the Vetreny belt, BalticShield: evidence for chondritic..Contributions to Mineralogy and Petrology, Vol. 140, No. 5, pp. 588-606.Baltic ShieldGeochronology, Hot spot - plume 2.45 Ga
DS200412-1598
2004
Puchtel, I.S.Puchtel, I.S., Brandon, A.D., Humayun, M.Precise Pt Re O isotope systematics of the mantle from 2.7 Ga komatiites.Earth and Planetary Science Letters, Vol. 224, 1-2, pp. 157-174.MantleGeochronology
DS200512-0881
2005
Puchtel, I.S.Puchtel, I.S., Brandon, A.D., Humayun, M., Walker, R.J.Evidence for the early differentiation of the core from Pt-Re-Os isotope systematics of 2.8 Ga komatiites.Earth and Planetary Science Letters, Vol. 237, 1-2, Aug, 30, pp. 118-134.Europe, Baltic ShieldGeochronology, core-mantle interaction
DS200612-0165
2006
Puchtel, I.S.Brandon, A.D., Walker, R.J., Puchtel, I.S.Platinum osmium isotope evolution of the Earth's mantle: constraints from chondrites and Os rich alloys.Geochimica et Cosmochimica Acta, In pressMantleKomatiitie, chondrites, PGE, geochronology
DS200912-0001
2009
Puchtel, I.S.Ackerman, L., Walker, R.J., Puchtel, I.S., Pitcher, L., Jelinek, E., Strnad, L.Effects of melt percolation on highly siderophile elements and Os isotopes in subcontinental lithospheric mantle: a study of upper mantle profile central EuropeGeochimica et Cosmochimica Acta, Vol. 73, 8, pp. 2400-2414.Europe, Czech RepublicGeochonology
DS200912-0114
2009
Puchtel, I.S.Chu, Z-Y., Wu, F-Y., Walker, R.J., Rudnick, R.L., Pitcher, L., Puchtel, I.S., Yang, Y-H., Wilde, S.A.Temporal evolution of the lithospheric mantle beneath the North Chin a Craton.Journal of Petrology, Vol. 50, 10, pp. 1857-1898.ChinaGeodynamics
DS200912-0866
2009
Puchtel, I.S.Zhu-Yin Chu, Wu, F-Y., Walker, R.J., Rudnick, R.L., Pitcher, L., Puchtel, I.S., Yang, Y-H., Wilde, S.A.Temporal evolution of the lithospheric mantle beneath the eastern north Chin a craton.Journal of Petrology, Vol. 50, 10, October, pp. 1857-1898.ChinaTectonics
DS201012-0058
2010
Puchtel, I.S.Blichert-Toft, J., Puchtel, I.S.Depleted mantle sources through time: evidence from Lu Hf and Sm Nd isotope systematics of Archean komatiites.Earth and Planetary Science Letters, Vol. 297, 3-4, pp. 598-606.MantleGeochronology
DS201312-0746
2013
Puchtel, I.S.Rizo, H., Touboul, M., Carlson, R.W., Boyet, M., Puchtel, I.S., Walker, R.J.Early mantle composition and evolution inferred from 142 ND and 182 W variations in Isua samples.Goldschmidt 2013, AbstractMantleMineralogy
DS201601-0039
2015
Puchtel, I.S.Puchtel, I.S.When was the Earth's conveyor belt set in motion?American Mineralogist, Vol. 100, pp. 2369-2370.MantlePlate Tectonics

Abstract: The start of plate tectonics on Earth is one of the most controversial issues in modern geology, with proposed timings covering almost the entire history of our planet. On page 2387 of this issue (vol. 100, 2015), Blichert-Toft and co-authors report Sm-Nd and Lu-Hf isotopic and lithophile trace element data for early Archean komatiites from the Barberton Greenstone Belt (GB) in South Africa, and argue for the onset of plate tectonics on Earth as early as 3.5 Ga. The studied komatiites show a large decoupling of the two isotopic systems and lithophile trace element signatures that are most consistent with deep-water, pelagic sediments being present in the lower-mantle source of these lavas. Their conclusions have far-reaching implications for advancing our understanding of how the Earth system operated in the distant geological past.
DS201801-0043
2018
Puchtel, I.S.Nicklas, R.W., Puchtel, I.S., Ash, R.D.Redox state of the Archean mantle: evidence from V partioning in 3.5-2.4 komatitites.Geochimica et Cosmochimica Acta, Vol. 222, Feb. 1, pp. 447-466.MantleThermodynamics

Abstract: Oxygen fugacity of the mantle is a crucial thermodynamic parameter that controls such fundamental processes as planetary differentiation, mantle melting, and possible core-mantle exchange. Constraining the evolution of the redox state of the mantle is of paramount importance for understanding the chemical evolution of major terrestrial reservoirs, including the core, mantle, and atmosphere. In order to evaluate the secular evolution of the redox state of the mantle, oxygen fugacities of six komatiite systems, ranging in age from 3.48 to 2.41?Ga, were determined using high-precision partitioning data of the redox-sensitive element vanadium between liquidus olivine, chromite and komatiitic melt. The calculated oxygen fugacities range from ?0.11?±?0.30 ?FMQ log units in the 3.48?Ga Komati system to +0.43?±?0.26 ?FMQ log units in the 2.41?Ga Vetreny system. Although there is a slight hint in the data for an increase in the oxygen fugacity of the mantle between 3.48 and 2.41?Ga, these values generally overlap within their respective uncertainties; they are also largely within the range of oxygen fugacity estimates for modern MORB lavas of +0.60?±?0.30 ?FMQ log units that we obtained using the same technique. Our results are consistent with the previous findings that argued for little change in the mantle oxygen fugacity since the early Archean and indicate that the mantle had reached its nearly-present day redox state by at least 3.48?Ga.
DS201809-2075
2018
Puchtel, I.S.Nicklas, R.W., Puchtel, I.S., Ash, R.D.Redox state of the Archean mantle: evidence from V partioning in 3.5-2.4 Ga komatiites. Kidd-Munro, Pyke Hill, AlexoGeochimica et Cosmochimica Acta, Vol. 222, 1, pp. 447-466.Canada, Ontariokomatiites

Abstract: Oxygen fugacity of the mantle is a crucial thermodynamic parameter that controls such fundamental processes as planetary differentiation, mantle melting, and possible core-mantle exchange. Constraining the evolution of the redox state of the mantle is of paramount importance for understanding the chemical evolution of major terrestrial reservoirs, including the core, mantle, and atmosphere. In order to evaluate the secular evolution of the redox state of the mantle, oxygen fugacities of six komatiite systems, ranging in age from 3.48 to 2.41 Ga, were determined using high-precision partitioning data of the redox-sensitive element vanadium between liquidus olivine, chromite and komatiitic melt. The calculated oxygen fugacities range from -0.11 ± 0.30 ?FMQ log units in the 3.48 Ga Komati system to +0.43 ± 0.26 ?FMQ log units in the 2.41 Ga Vetreny system. Although there is a slight hint in the data for an increase in the oxygen fugacity of the mantle between 3.48 and 2.41 Ga, these values generally overlap within their respective uncertainties; they are also largely within the range of oxygen fugacity estimates for modern MORB lavas of +0.60 ± 0.30 ?FMQ log units that we obtained using the same technique. Our results are consistent with the previous findings that argued for little change in the mantle oxygen fugacity since the early Archean and indicate that the mantle had reached its nearly-present day redox state by at least 3.48 Ga.
DS201904-0761
2019
Puchtel, I.S.Nicklas, R.W., Puchtel, I.S., Ash, R.D., Piccoli, P.M., Hanski, M., Eero, Nisbet, E.G., Waterton, P., Pearson, D.G., Anbar, A.D.Secular mantle oxidation across the Archean - Proterozoic boundary: evidence from V partitioning in komatiites and picrites.Geochimica et Cosmochimica Acta, Vol. 250, 1, pp. 49-75.Mantlepicrites

Abstract: The oxygen fugacities of nine mantle-derived komatiitic and picritic systems ranging in age from 3.55?Ga to modern day were determined using the redox-sensitive partitioning of V between liquidus olivine and komatiitic/picritic melt. The combined set of the oxygen fugacity data for seven systems from this study and the six komatiite systems studied by Nicklas et al. (2018), all of which likely represent large regions of the mantle, defines a well-constrained trend indicating an increase in oxygen fugacity of the lavas of ?1.3 ?FMQ log units from 3.48 to 1.87?Ga, and a nearly constant oxygen fugacity from 1.87?Ga to the present. The oxygen fugacity data for the 3.55?Ga Schapenburg komatiite system, the mantle source region of which was previously argued to have been isolated from mantle convection within the first 30?Ma of the Solar System history, plot well above the trend and were not included in the regression. These komatiite’s anomalously high oxygen fugacity data likely reflect preservation of early-formed magma ocean redox heterogeneities until at least the Paleoarchean. The observed increase in the oxygen fugacity of the studied komatiite and picrite systems of ?1.3 ?FMQ log units is shown to be a feature of their mantle source regions and is interpreted to indicate secular oxidation of the mantle between 3.48 and 1.87?Ga. Three mechanisms are considered to account for the observed change in the redox state of the mantle: (1) recycling of altered oceanic crust, (2) venting of oxygen from the core due to inner core crystallization, and (3) convection-driven homogenization of an initially redox-heterogeneous primordial mantle. It is demonstrated that none of the three mechanisms alone can fully explain the observed trend, although mechanism (3) is best supported by the available geochemical data. These new data provide further evidence for mantle involvement in the dramatic increase in the oxygen concentration of the atmosphere leading up to the Great Oxidation Event at ?2.4?Ga.
DS201012-0603
2009
Puchtov, V.N.Puchtov, V.N.The controversy over plumes: who is actually right?Geotectonics, Vol. 43, 1, pp. 1-17.MantleHotspots
DS1970-0389
1971
Puckett, J.L.Puckett, J.L.Geophysical Study of Shear Zones in the East Central Medicine Bow Mountains, Wyoming and of Kimberlitic Diatremes in Northern Colorado.Fort Collins: Msc. Thesis, Colorado State University, 83P.Colorado, United States, Rocky Mountains, State LineKimberlite, Geophysics
DS1970-0584
1972
Puckett, J.L.Puckett, J.L., Mccallum, M.E., Johnson, R.B., Filson, R.H.Preliminary Geophysical Evaluation of Kimberlitic Diatremesin Northern Colorado and Southern Wyoming.Geological Society of America (GSA), Vol. 4, No. 6, P. 403, (abstract.).Colorado, Wyoming, United States, State Line, Rocky MountainsKimberlite, Geophysics
DS1995-1405
1995
Puckette, J.Ortoleva, P., Al-Shaieb, Z., Puckette, J.Genesis and dynamics of basin compartments and sealsAmerican Journal of Science, Vol. 295, April pp. 345-427GlobalBasin, Overview -genesis, dynamics, feedback phenomena
DS2001-0839
2001
PucletNomade, S., Chen, Y., Feraud, G., Puclet, TheveniautFirst paleomagnetic and 40 Ar-39 Ar study of Paleoproterozoic rocks from the French Guyana.Precambrian Research, Vol. 109, No. 3-4. July, pp. 239-56.GlobalCamopi and Oyapok rivers, Geochronology, Argon
DS2002-1152
2002
Puclet, A.Nomade, S., Puclet, A., Chen, Y.The French Guyana dolerite dykes: geochemical evidence of three populations and new dat a for the Jurassic central Atlantic magmatic province.Journal of Geodynamics, Vol. 34, 5, pp. 595-614.French GuianaDyke - geochemistry, Brief - update on activity
DS200412-0341
2004
Pudsey, C.J.Cofaigh, C.O.,Taylor, J., Dowdeswell, J.A., Pudsey, C.J.Paleo-ice stream, trough mouth fans and high latitude continental slope sedimentation.Boreas, Vol. 32, 1, pp. 37-55.TechnologyGeomorphology - not specific to diamonds
DS201707-1316
2017
Puetz, S.J.Condie, K., Arndt, N., Davaille, A., Puetz, S.J.Zircon age peaks: production or preservation of continental crust?Geosphere, Vol. 10, 6, pp. 397-398.Mantlegeochronology

Abstract: Zircon age peaks are commonly interpreted either as crustal production peaks or as selective preservation peaks of subduction-produced crust selectively preserved during continent-continent collision. We contribute to this ongoing debate, using the Nd isotopic compositions of felsic igneous rocks and their distribution during the accretionary and collisional phases of orogens. The proportion of juvenile input into the continental crust is estimated with a mixing model using arc-like mantle and reworked continental crust end members. Orogen length and duration proxies for juvenile crustal volume show that the amount of juvenile crust produced and preserved at zircon age peaks during the accretionary phase of orogens is ?3 times that preserved during the collisional phase of orogens. The fact that most juvenile crust is both produced and preserved during the accretionary phase of orogens does not require craton collisions for its preservation, thus favoring the interpretation of zircon age peaks as crustal production peaks. Most juvenile continental crust older than 600 Ma is produced and preserved before final supercontinent assembly and does not require supercontinent assembly for its preservation. Episodic destabilization of a compositionally heterogeneous layer at the base of the mantle may produce mantle plume events leading to enhanced subduction and crustal production. Our Nd isotope model for cumulative continental growth based on juvenile crust proxies for the past 2.5 b.y. suggests a step-like growth curve with rapid growth in accretionary orogens at the times of zircon age peaks.
DS201806-1217
2018
Puetz, S.J.Condie, K.C., Puetz, S.J., Davaille, A.Episodic crustal production before 2.7 Ga.Precambrian Research, Vol. 312, pp. 16-22.Mantlegeochronology - zircon

Abstract: Before 2.7?Ga, 14 igneous and detrital zircon age peaks and 9 large igneous province (LIP) age peaks are robust and statistically significant. Correlation analysis indicates a synchronous association among these peaks and power spectral analysis shows 91, 114-127 and 182-Myr cycles. These age cycles may be related to mantle plume or mantle overturn events, and to the time it takes to reach threshold temperature gradients for thermo-chemical destabilization in the lowermost mantle. Most zircon age peaks are transferred into younger detrital sediments, which does not favor an origin of the peaks by selective erosion. Correlation of eight pre-2.7-Ga LIP age peaks with zircon age peaks is consistent with a genetic relationship between mantle melting events and felsic crustal production and supports an interpretation of pre-2.7-Ga age peaks as growth rather than preservation peaks produced during craton collisions. Also consistent with the growth peak interpretation is the apparent absence of collisional orogens older than 2.7?Ga. An increasing number of geographic age peak sites from 4 to 2.8?Ga suggests production and survival of only small volumes of continental crust during this time and supports an episodic model for continental crustal growth.
DS201907-1536
2019
Puetz, S.J.Condie, K.C., Puetz, S.J.Time series analysis of mantle cycles Part II: the geologic record in zircons, large igneous provinces and mantle lithosphere.Geoscience Frontiers, Vol. 10, pp. 1327-1336Mantleboundary

