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SDLRC - Scientific Articles all years by Author - Ti+


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 - Ti+
Posted/
Published
AuthorTitleSourceRegionKeywords
DS202012-2253
2020
Tian, D.Tian, D., Lv, M., Wei, S.S., Dorfman, S.M., Shearer, P.M.Global variations of Earth's 520- and 550-km discontinuities.Earth and Planetary Letters, Vol. 552, 116600, 13p. PdfMantlecore-mantle boundary

Abstract: We investigate seismic discontinuities in the mantle transition zone (MTZ) by analyzing SS precursors recorded at global seismic stations. Our observations confirm the global existence of the 520-km discontinuity. Although substantial regional depth variations in the 520-km discontinuity are generally correlated with temperature in the mid-MTZ, they cannot be fully explained by the Clapeyron slope of the wadsleyite-ringwoodite phase transition, suggesting both thermal and compositional heterogeneities in the MTZ. A second discontinuity at ~560-km depth, previously interpreted as splitting of the 520-km discontinuity, is most commonly detected in cold subduction zones and hot mantle regions. The depth separation between the 520- and 560-km discontinuities varies from ~80 km in cold regions to ~40 km in hot areas. The exsolution of calcium-perovskite (Ca-pv) from majorite garnet has been proposed to explain the velocity and density changes across the 560-km discontinuity. However, the gradual exsolution of perovskite and partitioning of Ca and Al between perovskite and garnet appear inconsistent with the relatively “sharp” discontinuity in seismic observations and thus need to be revisited in the future. Nevertheless, because the only known transition in major minerals at this depth in the MTZ is the formation of Ca-pv, the existence of the 560-km discontinuity may imply localized high calcium concentrations in the mid-MTZ possibly related to the recycling of oceanic crust.
DS202011-2064
2020
Tian, G.Tian, G., Liu, J., Scott, J.M., Chen, L-H., Pearson, D.G., Chu, Z.Architecture and evolution of the lithospheric roots beneath circum-cratonic orogenic belts - the Xing'an Mongolian orogenic belt and its relationship with adjacent North China and Siberian cratonic roots.Lithos, Vol. 376-377, 18p. PdfChina, Russia, Siberiaxenoliths

Abstract: The accretionary mobile belts surrounding ancient cratonic cores are an important facet of the growth and preservation of continental landmasses. Peridotites from Nuominhe in the Xing'an Mongolia Orogenic Belt (XMOB) provide an additional opportunity to examine the age, structure and evolution of mantle lithosphere separating two of the largest existing ancient continental nuclei: the North China Craton and the Siberian Craton. This suite of mantle rocks comprises fertile to refractory garnet- and spinel-facies harzburgites and lherzolites. Their lithophile element systematics show that the peridotites were metasomatized to variable extent by silicate-carbonate melts. Despite this, the highly siderophile element and Os isotope systematics appear to have been largely undisturbed. The Nuominhe peridotites have Re-depletion Os model ages (TRD) that range from 0.5 Ga to 2.4 Ga, with three peaks/major ranges at ~2.0-2.4 Ga, ~1.4-1.5 Ga and ~ 0.8 Ga, of which the latter two are closely similar to those data from other XMOB localities reported in the literature. The only section of the mantle that appears to have ages which correlate with crust formation is the suite with Neoproterozoic (~0.8 Ga) depletion ages, while the older mantle domains document older episodes of mantle depletion. Given the lack of correlation between equilibrium temperatures and bulk composition or TRD ages, the Nuominhe peridotites were inter-mixed in the mantle column, most likely as a result of incorporation of recycled older continental mantle fragments into juvenile Neoproterozoic mantle during the orogenic processes responsible for new lithosphere formation. Geothermobarometry of the Nuominhe peridotites indicates a conductive geotherm of ~60 mWm-2 and therefore a lithosphere thickness of ~125 km, which is thicker than most Phanerozoic continental terranes, and even thicker than Proterozoic regions that comprise the larger cratonic unit of the Siberian craton. This thick Proterozoic lithosphere sandwiched between the converging North China and Siberian cratons was evidently partly constructed from recycled refractory continental mantle fragments, perhaps extant in the convecting mantle, or in-part derived from the surrounding cratons, leading to a composite nature of the mantle in this re-healed continental suture. Re-accretion of recycled refractory old continental mantle fragments plays a significant role in affecting mantle composition and controlling the thickness of circum-cratonic landmasses between cratonic blocks.
DS201711-2507
2017
Tian, M.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.
DS200612-0603
2006
Tian, S.Hou, Z., Tian, S., Yuan, Z., Xie, Y., Yin, S., Yi, L., Fei, H., Yang, Z.The Himalayan collision zone carbonatites in western Sichuan, SW China: petrogenesis, mantle source and tectonic implication.Earth and Planetary Science Letters, in pressAsia, ChinaCarbonatite
DS200812-1172
2008
Tian, S.Tian, S., Hou, Ding, Yang, Yang, Yuan, Xie, Liu, Li.Ages of carbonatite and syenite from the Mianning Dechang REE belt in eastern Indo-Asian collision zone, SW Chin a and their geological significance.Goldschmidt Conference 2008, Abstract p.A947.ChinaCarbonatite
DS200912-0313
2009
Tian, S.Hou, Z., Tian, S., Xie, Y., Yang, Z., Yuan, Z., Yin, S., Yi, L., Fei, H., Zou, T., Bai, G., Li, X.The Himalayan Mianning Dechang REE belt associated with carbonatite alkaline complexes eastern Indo Asian collision zone, SW China.Ore Geology Reviews, Vol. 36, 1-3, pp. 65-89.ChinaCarbonatite
DS201112-1040
2011
Tian, W.Tian, W., Chen, B., Ireland, T.R., Green, D.H., Suzuki, K., Chu, Z.Petrology and geochemistry of dunites, chromitites and mineral inclusions from the Gaositai Alaskan type complex, North Chin a craton: mantle source charactersLithos, Vol. 127, 1-2, pp. 165-175.ChinaCarbonatite
DS201502-0050
2015
Tian, W.Chen, M., Tian, W.Surface and mantle expression of the Early Permian Tarim mantle plume.Economic Geology Research Institute 2015, Vol. 17,, # 1147, 1p. AbstractChinaPeridotite, xenoliths

Abstract: The mantle process during the Early Permian Tarim plume event is revealed by flood basalt and mantle xenoliths. Permian Tarim flood basalts have typical two pulses' eruption. The first pulse of the Tarim flood basalt was erupted at 291-290Ma, characterized by OIB-like Zr/Nb (~5.83), Nb/La and Ce/Pb ratios, and PUM-like initial 187Os/188Os ratios (0.1308-0.1329). They're plotted along a 290±11Ma isochron, implying a pristine "plume mantle" source. The second pulse of the Tarim flood basalt was erupted at 283-281 Ma, with Zr/Nb (~13.6), Nb/La and Ce/Pb ratios similar or close to the lower crust and initial 187Os/188Os ratios (0.1743~19.6740) that deviated from the ~290 Ma isochron line, indicative of significant crustal assimilation. Mantle-derived peridotite and pyroxenite xenoliths hosted in Cenozoic alkali basalts (~20 Ma) are found in the Xikeer, western Tarim Block. Based on their petrographic and geochemical characteristics, peridotite xenoliths can be divided into three groups. Group 1 peridotites, with the presence of the high Mg-number of olivines (91-93) and spinel-pyroxenes clusters, experienced high-degree melt extraction (~17% fractional melting) from garnet- to spinel-stable field. Groups 2 and 3 peridotites, characterized by the clinopyroxenes with spoon-shaped and highly fractionated REE patterns respectively, underwent extensive silicate melt metasomatism at low melt/rock ratios (15) and that the host basanite is incapable of being the metasomatic agent. The Re-Os isotopic systematics of the Xikeer peridotites and pyroxenites yield an isochron of 290±11 Ma, virtually identical to the age of Tarim flood basalts. Their PUM-like Os initial ratios and convecting mantle-like É?Nd(t=290 Ma) strongly suggest that the Xikeer mantle xenoliths derive from the plume mantle. We propose that the Xikeer xenolith suite recorded mantle 'auto-refertilization' process, i.e., they may have been initially formed by melt extraction from the convecting mantle and, shortly after, was refertilized by plume melts during the Early Permian.
DS201212-0271
2012
Tian, X.Guo, X., Encarnacion, J., Deino, A., Xu, X., Li, Z., Tian, X.Collision and rotation of the South Chin a block and their role in the formation and exhumation of ultrahigh pressure rocks in the Dabie Shan orogen.Terra Nova, in press availableChinaUHP
DS201212-0272
2012
Tian, X.Guo, X., Encarnacion, J., Xu, X., Deino, A., Li, Z.,Tian, X.Collision and rotation of the South Chin a block and their role in the formation and exhumation of ultrahigh pressure rocks in the Dabie Shan orogen.Terra Nova, Vol. 24, 5, pp. 339-350.ChinaUHP
DS200512-1231
2005
Tian, Y.Zang, C.Y., Jia, X.P., Ma, H.A., Tian, Y., Xiao, H.Y.Effect of regrown graphite on the growth of large gem diamonds by temperature gradient method.Chinese Physics Letters , Vol. 22, 9, pp. 2415-2417.TechnologyDiamond morphology
DS200912-0759
2009
Tian, Y.Tian, Y., Sigloch, K., Nolet, G.Multiple frequency tomography of the western US upper mantle.Geophysical Journal International, Vol. 178, 3, pp. 1384-1402.MantleGeophysics, seismics
DS200912-0760
2009
Tian, Y.Tian, Y., Sigloch, K., Nolet, G.Multiple frequency SH wave tomography of the western US upper mantle.Geophysical Journal International, Vol. 178, bo. 3 Sept. oo, 1384-1402.United StatesTomography - not specific to diamonds
DS200912-0761
2009
Tian, Y.Tian, Y., Zhao, D., Sun, R., Teng, J.Seismic imaging of the crust and upper mantle beneath the North Chin a Craton.Physics of the Earth and Planetary Interiors, Vol. 172, 3-4, pp. 169-182.ChinaGeophysics - seismics
DS201112-1041
2011
Tian, Y.Tian, Y., Zhao, D.Destruction mechanism of the North Chin a craton: insight into O and S wave mantle tomography.Journal of Asian Earth Sciences, Vol. 42, 6, pp. 1132-1145.ChinaGeophysics - seismics, tectonics
DS201412-0383
2014
Tian, Y.Huang, Q., Yu, D., Xu, B., Hu, W., Ma, Y., Wang, Y., Zhao, Z., Wen, B., He, J., Liu, Z., Tian, Y.Nanotwinned diamond with unprecedented hardness and stability.Nature, Vol. 510, June 12, pp. 250-253.TechnologyDiamond synthetic
DS201506-0297
2015
Tian, Y.Tian, Y., Yang, J., Robinson, P.T., Xiong, F., Li, Y., Zhang, Z., Liu, Z., Liu, F., Niu, X.Diamond discovered in high Al chromitites of the Sartohay ophiolite, Xinjiang province China.Acta Geologica Sinica, Vol. 89, 2, pp. 332-340.ChinaChromitite
DS201510-1816
2015
Tian, Y.Yang, J-S., Wirth, R., Xu, X., Tian, Y., Huang, Z., Robinson, P.T., Dilek, Y.Formation of ophiolite hosted diamonds by deep subduction of oceanic lithosphere: evidence from mineral inclusions.GSA Annual Meeting, Paper 81-2, 1p. Abstract onlyMantleMineral inclusions