Abstract: Igneous and detrital zircons have six major U/Pb isotopic age peaks in common (2700 Ma, 1875 Ma, 1045 Ma, 625 Ma, 265 Ma and 90 Ma). For igneous rocks, each age peak is comprised of subpeaks with distinct geographic distributions and a subpeak age range per age peak ?100 Myr. There are eight major LIP age peaks (found on ? 10 crustal provinces) of which only four are in common to major detrital zircon age peaks (2715 Ma, 1875 Ma, 825 Ma, 90 Ma). Of the whole-rock Re depletion ages, 58% have corresponding detrital zircon age peaks and 55% have corresponding LIP age peaks. Ten age peaks are found in common to igneous zircon, detrital zircon, LIP, and Re depletion age time series (3225 Ma, 2875 Ma, 2145 Ma, 2085 Ma, 1985 Ma, 1785 Ma, 1455 Ma, 1175 Ma, 825 Ma, and 90 Ma), and these are very robust peaks on a global scale as recorded in both crustal and mantle rocks. About 50% of the age peaks in each of these time series correspond to predicted peaks in a 94-Myr mantle cycle, including four of the ten peaks in common to all four time series (2875 Ma, 1785 Ma, 825 Ma and 90 Ma). Age peak widths and subpeak ranges per age peak suggest that mantle events responsible for age peaks are <100 Myr and many <50 Myr in duration. Age peak geographic distributions show three populations (?1000 Ma, 2500-1000 Ma, ?2500 Ma), with the number of new provinces in which age peaks are represented decreasing with time within each population. The breaks between the populations (at 2.5 Ga and 1 Ga) fall near the onsets of two transitions in Earth history. The First Transition may represent a change from stagnant-lid tectonics into plate tectonics and the Second Transition, the onset of subduction of continental crust. The major factor controlling geographic distribution of age peaks is the changing locations of orogeny. Before ?2 Ga, age subpeaks and peaks are housed in orogens within or around the edges of crustal provinces, mostly in accretionary orogens, but beginning at 1.9 Ga, collisional orogens become more important. The coincidence in duration between magmatic flare-ups in Phanerozoic arcs and duration of age subpeaks (10-30 Myr) is consistent with subpeaks representing periods of enhanced arc-related magmatism, probably caused by increased subduction flux. The correlation of isotopic age peaks between time series supports a cause and effect relationship between mantle plume activity, continental magma production at convergent margins, and crustal deformation. Correlation of over half of the detrital zircon age peaks (and six of the nine major peaks) with Re depletion age peaks supports an interpretation of the zircon peaks as crustal growth rather than selective preservation peaks.
DS201907-1570
2019
Puetz, S.J.Puetz, S.J., Condie, K.C.Time series analysis of mantle cycles Part I: periodicities and correlations among seven global isotopic databases.Geoscience Frontiers, Vol. 10, pp. 1305-1326.Mantleboundary

Abstract: In this study, seven isotopic databases are presented and analyzed to identify mantle and crustal episodes on a global scale by focusing on periodicity ranging from 70 to 200 million years (Myr). The databases are the largest, or among the largest, compiled for each type of data - with an objective of finding some samples from every region of every continent, to make each database as global as conceivably possible. The databases contain zircon Lu/Hf isotopic data, whole-rock Sm/Nd isotopic data, U/Pb detrital zircon ages, U/Pb igneous zircon ages, U/Pb non-zircon ages, whole-rock Re/Os isotopic data, and large igneous province ages. Part I of this study focuses on the periodicities of age histograms and geochemical averages developed from the seven databases, via spectral and cross-correlation analyses. Natural physical cycles often propagate in exact integer multiples of a fundamental cycle, referred to as harmonics. The tests show that harmonic geological cycles of ?93.5 and ?187 Myr have persisted throughout terrestrial history, and the cyclicities are statistically significant for U/Pb igneous zircon ages, U/Pb detrital zircon ages, U/Pb zircon-rim ages, large igneous province ages, mean ?Hf(t) for all samples, mean ?Hf(t) values for igneous-only samples, and relative abundance of mafic rocks. Equally important, cross-correlation analyses show these seven time-series are nearly synchronous (±7 Myr) with a model consisting of periodicities of 93.5 and 187 Myr. Additionally, the similarities between peaks in the 93.5 and 187 Myr mantle cycles and terminal ages of established and suspected superchrons provide a framework for predicting and testing superchron periodicity.
DS201706-1100
2017
Pufahl, P.K.Pufahl, P.K., Groat, L.A.Sedimentary and igneous phosphate deposits: formation and exploration: an invited paper. ( carbonatite)Economic Geology, Vol. 112, pp. 483-516.Russia, Kola Peninsula, Europe, Finland, Canada, British Columbiadeposit - Khibina, Fir, Siilinjarvi

Abstract: Phosphorus is the central ingredient in fertilizer that allows modern agriculture to feed the world’s population. This element, also critical in a host of industrial applications, is a nonrenewable resource that is sourced primarily from the phosphatic mineral apatite, hosted in sedimentary and igneous ores. World phosphate resources are estimated by the U.S. Geological Survey at ca. 300,000 Mt, of which 95% are sedimentary and 5% are igneous. Current known USGS reserve estimates are sufficient for a maximum of 200 to 300 years; the exploration and discovery of new resources, enhanced mining technologies, and new technologies aimed at the recovery and recycling of P from sewage and agricultural runoff will all contribute to extending P production. Igneous ores are generally associated with Phanerozoic carbonatites and silica-deficient alkalic intrusions that typically average 5 to 15 wt % P2O5, which can be beneficiated to high-grade concentrates of at least 30 wt % P2O5 with few contaminants. Carbonatites are typically the smallest and youngest parts of a carbonatite-alkaline rock complex that formed during fractional crystallization of a calcic parental alkaline silicate melt, or from liquid immiscibility of a carbonate-rich nephelinite that underwent magmatic fractionation and differentiation during ascent from the mantle source. Fluorapatite generally crystallizes early, near the liquidus, and over a small temperature interval below the apatite saturation temperature that varies strongly with temperature, SiO2 and CaO concentrations, and the aluminosity of the melt. Carbonatite-alkaline rock complexes commonly possess a concentric, zonal structure thought to reflect caldera volcanism. Pathfinder elements in soils, sediments, tills, and vegetation include Nb, rare earth elements (REEs), P, Ba, Sr, F, U, and Th, and in water, F, Th, and U are indicators. Remote sensing techniques with the ability to identify minerals rich in CO3, REEs, and Fe2+ that are characteristic of carbonatites are also important exploration tools that may provide vectors to ore. Sedimentary phosphorite is a marine bioelemental sedimentary rock that contains >18 wt % P2O5. While small peritidal phosphorites formed in Precambrian coastal environments, economically significant upwelling-related phosphorite did not accumulate until the late Neoproterozoic and continued through the Phanerozoic. Coastal upwelling delivered deep, P-rich waters to continental shelves and in epeiric seas to drive phosphogenesis and form the largest phosphorites on Earth. High-grade deposits formed as a result of hydraulic concentration of phosphate grains to form granular beds with minimal gangue. The amalgamation of these beds into decameter-thick, stratiform ore zones is generally focused along the maximum flooding surface, which is a primary exploration target in upwelling-related phosphorite. In addition to P, other elements concentrated in igneous and sedimentary phosphorites are Se, Mo, Zn, Cu, and Cr, which are important agricultural micronutrients. Other saleable by-products include U and REEs. The U concentration in sedimentary phosphorite is generally between 50 and 200 ppm, but can be as high as 3,000 ppm, making it an increasingly important source of U for the nuclear industry. The concentration of REEs in some sedimentary phosphorites is comparable to the world’s richest igneous and Chinese clay-type REE deposits. The source of the dissolved P in upwelling ocean water is ultimately derived from the chemical weathering of continental rocks, the process that links igneous and sedimentary phosphorites through time and space. The covarying temporal relationship of igneous and sedimentary deposits suggests that plate tectonics and the concentration of apatite in a progressively more felsic crust underpins the feedback processes regulating the biogeochemical cycling of P. Critical to the generation of greenfield exploration targets is the recognition that large P deposits emerged in the late Neoproterozoic. The geological environments conducive for exploration can be constrained from an understanding of ore-forming processes by the use of complementary petrological techniques, including fieldwork, petrography, sedimentology, sequence stratigraphy, and geochemistry.
DS1991-1385
1991
Puffer, J.H.Puffer, J.H., Vokert, R.A., Hozik, M.J.Probable late Proterozoic mafic dikes in the New Jersey HighlandsGeological Society of America Abstracts, Vol. 23, No. 1, February p. 118GlobalDikes, Paleomagnetics
DS1992-1240
1992
Puffer, J.H.Puffer, J.H., Ragland, P.C.Eastern North American Mesozoic magmatismGeological Society of America Special Paper, No. 268, 420pAppalachiaMagmatism, Table of contents
DS2001-0954
2001
Puffer, J.H.Puffer, J.H.Contrasting high field strength element contents of continental flood basalts from plume versus arc..Geology, Vol. 29, No. 8, Aug. pp. 675-8.Russia, SiberiaPlumes, arcs, geochemistry
DS2002-1287
2002
Puffer, J.H.Puffer, J.H.A late Neoproterozoic eastern Laurentian superplume: location, size, chemical composition and environmental impact.American Journal of Science, Vol.302,1, pp. 1-27.Appalachia, United StatesHot spot, Geochemistry
DS1995-1197
1995
Puffer, S.M.McCarthy, D.J., Puffer, S.M.Diamonds and rust on Russia road to privitization - the profits and pit falls for western managers.Columbia Jour W., Vol. 30, No. 3, Fall, pp. 56-69.RussiaEconomics
DS2003-0105
2003
Pugen, A.J.M.Bexfield, C.E., McBride, J.H., Pugen, A.J.M., Nelson, W.J.Mesozoic Cenozoic deformation near the northern tip of the Madrid seismic zoneGeological Society of America, Annual Meeting Nov. 2-5, Abstracts p.15.IllinoisGeophysics - seismics, lithosphere
DS200412-0144
2003
Pugen, A.J.M.Bexfield, C.E., McBride, J.H., Pugen, A.J.M., Nelson, W.J.Mesozoic Cenozoic deformation near the northern tip of the Madrid seismic zone.Geological Society of America, Annual Meeting Nov. 2-5, Abstracts p.15.United States, IllinoisGeophysics - seismics, lithosphere
DS201711-2524
2017
Pugh, S.Liddell, M.V., Bastow, I., Darbyshire, F., Gilligan, A., Pugh, S.The formation of Laurentia: evidence from shear wave splitting.Earth and Planetary Science Letters, Vol. 479, pp. 170-178.Canada, Nunavut, Baffin Islandgeophysics - seismics

Abstract: The northern Hudson Bay region in Canada comprises several Archean cratonic nuclei, assembled by a number of Paleoproterozoic orogenies including the Trans-Hudson Orogen (THO) and the Rinkian-Nagssugtoqidian Orogen. Recent debate has focused on the extent to which these orogens have modern analogues such as the Himalayan-Karakoram-Tibet Orogen. Further, the structure of the lithospheric mantle beneath the Hudson Strait and southern Baffin Island is potentially indicative of Paleoproterozoic underthrusting of the Superior plate beneath the Churchill collage. Also in question is whether the Laurentian cratonic root is stratified, with a fast, depleted, Archean core underlain by a slower, younger, thermally-accreted layer. Plate-scale process that create structures such as these are expected to manifest as measurable fossil seismic anisotropic fabrics. We investigate these problems via shear wave splitting, and present the most comprehensive study to date of mantle seismic anisotropy in northern Laurentia. Strong evidence is presented for multiple layers of anisotropy beneath Archean zones, consistent with the episodic development model of stratified cratonic keels. We also show that southern Baffin Island is underlain by dipping anisotropic fabric, where underthrusting of the Superior plate beneath the Churchill has previously been interpreted. This provides direct evidence of subduction-related deformation at 1.8 Ga, implying that the THO developed with modern plate-tectonic style interactions.
DS1987-0599
1987
Pugin, V.A.Pugin, V.A.Eclogites in the mantleGeochemistry International, Vol. 24, No. 2, pp. 21-27RussiaGeochemistry, Eclogite
DS1995-1531
1995
Puglsey, T.F.Puglsey, T.F., Von Fersen, N.Location -access, terrain and climate issuesProspectors and Developers Association of Canada (PDAC) Short Course, March 4, pp. 41-55GlobalDue diligence, Legal -Ore reserves
DS2001-0955
2001
Pui Kwan TsePui Kwan TseChina, 2000Mining Annual Review, 12p.ChinaCountry - overview, economics, mining, Overview - brief
DS201112-0832
2011
Pujol, M.Pujol, M., Marty, B., Burgess, R.Chondritic like xenon trapped in Archean rocks: a possible signature of the ancient atmosphere.Earth and Planetary Science Letters, Vol. 308, 3-4, pp. 298-306.MantleGeochronology
DS201312-0581
2013
Pujol, M.Marty, B., Zimmermann, L., Pujol, M., Burgess, R., Philippot, P.Nitrogen isotopic composition and density of the Archean atmosphere.Science, Vol. 342, 6154, pp. 101-104.MantleVolatiles
DS202010-1869
2020
Pujol-Sola, N.Pujol-Sola, N., Garcia-Casco, A., Proenza, J.A., Gonzalez-Jiminez, J.M., del Camp, A., Colas, V., Canals, A., Sanchez-Navas, A., Roque-Rosell, J.Diamond forms during low pressure serpentinisation of oceanic lithosphere.Geochemical Perspectives Letters, 7p. PdfCentral America, Cubadiamond genesis

Abstract: Diamond is commonly regarded as an indicator of ultra-high pressure conditions in Earth System Science. This canonical view is challenged by recent data and interpretations that suggest metastable growth of diamond in low pressure environments. One such environment is serpentinisation of oceanic lithosphere, which produces highly reduced CH4-bearing fluids after olivine alteration by reaction with infiltrating fluids. Here we report the first ever observed in situ diamond within olivine-hosted, CH4-rich fluid inclusions from low pressure oceanic gabbro and chromitite samples from the Moa-Baracoa ophiolitic massif, eastern Cuba. Diamond is encapsulated in voids below the polished mineral surface forming a typical serpentinisation array, with methane, serpentine and magnetite, providing definitive evidence for its metastable growth upon low temperature and low pressure alteration of oceanic lithosphere and super-reduction of infiltrated fluids. Thermodynamic modelling of the observed solid and fluid assemblage at a reference P-T point appropriate for serpentinisation (350 °C and 100 MPa) is consistent with extreme reduction of the fluid to logfO2 (MPa) = ?45.3 (?logfO2[Iron-Magnetite] = ?6.5). These findings imply that the formation of metastable diamond at low pressure in serpentinised olivine is a widespread process in modern and ancient oceanic lithosphere, questioning a generalised ultra-high pressure origin for ophiolitic diamond.
DS202012-2241
2020
Pujol-Sola, N.Pujol-Sola, N.Diamond forms during low pressure serpentinization of oceanic lithosphere.Geochemical perspective Letters, Globalnanodiamonds

Abstract: Diamond is commonly regarded as an indicator of ultra-high pressure conditions in Earth System Science. This canonical view is challenged by recent data and interpretations that suggest metastable growth of diamond in low pressure environments. One such environment is serpentinisation of oceanic lithosphere, which produces highly reduced CH4-bearing fluids after olivine alteration by reaction with infiltrating fluids. Here we report the first ever observed in situ diamond within olivine-hosted, CH4-rich fluid inclusions from low pressure oceanic gabbro and chromitite samples from the Moa-Baracoa ophiolitic massif, eastern Cuba. Diamond is encapsulated in voids below the polished mineral surface forming a typical serpentinisation array, with methane, serpentine and magnetite, providing definitive evidence for its metastable growth upon low temperature and low pressure alteration of oceanic lithosphere and super-reduction of infiltrated fluids. Thermodynamic modelling of the observed solid and fluid assemblage at a reference P-T point appropriate for serpentinisation (350 °C and 100 MPa) is consistent with extreme reduction of the fluid to logfO2 (MPa) = ?45.3 (?logfO2[Iron-Magnetite] = ?6.5). These findings imply that the formation of metastable diamond at low pressure in serpentinised olivine is a widespread process in modern and ancient oceanic lithosphere, questioning a generalised ultra-high pressure origin for ophiolitic diamond.
DS202106-0965
2021
Pujol-Sola, N.Pujol-Sola, N., Dominguez-Carretero, D., Proenza, J.A., Haissen, F., Ikenne, M., Gonzales-Jiminez, J.M., Colas, V., Maacha, L., Garcia-Casco, A.The chromitites of the Neoproterozoic Bou Azzer ophiolite ( central Anti-Atlas, Morocco) revisited.Ore Geology Reviews, Vol. 134, 104166, 24p. PdfAfrica, Moroccomoissanite