Abstract: In recent years we have confirmed the existence of ophiolite-hosted diamonds on Earth, which occur in mantle peridotites and podiform chromitites of many ophiolites. These diamonds differ significantly from most kimberlite varieties, particularly in their inclusions. The typical inclusions in the diamonds are Mn-rich phases, i.e., NiMnCo alloy, native Mn, MnO, galaxite, Mn olivine and Mn garnet. Ca-silicate perovskite, a typical lower mantle mineral, was identified as mineral inclusions in diamond. One occurs as a 60-nanometer, euhedral grain associated with NiMnCo alloy and graphite, while another one occurs as a 50-nanometer grain within a large inclusion containing both NiMnCo alloy and Nd-Se-Cu-S phase. By EDS the perovskite has Ca 48.3%, Si 37.7% and Mn 14.1% with oxygen. TEM diffraction data show that the inclusion has d-spacings and angles between adjacent lattice planes are consistent to the Ca-silicate perovskite with an orthorhombic structure. The only known source of such light carbon is organic material in surface sediments and the best known sources of abundant manganese are Fe-Mn-rich sediments and Mn nodules, both of which are common on the seafloor. Many parts of the modern seafloor are also covered by sediments with a continental provenance. Phases such as SiO2 and Al2O3 are not expected in mantle peridotites and must have been introduced from shallow levels. We propose that subduction of oceanic lithosphere carries C, Mn, Si, Al and REE to the transition zone or lower mantle where the material is mixed with highly reduced material, perhaps derived from greater depths. Crystallization of diamond from a C-rich fluid encapsulates the observed inclusions. The diamonds and associated minerals are incorporated into chromite grains during chromite crystallization at depth of mantle transition zone, and are carried to shallower levels by mantle convection. Accumulation of chromite grains produces podiform chromitites containing a range of exotic minerals. However, the presence of diamonds and other UHP minerals in ophiolitic peridotites indicates that such phases can persist far outside their normal stability fields.
DS201601-0050
2015
Tian, Y.Yang, J., Wirth, R., Xiong, F., Tian, Y., Huang, Z., Robinson, P.T., Dilek, Y.The lower mantle minerals in ophiolite hosted diamond.Acta Geologica Sinica, Vol. 89, 2, pp. 108-109.MantleMineralogy
DS201710-2262
2017
Tian, Y.Robinson, P.T., Yang, J., Tian, Y., Zhu, H.Diamonds, super reduced and crustal minerals in chromitites of the Hegenshan and Sartohay ophiolites, central Asian orogenic belt, China.Acta Geologica Sinica, Vol. 91, s1, p. 32 abstractChinadiamond inclusions

Abstract: The Central Asian Orogenic Belt (CAOB) is a huge tectonic mélange that lies between the North China Craton and the Siberian Block. It is composed of multiple orogenic belts, continental fragments, magmatic and metamorphic rocks, suture zones and discontinuous ophiolite belts. Although the Hegenshan and Sartohay ophiolites are separated by nearly 3000 km and lie in completely different parts of the CAOB, they are remarkably similar in many respects. Both are composed mainly of serpentinized peridotite and dunite, with minor gabbro and sparse basalt. They both host significant podiform chromitites that consist of high-Al, refractory magnesiochromite with Cr#s [100Cr/(Cr+Al)] averaging >60. The Sartohay ophiolite has a zircon U-Pb age of ca. 300 Ma and has been intruded by granitic plutons of similar age, resulting in intense hydrothermal activity and the formation of gold-bearing listwanites. The age of the Hegenshan is not firmly established but is thought to have formed in the Carboniferous. Like many other ophiolites that we have investigated in other orogenic belts, the chromitites in these two bodies have abundant diamonds, as well as numerous super-reduced and crustal minerals. The diamonds are mostly, colorless to pale yellow, 200-300 µm across and have euhedral to anhedral shapes. They all have low carbon isotopes (d14C = -18 to -29) and some have visible inclusions. These are accompanied by numerous super-reduced minerals such as moissanite, native elements (Fe, Cr, Si, Al, Mn), and alloys (e.g., Ni-Mn-Fe, Ni-Fe-Al, Ni-Mn-Co, Cr-Ni-Fe, Cr-Fe, Cr-Fe-Mn), as well as a wide range of oxides, sulfides and silicates. Grains of zircon are abundant in the chromitites of both ophiolites and range in age from Precambrian to Cretaceous, reflecting both incorporation of old zircons and modification of grains by hydrothermal alteration. Our investigation confirms that high-Al, refractory chromitites in these two ophiolites have the same range of exotic minerals as high-Cr metallurgical chromitites such as those in the Luobusa ophiolite of Tibet. These collections of exotic minerals in ophiolitic chromitites indicate complex, multi-stage recycling of oceanic and continental crustal material at least to the mantle transition zone, followed by uprise and emplacement of the peridotites into relatively shallow ophiolites.
DS201710-2279
2017
Tian, Y.Wu, W., Yang, J., Ma, C., Milushi, I., Lian, D., Tian, Y.Discovery and significance of diamonds and moissanites in chromitites within the Skenderbeu Massif of the Mirdita zone ophiolite, west Albania.Acta Geologica Sinica, Vol. 91, 3, pp. 882-897.Europe, Albaniamoissanites

Abstract: In recent years diamonds and other unusual minerals (carbides, nitrides, metal alloys and native elements) have been recovered from mantle peridotites and chromitites (both high-Cr chromitites and high-Al chromitites) from a number of ophiolites of different ages and tectonic settings. Here we report a similar assemblage of minerals from the Skenderbeu massif of the Mirdita zone ophiolite, west Albania. So far, more than 20 grains of microdiamonds and 30 grains of moissanites (SiC) have been separated from the podiform chromitite. The diamonds are mostly light yellow, transparent, euhedral crystals, 200-300 µm across, with a range of morphologies; some are octahedral and cuboctahedron and others are elongate and irregular. Secondary electron images show that some grains have well-developed striations. All the diamond grains have been analyzed and yielded typical Raman spectra with a shift at ~1325 cm-1. The moissanite grains recovered from the Skenderbeu chromitites are mainly light blue to dark blue, but some are yellow to light yellow. All the analyzed grains have typical Raman spectra with shifts at 766 cm-1, 787 cm-1, and 967 cm-1. The energy spectrums of the moissanites confirm that the grains are composed entirely of silicon and carbon. This investigation expands the occurrence of diamonds and moissanites to Mesozoic ophiolites in the Neo-Tethys. Our new findings suggest that diamonds and moissanites are present, and probably ubiquitous in the oceanic mantle and can provide new perspectives and avenues for research on the origin of ophiolites and podiform chromitites.
DS201712-2702
2017
Tian, Y.Mackintosh, V., Kohn, B., Gleadow, A., Tian, Y.Phanerozoic morphotectonic evolution of the Zimbabwean craton: unexpected outcomes from a multiple low temperature thermochronology study.Tectonics, Vol. 36, 10, in press availableAfrica, Zimbabwecraton, geothermometry

Abstract: The fragmentary Phanerozoic geological record of the anomalously elevated Zimbabwe Craton makes reconstructing its history difficult using conventional field methods. Here we constrain the cryptic Phanerozoic evolution of the Zimbabwe Craton using a spatially extensive apatite (U-Th-Sm)/He (AHe), apatite fission track (AFT), and zircon (U-Th)/He (ZHe) data set. Joint thermal history modeling reveals that the region experienced two cooling episodes inferred to be the denudational response to surface uplift. The first and most significant protracted denudation period was triggered by stress transmission from the adjacent ~750-500 Ma Pan-African orogenesis during the amalgamation of Gondwana. The spatial extent of this rejuvenation signature, encompassing the current broad topographic high, could indicate the possible longevity of an ancient topographic feature. The ZHe data reveal a second, minor denudation phase which began in the Paleogene and removed a kilometer-scale Karoo cover from the craton. Within our data set, the majority of ZHe ages are younger than their corresponding AHe and AFT ages, even at relatively low eU. This unexpectedly recurrent age “inversion” suggests that in certain environments, moderately, as well as extremely, damaged zircons have the potential to act as ultra-low-temperature thermochronometers. Thermal history modeling results reveal that the zircon radiation damage accumulation and annealing model (ZRDAAM) frequently overpredicts the ZHe age. However, the opposite is true for extremely damaged zircons where the ZHe and AHe data are also seemingly incompatible. This suggests that modification of the ZRDAAM may be required for moderate to extreme damage levels.
DS201802-0261
2017
Tian, Y.Robinson, P.T., Yang, J., Tian, Y., Zhu, H.Diamonds, super reduced and crustal minerals in chromitites of the Hegenshan and Sartohay ophiolites, central Asian orogenic belt, China.Acta Geologica Sinica, Vol. 91, 1, p. 32.Asia, Chinamineralogy