Abstract: The Neoproterozoic Bou Azzer ophiolite in the Moroccan Anti-Atlas Panafrican belt hosts numerous chromitite orebodies within the peridotite section of the oceanic mantle. The chromitites are strongly affected by serpentinization and metamorphism, although they still preserve igneous relicts amenable for petrogenetic interpretation. The major, minor and trace element composition of unaltered chromite cores reveal two compositional groups: intermediate-Cr (Cr# = 0.60 - 0.74) and high-Cr (Cr# = 0.79 - 0.84) and estimates of parental melt compositions suggest crystallization from pulses of fore-arc basalts (FAB) and boninitic melts, respectively, that infiltrated the oceanic supra-subduction zone (SSZ) mantle. A platinum group elements (PGE) mineralization dominated by Ir-Ru-Os is recognized in the chromitites, which has its mineralogical expression in abundant inclusions of Os-Ir alloys and coexisting magmatic laurite (RuS2) and their products of metamorphic alteration. Unusual mineral phases in chromite, not previously reported in this ophiolite, include super-reduced and/or nominally ultra-high pressure minerals moissanite (SiC), native Cu and silicates (oriented clinopyroxene lamellae), but “exotic” zircon and diaspore have also been identified. We interpret that clinopyroxene lamellae have a magmatic origin, whereas super-reduced phases originated during serpentinization processes and diaspore is linked to late circulation of low-silica fluids related to rodingitization. Zircon grains, on the other hand, with apatite and serpentine inclusions, could either have formed after the interaction of chromitite with mantle-derived melts or could represent subducted detrital sediments later incorporated into the chromitites. We offer a comparison of the Bou Azzer chromitites with other Precambrian ophiolitic chromitites worldwide, which are rather scarce in the geological record. The studied chromitites are very similar to the Neoproterozoic chromitites reported in the Arabian-Nubian shield, which are also related to the Panafrican orogeny. Thus, we conclude that the Bou Azzer chromitites formed in a subduction-initiation geodynamic setting with two-stages of evolution, with formation of FAB-derived intermediate-Cr chromitites in the early stage and formation of boninite-derived high-Cr chromitites in the late stage.
DS1993-1268
1993
Pukhtel, I.S.Pukhtel, I.S., Zhuravlev, D.Z.neodymium isotope systematics and petrogenesis of Early Proterozoic picrites In the Olkema granite-greenstone region.Geochemistry International, Vol. 30, No. 3, pp. 37-49.RussiaPicrite, Dike
DS1993-1269
1993
Pukhtel, I.S.Pukhtel, I.S., Zhuravlev, D.Z.neodymium isotope systematics and petrogenesis of the early Proterozoic picrites in the Olekema granite-greenstone region.Geochemistry International, Vol.30, No. 3, March pp. 37-49.RussiaPicrites, Alkaline rocks
DS1991-1386
1991
Puktiel, I.S.Puktiel, I.S., Frikh-Khar, D.I., Ashikmina, N.A., Tomashpol'skiyMetamorphic olivines in ultramafic rocks of the Olonda greenstone belt And the komatiite identification probleM.International Geology Review, Vol. 33, No. 2, February pp. 161-173RussiaGreenstone belt -Olonda, Komatiite
DS201804-0672
2017
Pul, E.K.Baryshnikov, V.D., Fedyanin, A.S., Pul, E.K., Baryshnikov, D.V.Geomechanical monitoring of open pit bottom reserves in Mir mine, Alrosa: results.Journal of Mining Science, Vol. 53, 1, pp. 34-42.Russiadeposit - Mir

Abstract: The authors propose methods and means to monitor deformation and subsidence of ore crown under mining of open-pit bottom reserves by room-and-pillar system with cemented backfill in Mir Mine, ALROSA. The article describes layout and data of geomechanical monitoring. The mechanism of ore subsidence at the lower boundary of the safety pillar is determined.
DS1984-0402
1984
Pulatova, D.S.Khakimov, Z.M., Pulatova, D.S., Makhumod, A.S., Levin, A.A., et al.Genealogy of Localized States in Diamond Like CrystalsDoklady Academy of Sciences AKAD. NAUK SSSR., Vol. 279, No. 1, PP. 153-156.RussiaDiamond Cystallography
DS2003-1117
2003
Pulfrich, A.Pulfrich, A., Parkins, C.A., Branch, G.M.The effects of shore based diamond diving on intertidal and subtidal biologicalAquatic Conservation, Vol. 13, 3, pp. 233-56. Ingenta 1032281873NamibiaEnvironment
DS2003-1118
2003
Pulfrich, A.Pulfrich, A., Parkins, C.A., Branch, G.M., Bustamante, R.H., Velasquez, C.R.The effects of sediment deposits from Namibian diamond mines on intertidal andAquatic Conservation, Vol. 13, 3, pp. 257-78. Ingenta 1032281872NamibiaEnvironment
DS200412-1599
2003
Pulfrich, A.Pulfrich, A., Parkins, C.A., Branch, G.M.The effects of shore based diamond diving on intertidal and subtidal biological communities and rock lobsters in southern NamibiAquatic Conservation, Vol. 13, 3, pp. 233-56. Ingenta 1032281873Africa, NamibiaEnvironment
DS200412-1600
2003
Pulfrich, A.Pulfrich, A., Parkins, C.A., Branch, G.M., Bustamante, R.H., Velasquez, C.R.The effects of sediment deposits from Namibian diamond mines on intertidal and subtidal reefs and rock lobster populations.Aquatic Conservation, Vol. 13, 3, pp. 257-78. Ingenta 1032281872Africa, NamibiaEnvironment
DS201212-0204
2012
PulgarFlor De Lis, M., Stitch, Morales, Juli, Diaz, Cordoba, Pulgar, Ibarra, Harnafi, Gonzalez-LodeiroCrustal thickness variations in northern Morocco.Journal of Geophysical Research, Vol. 117, B2, B02312.Africa, MoroccoGeophysics - seismics
DS200712-0223
2007
Pulikkathara, M.X.Davydov, V.A., Rakhmanina, A.V., Rols, S., Agafonov, V., Pulikkathara, M.X., Wal, R.V., Khabashesku, V.N.Size dependent phase transition of diamond to graphite at high pressures.Journal of Physical Chemistry , Vol. 111, no. 35, pp. 12918-12925. Ingenta 1074185621TechnologyUHP
DS1991-1387
1991
Pulkkinen, E.Pulkkinen, E.Environmental geochemistry in northern EuropeGeological Survey of Finland Special Paper No. 9, 330pFinlandEnvironmental geochemistry, Book -table of contents
DS200812-0105
2008
Pullia, A.Berderman, E., Caragheorgheopol, A., Clobanu, M., Pomorski, M., Pullia, A., Riboldi, S.,Traeger, M., Weick, H.Ion spectroscopy - a diamond characterization tool.Diamond and Related Materials, Vol. 17, 7-10, pp. 1159-1163.TechnologySpectroscopy
DS201908-1800
2019
Pulliam, J.Netto, A., Pulliam, J., Persaud, P.Synoptic view of lithospheric S-wave velocity structure in the southern United States: a comparison of 3D seismic tomographic models.GSA Today, Vol. 29, 7, pp. 4-10. United Statesgeophysics - seismic

Abstract: The southern U.S. continental margin records a history spanning ca. 1.2 Ga, including two Wilson cycles. However, due to a thick sediment cover, the paucity of significant local seismicity, and, until recently, sparse instrumentation, details of this passive margin’s tectonomagmatic evolution remain disputed. This paper compares recent S-wave tomography and crustal thickness models based on USArray data to help establish a framework for geodynamic interpretation. Large-scale patterns of crustal velocity anomalies, corresponding to major regional features such as the Ouachita orogenic front and the Precambrian margin, are generally consistent between the models. The spatial extent of smaller-scale tectonic features, such as the Sabine Uplift and Wiggins block, remains poorly resolved. An inverse relationship between crustal thickness and Bouguer gravity across the continental margin is observed. This model comparison highlights the need for additional P-wave tomography studies and targeted, higher density station deployments to better constrain tectonic features.
DS1970-0808
1973
Puminov, A.P.Puminov, A.P., Zhukov, V.V.Alluvial Deposits of Central SiberiaLeningrad: Naichno Izzled. Institute, 59P.Russia, Central SiberiaKimberlite, Kimberley, Diamond
DS1999-0648
1999
Pun, A.Selverstone, J., Pun, A., Condie, K.C.Xenolithic evidence for Proterozoic crustal evolution beneath the ColoradoPlateau.Geological Society of America (GSA) Bulletin., Vol. 111, No. 4, Apr. pp. 590-606.Colorado, Utah, Arizona, New Mexico, Colorado PlateauMinettes, Navajo volcanic field
DS1989-1012
1989
Pun, P.Merry, S., Penman, C., Pun, P.The Canadian connection: business onlineDatabase, Vol. 12, No. 5, pp. 15-27. Database # 18155GlobalDatabase useage, Business
DS1980-0183
1980
Pundarikakshudu, T.Jegadessan, K., Pundarikakshudu, T.Pilot Processing Plant for Exploration of DiamondsIndia Geological Survey Spec. Publishing, No. 4, PP. 602-606.India, WajrahkarurMining Engineering
DS200612-1400
2006
Pundhir, N.K.S.Swami, R.K., Pundhir, N.K.S., Mathur, S.Utilization of kimberlite tailings in road works.Indian Highways, Ingenta 1062075270, Vol. 34, 4, pp. 51-62.IndiaMining - environment
DS1970-0435
1971
Punglia, J.Tolansky, S., Punglia, J.Truncated Cubo-octahedroids in the Premier Mine Small Diamonds.International DIAMOND Conference HELD OXFORD., ABSTRACT No. 28.South AfricaMicro-diamonds, Crystallography, Diamond Genesis
DS1984-0600
1984
Punkari, M.Punkari, M.The relations between glacial dynamics and tills in the eastern part of the Baltic Shield.Striae, Vol. 20, pp. 49-54.Finland, Karelia, Kola, Russia, ScandinaviaGeomorphology, Drumlin Fields
DS200512-1258
2005
Punzalan, H.Zheng Fu, G., Hertogen, J., Liu, J., Pasteels, A., Boven, L., Punzalan, H., Xiangiun, L., Zhang, W.Potassic magmatism in western Sichuan and Yunnan Provinces, SE Tibet, China: petrological and geochemical constraints on petrogenesis.Journal of Petrology, Vol. 46, 1, pp. 33-78.China, TibetMagmatism
DS201412-0374
2014
Puplampu, S.Howarth, G.H., Sobolev, N.V., Pernet-Fisher, J.F., Barry, P.H., Penumado, D., Puplampu, S., Ketcham, R.A., Maisano, J.A., Taylor, D., Taylor, L.A.The secondary origin of diamonds: multi-modal radiation tomography of Diamondiferous mantle eclogites.International Geology Review, Vol. 56, 9, pp. 1172-1180.Russia, Siberia3D
DS200912-0601
2009
Purcell, W.Purcell, W.Diamond summary. Darnley Bay, Sierra Gold, Diamcor, Shear, BRC DiamondCore, Gold Standard Ventures.Stockwatch, Nov. 19, 2p.GlobalNews item - brief comments
DS201112-0833
2011
Purcell, W.Purcell, W.Diamond summary for July 14, briefs on Harry Winston's Diavik production, Shore Gold's feasibility, Shear's progress on Jericho and their other properties .Stockwatch, July 14, 2p.Canada, Northwest Territories, Nunavut, SaskatchewanNews item - Diavik
DS201112-0834
2011
Purcell, W.Purcell, W.Diamonds summary for June 30, 2011. Prices - companies mentioned BHP, Big Red Diamond, Metalex, Talmora, Ditem. 49 North Resources, KWG,Stockwatch, July 4, 1p.CanadaNews item - brief comments on companies listed above
DS201112-0835
2011
Purcell, W.Purcell, W.Diamond summary for July 7, 2011 History related to Rex Mining ( Koidu); KWG Debut Diamonds; Harry Winston and speculation about interest in see list belowStockwatch, July 7, 1p.CanadaNews item - Shore, Mountain Prov.,Stornoway, Adroit
DS200912-0595
2009
Purchase, M.Potgeiter, J., Sommer, H., Regenauer-Lieb, K., Gasharova, B., Purchase, M.OH and CO2 diffusion profiles in garnets from eclogite xenoliths from the Rovic diamond mine, South Africa. ( Unesco IGCP 557)Goldschmidt Conference 2009, p. A1046 Abstract.Africa, South AfricaDeposit - Rovic
DS200912-0602
2008
Purchase, M.Purchase, M., Sommer, H.Diffusion profiles of OH towards melt inclusions in garnets in lherzolite xenoliths from the Victor diamond mine.American Geological Union, Fall meeting Dec. 15-19, Eos Trans. Vol. 89, no. 53, meeting supplement, 1p. abstractAfrica, South AfricaDeposit - Roberts Victor
DS200912-0603
2009
Purchase, M.Purchase, M., Sommer, H., Regenauer-Lieb, K., Gasharova, B., Potgeiter, J.OH partitioning coefficient between garnets and melt inclusions in lherzolite xenoliths from the Kimberley diamond mine, South Africa.Goldschmidt Conference 2009, p. A1059 Abstract.Africa, South AfricaDeposit - Kimberley
DS201112-0836
2011
Purchase, M.Purchase, M., Sommer, H., Regenauer-Lieb, K., Jung, H., Gasharova, B.Coexistent aqueous fluid phase and melt in lherzolites from Bultfontein, South Africa.Goldschmidt Conference 2011, abstract p.1675.Africa, South AfricaDeposit - Bultfontein
DS1900-0697
1908
Purdue, A.H.Purdue, A.H.A New Discovery of Peridotite in ArkansawEconomic Geology, Vol. 3, PP. 525-528.United States, Gulf Coast, Arkansas, PennsylvaniaGeology
DS1910-0301
1912
Purdue, A.H.Purdue, A.H.Arkansaw DIAMOND BEARING PERIDOTITE AREA.Geological Society of America (GSA) Bulletin., Vol. 23, P. 726.United States, Gulf Coast, Arkansas, PennsylvaniaGeology
DS1920-0460
1929
Purdue, A.H.Miser, H.D., Purdue, A.H.Geology of the Dequeen and Caddo Gap Quadrangles, ArkansawUnited States Geological Survey (USGS) Bulletin., No. 808, 195P.United States, Gulf Coast, ArkansasGeology
DS1990-0936
1990
Purdy, G.M.Lin, J., Purdy, G.M., Schouten, H., Semopere, J.C., Zervas, C.Evidence from gravity dat a for focused magmatic accretion along the mid-Atlantic RidgeNature, Vol. 344, No. 6267, April 12, pp. 627-632Mid-Atlantic RidgeGeophysics -gravity, Magma
DS1993-0341
1993
Purdy, S.M.Detrick, R.S., White, R.S., Purdy, S.M.Crustal structure of North Atlantic fracture zonesReviews of Geophysics, Vol. 31, No. 4, November pp. 439-458North AtlanticTectonics, Fracture zones
DS1860-0390
1882
Purgold, A.Purgold, A.Zwei Abnormale DiamantkrystalleZeitschr. Kryst. (leipzig), Vol. 6, PP. 595-598.Africa, South Africa, Asia, BorneoDiamond crystallography
DS1950-0280
1956
Puri, S.N.Jhingran, A.G., Puri, S.N.A New Find of Agglomeratic Tuff in Bundelk hand Granite Area in Chhatarpur District.Proceedings FOURTY THIRD INDIA SCI. CONG., PT. II, P. 169. (abstract.).India, Madhya PradeshAngore
DS1970-0585
1972
Puri, S.N.Puri, S.N.A Note on the Angor KimberliteIndian Minerals, Vol. 26, No. 4, PP. 133-134.India, Madhya PradeshMineralogy
DS1985-0649
1985
Puri, S.N.Subrahmanyam, B., Puri, S.N.Kimberlites: Regional Gravity AnomaliesJournal of Association Exploration Geophysicists, Vol.6, No. 1, pp. 25-31IndiaAndhra Pradesh, Madhya Pradesh
DS1989-1245
1989
Puris, E.M.Puris, E.M., Wickham, S.M.An oxygen isotope study of the Kapuskasing UpliftGeological Society of America (GSA) Annual Meeting Abstracts, Vol. 21, No. 6, p. A189. AbstractOntarioTectonics, Kapuskasing Rift
DS1930-0040
1930
Purkyne, C.Purkyne, C.Diamanty V Jizni AfriceHorn. Vestn., Vol. 12, No. 31South AfricaDiamonds
DS200912-0604
2009
Purohit, M.K.Purohit, M.K., Kathal, P.K., Adel, S.H.Discovery of micro-diamonds in beach sands of the Negapattinam and Vedaranniyam beaches, southern east coast of India.Current Science, Vol. 98, 6, March 25, pp.767-8.IndiaMicrodiamonds
DS201801-0041
2017
Purohit, R.K.Nanda. L.K., Verma, M.B., Purohit, R.K., Khandelwal, M.K., Rai, S.D., Mundra, K.L.LREE and Nb multi metal potentiality of the Amba Dongar carbonatite complex, Chhota Udepur district, Gujarat.Carbonatite-alkaline rocks and associated mineral deposits , Dec. 8-11, abstract p. 43-44.Indiadeposit - Amba Dongar

Abstract: Rare earth elements (REE) are used in science innovations, due to their unique magnetic, fluorescent and chemical properties. REE are key components in rnany technological devices, like hybrid rechargeable batteries, catalysts, glass polishing, magnets, lasers, TV colour components, superconductors, ceramics etc. They are in great demand for hybrid cars, CD, cameras and high end defence systems. Similarly, niobium (Nb) finds its usage in diverse high tech applications including atomic energy. With increasing technological applications of REE and Nb, their global demand has enhanced over the years. To keep pace with the current demand, many carbonatite complexes in India including the Amba Dongar were revisited to assess their REE and Nb content. Amba Dongar is a classic carbonatite-alkalic rock complex of the Deccan basalt plateau and is emplaced in close proximity to Narmada rift zone. The main rock types of carbonatite affinity include sovite (calcium carbonatite), ankerite (Fe-Mg•Mn carbonatite), siderite (Fe carbonatite), carbonatite breccia (mixed rock. fragments with carbonate cement) etc. Sovite forms a large ring-dyke (nearly 1.5 km dia.) surrounding an incomplete ring of carbonatite breccia. Plugs of ankeritic carbonatite intrude the sovite. To assess rare metal and REE potential of the carbonatite complex geological and radiometric surveys followed by core drilling were carried out in western part of the complex. Rocks of carbonatite affinity have been intercepted in all the boreholes upto a maximum drilled depth of 150 m. It is for the first time that presence of carbonatite and carbonatite breccia has been reported below central basalt in the Amba Dongar complex. Continuity of carbonatites beyond the drilled depth is inferred. Petromineralogical and X-Ray Diffraction studies indicated presence of REE minerals such as monazite, thorite, cerite, synchisite and bastnasite. Besides, rare earth fluorocarbonates, parisite, florencite, barite, strontianite and columbite have also been reported by earlier investigators. Fairly good amount of pyrochlore (Nb mineral) is also present in all the variants of carbonatite. Detailed chemical analysis core at 1 m interval and of composite samples from every borehole was carried out. The results indicate homogeneity of mineralisation in the entire column upto an explored vertical depth of 120 m. Except a few lean zones, the entire column hosts REE mineralisation of the order of >1% ?REE. Some zones have indicated REE mineralisation of the order of >4 % also. Major element analysis of a composite sample representing a small block (400 m x 100 m x 113 m) indicates 14.69% SiO2, 10.57% Fe2O3, 7 21% MgO, 32.23% CaO, 2.77%, Al2O3, 1.48% P2O5, 2.13% MnO, 0.84% FeO, 0.37% TiO2, 0.95% Na2O, 1.35% K2O, and 23.50% LOI. 1.16% LREE (including 161 ppm HREE), 215 ppm Y, 650 ppm Nb, 310 ppm Th and 467 ppm V appear to be of economic significance. Additionally, presence of high content of Ba (2.65%), Sr (0.50%), Pb (530 ppm), F (1.95%) and Zn (1248 ppm) is also important. Taking into consideration these results, resource estimation of a small block of 400 m x 100 m (0.04 sq. km) with an average depth of 113 m was carried out Inferred REE resources ~140000 tonnes contained in 12.00 million tonne ore have been estimated with an average grade of 1.16% REE. Additionally, this block contains 9,600 tonnes Nb2O5 at an average grade of 0 08 % Nb2O5. These values indicate high potential of Amba Dongar carbonatite complex.
DS1990-1579
1990
Purser, G.C.Woods, G.S., Purser, G.C., Mtimkulu, A.S.S., Collins, A.T.Nitrogen content of Type 1A natural diamondsJournal of Phys. Chem. Solids, Vol. 51, No. 10, pp. 1191-1197GlobalDiamond morphology, Natural diamonds -type 1A.
DS200412-0220
2003
PurtBrooker, R.A., Du, Z., Blundy, J.D., Kelley, S.P., Allan, N.L., Wood, B.J., Chamorro, E.M., Wartho, J.A., PurtThe zero charge partitioning behaviour of noble gases during mantle melting.Nature, No. 6941, June 12, pp. 738-41.MantleMelt, geochemistry
DS1998-1518
1998
PurtonVan Westerenen, W., Blundy, Purton, WoodTowards a predictive model for garnet melt trace element partitioning:experimental and computational..Mineralogical Magazine, Goldschmidt abstract, Vol. 62A, p. 1580-1.MantleGeochemistry, Garnets, grossular
DS1999-0476
1999
Purtscheller, F.Miller, C., Schuster, R., Purtscheller, F.Post collisional potassic and ultrapotassic magmatism in southwest Tibet:geochemical and Sr neodymium lead O isotopic ....Journal of Petrology, Vol. 40, No. 9, Sept. pp. 1399-24.MantlePetrogenesis, Geochemistry
DS1996-1144
1996
Purucker, M.E.Purucker, M.E., Sabaka, T.J., Langel, R.A.Conjugate gradient analyses - a new tool for studying satellite magneticdat a setsGeophys. Research Letters, Vol. 23, No. 5, March 1, pp 507-510GlobalRemote sensing, Geophysics -magnetics
DS200912-0610
2009
Purucker, M.E.Rajaram, M., Anand, S.P., Hermant, K., Purucker, M.E.Currie isotherm map of Indian subcontinent from satellite and aeromagnetic data.Earth and Planetary Science Letters, Vol. 281, 3-4, May 15, pp. 147-158.IndiaGeophysics - magnetics
DS200512-0882
2005
Purves, M.C.Purves, M.C., Heaman, L.M., Creaser, R.A., Schmidberger, S.S., Simoneti, A.Origin and isotopic evolution of the Muskox intrusion, Nunavut.GAC Annual Meeting Halifax May 15-19, Abstract 1p.Canada, NunavutLayered intrusion - ultramafic
DS201312-0722
2013
Purwin, H.Purwin, H., Lauterbach, S., Brey, G.P., Woodland, A.B., Kleebe, H-J.An experimental study of Fe oxidation states in garnet and clinopyroxene as a function of temperature in the system CaO FeO Fe2O3 MgO Al2O3 SiO2: implications for garnet-clinopyroxene geothermometry.Contributions to Mineralogy and Petrology, Vol. 164, 4, pp. 623-639.TechnologyGeobarometry
DS1960-1193
1969
Puryear, S.M.Puryear, S.M., Stearns, D.G.Control of Fabric of the Wells Creek Structure by Pre-existing Joints.Geological Society of America (GSA) SPECIAL PAPER., No. 121, P. 462, (abstract.).GlobalKimberlite, Western Tennessee, Cryptoexplosion, Central States
DS1984-0475
1984
Pushcharovski.Malkov, B.A., Milanovskiy, Y.Y., Kropotkin, P.N., Pushcharovski.Archean Diamond Bearing Mantle and Kimberlite Volcanism in The Expanding Earth Theory.Izd. Nauka, Moscow., PP. 56061.RussiaIgneous Rocks, Kimberlite, Genesis, Plate Tectonics
DS1998-1196
1998
Pushcharovskii, Y.M.Pushcharovskii, Y.M.Seismic tomography, tectonics and deep geodynamicsDoklady Academy of Sciences, Vol. 360, No. 4, pp. 514-7.MantleGeophysics - seismic, Tectonics
DS1991-1388
1991
Pushcharovskiy, Yu.M.Pushcharovskiy, Yu.M., Ruzhentsev, S.V., et al.Tectonic delamination of the lithosphere and its implications for geologicmappingInternational Geology Review, Vol. 33, No. 12, December pp. 1164-1183RussiaLithosphere, Tectonic delamination, layering
DS202008-1462
2020
Pushcharovsky, D. Yu.Zubkova, N.V., Chukanov, N.V., Schafer, C., van Konstantin, V., Pekov,I.V., Pushcharovsky, D. Yu.Al analogue of chayvesite from a lamproite of Cancarix, SE Spain, and its crystal structure.Neues Jahbuch fur Mineralogie, Vol. 196, 3, pp. 193-196.Europe, Spainlamproite

Abstract: Al analogue of chayesite (with Al > Fe3+) was found in a lamproite from Cancarix, SE Spain. The mineral forms green thick-tabular crystals up to 0.4 mm across in cavities. The empirical formula derived from EMP measurements and calculated on the basis of 17 Mg + Fe + Al + Si apfu is (K0.75 Na0.20 Ca0.11)Mg3.04 Fe0.99 Al1.18 Si11.80 O30. The crystal structure was determined from single crystal X-ray diffraction data ( R = 2.38%). The mineral is hexagonal, space group P 6/ mcc, a = 10.09199(12), c = 14.35079(19) Ĺ, V = 1265.78(3) Ĺ3, Z = 2. Fe is predominantly divalent. Al is mainly distributed between the octahedral A site and the tetrahedral T 2 site. The crystal chemical formula derived from the structure refinement is C (K0.73 Na0.16 Ca0.11) B (Na0.02)4 A (Mg0.42 Al0.29 Fe0.29)2 T 2(Mg0.71 Fe0.16 Al0.13)3 T 1(Si0.985 Al0.015)12 O30.
DS200712-0861
2007
Pushcharovsky, D.Y.Pushcharovsky, Y.M., Pushcharovsky, D.Y.An approach to the geologic history of the Earth's mantle geospheres.Geotectonics, Vol. 94, 1-4, pp. 111-131.MantleGeospheres
DS200812-0928
2008
Pushcharovsky, D.Y.Pushcharovsky, Y.M., Pushcharovsky, D.Y.The middle mantle of the Earth.Geotectonics, Vol. 42, 1, pp. 1-7.MantleCore, boundary
DS201904-0766
2018
Pushcharovsky, D.Y.Pekov, I.V., Zubkova, N.V., Yapaskurt, V.O., Lykova, I.S., Chukanov, N.V., Belakovskiy, D.I., Britvin, S.N., Turchkova, A.G., Pushcharovsky, D.Y.Alexhomyakovite, K6(Ca2Na) (CO3)5CI.6h2O, a new mineral from the Khibiny alkaline complex, Kola Peninsula, Russia.European Journal of Mineralogy, Vol. 31, pp. 13-143.Russia, Kola Peninsuladeposit - Khibiny

Abstract: The new mineral alexkhomyakovite K6(Ca2Na)(CO3)5Cl?6H2O (IMA2015-013) occurs in a peralkaline pegmatite at Mt. Koashva, Khibiny alkaline complex, Kola peninsula, Russia. It is a hydrothermal mineral associated with villiaumite, natrite, potassic feldspar, pectolite, sodalite, biotite, lamprophyllite, titanite, fluorapatite, wadeite, burbankite, rasvumite, djerfisherite, molybdenite and an incompletely characterized Na-Ca silicate. Alexkhomyakovite occurs as equant grains up to 0.2 mm, veinlets up to 3 cm long and up to 1 mm thick and fine-grained aggregates replacing delhayelite. Alexkhomyakovite is transparent to translucent, colourless, white or grey, with vitreous to greasy lustre. It is brittle, the Mohs hardness is ca. 3. No cleavage was observed, the fracture is uneven. D meas = 2.25(1), D calc = 2.196 g cm?3. Alexkhomyakovite is optically uniaxial (-), ? = 1.543(2), ? = 1.476(2). The infrared spectrum is reported. The chemical composition [wt%, electron microprobe data, CO2 and H2O contents calculated for 5 (CO3) and 6 (H2O) per formula unit (pfu), respectively] is: Na2O 4.09, K2O 35.72, CaO 14.92, MnO 0.01, FeO 0.02, SO3 0.11, Cl 4.32, CO2 28.28, H2O 13.90, -O=Cl -0.98, total 100.39. The empirical formula calculated on the basis of 9 metal cations pfu is K5.90Ca2.07Na1.03(CO3)5(SO4)0.01O0.05Cl0.95?6H2O. The numbers of CO3 groups and H2O molecules are based on structure data. Alexkhomyakovite is hexagonal, P63/mcm, a = 9.2691(2), c = 15.8419(4) Ĺ, V = 1178.72(5) Ĺ3 and Z = 2. The strongest reflections of the powder X-ray diffraction pattern [d Ĺ(I)(hkl)] are: 7.96(27)(002), 3.486(35)(113), 3.011(100)(114), 2.977(32)(211), 2.676(36)(300), 2.626(42)(213, 115), 2.206(26)(311) and 1.982(17)(008). The crystal structure (solved from single-crystal X-ray diffraction data, R = 0.0578) is unique. It is based on (001) heteropolyhedral layers of pentagonal bipyramids (Ca,Na)O5(H2O)2 interconnected via carbonate groups of two types, edge-sharing ones and vertex-sharing ones. Ca and Na are disordered. Ten-fold coordinated K cations centre KO6Cl(H2O)3 polyhedra on either side of the heteropolyhedral layer. A third type of carbonate group and Cl occupy the interlayer. The mineral is named in honour of the outstanding Russian mineralogist Alexander Petrovich Khomyakov (1933-2012).
DS1990-1204
1990
Pushcharovsky, D.Yu.Pushcharovsky, D.Yu., Yamnova, N.A., Nadezhina, T.N.Comparative crystal chemistry of new minerals from alkaline rocksInternational Mineralogical Association Meeting Held June, 1990 Beijing China, Vol. 1, extended abstract p. 334-335RussiaAlkaline rocks, Geochemistry
DS201212-0575
2012
Pushcharovsky, D.Yu.Pushcharovsky, D.Yu., Pushcharovsky, Yu.M.The mineralogy and the origin of deep geospheres: a review.Earth Science Reviews, Vol. 113, 1-2, pp. 94-109.MantleMineralogy
DS202003-0374
2020
Pushcharovsky, D.Yu.Zubkova, N.V., Chukanov, N.V., Schaefer, C., Kan, K.V., Pekov, I., Pushcharovsky, D.Yu.A1 analogue of chayesite from a lamproite of Canacarix, SE Spain, and its crystal structure.Journal of Mineralogy and Geochemistry ( formerly Neues Jahrbuch fur Mineralogie), in press NOT availableEurope, Spainlamproite
DS202006-0935
2020
Pushcharovsky, D.Yu.Matrosova, E.A., Bobrov, A.V., Bindi, L., Pushcharovsky, D.Yu., Irifune, T.Titanium-rich phases in the Earth's transition zone and lower mantle: evidence from experiments in the system Mg)-Si)2-TiO2(+- Al2O3Lithos, Vol. 366-367, 14p. PdfMantlewebsterite, bridgmanite