Abstract: The Central Asian Orogenic Belt (CAOB) is a huge tectonic mélange that lies between the North China Craton and the Siberian Block. It is composed of multiple orogenic belts, continental fragments, magmatic and metamorphic rocks, suture zones and discontinuous ophiolite belts. Although the Hegenshan and Sartohay ophiolites are separated by nearly 3000 km and lie in completely different parts of the CAOB, they are remarkably similar in many respects. Both are composed mainly of serpentinized peridotite and dunite, with minor gabbro and sparse basalt. They both host significant podiform chromitites that consist of high-Al, refractory magnesiochromite with Cr#s [100Cr/(Cr+Al)] averaging >60. The Sartohay ophiolite has a zircon U-Pb age of ca. 300 Ma and has been intruded by granitic plutons of similar age, resulting in intense hydrothermal activity and the formation of gold-bearing listwanites. The age of the Hegenshan is not firmly established but is thought to have formed in the Carboniferous.Like many other ophiolites that we have investigated in other orogenic belts, the chromitites in these two bodies have abundant diamonds, as well as numerous super-reduced and crustal minerals. The diamonds are mostly, colorless to pale yellow, 200-300 µm across and have euhedral to anhedral shapes. They all have low carbon isotopes (d14C = -18 to -29) and some have visible inclusions. These are accompanied by numerous super-reduced minerals such as moissanite, native elements (Fe, Cr, Si, Al, Mn), and alloys (e.g., Ni-Mn-Fe, Ni-Fe-Al, Ni-Mn-Co, Cr-Ni-Fe, Cr-Fe, Cr-Fe-Mn), as well as a wide range of oxides, sulfides and silicates. Grains of zircon are abundant in the chromitites of both ophiolites and range in age from Precambrian to Cretaceous, reflecting both incorporation of old zircons and modification of grains by hydrothermal alteration. Our investigation confirms that high-Al, refractory chromitites in these two ophiolites have the same range of exotic minerals as high-Cr metallurgical chromitites such as those in the Luobusa ophiolite of Tibet. These collections of exotic minerals in ophiolitic chromitites indicate complex, multi-stage recycling of oceanic and continental crustal material at least to the mantle transition zone, followed by uprise and emplacement of the peridotites into relatively shallow ophiolites.
DS201809-2010
2018
Tian, Y.Chen, Y., Yang, J., Xu, Z., Tian, Y., Shengmin, L.Diamonds and other unusual minerals from peridotites of the Myitkyin a ophiolite, Myanmar.Journal of Asian Earth Sciences, Vol. 164, pp. 179-193.Asia, Myanmarperidotites

Abstract: Peridotites from the Myitkyina ophiolite are mainly composed of lherzolite and harzburgite. The lherzolites have relatively fertile compositions, with 39.40-43.40?wt% MgO, 1.90-3.17?wt% Al2O3 and 1.75-2.84?wt% CaO. They contain spinel and olivine with lower Cr# (12.6-18.2) and Fo values (88.7-91.6) than those of the harzburgites (24.5-59.7 and 89.6-91.6 respectively). The harzburgites have more refractory compositions, containing 42.40-46.23?wt% MgO, 0.50-1.64?wt% Al2O3 and 0.40-1.92?wt% CaO. PGE contents of the peridotites show an affinity to the residual mantle. Evaluation of petrological and geochemical characteristics of these peridotites suggests that the lherzolites and harzburgites represent residual mantle after low to moderate degrees of partial melting, respectively, in the spinel stability field. The U-shaped, primitive mantle-normalized REE patterns and strong positive Ta and Pb anomalies of the harzburgites suggest melt/fluid refertilization in either a MOR or SSZ setting after their formation at a MOR. Mineral separation of the peridotites has yield a range of exotic minerals, including diamond, moissanite, native Si, rutile and zircon, a collection similar to that reported for ophiolites of Tibet and the Polar Urals. The discovery of these exotic minerals in the Myitkyina ophiolite supports the view that they occur widely in the upper oceanic mantle.
DS202001-0047
2020
Tian, Y.Wang, X., Xiao, Y., Sun, Y., Wang, Y., Liu, J., Yang, K., Gu, H., Hou, Z., Tian, Y., Wu, W., Ma, Y.Initiation of the North China craton destruction: constraints from the diamond bearing alkaline basalts from Langan, China.Gondwana Research, Vol. 80, pp. 228-243.Chinacraton

Abstract: The North China Craton (NCC) is an atypical ancient landmass that suffered lithospheric destruction. Previous studies suggest that the eastern part of the lithospheric mantle of the NCC has been thinned and modified in the Mesozoic. However, the initiation time and mechanism of the destruction remain controversial. Mafic magmatismcould provide a unique windowinto deciphering the lithospheric mantle composition and its evolution. Here we present geochemical and geochronological data of the diamond-bearing alkaline basalts from Lan'gan, located in the southeastern margin of the NCC. Zircon U-Pb dating yielded an average age of 174 ± 14 Ma, representing the first reported Jurassic basalts in the eastern NCC. The Lan'gan basalts are enriched in light rare earth elements (LREE) and large ion lithosphile elements (LILE). Sr-Nd-Pb-Hf isotopic compositions (87Sr/86Sr(t) = 0.70646-0.70925, eNd(t) = -2.1 to -4.9, 206Pb/204Pb(t) = 17.14-18.12, 207Pb/204Pb(t) = 15.28-15.61, 208Pb/204Pb(t) = 37.82-38.67, and zircon eHf(t) = -17 to -21) are enriched compared to depleted mantle. The presence of primary amphibole indicates that the magma source of the basalts was water enriched. These observations suggest that, the lithospheric mantle of the eastern NCC were significantly refertilized, likely by slab derived fluids/melts fromthe Paleo-Pacific subduction. Owing to the Paleo-Pacific subduction, the lithosphericmantle of the eastern NCCwere reduced in viscosity and intensity, and finally promoted partialmelting in a limited scale to generate the investigated alkaline basalts. Hence, the discovery of diamond in the Lan'gan basalts demonstrates that the lithosphere of the NCC remained thick, and that large-scale destruction had not initiated in the early Jurassic beneath this region.
DS202004-0542
2020
Tian, Y.Wang, X., Xiao, Y., Wang, Y., Liu, J., Yang, K., Gu, H., Hou, Z., Tian, Y., Wu, W., Ma, Y.Initiation of the North China Craton destruction: constraints from the diamond bearing alkaline basalts from Langan China.Gondwana Research, Vol. 80, pp. 228-243.Chinadeposit - Langan

Abstract: The North China Craton (NCC) is an atypical ancient landmass that suffered lithospheric destruction. Previous studies suggest that the eastern part of the lithospheric mantle of the NCC has been thinned and refertilized in the Mesozoic. However, the initiation time and mechanism of the destruction remain controversial. Mafic magmatism could provide a unique window into deciphering the lithospheric mantle composition and its evolution. Here we present geochemical and geochronological data of the diamond-bearing alkaline basalts from Lan'gan, located in the southeastern margin of the NCC. Zircon UPb dating yielded an average age of 174?±?14?Ma, representing the first reported Jurassic basalts in the eastern NCC. The Lan'gan basalts are enriched in light rare earth elements (LREE) and large ion lithosphile elements (LILE). Sr-Nd-Pb-Hf isotopic compositions (87Sr/86Sr(t)?=?0.70646-0.70925, eNd(t)?=?-2.1 to -4.9, 206Pb/204Pb(t)?=?17.14-18.12, 207Pb/204Pb(t)?=?15.28-15.61, 208Pb/204Pb(t)?=?37.82-38.67, and zircon eHf(t)?=?-17 to -21) are slightly enriched compared to depleted mantle. The presence of primary amphibole indicates that the magma source of the basalts was water enriched. These observations suggest that, the lithospheric mantle of the eastern NCC were significantly refertilized, likely by slab derived fluids/melts from the Paleo-Pacific subduction. Owing to the Paleo-Pacific subduction, the lithospheric mantle of the eastern NCC were reduced in viscosity and intensity, and finally promoted partial melting in a limited scale to generate the investigated alkaline basalts. Hence, the discovery of diamond in the Lan'gan basalts demonstrates that the lithosphere of the NCC remained thick, and that large-scale destruction had not initiated in the early Jurassic beneath this region.
DS202006-0956
2020
Tian, Y.Wang, K., Guo, R., Zhang, Y., Tian, Y.Photoluminescence and annealing of nitrogen-interstitials defects in electron irradiated diamond.Spectroscopy Letters, Vol. 53, 4, pp. 270-276.Globalluminescence

Abstract: There are a few studies reported in the literature describing the conversion of intrinsic defects but the involvement of nitrogen-interstitials in diamond has not been reported so far. In this paper, a detailed study on the conversion of nitrogen-interstitials in diamond during the irradiation and further annealing were presented by the micro-photoluminescence spectra. The results indicated that the interstitials were immobile until 300?°C and then escaped from the nitrogen capture, followed by migration and recombination with vacancies in the structure of nitrogen-vacancy and vacancy centers.
DS201312-0960
2013
Tian, Z.L.Wei, C.J., Qian, J.H., Tian, Z.L.Metamorphic evolution of medium temperatire ultra high pressure ( MT-UHP) eclogites from the South Dabie orogen, central China: an insight from phase equilibration temperatures modelling.Journal of Metamorphic Geology, Vol. 31, 7, pp. 755-774,ChinaUHP
DS201702-0243
2017
Tian, Z-Z.Tian, Z-Z., Liu, J., Xia, Q-K., Ingrin, J., Hao, Y-T., Depecker, C.Water concentraion profiles in natural mantle orthopyroxenes: a geochronometer for long annealing of xenoliths within magma.Geology, Vol. 45, 1, pp. 87-90.ChinaBasanites, Foidites