Abstract: Phase relations in the MgSiO3-MgTiO3 and Mg3Al2Si3O12-MgTiO3 systems were studied at 10-24 GPa and 1600 °C using a high-pressure Kawai-type multianvil apparatus. We investigated the full range of starting compositions for the enstatite-geikielite system to derive a P-X phase diagram and synthesize titanium-bearing phases, such as olivine/wadsleyite, rutile, pyroxene, MgTiSi2O7 weberite, bridgmanite and MST-bridgmanite in a wide pressure range. Olivine and pyroxene in run products are characterized by a low titanium content (<0.6 and <0.3 wt% TiO2, respectively) whereas the content of TiO2 in wadsleyite reaches 2 wt% at 12 GPa. The concentration of Ti in MgTiSi2O7 weberite decreases with pressure from 52 wt% TiO2 at 14 GPa to 43 wt% TiO2 at 18 GPa. Two perovskite-type structures (MgSiO3 bridgmanite and Mg(Si,Ti)O3 bridgmanite) were detected in the studied system. MgSiO3 bridgmanite (Brd) is formed at a pressure of >20 GPa and characterized by significant titanium solubility (up to 13 wt% TiO2 at 24 GPa). Mg(Si,Ti)O3 perovskite is formed at a pressure of >17 GPa. The concentration of TiO2 in this phase varies from 29 wt% to 49 wt%. It was found that addition of Ti to the system moves the boundaries of Ol/Wad phase transformations to lower pressures. Addition of Al to the starting material allows us to simulate the composition of natural Ti-rich garnets and bridgmanites. It is important to note that garnet in the Prp-Gkl system is stable throughout a wide pressure range (10-24 GPa). Al incorporation does not affect the distribution of titanium between two types of bridgmanite. It is shown that high contents of Ti stabilize bridgmanite-like compounds at considerably lower pressure than that at the lower mantle/transition zone boundary. Our experiments simulate the composition of natural Ti-rich primary garnet found in eclogite from the Sulu ultrahigh-pressure (UHP) terrane.
DS202008-1420
2020
Pushcharovsky, D.Yu.Matrosova, E.M., Bobrov, A.V., Bindi, L., Pushcharovsky, D.Yu., Irifune, T.Titanium rich phases in the Earth's transition zone and lower mantle: evidence from experiments in the system MgO-SiO2-TiO2(+-Al2O3) at 10-24 Gpa and 1600 C.Lithos, Vol. 366-367 1055539 14 p. pdfMantlebridgemanite

Abstract: Phase relations in the MgSiO3-MgTiO3 and Mg3Al2Si3O12-MgTiO3 systems were studied at 10-24 GPa and 1600 °C using a high-pressure Kawai-type multianvil apparatus. We investigated the full range of starting compositions for the enstatite-geikielite system to derive a P-X phase diagram and synthesize titanium-bearing phases, such as olivine/wadsleyite, rutile, pyroxene, MgTiSi2O7 weberite, bridgmanite and MST-bridgmanite in a wide pressure range. Olivine and pyroxene in run products are characterized by a low titanium content (<0.6 and <0.3 wt% TiO2, respectively) whereas the content of TiO2 in wadsleyite reaches 2 wt% at 12 GPa. The concentration of Ti in MgTiSi2O7 weberite decreases with pressure from 52 wt% TiO2 at 14 GPa to 43 wt% TiO2 at 18 GPa. Two perovskite-type structures (MgSiO3 bridgmanite and Mg(Si,Ti)O3 bridgmanite) were detected in the studied system. MgSiO3 bridgmanite (Brd) is formed at a pressure of >20 GPa and characterized by significant titanium solubility (up to 13 wt% TiO2 at 24 GPa). Mg(Si,Ti)O3 perovskite is formed at a pressure of >17 GPa. The concentration of TiO2 in this phase varies from 29 wt% to 49 wt%. It was found that addition of Ti to the system moves the boundaries of Ol/Wad phase transformations to lower pressures. Addition of Al to the starting material allows us to simulate the composition of natural Ti-rich garnets and bridgmanites. It is important to note that garnet in the Prp-Gkl system is stable throughout a wide pressure range (10-24 GPa). Al incorporation does not affect the distribution of titanium between two types of bridgmanite. It is shown that high contents of Ti stabilize bridgmanite-like compounds at considerably lower pressure than that at the lower mantle/transition zone boundary. Our experiments simulate the composition of natural Ti-rich primary garnet found in eclogite from the Sulu ultrahigh-pressure (UHP) terrane.
DS2001-0809
2001
Pushcharovsky, Y.M.Mosskovsky, A.A., Pushcharovsky, Y.M., Ruzhentsev, S.V.Indo-Atlantic segment of the Earth: tectonic and geodynamic reconstructionsDoklady Academy of Sciences, Vol. 378, No. 4, pp. 385-87.MantleGeodynamics
DS200512-0883
2004
Pushcharovsky, Y.M.Pushcharovsky, Y.M.Some modern problems of the Earth's tectonics.Geotectonics, Vol. 38, 5, pp. 323-328.Tectonics
DS200712-0861
2007
Pushcharovsky, Y.M.Pushcharovsky, Y.M., Pushcharovsky, D.Y.An approach to the geologic history of the Earth's mantle geospheres.Geotectonics, Vol. 94, 1-4, pp. 111-131.MantleGeospheres
DS200812-0928
2008
Pushcharovsky, Y.M.Pushcharovsky, Y.M., Pushcharovsky, D.Y.The middle mantle of the Earth.Geotectonics, Vol. 42, 1, pp. 1-7.MantleCore, boundary
DS201212-0575
2012
Pushcharovsky, Yu.M.Pushcharovsky, D.Yu., Pushcharovsky, Yu.M.The mineralogy and the origin of deep geospheres: a review.Earth Science Reviews, Vol. 113, 1-2, pp. 94-109.MantleMineralogy
DS200912-0269
2009
Pushcharvsky, D.Yu.Grigorieva, A.A., Zubkova, N.V., Pekov, I.V., Pushcharvsky, D.Yu.Crystal structure of hilarite from Khibiny alkaline massif ( Kola Peninsula).Doklady Earth Sciences, Vol. 428, 1, pp. 1051-1053.Russia, Kola PeninsulaAlkalic
DS1984-0536
1984
Pushkarc, A.L.Mudryi, A.V., Pushkarc, A.L., Tkachev, V.D., Ulyashin, A.G.Noble Gas Atoms as Interstitials in Silicon and DiamondPhys. St. S-b., Vol. 125, No. 1, SEPTEMBER PP. K75-K78.RussiaMineral Chemistry
DS2002-1481
2002
Pushkarev, E.V.Shumilova, T.G., Kablis, G.N., Pushkarev, E.V.Typomorphic features of graphite mineralization of probable alternative high pressure sources of diamond: cubic graphite.Doklady Earth Sciences, Vol. 387,8, pp. 958-62.GlobalDiamond morphology
DS201510-1776
2015
Pushkarev, E.V.Kamenetsky, V.S.,Park, J-W., Mungall, J.E., Pushkarev, E.V., Ivanov, A.V., Kamenetsky, M.B., Yaxley, G.M.Crystallization of platinum group minerals from silicate melts: evidence from Cr-spinel hosted inclusions in volcanic rocks.Geology, Vol. 43, 10, pp. 903-906.RussiaMeimechite

Abstract: The formation of platinum-group minerals (PGM) during magma differentiation has been suggested to be an important process in primitive magma evolution, but decisive textural evidence is difficult to obtain because PGM tend to be very small and very rare. We have investigated Cr-spinel phenocrysts from two oxidized magmas (Siberian meimechite and Vanuatu [Ambae Island] arc picrite) and one reduced magma (Uralian [Russia] ankaramite) for PGM inclusions and their platinum-group element (PGE) contents. We observed Os-Ir and Pt-Fe alloys entrapped as inclusions in Cr-spinel in all three suites of lava. The alloys may occur in association with PGE-bearing sulfides and co-trapped silicate melt. Cr-spinel crystals also contain measurable amounts of Os, Ir, Ru, and Rh, which are at concentrations 2×–100× higher than mantle values. Thermodynamic models indicate that the arc picrite and ankaramite melts were probably both saturated with the observed PGM phases, whereas the Os-Ir alloy grain observed in the meimechite is not in equilibrium with the “bulk” melt. Our results demonstrate that PGM (alloys and sulfides) occur as liquidus phases in primitive (unfractionated) melts at high temperature and at a variety of redox conditions, and that Cr-spinel is a significant host of PGE, either in the crystal structure or as PGM inclusions.
DS200912-0253
2009
Pushkarev, M.S.Glebovitsky, V.A., Nikitina, L.P., Vrevskii, A.B., Pushkarev, M.S., Babushkina, M.S.,Goncharov, A.G.Nature of chemical heterogeneity of the continental lithospheric mantle.Geochemistry International, Vol. 47, 9., Sept. pp. 857-881.MantleGeochemistry
DS200412-1601
2004
Pushkarev, Y.Pushkarev, Y.The bulk silicate Earth as MORB source and isotope geochemical approach to the origin of the D'-layer.Geochimica et Cosmochimica Acta, 13th Goldschmidt Conference held Copenhagen Denmark, Vol. 68, 11 Supp. July, ABSTRACT p.A559.MantleGeochemistry
DS2003-0947
2003
Pushkarev, Y.D.Miller, Y.V., Lvov, A.B., Myskova, T.A., Bogomolov, E.S., Pushkarev, Y.D.Search for ancient continental crust at the junction of the Karelian craton - BelomorianDoklady Earth Sciences, Vol. 389A, 3, pp. 302-5.Russia, KareliaTectonics
DS200412-1311
2003
Pushkarev, Y.D.Miller, Y.V., Lvov, A.B., Myskova, T.A., Bogomolov, E.S., Pushkarev, Y.D.Search for ancient continental crust at the junction of the Karelian craton - Belomorian mobile belt: evidence from isotope geocDoklady Earth Sciences, Vol. 389A, 3, pp. 302-5.Russia, KareliaTectonics
DS200712-0364
2007
Pushkarev, Y.D.Glebovitskii, V.A., Nikitina, L.P., Saltykova, A.K., Pushkarev, Y.D., Ovchinnikov, Babushkina, AshchepkovThermal and chemical heterogeneity of the upper mantle beneath the Baikal Mongolia territory.Petrology, Vol. 15, 1, pp. 58-89.RussiaGeothermometry
DS200812-0929
2008
Pushkarev, Y.D.Pushkarev, Y.D.D layer as a result of the Earth protocore disintegration and as a source of primordial noble gases?Goldschmidt Conference 2008, Abstract p.A767.MantleD layer
DS201012-0238
2010
Pushkarev, Y.D.Glebovitskii, R.V.A., Nikitina, L.P., Pushkarev, Y.D., Vrevskii, A.B., Goncharov, A.G., Bogomolov, E.S.Sm and Nd geochemistry of mantle xenoliths: the problem of mantle material classification.Doklady Earth Sciences, Vol. 433, 1, pp. 890-893.MantleMantle magmatism
DS201312-0723
2012
Pushkarev, Y.D.Pushkarev, Y.D., Starchenko, S.V.Hypothesis of the eroding protocore: new view on the nature of the geomagnetic field.Vladykin, N.V. ed. Deep seated magmatism, its sources and plumes, Russian Academy of Sciences, pp. 104-109.MantleGeomagnetics
DS201412-0715
2014
Pushkarev, Y.D.Pushkarev, Y.D.Fundamental problems of the Earth evolution and the nature of D" layer as one of them.Deep Seated Magmatism, its sources and plumes, Ed. Vladykin, N.V., pp. 104-123.MantleCore, mantle boundary
DS201510-1799
2014
Pushkarev, Y.D.Pushkarev, Y.D.Fundamental problems of the Earth evolution and the nature of D" layer as one of them.Deep-seated magmatism, its sources and plumes, Proceedings of XIII International Workshop held 2014., Vol. 2014, pp. 104-123.MantleGeodynamics
DS1991-1389
1991
Pushkarev, Ye.V.Pushkarev, Ye.V.Olivine-clinopyroxene paragenesis of the phenocrysts in clinopyroxenite Of the southern UralsDoklady Academy of Sciences, Earth Sci. Section, Vol. 307, No. 1-6, pp. 151-154RussiaUltramafics, Pyroxenite -analyses
DS2003-0948
2003
Pushkarev, Yu.D.Miller, Yu.V., Lvov, A.B., Myskova, T.A., Bogomolov, E.S., Pushkarev, Yu.D.Search for ancient continental crust at the junction of the Karelian Craton-BelomorianDoklady Earth Sciences, Vol. 389A, 3, March-April, pp. 302-6.RussiaCraton
DS1986-0658
1986
Pushkin, A.N.Pushkin, A.N., Kulanova, I.I., Rudenko, A.P.Influence of the nature of gases and conditions of their adsorption on the change of diamond wettability.(Russian)Zhur. Fiz. Khim., (Russian), Vol. 60, No. 8, August, pp. 1947-1950RussiaDiamond morphology
DS1988-0685
1988
Pushkin, A.N.Tapraeva, A., Pushkin, A.N., Kulakova, I.I., Rudenko, A.P.Kinetics of oxidation of kimberlite diamonds as modified by methane andhydrogen.(Russian)V. Mosk. U. Kh., (russian), Vol, 29, No. 2, March-April pp. 211-215RussiaBlank
DS201811-2600
2018
Puskar, L.Petit, T., Puskar, L.FTIR spectroscopy of nanodiamonds: methods and interpretation.Diamond & Related Materials, Vol. 89, pp. 52-66.Mantlenanodiamonds

Abstract: Fourier transform infrared spectroscopy (FTIR) is highly sensitive to the surface chemistry of nanodiamonds. In this review, we discuss the different FTIR methods available to characterize nanodiamonds and highlight their advantages and limitations. We also summarize the possible assignments of FTIR spectra of nanodiamonds reported in the literature and discuss FTIR spectra of nanodiamonds modified by different surface treatments. Current work of FTIR applied to in situ and operando characterization of nanodiamonds, in particular nanodiamonds exposed to water or characterized during electrochemical and photocatalytic processes, are also discussed. Finally, perspectives regarding possible future FTIR development for nanodiamonds characterization are proposed.
DS201812-2863
2018
Puskar, L.Petit, T., Puskar, L.FTIR spectroscopy of nanodiamonds: methods and interpretation.Diamond & Related Materials, Vol. 89, pp. 52-66.Europe, Germanynanodiamonds
DS1980-0205
1980
Puskin, A.N.Kulakova, I.I., Puskin, A.N., et al.Research on the Catalytic Oxidation of Diamonds in Relation to Problems of Their Growth; Solutions Under Natural Conditions.Tsnigri, No. 153, PP. 57-64.RussiaBlank
DS201412-1007
2014
Pustavarov, V.Yelisseyev, A., Khrenov, A., Afanasiev, V., Pustavarov, V., Gromilov, S., Panchenko, A., Poikilenko, N., Litasov, K.Luminesence of impact diamonds from the Popigai astrobleme.V.S. Sobolev Institute of Geology and Mineralogy Siberian Branch Russian Academy of Sciences International Symposium Advances in high pressure research: breaking scales and horizons ( Courtesy of N. Poikilenko), Held Sept. 22-26, 2p. AbstractRussia, SiberiaDiamond luminescence
DS1997-0935
1997
Puster, P.Puster, P., Jordan, T.H.How stratified is mantle convection?Journal of Geophysical Research, Vol. 102, No. 4, April 10, pp. 7625-46.MantleConvection, Stratigraphy
DS1960-0730
1966
Pustovalov, L.Pustovalov, L., Ivenseon, YU.Diamonds of the Russian PlatformMining And Minerals Engineering, Vol. 2, No. 3, MARCH PP. 113-115.RussiaDiamond Mining Recovery, History
DS201312-0995
2013
Pustovarov, V.Yelisseyev, A., Meng, G.S., Afanasyev, V., Pokhilenko, N., Pustovarov, V., Isakova, A., Lin, Z.S, Lin, H.Q.Optical properties of impact diamonds from the Popigai astroblemes.Diamond and Related Materials, Vol. 37, pp. 8-16.Russia, SiberiaMeteortic diamonds
DS201509-0439
2015
Pustovarov, V.Yelisseyev, A., Khrenov, A., Afanasiev, V., Pustovarov, V., Gromilov, S., Panchenko, A., Pokhilenko, N., Litasov, K.Luminescence of natural carbon nanomaterial: impact diamonds from the Popigai crater.Diamond and Related Materials, Vol. 58, pp. 69-77.RussiaDeposit - Popigai