Abstract: Both mantle-derived clinopyroxene and orthopyroxene are generally homogeneous in water concentration, while water content in the coexisting olivine is affected by partial or complete loss during the ascent of the hosting magma. Here, we report the first record of water content profiles (higher water in the cores than in the rims) in natural orthopyroxene grains in peridotite xenoliths hosted by Cenozoic alkali basalts in Tianchang volcano, eastern China. The water contents of the coexisting clinopyroxene grains are homogeneous and are twice that measured in the cores of orthopyroxene grains, confirming previous chemical equilibrium between the two pyroxenes. The olivines (ol) are nearly dry (~0 ppm). These observations demonstrate that H diffusion in mantle orthopyroxene (opx) is faster than in clinopyroxene (cpx), and the relative mobility of H in each mineral phase could be quantified as: Graphic (where is the chemical diffusion coefficient of hydrogen). Combining this with experimental diffusion coefficients from the literature, we infer that (1) the xenoliths remained in contact with the magma below 900 °C for several months, and (2) clinopyroxene remains the more reliable recorder of water from depth, and orthopyroxene should be used more cautiously but can be considered with olivine for tracing slow transport and cooling of magma.
DS200512-1087
2005
Tibaldi, A.Tibaldi, A.Volcanism in compressional tectonic settings: is it possible?Geophysical Research Letters, Vol. 32, 6, March 28, DO 1029/2004 GLO21798MantleTectonics
DS200912-0762
2008
Tibbetts, N.J.Tibbetts, N.J., Bzimis, M., Salters, V.J., Rudnick, R.L.The Hf Nd systematics of rutile bearing eclogites from Koidu, Sierra Leone.American Geological Union, Fall meeting Dec. 15-19, Eos Trans. Vol. 89, no. 53, meeting supplement, 1p. abstractAfrica, Sierra LeoneSubduction chemistry
DS201709-2040
2017
Tiberi, D.Parat, F., Baudoin, C., Michel, T., Tiberi, D., Gautier, S.CO2 rich nephelinite differentiation and carbonate silicate immiscibility ( North Tanzanian divergence.)Goldschmidt Conference, abstract 1p.Africa, Tanzaniacarbonatites

Abstract: North Tanzanian Divergence is the first stage of continental break-up of East African Rift and one of the most concentrated areas of carbonatite magmatism with Natron basin in the North (2 Ma-present - Lengai) and Manyara basin in the southern part (0.4-0.9 Ma). The Manyara basin has volcanic activities with mafic magmas as melilitites (Labait), Mg-nephelinites and carbonatite (Kwaraha), and more differentiated magmas as Mg-poor nephelinites (Hanang) recording deep magmatic environment and differentiation in the crust of CO2-rich alkaline magmas. Melilitite and Mg-nephelinite with olivine-cpx-phlogopite record mantle environment at 1.5 GPa-1300°C with water content in melt of 0.1- 0.4 wt% H2O (1-4 ppm in olivine, FTIR). Although fractional crystallization can be considered as an important process during ascent, leading to Mg-poor nephelinite with cpx-melanite-nepheline, complex zonation of cpx (e.g. abrupt change of Mg#, Nb/Ta, and H2O) recorded open system with multiple carbonate-rich silicate immiscibility and melilititic melt replenishment. The low water content of cpx (25 ppm H2O; FTIR) indicates that 0.3 wt% H2O was present during carbonate-rich nephelinite crystallization at crustal level (600 MPa - 1050°C). The interstitial melt entrapped as melt inclusions (MI) in nepheline evolved to CO2-rich and H2O-poor phonolitic composition with 6 wt% CO2 and 1 wt% S at logfO2=FMQ+1 to 1.5 (Fe3+/SFe=0.3 - S6+/SS=0.55, XANES). At 200 MPa, phonolitic melt in MI reaches carbonate saturation and immiscibility process leads to trachytic melt with high CO2, S and halogen content (0.43 wt% CO2, SIMS; 2 wt% S, 0.84 wt% Cl; 2.54 wt% F) and very low H2O content (<0.1wt%, Raman) and an anhydrous Ca-Na±S,K carbonate liquid. The Ca-Na carbonatitic liquid in Mg-poor nephelinite represents an early stage of the evolution path towards carbonatitic magmatism as observed in Kwaraha and Lengai. Manyara volcanism has similarities with the Natron volcanism with multistage evolution and silicate-carbonatite magmatism but differ by their volatile components (up to 10 H2O wt% in Lengai nephelinite). This can be interpreted in term of depth of partial melting with H2O-CO2 lithospheric mantle source (Natron) and deep anhydrous CO2-rich asthenospheric mantle source in the southern part of rift initiation (Manyara) and percolation of deep CO2-rich silicate liquid leading to lithospheric mantle metasomatism.
DS201802-0232
2017
Tiberi, M.S.Ebinger, C.J., Keir, D., Bastow, I.D., Whaler, K., Hammond, J.O.S., Miller, A.A., Tiberi, M.S., Hautot, S.Crustal structure of active deformation zones in Africa: implications for global crustal processes.Tectonics, Vol. 36, 10.1002/2017TC004526Africatectonics

Abstract: The Cenozoic East African rift (EAR), Cameroon Volcanic Line (CVL), and Atlas Mountains formed on the slow-moving African continent, which last experienced orogeny during the Pan-African. We synthesize primarily geophysical data to evaluate the role of magmatism in shaping Africa's crust. In young magmatic rift zones, melt and volatiles migrate from the asthenosphere to gas-rich magma reservoirs at the Moho, altering crustal composition and reducing strength. Within the southernmost Eastern rift, the crust comprises ~20% new magmatic material ponded in the lower crust and intruded as sills and dikes at shallower depths. In the Main Ethiopian Rift, intrusions comprise 30% of the crust below axial zones of dike-dominated extension. In the incipient rupture zones of the Afar rift, magma intrusions fed from crustal magma chambers beneath segment centers create new columns of mafic crust, as along slow-spreading ridges. Our comparisons suggest that transitional crust, including seaward dipping sequences, is created as progressively smaller screens of continental crust are heated and weakened by magma intrusion into 15-20 km thick crust. In the 30 Ma Recent CVL, which lacks a hot spot age progression, extensional forces are small, inhibiting the creation and rise of magma into the crust. In the Atlas orogen, localized magmatism follows the strike of the Atlas Mountains from the Canary Islands hot spot toward the Alboran Sea. CVL and Atlas magmatism has had minimal impact on crustal structure. Our syntheses show that magma and volatiles are migrating from the asthenosphere through the plates, modifying rheology, and contributing significantly to global carbon and water fluxes.
DS201012-0444
2010
Tiberindwa, J.V.Link, K., Koehm, D., Barth, M.G., Tiberindwa, J.V., Barifaijo, E., Aanyu, K., Foley, S.F.Continuous cratonic crust between the Congo and Tanzania blocks in western Uganda.International Journal of Earth Sciences, Vol. 99, 7, pp. 1559-1573.Africa, Uganda, TanzaniaGeophysics - seismics
DS201112-0327
2011
Tiberindwa, J.V.Foley, S.F., Link, K., Tiberindwa, J.V., Barifaijo, E.Patterns and origin of igneous activity around the Tanzanian Craton. Mentions kimberlites and minettesJournal of African Earth Sciences, Vol. 62, 1, pp. 1-18.Africa, TanzaniaKimberlite
DS201212-0205
2012
Tiberindwa, J.V.Foley, S.F., Link, K., Tiberindwa, J.V., Barifaijo, E.Patterns and origin of igneous activity around the Tanzanian craton.Journal of African Earth Sciences, Vol. 62, pp. 1-18.Africa, TanzaniaKimberlite, carbonatite
DS201112-0858
2011
Tibi, R.Reusch, A.M., Nyblade, A.A., Tibi, R., Wiens, D.A., Shore, P.J., Bekoa, A., Tabod, C.T., Mnange, J.M.Mantle transition zone thickness beneath Cameroon: evidence for an upper mantle origin for the Cameroon Volcanic Line.Geophysical Journal International, Vol. 187, 3, pp.1146-1150.Africa, CameroonMantle zone
DS201212-0363
2012
Tibi, R.Koch, F.W., Wiens, D.A., Nyblade, A.A., Shore, P.J., Tibi, R., Ateba, B., Tabod, C.T., Nnange, J.M.Upper mantle anisotropy beneath the Cameroon Volcanic Line and Congo Craton from shear wave splitting measurements.Geophysical Journal International, in press availableAfrica, CameroonGeophysics - seismics
DS200412-1180
2004
Tice, M.M.Lowe, D.R., Tice, M.M.Geologic evidence for Archean atmospheric and climatic evolution: fluctuating levels of CO2, CH4 and O2 with an overriding tectoGeology, Vol. 32, 6, June pp. 493-6.TechnologyTectonics
DS200612-1427
2006
Tichomirowa, M.Tichomirowa, M., Grosche, G., Gotze, J., Belyatsky, B.V., Savva, E.V., Keller, J., Todt, W.The mineral isotope composition of two Precambrian carbonatite complexes from the Kola Alkaline Province - alteration versus primary magmatic signatures.Lithos, In press available,Russia, Kola PeninsulaCarbonatite, geochronology, Tiksheozero, Siilinkarvi
DS201112-1042
2011
Tichomirowa, M.Tichomirowa, M., EIMF, Whitehouse, M.Formation and transformation of zircon grains from the Archean carbonatite Siilinjarvi - evidence from cathodluminescence, rare earth elements and U/Pb geochrPeralk-Carb 2011, workshop held Tubingen Germany June 16-18, PosterEurope, FinlandCarbonatite
DS201112-1043
2011
Tichomirowa, M.Tichomirowa, M., Whitehouse, M.Formation and transformation of zircon grains from the Archean carbonatite Siilinjarvi ( Finland) - evidence from cathodluminescence, rare earth elements and U/TbPeralk-Carb 2011... workshop June 16-18, Tubingen, Germany, Abstract p.151-152.Europe, FinlandSiilinjarvi
DS201112-1044
2011
Tichomirowa, M.Tichomirowa, M., Whitehouse, M.Formation and transformation of zircon grains from the Archean carbonatite Siilinjarvi ( Finland) - evidence from cathodluminescence, rare earth elements and U/TbPeralk-Carb 2011... workshop June 16-18, Tubingen, Germany, Abstract p.151-152.Europe, FinlandSiilinjarvi
DS201212-0534
2012
Tichomirowa, M.Owona, S., Tichomirowa, M., Ratschbacher, L., Ondoa, J.M., Youmen, D., Pfander, J., Tchoua, F.M., Affaton, P., Ekodeck, G.E.New igneous zircon Pb/Pb and metamorphic Rb/Sr ages in the Yaounde Group, Cameroon, Central Africa): implications for the Central African fold belt evolution close to the Congo Craton.International Journal of Earth Sciences, Vol. 101, 7, pp. 1689-1703.Africa, CameroonGeochronology
DS201212-0535
2012
Tichomirowa, M.Owona, S., Tichomirowa, M., Ratschbacher, L., Ondoa, W.J., Youmen, D., Pfander, J., Tchoua, F.M., Affaton, P., Ekodeck, G.E.New igneous zircon Pb/Pb and metamorphic Rb/Sr ages in the Yaounde Group ( Cameron, Central Africa): implications for the Central African fold belt evolution close to the Congo Craton.International Journal of Earth Sciences, Vol. 101, pp. 1689-1703.Africa, CameroonGeochronology
DS201212-0729
2012
Tichomirowa, M.Tichomirowa, M., Whitehouse, M., Gerdes, A., Gotze, J.Carbonatite metasomatism: evidence from geochemistry and isotope composition ( U-Pb, Hf, O) on zircons from two Precambrian carbonatites of the Kola alkaline province.Goldschmidt Conference 2012, abstract 1p.Russia, Kola Peninsula, ArchangelCarbonatite
DS201312-0914
2013
Tichomirowa, M.Tichomirowa, M., Whitehouse, M.J., Gerdes, A., Gotze, J., Schulz, B., Belyatsky, B.V.Different zircon recrystallization types in carbonatites caused by magma mixing: evidence from U-Pb dating, trace element and isotope composition ( Hf and O) of zircons from two Precambrian carbonatites from Fennoscandia.Chemical Geology, Vol. 353, pp. 173-198.Europe, Finland, SwedenCarbonatite
DS200412-0367
2004
Tichy, G.Cordier, P., Ungar, T., Zsoldos, L., Tichy, G.Dislocation creep in MgSiO3 perovskite at conditions of the Earth's uppermost lower mantle.Nature, No. 6985, April 22, pp. 837-839.MantleMineralogy
DS201201-0850
2011
Tieguhong, J.C.Ingram, V., Tieguhong, J.C., Schure, J., Nkamgnia, E.Where artisanal mines and forest meet: socio-economic and environmental impacts in the Congo Basin.Natural Resources Forum, Vol. 35, 4, pp.304-320.Africa, Democratic Republic of CongoCSR
DS1995-1909
1995
Tiejun, W.Tiejun, W.Policies and legislation for mineral development in ChinaWorld Mining Congress, Institute International Research held May, 8pChinaEconomics -investment, Legal resource law
DS1993-0024
1993
Tielens, A.G.G.M.Allamandola, L.J., Sandford, S.A., Tielens, A.G.G.M., Herbst, T.M.Diamonds in dense molecular clouds: a challenge to the standard interstellar medium paradigM.Science, Vol. 260, April 2, pp. 64-66GlobalDiamond formation, Meteoritic
DS201112-1045
2011
Tien, Y.Tien, Y., Zhou, Y., Sigloch, K., Nolet, G., Lake, G.Structure of North American mantle constrained by simultaneous inversion of multiple frequency SH, SS and Love waves.Journal of Geophysical Research, Vol. 116, B2, B02307..MantleGeophysics - seismics
DS201312-0506
2013
TiepoloKosler, J., Slama, Belousova, Corfu, Gehrels, Gerdes, Horstwood, Sircombe, Sylvester, Tiepolo, Whitehouse, WoodheadU-Pb detrital zircon analysis - results of an inter-laboratory comparison. (not specific to diamonds)Geostandards and Geoanalytical Research, Vol. 37, 3, pp. 243-259.GlobalZircon analyses
DS2003-1380
2003
Tiepolo, M.Tiepolo, M., Zanetti, A., Oberti, R., Brumm, R., Foley, S., Vannucci, R.Trace element partitioning between synthetic potassic richterites and silicate melts, andEuropean Journal of Mineralogy, Vol. 15, 2, pp. 329-40.GlobalMineralogy
DS200412-0563
2004
Tiepolo, M.Foley, S., Vannucci, R., Jacob, D., Tiepolo, M.The geochemical signature and origin of Archean TTG gneisses: melting of amphibolite or eclogite?Lithos, ABSTRACTS only, Vol. 73, p. S38. abstractTechnologySubduction
DS200412-1575
2004
Tiepolo, M.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
DS200412-1992
2003
Tiepolo, M.Tiepolo, M., Zanetti, A., Oberti, R., Brumm, R., Foley, S., Vannucci, R.Trace element partitioning between synthetic potassic richterites and silicate melts, and contrasts with the partitioning behaviEuropean Journal of Mineralogy, Vol. 15, 2, pp. 329-40.TechnologyMineralogy
DS200412-2197
2004
Tiepolo, M.Zanetti, A., Tiepolo, M., Oberti, R., Vannucci, R.Trace element partitioning in olivine: modelling of a complete dat a set from a synthetic hydrous basanite melt.Lithos, Vol. 75, 1-2, July, pp. 39-54.TechnologyGeochemistry - petrogenetic processes, fingerprinting
DS201312-0923
2013
Tiepolo, M.Tribuzio, R., Henjes-Kunst, F., Braga, R., Tiepolo, M.Boninite derived mafic ultramafic intrusives from northern Victoria Land ( Antarctica): implications for mantle source metasomatism.Goldschmidt 2013, 1p. AbstractAntarcticaBoninites
DS202007-1127
2020
Tiepolo, M.Cannao, E., Tiepolo, M., Bebout, G.E., Scambelluri, M.Into the deep and beyond: carbon and nitrogen subduction recycling in secondary peridotites. Gagnone metaperidotitesEarth and Planetary Science Letters, Vol. 543, 116328 14p. PdfEurope, Switzerland, Alpsboron diamonds

Abstract: Understanding the volatile cycles at convergent margins is fundamental to unravel the Earth's evolution from primordial time to present. The assessment of fluid-mobile and incompatible element uptake in serpentinites via interaction with seawater and subduction-zone fluids is central to evaluate the global cycling of the above elements in the Earth's mantle. Here, we focus on the carbon (C), nitrogen (N) and C isotope compositions of chlorite harzburgites and garnet peridotites deriving from subduction-zone dehydration of former oceanic dehydration of serpentinite - i.e., metaperidotites (Cima di Gagnone, Swiss Central Alps) with the aim of evaluating the contribution of these rocks to the global C-N cycling. These ultramafic rocks, enclosed as lenses in a metasedimentary mélange, represent the destabilization of antigorite and chlorite at high-pressure/temperature (P/T) along a slab-mantle interface. Chlorite- and garnet-bearing rocks have similar ranges in C concentration ([C] = 210 - 2465 ppm and 304 - 659 ppm, respectively), with one magnesite-bearing chlorite harzburgite hosting 11000 ppm C. The average N concentrations ([N]) of the garnet peridotites (54 ± 15 ppm, one standard deviation indicated) are higher than those of the chlorite harzburgites (29 ± 6 ppm). The C of total C (TC) and total organic C (TOC) values of the Gagnone metaperidotites range from -12.2 to -17.8‰ and from -27.8 to -26.8‰, respectively, excluding the magnesite-bearing chlorite harzburgites with higher values of -7.2‰ (TC) and -21.2‰ (TOC). The [C] of these rocks are comparable to those of serpentinites form modern and ancient oceanic environments and with [C] of high-P serpentinites. However, the lack of preserved serpentinite precursors makes it difficult to determine whether release of H2O during high-P breakdown of antigorite and chlorite is coupled with significant C release to fluids. The C values appear to reflect mixing between seawater-derived carbonate and a reduced C source and a contribution from the host metasedimentary rocks ([C] = 301 ppm; [N] = 33 ppm; TC C = -24.4‰; TOC C = -27.0‰) cannot be completely excluded. The C-O isotope composition of the carbonate in magnesite-bearing chlorite harzburgites is compatible with progressive devolatilization at oxidized conditions, whereas the signatures of the majority of the other Gagnone samples appear to reflect different degree of interaction with sedimentary fluids. The [N] of the Gagnone metaperidotites are higher than those of oceanic and subducted serpentinites and show a range similar to that of high-P antigorite-serpentinites from mantle wedges. This enrichment is compatible with fluid-mediated chemical exchange with the surrounding metasedimentary rocks leading to strong modification of the Gagnone metaperidotites' geochemistry during prograde subduction along the slab-mantle interface. Comparing the C data reported in this study with published C values for diamonds, we suggest that the volatile recycling via Gagnone-like metaperidotites in subduction zones could contribute to deep-Earth diamond genesis and in particular to the formation of blue boron (B)-bearing diamonds. Our results highlight that the subduction of secondary peridotites evolved along the slab-mantle interface is a viable mechanism to inject volatiles into the deep mantle, particularly in hotter geothermal regimes such as the ones active during the early Earth's history.
DS1988-0693
1988
Tiercelin, J.J.Tiercelin, J.J., Chorowicz, J., Bellon, H., Richert, J.P., et al.East African rift system: offset, age and tectonic significance of the Tanganyika-Rukwa -Malawi intracontinental transcurrent fault zoneTectonophysics, Vol. 148, No. 3/4, May 1, pp. 241-252East AfricaBlank
DS1994-0349
1994
Tiercelin, J.J.Coussement, C., Gente, P., Rolet, J., Tiercelin, J.J.The North Tanganyika hydrothermal fields, East African Rift system: their tectonic control, rift segregationTectonophysics, Vol. 237, pp. 155-173.Democratic Republic of CongoTectonics, East African Rift
DS2000-0558
2000
Tiercelin, J.J.Le Gall, B., Tiercelin, J.J., Richert, Gente, SturchioA morphotectonics study of an extensional fault zone in a magma rich rift:the Baringo trachyte fault systemTectonophysics, Vol. 320, No. 2, May 15, pp. 87-106.KenyaTectonics - central Kenya Rift
DS2002-0924
2002
Tiercelin, J.J.Le Gall, B., Tshoso, G., Jourdan, F., Feraud, G., Bertrand, H., Tiercelin, J.J.40 Ar/39 Ar geochronology and structural dat a from the giant Okavango and relatedEarth and Planetary Science Letters, Vol. 202, 3-4, pp. 595-606.BotswanaMagmatism - not specific to diamonds
DS200412-0935
2004
Tiercelin, J.J.Jourdan, F., Feraud, G., Betrand, H., Kampunzu, A.B., Tshoso, G., Le Gall, B., Tiercelin, J.J., Capiz, P.The Karoo triple junction questioned: evidence from Jurassic and Proterzoic 40 Ar 39 Ar ages and geochemistry of the giant OkavaEarth and Planetary Science Letters, Vol. 222, 3-4, June 15, pp. 989-1006.Africa, BotswanaGeochronology, mantle plume
DS1989-1499
1989
Tiercelin, J-J.Tiercelin, J-J., Mondeguer, A., Scholz, C.A.Seismic and sedimentary discontinuities in the Lake Tanganyika Rift, EastAfricaEos, Vol. 70, No. 43, October 24, p. 1362. AbstractEast AfricaGeophysics, Rift
DS201712-2722
2017
Tierney, J.E.Reyes, A.V., Wolfe, A.P., Tierney, J.E., Silver, P.A., Royer, D.L., Greenwood, D.R., Buryak, S., Davies, J.H.F.L.Paleoenvironmental research on early Cenozoic sediment fills in Lac de Gras kimberlite pipes: progress and prospects.45th. Annual Yellowknife Geoscience Forum, p. 65 abstractCanada, Northwest Territoriesdeposit - Giraffe