Abstract: Impact diamonds (IDs) from the Popigai crater are aggregates of nanoparticulate graphite and cubic and hexagonal diamonds. IDs demonstrate broad-band emissions at 3.05, 2.8, 2.3 and 2.0 eV, which are associated with structural defects and are similar to those in detonation ultra-dispersed diamonds and CVD diamond films. A doublet with components at 1.7856 and 1.7892 eV in some ID samples is related to R1,2 lines of Cr3 + ions in corundum inclusions. The presence of N3, H3, NV0 and NV? vibronic systems in some of the ID samples shows that (i) there is nitrogen impurity and (ii) samples underwent high temperature annealing that promoted vacancies and nitrogen diffusion and defect aggregation. The luminescence decay fits with a sum of two exponential components: lifetime of the fast one is in the 5 to 9 ns range. Parameters of the traps responsible for broad thermoluminescence peaks at 148, 180, 276 and 383 K were estimated.
DS1993-1270
1993
Pustovetsov, A.A.Pustovetsov, A.A., Mitina, Ye.A., Ukhanov, A.V., Nikolskaya, N.Ye.In homogeneity in accessory chrome spinel as a geothermometerGeochemistry International, Vol. 30, No. 5, pp. 31-41.Russia, Urals, RussiaHarzburgite, Kemirsay intrusion
DS2000-0666
2000
Pustovoi, A.A.Mironov, Yu.V., Rhyakhovskii, V.M., Pustovoi, A.A.Strontium, neodymium, lead isotopic zoning in the world ocean and mantle plumes.Geochemistry International, Vol. 38, No.S1, pp. S20-7.MantleSuperplumes, Subduction
DS1970-0390
1971
Putell, J.Putell, J.The Tiffany TouchNew York: Random House., 309P.United StatesKimberley, History
DS2002-1288
2002
Puti, M.Puti, M., Korikovsky, Wallbrecher, Unzog, Olesen, FritzEvolution of an eclogitized continental fragment in the Eastern Alps ( Sieggraben Austria).Journal of Structural Geology, Vol. 24, No. 1, pp. 339-57.AustriaEclogites
DS2000-0962
2000
Putintseva, E.V.Ulianov, A.G., Putintseva, E.V.Deep seated mineral association from kimberlites of the Kaavi district central Finland.IN RUSSIAN.Proceedings Russ. Min. Soc. *RUSS, Vol. 129, No. 2, pp. 10-28.FinlandKimberlite mineralogy, Deposit - Kaavi district
DS201904-0768
2018
Putintseva, E.V.Putintseva, E.V., Spiridonov, E.M.Ilmenite Group minerals in the Russia's oldest diamondiferous kimberlites of Kimozero, Karelia.Geology of Ore Deposits, Vol. 60, 7, pp. 625-635.Russiadeposit - Kimozero

Abstract: The paper discusses the morphology and compositional variations of ilmenite group minerals from kimberlites of two phases at the Kimozero locality, the oldest in Russia. Phenocrysts of Mn-rich picroilmenite and Fe-rich geikielite in kimberlites of both phases are similar in morphology and composition. Ilmenite from cement in the second-phase kimberlites enriched in Mg and rimming small regularly shaped chrome spinel phenocrysts is not present in the first-phase kimberlites. Ilmenite, manganilmenite, and Fe-bearing pyrophanite (22-24 wt % MnO) abundant in the cement of the second-phase kimberlites are twice as rich in Nb and substantially richer in Mn than ilmenite up to manganilmenite from the cement of the first-phase kimberlites. Ilmenite and manganilmenite of the first-phase kimberlites is enriched in Zn (up to 1.5 wt % ZnO). Ilmenite from the second-phase kimberlites contains up to 3 wt % Cr2O3. In Nb concentration, kimberlitic rocks of the Kimozero are similar to those found in other parts of the world (up to 3.5 wt % Nb2O5). Significant Mn-enrichment of the ilmenite group minerals is a common feature of Kimozero kimberlitic rocks. It is suggested that kimberlites in which all ilmenite group minerals—from megacrysts and phenocrysts to small segregations in the cement—are enriched in Me, formed with the participation of carbonatite melts with increased alkalinity.
DS1999-0573
1999
Putirka, K.Putirka, K.Clinopyroxene and liquid equilibration temperatures to 100 kbar and 2450 KContributions to Mineralogy and Petrology, Vol. 135, No. 2-3, pp. 151-63.MantleMineralogy
DS201808-1780
2018
Putirka, K.Putirka, K., Tao, Y., Hari, K.R., Perfit, M., Jackson, M.G., Arevalo, Jr. R.The mantle source of thermal plumes: trace and minor element & major oxides of primitive liquids ( and why olivine compositions don't matter).minoscam.org, doi.org/10.2138/am-2018-6192 59p.Mantleforsterite

Abstract: We estimate the mantle source compositions for mantle plumes, and by implication Earth’s lower mantle, by: (a) measuring trace (e.g, Sc, V, Cu) and minor (e.g., Ca, Mn, Ni) element concentrations of high forsterite olivine grains from several plume localities, (b) estimating the parent liquid compositions from which they crystallized, (c) calculating mantle potential temperatures and degrees of partial melting and (d) estimating trace element compositions of depleted and enriched mantle sources. Our sample set includes two continental flood basalt provinces (Emeishan and Deccan), a flood basalt that erupted in a continental rift setting (Baffin Island), our type example of a thermal mantle plume (Hawaii) and lavas from the Siqueiros Transform at the East Pacific Rise, which represent the mid-ocean ridge system. We also present olivine compositions for the peridotite xenoliths from Kilbourne Hole, New Mexico, USA, which are commonly used as primary and secondary analytical standards. We find that trace elements in lava-hosted olivine grains are too far removed from their mantle source to provided anything but greatly hindered views of such. Olivine compositions reflect not only evolving liquid compositions (including partial melting conditions and later fractionation), but also evolving Ol+liq partition coefficients, which mostly increase with decreasing T during crystallization. Mantle compositions, delimited by maximum forsterite contents and estimates of parental magmas (and experimentally determined partition coefficients) indicate that our selected plumes reflect some combination of (1) a depleted mantle source that is quite similar to that obtained by other methods, and (2) a variably enriched plume source that is more enriched than current estimates of pyrolite. The enriched plume mantle sources can be explained remarkably well as a mixture of subducted mid-ocean ridge basalt (MORB; Gale et al. 2013) and depleted MORB mantle (DM; Salters and Stracke 2004), with MORB:DM ratios of 1:5 to 1:4. These ratios are most sensitive to estimates of melt fraction where plume parental magmas are last equilibrated with their mantle source, but are nonetheless consistent across a wide range of chemically very different elements, and estimates of MORB and DM obtained by very different means. Baffin Island is of particular interest. Like prior studies, we verify a high mantle potential temperature (Tp) of 1630oC (compared to Tp = 1320-1420oC for MORB from Cottrell and Kelley 2011 for Ol of Fo89.3-91.4). The Baffin source is also within error the same as DM with respect to trace elements, although still isotopically distinct; Baffin appears to be sourced in something that is akin to DM that lies at the base of the mantle, where plumes acquire their excess heat. Thus while part of our analysis supports the concept of a "slab graveyard" at the bottom of the lower mantle (e.g., Wyession 1996), that cemetery is by no means ubiquitous at the CMB: subducted slabs are either unevenly interred, or efficiently excavated by later upwellings.
DS200512-0884
2005
Putirka, K.D.Putirka, K.D.Mantle potential temperature at Hawaii, Iceland, and the mid-Ocean Ridge system, as inferred from olivine phenocrysts: evidence thermally driven mantle plumesGeochemistry, Vol. 6, doi. 10.1029/2005 GC000915Europe, IcelandGeothermometry, thermobarometry
DS200712-0862
2007
Putirka, K.D.Putirka, K.D., Perfit, M., Ryerson, F.J., Jackson, M.G.Ambient and excess mantle temperatures, olivine thermometry and active vs. passive upwelling.Chemical Geology, Vol. 241, 3-4, pp. 177-206.MantleGeothermometry
DS201704-0644
2017
Putirka, K.D.Putirka, K.D.Down the crater: where magmas are stored and why they erupt. Elements, Vol. 13, 1, pp. 11-16.MantleMagmatism

Abstract: Magmas are erupted from a wide range of depths. Olivine compositions, for example, indicate magma storage in the lower crust and upper mantle, while clinopyroxene and amphibole record middle to upper crust storage. Pre-eruptive magmas also often cool by 100-300?°C, frequently at middle-upper crust depths, indicating clogged, ephemeral volcanic pathways. These coolings imply that mafic recharge is not a sufficient cause for eruption and that crystallization-induced vapor saturation is a more proximal eruption trigger. But an improved understanding of eruption mechanisms require precise identifications of what are herein termed "ultimate", "proximal," and "immediate" causes of eruption.
DS202103-0386
2021
Putkinen, N.Hall, A.M., Putkinen, N., Hietala,, S., Lindsberg, E., Holma, M.Ultra-slow cratonic denudation in Finland since 1.5 Ga indicated by tiered unconformities and impact structures.Precambrian Research, Vol. 352, 106000, 18p. PdfEurope, Finlandgeothermometry