Abstract: Several Lac de Gras kimberlite pipes host thick accumulations of stratified post-eruptive lacustrine sediment and peat. Given the range of Lac de Gras kimberlite emplacement ages, these fills - though rare - provide a unique sedimentary archive of paleoenvironments during the sustained Early Cenozoic “greenhouse” interval, in a high-latitude region otherwise devoid of Phanerozoic sediment cover. Extensive exploration drilling has provided a valuable window into this unique sedimentary record, which would have otherwise remained covered by Quaternary glacial deposits. Our focus to date has been multidisciplinary study of the Giraffe pipe sediment fill: an ~80 m-thick sequence of post-eruptive lacustrine silt overlain by peat, which paints a remarkable picture of a humid-temperate Middle Eocene forest ecosystem on the Canadian Shield. Post-eruptive chronology is provided by interbedded distal tephra horizons, likely sourced from Alaska, that have been dated by glass fission-track and zircon U-Pb techniques. Paleoclimate proxies derived from pollen, wood cellulose oxygen isotopes, and biomarkers converge on reconstructed mean annual temperatures >17 °C warmer than present, with mean winter temperatures above freezing, and mean annual precipitation ~4x present. Two independent reconstructions of CO2 from well preserved conifer foliage suggest that this warming occurred under relatively modest atmospheric CO2 concentrations of 430-630 ppm. These findings provide direct field-based evidence for dramatic past arctic warming at CO2 concentrations that were well within the range of projections under “business-as-usual” emissions scenarios, underscoring the capacity for exceptional polar amplification of climate change under modest CO2 concentrations once both fast and slow feedbacks processes become expressed. Our studies at Giraffe pipe also highlight the scientific value of archived exploration drill core in the Lac de Gras kimberlite field, particularly with respect to pipes that are unremarkable for the purpose of diamond exploration.
DS201212-0584
2012
Tierney, S.Rice, M.D., Tierney, S., O'Hagan, S., Lyons, D., Green, M.B.Knowledge, influence and firm level change: a geographic analysis of board membership associated with Canada's growing and declining businesses.Geoforum, Vol. 43, pp. 959-968.CanadaCSR - governance
DS1994-1979
1994
Tietz, G.F.Zeese, R., Scwertmann, U., Tietz, G.F., Jux, U.Mineralogy and stratigraphy of three deep lateritic profiles of the Josplateau (Central Nigeria)Catena, Laterization and Supergene Ore, Vol. 21, No. 2-3, pp. 195-214NigeriaMIneralogy, Laterization
DS201212-0766
2012
Tietze, K.Weckmann, U., Ritter, O., Chen, X., Tietze, K., de Wit, M.Magnetotelluric image linked to surface geology across the Cape Fold Belt, South Africa.Terra Nova, Vol. 24, 3, pp. 207-212.Africa, South AfricaGeophysics
DS1920-0328
1927
Tietze, O.Dammer, B., Tietze, O.Die Nutzbaren MineralienStuttgart: Enke., Vol. 1, 560P. ( DIAMOND PP. 1-62 ). XEROX.GlobalKimberley, Mineralogy, Janlib, Kimberlite
DS200412-1993
2004
Tiffany & Co.Tiffany & Co.Tiffany & Co. stakes out bold position on responsible mining.Tiffany & Co., March 24, 1p.United States, MontanaNews item - press release, silver mine, environment
DS200412-1994
2004
Tiffany & Co.Tiffany & Co.Tiffany rocks... dazzling sales and earnings numbers for fourth quarter of 2003.Tiffany & Co., Feb. 25, 1p.United StatesNews item - Aber Diamond
DS1994-1343
1994
Tihomirova, E.V.Patyk-Kara, N.G., Tihomirova, E.V.Geochemical prospecting of buried placers in unexposed Arctic regions10th. Prospecting In Areas Of Glaciated Terrain, pp. 109-110. AbstractRussiaGeochemistry -heavy minerals, Exploration prospecting
DS2001-1285
2001
Tiira, T.Yliniemi, J., Tiira, T., Luosto, Komminaho, Giese, et al.EUROBRIDGE'95: deep seismic profiling within the East European CratonTectonophysics, Vol. 339, No. 1-2, pp. 153-75.EuropeGeophysics - seismics, Craton
DS201501-0012
2014
Tiira, T.Grad, M., Tiira, T., Olsson, S., Komminaho, K.Seismic lithosphere asthenosphere boundary beneath the Baltic Shield.GFF, Vol. 136, 4, pp. 581-598.Europe, Finland, Sweden, NorwayGeophysics - seismic

Abstract: The problem of the existence of the asthenosphere for old Precambrian cratons is still discussed. In order to study the seismic lithosphere-asthenosphere boundary (LAB) beneath the Baltic Shield, we used records of nine local earthquakes with magnitudes ranging from 2.7 to 5.9. To model the LAB, original data were corrected for topography and Moho depth using a reference model with a 46-km-thick crust. For two northern events at Spitsbergen and Novaya Zemlya, we observe a low-velocity layer, 60-70-km-thick asthenosphere, and the LAB beneath Barents Sea was found at depth of c. 200 km. Sections for other events show continuous first arrivals of P-waves with no evidence for "shadow zone" in the whole range of registration, which could either be interpreted as the absence of the asthenosphere beneath the central part of the Baltic Shield, or that the LAB in this area occurs deeper (>200 km). The relatively thin low-velocity layer found beneath southern Sweden, 15 km below the Moho, could be interpreted as small-scale lithospheric heterogeneities, rather than asthenosphere. Differentiation of the lower lithosphere velocities beneath the Baltic Shield could be interpreted as regional heterogeneity or as anisotropy of the Baltic Shield lithosphere, with high velocities approximately in the east-west direction, and slow velocities approximately in the south-north direction.
DS202009-1671
2020
Tiira, T.Tiira, T., Janik, T., Skrzynik, T., Komminaho, K., Heinonen, A., Veikkolainen, T., Vakeva, S., Korja, A.Full scale crustal interpretation of Kokkola-Kymi ( KOKKY) seismic profile, Fennoscandian shield.Pure and Applied Geophysics, Vol. 177, 8, pp. 3775-3795. pdfEurope, Finlandgeophysics - seismics

Abstract: The Kokkola-Kymi Deep Seismic Sounding profile crosses the Fennoscandian Shield in northwest-southeast (NW-SE) direction from Bothnian belt to Wiborg rapakivi batholith through Central Finland granitoid complex (CFGC). The 490-km refraction seismic line is perpendicular to the orogenic strike in Central Finland and entirely based on data from quarry blasts and road construction sites in years 2012 and 2013. The campaign resulted in 63 usable seismic record sections. The average perpendicular distance between these and the profile was 14 km. Tomographic velocity models were computed with JIVE3D program. The velocity fields of the tomographic models were used as starting points in the ray tracing modelling. Based on collected seismic sections a layer-cake model was prepared with the ray tracing package SEIS83. Along the profile, upper crust has an average thickness of 22 km average, and P-wave velocities (Vp) of 5.9-6.2 km/s near the surface, increasing downward to 6.25-6.40 km/s. The thickness of middle crust is 14 km below CFGC, 20 km in SE and 25 km in NW, but Vp ranges from 6.6 to 6.9 km/s in all parts. Lower crust has Vp values of 7.35-7.4 km/s and lithospheric mantle 8.2-8.25 km/s. Moho depth is 54 km in NW part, 63 km in the middle and 43 km in SW, yet a 55-km long section in the middle does not reveal an obvious Moho reflection. S-wave velocities vary from 3.4 km/s near the surface to 4.85 km/s in upper mantle, consistently with P-wave velocity variations. Results confirm the previously assumed high-velocity lower crust and depression of Moho in central Finland.
DS2002-1524
2002
Tikare, V.Solomatov, V.S., ElKhozondar, R., Tikare, V.Grain size in the lower mantle: constraints from numerical modeling of grain growth in two phase systemsPhysics of the Earth and Planetary Interiors, Vol.129, 3-4, pp.265-82.MantleExperimental petrology
DS2001-0340
2001
TikhomirovFrolova, 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
DS2000-0078
2000
TikhomirovaBelyatsky, B.V., Tikhomirova, SavvaRUbidium-Strontium and Samarium-neodymium isotope characteristics of Proterozoic carbonatite of Tiksheozero Massif... Northern Karelia.Igc 30th. Brasil, Aug. abstract only 1p.Russia, KareliaGeochronology, isochrons, Carbonatite
DS1993-0105
1993
Tikhomirova, M.Belyatzky, B., Tikhomirova, M.Sm/neodymium and Rubidium-Strontium mineral isotope dat a on carbonatites from the Tiksheozero MassifTerra Abstracts, IAGOD International Symposium on mineralization related, Vol. 5, No. 3, abstract supplement p. 5RussiaCarbonatite
DS1994-1777
1994
Tikhomirova, M.Tikhomirova, M., Belyatzky, B.Rubidium/Strontium and Samarium/neodymium dating of the Proterozoic Tiksheozero carbonatite massif Karelia Russia.Geological Association of Canada (GAC) Abstract Volume, Vol. 19, p. PosterRussiaCarbonatite, Tiksheozero
DS1997-1159
1997
Tikhomirova, S.R.Tikhomirova, S.R.New dat a on Late Cenozoic hypabyssal alkaline and subalkaline rocks of the Kamchatskii Mys Peninsula.Doklady Academy of Sciences, in Eng., Vol. 354, No. 4, pp. 537-42.Russia, KamchatkaAlkaline magmatism
DS202008-1414
2020
Tikhomirova, Y.Lebedeva, N., Nosova, A., Kargin, A., Larionova, Y., Sazonova, L., Tikhomirova, Y.Grib kimberlite peridotitic xenoliths: isotopic evidence of variable source of mantle metasomatism.Goldschmidt 2020, 1p. AbstractRussia, Kola Peninsuladeposit - Grib

Abstract: We present petrography and mineral chemistry for both phlogopite, from mantle-derived xenoliths (garnet peridotite, eclogite and clinopyroxene-phlogopite rocks) and for megacryst, macrocryst and groundmass flakes from the Grib kimberlite in the Arkhangelsk diamond province of Russia to provide new insights into multi-stage metasomatism in the subcratonic lithospheric mantle (SCLM) and the origin of phlogopite in kimberlite. Based on the analysed xenoliths, phlogopite is characterized by several generations. The first generation (Phl1) occurs as coarse, discrete grains within garnet peridotite and eclogite xenoliths and as a rock-forming mineral within clinopyroxene-phlogopite xenoliths. The second phlogopite generation (Phl2) occurs as rims and outer zones that surround the Phl1 grains and as fine flakes within kimberlite-related veinlets filled with carbonate, serpentine, chlorite and spinel. In garnet peridotite xenoliths, phlogopite occurs as overgrowths surrounding garnet porphyroblasts, within which phlogopite is associated with Cr-spinel and minor carbonate. In eclogite xenoliths, phlogopite occasionally associates with carbonate bearing veinlet networks. Phlogopite, from the kimberlite, occurs as megacrysts, macrocrysts, microcrysts and fine flakes in the groundmass and matrix of kimberlitic pyroclasts. Most phlogopite grains within the kimberlite are characterised by signs of deformation and form partly fragmented grains, which indicates that they are the disintegrated fragments of previously larger grains. Phl1, within the garnet peridotite and clinopyroxene-phlogopite xenoliths, is characterised by low Ti and Cr contents (TiO2 < 1 wt.%, Cr2O3 < 1 wt.% and Mg# = 100 × Mg/(Mg + Fe) > 92) typical of primary peridotite phlogopite in mantle peridotite xenoliths from global kimberlite occurrences. They formed during SCLM metasomatism that led to a transformation from garnet peridotite to clinopyroxene-phlogopite rocks and the crystallisation of phlogopite and high-Cr clinopyroxene megacrysts before the generation of host-kimberlite magmas. One of the possible processes to generate low-Ti-Cr phlogopite is via the replacement of garnet during its interaction with a metasomatic agent enriched in K and H2O. Rb-Sr isotopic data indicates that the metasomatic agent had a contribution of more radiogenic source than the host-kimberlite magma. Compared with peridotite xenoliths, eclogite xenoliths feature low-Ti phlogopites that are depleted in Cr2O3 despite a wider range of TiO2 concentrations. The presence of phlogopite in eclogite xenoliths indicates that metasomatic processes affected peridotite as well as eclogite within the SCLM beneath the Grib kimberlite. Phl2 has high Ti and Cr concentrations (TiO2 > 2 wt.%, Cr2O3 > 1 wt.% and Mg# = 100 × Mg/(Mg + Fe) < 92) and compositionally overlaps with phlogopite from polymict breccia xenoliths that occur in global kimberlite formations. These phlogopites are the product of kimberlitic magma and mantle rock interaction at mantle depths where Phl2 overgrew Phl1 grains or crystallized directly from stalled batches of kimberlitic magmas. Megacrysts, most macrocrysts and microcrysts are disintegrated phlogopite fragments from metasomatised peridotite and eclogite xenoliths. Fine phlogopite flakes within kimberlite groundmass represent mixing of high-Ti-Cr phlogopite antecrysts and high-Ti and low-Cr kimberlitic phlogopite with high Al and Ba contents that may have formed individual grains or overgrown antecrysts. Based on the results of this study, we propose a schematic model of SCLM metasomatism involving phlogopite crystallization, megacryst formation, and genesis of kimberlite magmas as recorded by the Grib pipe.
DS202010-1856
2020
Tikhomirova, Y.S.Lebedeva, N.M., Nosova, A.A., Kargin, A.V., Larionova, Y.O., Sazonova, L.V., Tikhomirova, Y.S.S-Nd-O isotopic evidence of variable sources of mantle metasomatism in the subcratonic lithospheric mantle beneath the Grib kimberlite, northwestern Russia.Lithos, in press available, 54p. PdfRussia, Kola Peninsuladeposit - Grib