Abstract: The Earth’s cratons are traditionally regarded as tectonically stable cores that were episodically buried by thin sedimentary covers. Cratonic crust in southern Finland holds seven post-1.7 Ga tiered unconformities, with remnants of former sedimentary covers. We use the geometries of the tiered unconformities, along with previously dated impact structures and kimberlite and carbonatite pipes, to reconstruct the erosion and burial history of the craton and to derive estimates of depths of erosion in basement and former sedimentary rocks. The close vertical spacing (<200 m) of the unconformities and the survival of small (D ? 5 km) Neoproterozoic and Early Palaeozoic impact structures indicate minor later erosion. Average erosion rates (<2.5 m/Ma) in basement and cover are amongst the lowest reported on Earth. Ultra-slow erosion has allowed the persistence in basement fractures of Phanerozoic fracture coatings and Palaeogene groundwater and microbiomes. Maximum thicknesses of foreland basin sediments in Finland during the Sveconorwegian and Caledonide orogenies are estimated as ~1.0 km and <0.68-1.0 km, respectively. Estimated losses of sedimentary cover derived from apatite fission track thermochronology are higher by factors of at least 2 to 4. A dynamic epeirogenic history of the craton in Finland, with kilometre-scale burial and exhumation, proposed in recent thermochronological models is not supported by other geological proxies. Ultra-slow erosion rates in southern Finland reflect long term tectonic stability and burial of the craton surface for a total of ~1.0 Ga beneath generally thin sedimentary cover.
DS1996-1145
1996
Putnam, B.R.Putnam, B.R.Financing exploration and mining in the 90'sSeg Newsletter, No. 27, Oct., pp. 18-19GlobalEconomics, Financing - companies, discoveries
DS1988-0477
1988
Putnis, A.Mitchell, R.H., Putnis, A.Polygonal serpentine in segregation textured kimberliteCanadian Mineralogist, Vol. 26, pp. 991-997GlobalHam, Frank Smith, Petrography
DS2002-1289
2002
Putnis, A.Putnis, A.Mineral replacement reactions: from macroscopic observations to microscopic mechanisms.Mineralogical Magazine, Vol.66, 6, pp. 689-708.GlobalMineral chemistry - reactions
DS201012-0604
2010
Putnis, A.Putnis, A., John, T.Replacement processes in the Earth's crust.Elements, Vol. 6, 3, pp. 159-164.MantleMetasomatism
DS201412-0716
2014
Putnis, A.Putnis, A.Why mineral interfaces matter.Science, Vol. 343, 6178, March 28, pp. 1441-1442.TechnologyMineral conversions
DS2003-0958
2003
Putovoy, A.A.Mironov, Y.V., Ryakhovsky, V.M., Putovoy, A.A., Lapidus, I.V.Mantle plumes and isotopic heterogeneity of the mantle: evidence from the Atlantic andDoklady Earth Sciences, Vol. 391, 5, pp. 714-17.MantleGeochemistry, Alrosa
DS200412-1332
2003
Putovoy, A.A.Mironov, Y.V., Ryakhovsky, V.M., Putovoy, A.A., Lapidus, I.V.Mantle plumes and isotopic heterogeneity of the mantle: evidence from the Atlantic and adjacent continents.Doklady Earth Sciences, Vol. 391, 5, pp. 714-17.MantleGeochemistry
DS1950-0387
1958
Puttick, K.E.Frank, F.C., Puttick, K.E.Etch Pits and Trigons on DiamondsPhilosphical Magazine., Vol. 3, No. 35, PP. 1262-1279.GlobalDiamond Morphology
DS2002-0131
2002
Puttmann, W.Bechtel, A., Gratzer, R., Puttmann, W.,Oszczepalski, S.Geochemical characteristics across the oxic/anoxic interface Rote Faule front within the KuperschieferChemical Geology, Vol.185,1-2,pp.9-31.PolandGeochemistry, Deposit - Lubin Sieroszowice mining district
DS201708-1657
2017
Puumala, M.Campebll, D., Puumala, M., Eichenberg, D., Riemer, W., Wahl, R.Diamond field trip Marathon-White Ricer area. Guidebook, 15p. Pdf availableCanada, Ontarioguidebook
DS201811-2564
2018
Puumala, M.Cundari, R., Smyk, M., Campbell, D., Puumala, M., Woodruff, L.G.Possible emplacement controls on diamond bearing rocks North of Lake Superior.Proceedings and Abstracts - Institite on Lake Superior Geology, Vol. 64, pt. 1, pp. 19-20.Canada, Ontariodiamond genesis
DS1999-0373
1999
Puura, V.Konsa, M., Puura, V.Provenance of zircon of the lowermost sedimentary cover Estonia, East European craton.Geological Society Finland, Bulletin., Vol. 71, No. 2, pp. 253-73.FinlandZircons - not specific to diamonds, Craton
DS1986-0659
1986
Puustinen, K.Puustinen, K.Halpanen, a new carbonatite occurrence in Finland. *FINGeologi, *FIN., Vol. 38, No. 1, pp. 1-5FinlandCarbonatite
DS200612-1074
2006
Puzankov, M.Yu.Perepelov, A.B., Puzankov, M.Yu., Ivanov, A.V., Filosofova, T.M.Basanites of Mt. Khukhch: first mineralogical geochemical dat a on the Neogene K Al alkaline magmatism in western Kamchatka.Doklady Earth Sciences, Vol. 409, 5, pp. 762-764.RussiaBasanites, Foidites
DS200712-0834
2007
Puzankov, M.Yu.Perepelov, A.B., Puzankov, M.Yu., Ivanov, Filosfova, Demonetova, Smirnova, Chuvshaova, YasnyginaNeogene basanites in western Kamchatka: mineralogy, geochemistry and geodynamic setting.Petrology, Vol. 15, 5, Sept. pp. 488-508.Russia, KamchatkaBasanites, Foidites
DS2000-0247
2000
Puzankov, Y.M.Duchkov, A.D., Puzankov, Y.M., Sokolova, L.S.Heat flow of kimberlite provinces on cratonsRussian Geology and Geophysics, Vol. 40, No. 7, pp.1078-86.MantleHot spots, Craton - geothermometry
DS1987-0767
1987
Puzankov, Yu.M.Volynets, P.N., Anoshin, G.N., Puzankov, Yu.M., Perepelov, A.B.Potassic basaltic rocks of western Kamchatka. Emplacement oflamproiteseries. (Russian)Geol. Geofiz., (Russian), No. 11, pp. 41-50GlobalShonkinite, Absarokite, Lamproite
DS1999-0574
1999
Puzankov, Yu.M.Puzankov, Yu.M.Geochemical characteristics of Cenozoic basalt magmatism related to hotspotactivity.Geochemistry International, Vol. 37, No. 9, Sept. pp. 841-8.MantleMagmatism, Hotspot - plumes
DS200512-0844
2001
Puzankov, Yu.M.Perepelov, A.B., Volynets, O.N., Anoshin, G.N., Puzankov, Yu.M., Antipin, V.S., Kalukov, A.V.Western Kamchatka alkali potassic basaltoid volcanism: geological and geochemical review.Alkaline Magmatism and the problems of mantle sources, pp. 52-68.Russia, KamchatkaAlkalic
DS2001-0908
2001
Puzankov etcPerepelov, A.B., Volynets, O.N., Anoshin, Puzankov etcWestern Kamchatka alkali basaltoid volcanism: geological and geochemical review.Alkaline Magmatism -problems mantle source, pp. 52-68.Russia, KamchatkaAlkaline rocks, Geochemistry
DS1975-0840
1978
Puzanov, L.S.Puzanov, L.S., Kandinov, M.N., Khitarov, D.N., Kharlamov, YE.S.The Importance of Carbon Dioxide During the Formation of Carbonatite Fluorite Barite Iron Ore Mineralization in Easternsiberia.Iz. Nauk Dumka, Kiev Ukr. Ssr, Editor Dolenko, G.n., PP. 57-62.Russia, SiberiaBlank
DS1985-0114
1985
Puzikov, V.M.Chaikovskiy, E.F., Kostereno, A.B., Rozenberg, G.K., Puzikov, V.M.Equilibrium conditions of graphite-diamond for crystallites ofsmallsizes.(Russian)Dopov. Ukr. Akad.(Russian), No. 11, November pp. 50-53RussiaDiamond Morphology
DS2001-0340
2001
PyFrolova, Ti., Plechov, Py, Tikhomirov, ChurakovMelt inclusions in minerals of allivalites of the Kuril Kamchatka Island Arc.Geochemistry International, Vol. 39, No. 4, pp. 336-46.GlobalMantle - melt
DS1975-0698
1978
Pyatenko, I.K.Borodin, L.S., Pyatenko, I.K.General Petrological Aspects of Paleozoic Alkali Magmatism In the Kola Peninsula and the Rare Earth Distribution in Alkali Ultrabasic Lamprophyre Dikes.Geochemistry International (Geokhimiya), Vol. 15, No. 3, PP. 124-135.Russia, Kola PeninsulaPetrology
DS1983-0526
1983
Pyatenko, I.K.Pyatenko, I.K., Yegorova, N.F., Zilberman, A.M., Chernysheva, YE. M.Immiscibility as a possible factor in the genesis of melanocratic members of the basaltseries, as illustrated by the central Ural rock complexDoklady Academy of Science USSR, Earth Science Section, Vol. 273, Nov. Dec. pp. 104-107RussiaPetrology Similar To Kimberlites
DS1985-0550
1985
Pyatenko, I.K.Pyatenko, I.K., Yegorova, N.F., Zilberman, A.M., Chernysheva, Y.Immiscibility as a Possible Factor in the Genesis of MelanocDoklady Academy of Science USSR, Earth Science Section., Vol. 273, No. 1-6, PP. 104-107.Russia, UralsPicrite, Chemical Composition, Textures
DS1988-0558
1988
Pyatenko, I.K.Pyatenko, I.K., Osokin, E.D.Geochemical characteristics of the Kon to zero carbonatite paleovolcano, Kola Peninsula (USSR).(Russian)Geochemistry International (Geokhimiya), (Russian), No. 5, pp. 723-737RussiaCarbonatite
DS1998-1197
1998
Pybus, G.Q.J.Pybus, G.Q.J., Hussey, M.C., Linton, P.L.Spectral investigations of a variety of magnesium bearing rock types:implications for kimberlite Exploration7th. Kimberlite Conference abstract, pp. 717-19.Zimbabwe, South AfricaSpectral - SWIR.
DS2000-0482
2000
Pye, J.W.Kent, G.M., Singh, S.C., Pye, J.W.Evidence from three dimensional seismic reflectivity images for enhanced melt supply beneath mid ocean ridgeNature, Vol. 406, No. 6796, Aug. 10, pp. 614-8.MantleGeophysics - seismics, Melting
DS1993-1271
1993
Pye, K.Pye, K.The dynamics and environmental context of aeolian sedimentary systemsGeological Society of London Special Publication, No. 72, 330pCalifornia, Arizona, India, Spain, Morocco, China, FloridaBook -table of contents, Sedimentology -aeolian systems, dune, geomorphology
DS1994-1417
1994
Pye, K.Pye, K.Sediment transport and depositional processesBlackwell Scientific, 408p. $ 65.00 paperbackGlobalSedimentology, Depositional processes
DS201212-0074
2012
Pye, K.Blott, S.J., Pye, K.Particle size scales and classification of sediment types based on particle size distributions: review and recommended procedures.Sedimentology, in press availableTechnologyClassification of sediments
DS1993-0301
1993
Pyke, J.G.Cruikshank, B.I., Pyke, J.G.Analytical methods used in mineral and land use program's geochemicallaboratoryAustralia Geological Survey AGSO, Record No. 1993/26, $10.00AustraliaGeochemistry, Analytical technology
DS2003-0864
2003
Pylaev, N.F.Mahotkin, I.L., Robey, J., Kurszlaukis, S., Valuev, E.P., Pylaev, N.F.Pipe emplacement model of the Lomonosov diamond deposit, Arkangelsk region, NW8 Ikc Www.venuewest.com/8ikc/program.htm, Session 1, AbstractRussiaGeology, economics, Deposit - Lomonosov
DS200412-1203
2003
Pylaev, N.F.Mahotkin, I.L., Robey, J., Kurszlaukis, S., Valuev, E.P., Pylaev, N.F.Pipe emplacement model of the Lomonosov diamond deposit, Arkangelsk region, NW Russia.8 IKC Program, Session 1, AbstractRussiaGeology, economics Deposit - Lomonosov
DS1994-0401
1994
PyleDawson, J.B., Pinkerton, H., Norton, G.E., Pyle, BrowningPetrology and geochemistry of Oldoinyo Lengai lavas extruded in Nov. @magma source, ascent and cryst.Carbonatite volcanism, Ed. Bell, K., Keller, J., pp. 47-69.TanzaniaPetrology - Carbonatite volcanism., Deposit -Oldoinyo Lengai
DS200412-0777
2004
Pyle, D.Hanan, B., Blichert-Toft, J., Pyle, D., Christie, D.Contrasting origins of the upper mantle MORB source revealed by Hf and Pb isotopes from the Australian Antarctic discordance.Geochimica et Cosmochimica Acta, 13th Goldschmidt Conference held Copenhagen Denmark, Vol. 68, 11 Supp. July, ABSTRACT p.A553.India, Australia, AntarcticaSubduction
DS200512-0396
2004
Pyle, D.G.Hanan, B.B., Blichert Toft, J., Pyle, D.G., Christie, D.M.Contrasting origins of the upper mantle revealed by hafnium and lead isotopes from southeast Indian Ridge ( corrigendum).Nature, No. 7017, Dec. 2, pp. 653-654.Mantle, IndiaGeochronology
DS200512-0397
2004
Pyle, D.G.Hanan, N.B., Blichert Toft, J., Pyle, D.G., Christie, D.M.Contrasting origins of the upper mantle revealed by hafnium and lead isotopes from the southeast Indian Ridge.Nature, No. 7613, Nov. 4, pp. 91-93.Indian RidgeGeochronology
DS1989-0337
1989
Pyle, D.M.Dawson, J.B., Pyle, D.M., Pinkerton, H., Norton, G.Activity at the natrocarbonatite volcano of Oldoinyo LengaiNew Mexico Bureau of Mines Bulletin., Continental Magmatism Abstract Volume, Held, Bulletin. No. 131, p. 67. AbstractDemocratic Republic of CongoCarbonatite
DS1990-0393
1990
Pyle, D.M.Dawson, J.B., Pinkerton, H., Norton, G.E., Pyle, D.M.Physicochemical properties of alkali carbonatite lavas: dat a from the 1988eruption of Oldoinyo Lengai,TanzaniaGeology, Vol. 18, No. 3, March pp. 260-263TanzaniaCarbonatite, Oldoinyo Lengai
DS1990-1205
1990
Pyle, D.M.Pyle, D.M.Short-lived uranium series disequilibration temperatures in natrocarbonatite lavas from OlDoinyo Lengai, Tanzania: constraints on magmagenesisEos, Vol. 71, No. 43, October 23, p. 1658 AbstractTanzaniaCarbonatite, Natrocarbonatite
DS1991-0574
1991
Pyle, D.M.Gill, J.B., Pyle, D.M., Williams, R.W.Igneous rocksMineralogical Association of Canada -Short Course Handbook, Vol. 19, Chapter 9, pp. 287-335GlobalGeochronology, Magmatic evolution, volcanoes
DS1991-1390
1991
Pyle, D.M.Pyle, D.M., Dawson, J.B., Ivanovich, M.Short lived decay series disequilibration temperatures in the natrocarbonatite lavas of Oldoinyo Lengai, Tanzania: constraints on the timing of magma genesisEarth and Planetary Science Letters, Vol. 105, pp. 378-396TanzaniaCarbonatite, Oldoinyo Lengai
DS1994-0402
1994
Pyle, D.M.Dawson, J.B., Pinkerton, H., Pyle, D.M., Nyamweru, C.June 1993 eruption of Oldoinyo Lengai: viscous and large carbonatite lava flows and evidence coexisting silicate and carbonate magmas.Geology, Vol. 22, No. 9, September pp. 799-802.TanzaniaCarbonatite, Oldoinyo Lengai
DS1996-0345
1996
Pyle, D.M.Dawson, J.B., Pyle, D.M., Pinkerton, H.Evolution of natrocarbonatite from a wollastonite nephelinite parent:evidence from June 1993 eruptionJournal of Geology, Vol. 104, No. 1, pp. 41-54.TanzaniaCarbonatite, Deposit -Oldoinyo Lengai
DS1996-1157
1996
Pyle, D.M.Rao, C.N.V., Miller, J.A., Pyle, D.M., Madhavan, V.New Proterozoic K-Ar ages for some kimberlites and lamproites from the Cuddapah Basin, Dharwar Craton:Precambrian Research, Vol. 79, pp. 363-369.India, MahbubnagarLamproite, Geochronology, Deposit -Ramannapeta, Kotakonda, Chelima
DS200412-0304
2004
Pyle, D.M.Chalapathi Rao, N.V., Gibson, S.A., Pyle, D.M., Dickin, A.P.Petrogenesis of Proterozoic lamproites and kimberlites from the Cuddapah Basin and Dharwar Craton, southern India.Journal of Petrology, Vol. 45, 5, pp. 907-948.IndiaLamproites - Mahbubnagar, Anantapur, diamonds
DS200412-1474
2003
Pyle, D.M.Oppenheimer, C., Pyle, D.M., Barclay, J.Volcanic degassing.Geological Society London Special Publication, QE 527 .75 V 64, No. 213, 420p.TechnologyMagma degassing, volcanic emissions, water in potassic
DS1992-1241
1992
Pyle, J.M.Pyle, J.M., Haggerty, S.E.Metasomatism of upper mantle eclogites, Jagersfontein kimberlite, SouthAfricaEos Transactions, Vol. 73, No. 14, April 7, supplement abstracts p.324-5South AfricaEclogites, Metasomatism
DS1993-0610
1993
Pyle, J.M.Haggerty, S.E., Fung, A.T., Pyle, J.M.The mantle array and geochemistries of high pressure and high temperatureeclogites.Russian Geology and Geophysics, Vol. 34, No. 12, pp. 51-65.GlobalGeochemistry, Craton, Koidu, Jagersfontein, Eclogites
DS1993-1272
1993
Pyle, J.M.Pyle, J.M., Haggerty, S.E.Silicate-carbonate liquid immiscibility in upper mantle eclogites, Jagersfontein, kimberlite South Africa.Eos, Transactions, American Geophysical Union, Vol. 74, No. 16, April 20, supplement abstract p. 320.South AfricaPetrography, Mineral chemistry, microprobe
DS1994-1418
1994
Pyle, J.M.Pyle, J.M., Haggerty, S.E.Silicate-carbonate liquid immiscibility in upper mantle eclogites-implications for natrosilicic ,carbonatitesGeochimica et Cosmochimica Acta, Vol. 58, No. 14. July, pp. 2997-3011.GlobalCarbonatite, Eclogite
DS1995-1532
1995
Pyle, J.M.Pyle, J.M.The petrography, mineral chemistry and geochemistry of upper mantleeclogites, Jagersfontein kimberlite.Msc. Thesis, University Of Massachusetts, 394p. 96-66115-B.South AfricaPetrography, Deposit - Jagersfontein
DS1998-1198
1998
Pyle, J.M.Pyle, J.M., Haggerty, S.E.Eclogites and the metasomatism of eclogites from the Jagersfonteinkimberlite: punctuated transport...Geochimica et Cosmochimica Acta, Vol. 62, No. 7, Apr. pp. 1207-1232.South AfricaAlkaline magmatism, Deposit - Jagersfontein
DS2000-0786
2000
Pylypenko, V.Pylypenko, V., Goncharov, A.Seismic migration in near vertical and wide angle relection and refractionstudies: to unified approach.Exploration Geophysics, ASEG Bulletin, Vol. 31, No. 3, Sept. pp. 461-68.AustraliaGeophysics - seismics, Seismic migration - not specific to diamonds
DS1920-0081
1921
Pyms, F.B.Pyms, F.B.Gems; New York: Priv. Publishing, 1921New York: Priv. Publishing, 46P.South Africa, IndiaDiamonds Notable
DS1997-0936
1997
Pyper, D.J.Pyper, D.J.Creating value through income fundsInsight Press, CanadaEconomics, Investments
DS1860-0950
1896
Pyplev, M.I.Pyplev, M.I.Precious Stones, their Features, Deposits and UseSt. Petersburg:, Africa, South AfricaGemology
DS201708-1739
2017
Pypus, G.Pypus, G.New surprises at old discoveries: exploration and sampling of the AK11 kimberlite, Orapa kimberlite field, Botswana.11th. International Kimberlite Conference, PosterAfrica, Botswanadeposit - AK11
DS201708-1740
2017
Pypus, G.Pypus, G.Exploration and sampling of the BK02 kimberlite, Orapa field, Botswana.11th. International Kimberlite Conference, PosterAfrica, Botswanadeposit - BK02
DS202006-0946
2020
Pyryaev, A.N.Ponomarchuk, V.A., Dobretsov, N.L. , Lazareva, E.V., Zhmodik, S.M., Karmanov, N.S., Tolstov, A,V., Pyryaev, A.N.Evidence of microbial-induced mineralization in rocks of the Tomtor carbonatite complex ( Arctic Siberia).Doklady Earth Science, Vol. 490, 2, pp. 76-80.Russia, Siberiacarbonatite

Abstract: Carbonates of the Tomtor complex of ultramafic alkaline rocks and carbonatites (the northern part of the Republic of Sakha Yakutia) are distinguished by a wide range of carbon isotopic composition ?13C from +2 to -59.9‰. The geological position, localization patterns, mineral and chemical compositions and the relationship with REE mineralization of samples with values of ?13C carbonates from -25 to -59‰ are characterized. The formation of abnormally low ?13C in carbonates is determined by the biogenic oxidation of methane from ?13Cmet to -70‰.
DS202204-0531
2022
Pyryaev, A.N.Novikov, D.A., Ilin, A.V., Kashnirtsev, V.A., Chernykh, A.V., Pyryaev, A.N.Geochemistry of brines and oil occurrences in the Udachnaya kimberlite pipe ( Siberian platform).Russian Geology and Geophysics, Vol. 63, pp. 166-183.Russia, Siberiadeposit - Udachnaya

Abstract: Results of a geochemical study of brines and oil occurrences in the Udachnaya kimberlite pipe are presented. Like other intrusions in the Daldyn-Alakit diamondiferous region, this diamond deposit is a unique cryohydrogeologic microstructure differing from the host sedimentary rocks and other diamond pipes of the Yakutian diamond-bearing province. Two waterlogged zones distinguished in the section of orebodies at the explored depths of the deposit correspond to the upper and middle Cambrian aquifers. Predominantly acidic (average pH = 5.5) Cl-Ca and Cl-Ca-Na brines with TDS from 94.3 to 391.3 g/dm3 are widespread within the orebodies and host rocks. The brine mineralization and contents of major salt-forming components increase with depth, to the horizon at the -365 m elevation, where TDS reaches 391 g/dm3, while below, at the -650 m level with noted hydrogeochemical-field inversion, TDS is 253 g/dm3. The mineralization of Cl-Ca, Cl-Ca-Na, Cl-Ca-Mg, and Cl-Ca-Mg-Na brines in the upper Cambrian rocks varies from 102.9 to 192.9 g/dm3, and the pH values, from 4.9 to 6.2, averaging 5.6. Among the microcomponents, the highest average concentrations (mg/dm3) are found for Br1292.8 > S875.7 > Sr453.7 > Fe79.7 > Li53.4 > B32.7 > I13.3 > Si10.8 > Mn6.4 > Se3.6 > Rb2.3. The values of genetic coefficients vary widely: The rNa/rCl coefficient ranges from 0.18 to 0.31; rCa/rMg, from 1.03 to 3.60; Ca/Cl, from 0.2 to 0.3; and the integrated metamorphism index S (according to S.L. Shvartsev) varies from 193 to 277. The middle Cambrian rock complex, containing more saline brines, has been examined in much more detail. It hosts Cl-Ca, Cl-Ca-Na, Cl-Ca-Mg, and Cl-Na-Mg brines with TDS from 94.3 to 391.3 g/dm3 and high average concentrations (mg/dm3) of microcomponents: Br2224.9 > Sr1024.9 >S500.1 > B202.9 > Li147.1 > Fe97.0 > I33.2 > Rb11.4 > Si9.6 > Se9.5 > Mn3.6 > Ni1.7. As compared with brines in the overlying rocks, the middle Cambrian brines show a wider variation in element ratios: rNa/rCl from 0.14 to 0.34, rCa/rMg from 0.66 to 9.71, and Ca/Cl from 0.03 to 0.45. These brines are also characterized by a significantly higher metamorphism grade, which is indicated not only by the rNa/rCl and rCa/rMg ratios but also by the S index varying from 278 to 316. The composition of stable isotopes ?D and ?18O) and dissolved inorganic carbon ?13C) of the brines was investigated. The studied waters are assumed to be of sedimentary-metamorphic origin. Their isotopic composition reflects the climatic conditions existing at the time of their burial, which were probably aggravated by the contribution of the oxygen isotope exchange with water-bearing rocks. The ?13C values of carbon dioxide dissolved in water allow an inference about its biogenic origin. The biogenic carbon isotope exchange is governed by the relationship between methanogenic and SMT processes. Analysis of the 87Rb/86Sr and 87Sr/86Sr isotope ratios of the studied brines has revealed affinity between the isotopic compositions of waters in the Cambrian deposits and in ancient seawaters. The mass chromatograms of saturated-hydrocarbon (HC) fractions show at least two individual types of oils and malthas (naphthides). The third variety resulted from their mixing at different stages of migration. The fourth is from the contact zone; it changed during the explosion of kimberlites. The first, most common, type of naphthides (“postexplosive”) is similar in all geochemical parameters to oils from the Nepa-Botuobiya anteclise, in particular, to those from the Mirnyi arch. Oils of the second (pre-explosive) type are found only in the Udachnaya Formation, within the depth range 1130-1430 m.
DS2003-1119
2003
Pysklwec, R.N.Pysklwec, R.N., Shahnas, M.H.Time dependent surface topography in a coupled crust mantle convection modelGeophysical Journal International, Vol. 154, 2, pp. 268-78.MantleGeophysics - seismics
DS200412-1602
2003
Pysklwec, R.N.Pysklwec, R.N., Shahnas, M.H.Time dependent surface topography in a coupled crust mantle convection model.Geophysical Journal International, Vol. 154, 2, pp. 268-78.MantleGeophysics - seismics
DS1997-0937
1997
Pysklywec, R.N.Pysklywec, R.N., Mitrovica, J.X.Mantle avalanches and the dynamic topography of continentsEarth and Planetary Science Letters, Vol. 148, pp. 447-455MantleFlow, basins, Geodynamics
DS1998-1199
1998
Pysklywec, R.N.Pysklywec, R.N., Mitrovica, J.X.Mantle flow mechanisms for the large scale subsidence of continentalinteriors.Geology, Vol. 26, No. 8, Aug. pp. 687-90.MantleConvection, topography
DS2000-0787
2000
Pysklywec, R.N.Pysklywec, R.N., Beaumont, C., Fullsack, P.Modeling the behaviour of the continental mantle lithosphere during plate convergence.Geology, Vol. 28, No. 7, July, pp. 655-8.MantleSubduction, collision, modeling
DS2000-0788
2000
Pysklywec, R.N.Pysklywec, R.N., Mitrovica, J.X.Mantle flow mechanisms of epeirogeny and their possible role in evolution of Western Canada Sedimentary Basin.Canadian Journal of Earth Sciences, Vol.37, No.11, Nov.pp.1535-48.AlbertaTectonics - mantle flow dynamics
DS2000-0789
2000
Pysklywec, R.N.Pysklywec, R.N., Mitrovica, J.X.Mantle flow mechanisms of epirogeny and their possible role in evolution of Western Canada Sedimentary Basin.Canadian Journal of Earth Sciences, Vol.37, No.11, Nov.pp.1535-48.AlbertaTectonics - mantle flow dynamics
DS2001-0956
2001
Pysklywec, R.N.Pysklywec, R.N.Evolution of subducting mantle lithosphere at a continental plate boundaryGeophysical Research Letters, Vol. 28, No. 23, Dec. pp. 4399-4402.MantleBoundary, Subduction
DS2003-0234
2003
Pysklywec, R.N.Chambers, K., Pysklywec, R.N.The influence of phase boundary deflection on velocity anomalies of stagnant slabs inGeophysical Research Letters, Vol. 30, 18, 1965 DOI.1029/2003GLO17754MantleSubduction, tectonics, geodynamics, geophysics - seismi
DS200412-0306
2003
Pysklywec, R.N.Chambers, K., Pysklywec, R.N.The influence of phase boundary deflection on velocity anomalies of stagnant slabs in the transition zone.Geophysical Research Letters, Vol. 30, 18, 1965 DOI.1029/2003GLO17754MantleSubduction, tectonics, geodynamics, geophysics - seismi
DS200412-1603
2004
Pysklywec, R.N.Pysklywec, R.N., Beaumont, C.Interplate tectonics: feedback between radioactive thermal weakening and crustal deformation driven by mantle lithosphere instabEarth and Planetary Science Letters, Vol. 221, 1-4, pp. 275-292.MantleGeothermometry
DS200512-0841
2005
Pysklywec, R.N.Percival, J.A., Pysklywec, R.N.Archean lithospheric mantle inversion: key to diamond productivity of cratonic keels.GAC Annual Meeting Halifax May 15-19, Abstract 1p.MantleGeothermometry, Diamond evolution
DS200512-0885
2004
Pysklywec, R.N.Pysklywec, R.N., Cruden, A.R.Coupled crust mantle dynamics and intraplate tectonics: two dimensional numerical and three dimensional analogue modelling.Geochemistry, Geophysics, Geosystems: G3, Vol. 5, pp. Q10003 10.1029/2004 GC000748MantleTectonics, geodynamics
DS200512-0886
2005
Pysklywec, R.N.Pysklywec, R.N., Ishii, M.Time dependent subduction dynamics driven by the instability of stagnant slabs in the transition zone.Physics of the Earth and Planetary Interiors, Vol. 149, 1-2, March 15, pp.115-132.MantleSubduction
DS200712-0832
2007
Pysklywec, R.N.Percival, J.A., Pysklywec, R.N.Are Archean lithospheric keels inverted?Earth and Planetary Science Letters, Vol. 254, 3-4, pp. 393-403.MantleGeodynamics, tectonics
DS201012-0605
2010
Pysklywec, R.N.Pysklywec, R.N., Gogus, O., Percival, J., Cruden, A.R.Insights from geodynamical modeling on possible fates of continental mantle lithosphere: collision, removal, and overturn.Canadian Journal of Earth Sciences, Vol. 47, 4, pp. 541-563,MantleGeodynamics
DS201212-0259
2012
Pysklywec, R.N.Gray, R., Pysklywec, R.N.Geodynamic models of mature continental collision: evolution of an orogen from lithospheric suduction to continental retreat/delamination.Journal of Geophysical Research, Vol. 117, B03408, 14p.MantleGeodynamics - subduction
DS201212-0283
2012
Pysklywec, R.N.Hardebol, N.J., Pysklywec, R.N., Stephenson, R.Small scale convection at a continental back arc to craton transition: application to the southern Canadian Cordillera.Journal of Geophysical Research,, Vol. 117, B1, B01408.Canada, British ColumbiaConvection
DS201701-0014
2016
Pysklywec, R.N.Heron, P.J., Pysklywec, R.N., Stephenson, R.Identifying mantle lithosphere inheritance in controlling intraplate orogenesis.Journal of Geophysical Research, Vol. 121, 9, pp. 6966-6987.MantleGeodynamics

Abstract: Crustal inheritance is often considered important in the tectonic evolution of the Wilson Cycle. However, the role of the mantle lithosphere is usually overlooked due to its difficulty to image and uncertainty in rheological makeup. Recently, increased resolution in lithosphere imaging has shown potential scarring in continental mantle lithosphere to be ubiquitous. In our study, we analyze intraplate deformation driven by mantle lithosphere heterogeneities from ancient Wilson Cycle processes and compare this to crustal inheritance deformation. We present 2-D numerical experiments of continental convergence to generate intraplate deformation, exploring the limits of continental rheology to understand the dominant lithosphere layer across a broad range of geological settings. By implementing a "jelly sandwich" rheology, common in stable continental lithosphere, we find that during compression the strength of the mantle lithosphere is integral in generating deformation from a structural anomaly. We posit that if the continental mantle is the strongest layer within the lithosphere, then such inheritance may have important implications for the Wilson Cycle. Furthermore, our models show that deformation driven by mantle lithosphere scarring can produce tectonic patterns related to intraplate orogenesis originating from crustal sources, highlighting the need for a more formal discussion of the role of the mantle lithosphere in plate tectonics.
DS201805-0950
2018
Pysklywec, R.N.Heron, P.J., Pysklywec, R.N., Stephenson, R.Exploring the theory of plate tectonics: the role of mantle lithosphere structure.Geological Society of London, Special Publication, Vol. 470, doi:10.1144 /SP470.7Mantletectonics

Abstract: This review of the role of the mantle lithosphere in plate tectonic processes collates a wide range of recent studies from seismology and numerical modelling. A continually growing catalogue of deep geophysical imaging has illuminated the mantle lithosphere and generated new interpretations of how the lithosphere evolves. We review current ideas about the role of continental mantle lithosphere in plate tectonic processes. Evidence seems to be growing that scarring in the continental mantle lithosphere is ubiquitous, which implies a reassessment of the widely held view that it is the inheritance of crustal structure only (rather than the lithosphere as a whole) that is most important in the conventional theory of plate tectonics (e.g. the Wilson cycle). Recent studies have interpreted mantle lithosphere heterogeneities to be pre-existing structures and, as such, linked to the Wilson cycle and inheritance. We consider the current fundamental questions in the role of the mantle lithosphere in causing tectonic deformation, reviewing recent results and highlighting the potential of the deep lithosphere in infiltrating every aspect of plate tectonics processes.
DS201812-2817
2018
Pysklywec, R.N.Heron, P.J., Pysklywec, R.N., Stephenson, R.Exploring the theory of plate tectonics: the role of mantle lithosphere structure.http://sp.lyellcollection.org, doi.org/10.1144/ SP470.7Mantleplate tectonics

Abstract: This review of the role of the mantle lithosphere in plate tectonic processes collates a wide range of recent studies from seismology and numerical modelling. A continually growing catalogue of deep geophysical imaging has illuminated the mantle lithosphere and generated new interpretations of how the lithosphere evolves. We review current ideas about the role of continental mantle lithosphere in plate tectonic processes. Evidence seems to be growing that scarring in the continental mantle lithosphere is ubiquitous, which implies a reassessment of the widely held view that it is the inheritance of crustal structure only (rather than the lithosphere as a whole) that is most important in the conventional theory of plate tectonics (e.g. the Wilson cycle). Recent studies have interpreted mantle lithosphere heterogeneities to be pre-existing structures and, as such, linked to the Wilson cycle and inheritance. We consider the current fundamental questions in the role of the mantle lithosphere in causing tectonic deformation, reviewing recent results and highlighting the potential of the deep lithosphere in infiltrating every aspect of plate tectonics processes.
DS201911-2533
2019
Pysklywec, R.N.Heron, P.J., Pysklywec, R.N., Stephenson, R.Exploring the theory of plate tectonics: the role of mantle lithosphere.N: Cycle Concepts in Plate Tectonics, editors Wilson and Houseman , Geological Society of London special publication 470, pp. 137-155.Mantleplate tectonics

Abstract: This review of the role of the mantle lithosphere in plate tectonic processes collates a wide range of recent studies from seismology and numerical modelling. A continually growing catalogue of deep geophysical imaging has illuminated the mantle lithosphere and generated new interpretations of how the lithosphere evolves. We review current ideas about the role of continental mantle lithosphere in plate tectonic processes. Evidence seems to be growing that scarring in the continental mantle lithosphere is ubiquitous, which implies a reassessment of the widely held view that it is the inheritance of crustal structure only (rather than the lithosphere as a whole) that is most important in the conventional theory of plate tectonics (e.g. the Wilson cycle). Recent studies have interpreted mantle lithosphere heterogeneities to be pre-existing structures and, as such, linked to the Wilson cycle and inheritance. We consider the current fundamental questions in the role of the mantle lithosphere in causing tectonic deformation, reviewing recent results and highlighting the potential of the deep lithosphere in infiltrating every aspect of plate tectonics processes.
DS1997-0938
1997
Pysklywee, R.N.Pysklywee, R.N., Mitrovica, J.X.Mantle avalanches and the dynamic topography of continentsEarth and Planetary Science Letters, Vol. 148, No. 3-4, pp. 447-455.MantleGeodynamics
DS200612-1114
2006
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Author Index
A-An Ao+ B-Bd Be-Bk Bl-Bq Br+ C-Cg Ch-Ck Cl+ D-Dd De-Dn Do+ E F-Fn Fo+ G-Gh Gi-Gq Gr+ H-Hd He-Hn Ho+ I J K-Kg Kh-Kn Ko-Kq Kr+ L-Lh
Li+ M-Maq Mar-Mc Md-Mn Mo+ N O P-Pd Pe-Pn Po+ Q R-Rh Ri-Rn Ro+ S-Sd Se-Sh Si-Sm Sn-Ss St+ T-Th Ti+ U V W-Wg Wh+ X Y Z
 
 

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