Abstract: To provide new insights into the type and extent of mantle metasomatism in the subcratonic lithospheric mantle, we examined the Sr-Nd-O isotopic compositions of orthopyroxene, clinopyroxene, garnet, ilmenite and phlogopite from sheared garnet lherzolite, granular garnet harzburgites and lherzolites and clinopyroxene-phlogopite rocks from the Grib kimberlite in the Arkhangelsk diamond province in northwestern Russia. Clinopyroxene and orthopyroxene from sheared garnet lherzolite initially have a close value of 87Sr/86Sr(t) (~0.7034) and close weak positive eNd. Orthopyroxene and clinopyroxene are in oxygen isotope equilibrium with coexisting olivine. Clinopyroxene from a garnet harzburgite has a low 87Sr/86Sr(t) isotope ratio of 0.70266. Clinopyroxene from granular garnet lherzolites has a relatively narrow variation in 87Sr/86Sr(t) (0.70456-0.70582) and considerably larger variations in eNd (-4.3?-?+1.0) isotope ratios. Garnet displays elevated initial 87Sr/86Sr(t) values (0.70540-0.70633). Ilmenite shows a narrow range in 87Sr/86Sr(t) (0.70497-0.70522) coupled with eNd values of +0.4 and +3.5. These isotopic data suggest granular garnet lherzolite of mantle metasomatism took place during the interaction of kimberlite melts with SCLM that contained mica-amphibole-rutile-ilmenite-diopside (MARID)-type metasomes. Clinopyroxenes from clinopyroxene-phlogopite (phlogopite wehrlite) xenoliths display a broader range in 87Sr/86Sr(t) (0.70486-0.70813) that is significantly higher than the kimberlite values and a circa-chondritic eNd (-0.1 -?+1.3) with a restricted d18O range (5.11‰-5.33‰). More radiogenic Sr isotopic composition decoupled from Nd isotopes could have been induced by metasomatic melt/fluid related to a subducted material. The isotopic compositions of mantle minerals preserve Sr-Nd isotopic evidence of pre-kimberlite metasomatic events that were probably due to incomplete reequilibration with ultramafic carbonated melt. Based on mineral pairs Rb-Sr isochrons and a clinopyroxene-based Sm-Nd errochron, these mantle metasomatic events correspond to ~550-600?Ma and ~1200?Ma episodes of magmatic-thermal activity.
DS1993-1096
1993
Tikhonen, P.I.Murari, R., Krishnam, P., Tikhonen, P.I., Gopalan, K.Magnesian ilmenites in picrite basalts from Siberian and Deccan traps-additional mineralogical evidence for primary melt compositions.Mineralogical Magazine, Vol. 57, No. 389, December pp. 733-735.Russia, IndiaPicrite basalts
DS1991-1707
1991
Tikhonova, I.M.Telegin, A.N., Tikhonova, I.M.Potentialities of reflection shooting in searching for kimberlitic pipesSoviet Geology and Geophysics, Vol. 32, No. 8, pp. 109-113RussiaGeophysics
DS200512-0724
2004
Tikhotsky, S.Mikhailov, V., Tikhotsky, S., Diamant, M., Panet, I., Ballu, V.Can tectonic processes be recovered from new gravity satellite data?Earth and Planetary Science Letters, Vol. 228, 3-4, pp. 281-297.MantleGeophysics - gravity
DS2000-0473
2000
TikhovaKarpukhina, E.V., Pervov, V.A., Zhuravlev, TikhovaIsotope and geochemical indicators of the intraplate origin of mafic ultramafic rocks western slope of UralsDoklady Academy of Sciences, Vol. 370, No. 1, Jan-Feb pp. 153-6.Russia, UralsGeochemistry, Alkaline rocks
DS2001-0357
2001
TikhovaGaranin, 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
DS2001-0638
2001
Tikhova, M.A.Kudryavtseva, G.P., Tikhova, M.A., Gonzaga, G.M.Comparative charcteristics of specific morphological features of diamonds from northern and northeastern European Russia ( Urals, Timan, and Arkhangelsk).Moscow University Geology Bulletin, Vol. 56, 6, pp. 26-30.Russia, Urals, TimanDiamond - morphology
DS2001-0732
2001
Tikku, A.A.Marks, K.M., Tikku, A.A.Cretaceous reconstructions of the East Antarctica, Africa and MadagascarEarth and Planetary Science Letters, Vol. 186, No. 3-4, Apr. 15, pp. 479-96.Madagascar, Africa, AntarcticaTectonics, Gondwana
DS1995-1896
1995
Tikoff, B.Teyssier, C., Tikoff, B., Markley, M.Oblique plate motion and continental tectonicsGeology, Vol. 23, No. 5, May pp. 447-450GlobalStructure, Tectonics
DS1996-0909
1996
Tikoff, B.Maxson, J., Tikoff, B.Hit and run collision model for the Laramide Orogeny, western UnitedStatesGeology, Vol. 24, No. 11, Nov. pp. 968-972Nevada, California, OregonTectonics, Laramide Orogeny
DS1999-0739
1999
Tikoff, B.Tommasi, A., Tikoff, B., Vauchez, A.Upper mantle tectonics: three dimensional deformation, olivine, crystallographic fabrics and seismic propertyEarth and Planetary Science Letters, Vol. 169, 1-2, Apr.30, pp.173-86.MantleGeophysics - seismics, Tectonics
DS200412-0729
2004
Tikoff, B.Grocott, J., McCaffrey, K.J.W., Taylor, G., Tikoff, B.Vertical coupling and decoupling in the lithosphere.Geological Society of London Special Paper, No. 227, 352p. $140.MantleBook - lithosphere
DS200512-0286
2005
Tikoff, B.Ferr, E.C., Tikoff, B., Jackson, M.The magnetic anistropy of mantle peridotites: examples from the Twin Sisters dunite, Washington.Tectonophysics, Vol. 398, 3-4, pp. 141-166.United States, WashingtonPeridotite - not specific to diamonds
DS200512-0289
2005
Tikoff, B.Ferre, E.C., Tikoff, B., Jackson, M.The magnetic anisotropy of mantle peridotites: examples from the Twin Sisters dunite, Washington.Tectonophysics, Vol. 398, 3-4, April 13, pp. 141-166.United States, WashingtonGeophysics - AMS magnetometer, not specific to diamond
DS200512-0340
2004
Tikoff, B.Giorgis, S., Markley, M., Tikoff, B.Vertical axis rotation of rigid crustal blocks driven by mantle flow.Geological Society of London Special Paper, No. 226, pp. 83-100.MantleTectonics
DS200512-0371
2004
Tikoff, B.Grocott, J., McCaffrey, K.J.W., Taylor, G., Tikoff, B.Vertical coupling and decoupling of the lithosphere.Geological Society of London , Special Publication 227, 352p. $134.Book - mantle, orogeny, subduction
DS200512-1088
2004
Tikoff, B.Tikoff, B., Russo, R., Teyssier, C., Tommasi, A.Mantle driven deformation of orogenic zones and clutch tectonics.Geological Society of London Special Paper, No. 226, pp. 41-64.MantleTectonics
DS2003-1381
2003
Tikov, S.V.Tikov, S.V., Zudin, N.G., Gorshkov, A.I., Sivtsov, A.V., Magazina, L.O.An investigation into the cause of colour in natural black diamonds from SiberiaGems & Gemology, Vol. 39,3, Fall, pp. 200-209.Russia, SiberiaMineral inclusions - Mir
DS200412-1995
2003
Tikov, S.V.Tikov, S.V., Zudin, N.G., Gorshkov, A.I., Sivtsov, A.V., Magazina, L.O.An investigation into the cause of colour in natural black diamonds from Siberia.Gems & Gemology, Vol. 39,3, Fall, pp. 200-209.Russia, SiberiaMineral inclusions - Mir
DS1910-0441
1914
Tilby, A.W.Tilby, A.W.South Africa (1914)London:, South AfricaKimberlite, Kimberley, Geology, History, Politics
DS2003-0009
2003
Tiley, R.Al-Kindi, S., White, N., Sinha, M., England, R., Tiley, R.Crustal trace of a hot convective sheetGeology, Vol. 31, 3, pp. 207-10.IcelandGeophysics - seismics, Plumes, underplating, convection
DS200412-0017
2003
Tiley, R.Al-Kindi, S., White, N., Sinha, M., England, R., Tiley, R.Crustal trace of a hot convective sheet.Geology, Vol. 31, 3, pp. 207-10.Europe, IcelandGeophysics - seismics Plumes, underplating, convection
DS201709-1998
2017
Tilhac, R.Henry, H., Afonso, J.C., Satsukawa, T., Griffin, W.L., O'Reilly, S.Y., Kaczmarek, M-A., Tilhac, R., Gregoire, M., Ceuleneer, G.The unexplored potential impact of pyroxenite layering on upper mantle seismic properties.Goldschmidt Conference, abstract 1p.Europe, Spain, United States, Californiageophysics - seismics

Abstract: It is now accepted that significant volumes of pyroxenites are generated in the subduction factory and remain trapped in the mantle. In ophiolites and orogenic massifs the geometry of pyroxenite layers and their relationships with the host peridotite can be observed directly. Since a large part of what is known about the upper mantle structure is derived from the analysis of seismic waves, it is crucial to integrate pyroxenites in the interpretations. We modeled the seismic properties of a peridotitic mantle rich in pyroxenite layers in order to determine the impact of layering on the seimsic properties. To do so, EBSD data on deformed and undeformed pyroxenites from the Cabo Ortegal complex (Spain) and the Trinity ophiolite (California, USA) respectively are combined with either A or B-type olivine fabrics in order to model a realistic pyroxenite-rich upper mantle. Consideration of pyroxeniterich domains within the host mantle wall rock is incorporated in the calculations using the Schoenberg and Muir group theory [1]. This quantification reveals the complex dependence of the seismic signal on the deformational state and relative abundance of each mineral phase. The incorporation of pyroxenites properties into geophysical interpretations in understanding the lithospheric structure of subduction zones will lead to more geologically realistic models.
DS201810-2349
2018
Tilhac, R.Lu, J., Griffin, W.L., Tilhac, R., Xiong, Q., Zheng, J., O'Reilly, S.Y.Tracking deep lithospheric events with garnet-websterite xenoliths from southeastern Australia.Journal of Petrology, Vol. 59, 5, pp. 901-903.Australiabasanite

Abstract: Pyroxenites provide important information on mantle heterogeneity and can be used to trace mantle evolution. New major and trace element and Sr-, Nd-, and Hf-isotope analyses of minerals and whole-rock samples of garnet websterites entrained in basanite tuffs in Bullenmerri and Gnotuk maars, southeastern Australia, are here combined with detailed petrographic observations to constrain the sources and genesis of the pyroxenites, and to trace the dynamic evolution of the lithospheric mantle. Most garnet websterites have high MgO and Cr2O3 contents, relatively flat light rare earth element (LREE) patterns ([La/Nd]CN?=?0•77-2•22) and ocean island basalt-like Sr-, Nd-, and Hf-isotope compositions [87Sr/86Sr?=?0•70412-0•70657; eNd(t)?=?-0•32 to +4•46; eHf(t)=+1•69 to +18•6] in clinopyroxenes. Some samples show subduction-related signatures with strong enrichments in large ion lithophile elements and LREE, and negative anomalies in high field strength elements, as well as high 87Sr/86Sr (up to 0•709), and decoupled Hf- and Nd-isotope compositions [eNd(t)?=?-3•28; eHf(t) =?+11•6). These data suggest that the garnet pyroxenites represent early crystallization products of mafic melts derived from a convective mantle wedge. Hf model ages and Sm-Nd mineral isochrons suggest that these pyroxenites record at least two stages of evolution. The initial formation stage corresponds to the Paleozoic subduction of the proto-Pacific plate beneath southeastern Australia, which generated hydrous tholeiitic melts that crystallized clinopyroxene-dominated pyroxenites at ~1420-1450°C and ~75?km depth in the mantle wedge. The second stage corresponds to Eocene (c. 40?Ma) back-arc lithospheric extension, which led to uplift of the former mantle-wedge domain to 40-60?km depths, and subsequent cooling to the ambient geotherm (~950-1100°C). Extensive exsolution and recrystallization of garnet and orthopyroxene (±?ilmenite) from clinopyroxene megacrysts accompanied this stage. The timing of these mantle events coincides with vertical tectonism in the overlying crust.
DS202002-0219
2020
Tilhac, R.Tilhac, R., Oliveira, B., Griffin, W.L., O'Reilly, S.Y., Schaefer, B.F., Alard, O., Ceuleneer, G., Afonso, J.C., Gregoire, M.Reworking of old continental lithosphere: unradiogenic Os and decoupled Hf-Nd isotopes in sub-arc mantle pyroxenites.Lithos, Vol. 354-355, 19p. pdfEurope, Spainpyroxenites

Abstract: Mantle lithologies in orogenic massifs and xenoliths commonly display strikingly different Hf- and Nd-isotope compositions compared to oceanic basalts. While the presence of pyroxenites has long been suggested in the source region of mantle-derived magmas, very few studies have reported their combined HfNd isotope compositions. We here report the first LuHf data along with ReOs data and S concentrations on the Cabo Ortegal Complex, where the pyroxenite-rich Herbeira massif has been interpreted as remnants of a delaminated arc root. The pyroxenites, chromitites and their host harzburgites show a wide range of whole-rock 187Re/188Os and 187Os/188Os (0.16-1.44), indicating that Re was strongly mobilized, partly during hydrous retrograde metamorphism but mostly during supergene alteration that preferentially affected low-Mg#, low Cu/S pyroxenites. Samples that escaped this disturbance yield an isochron age of 838 ± 42 Ma, interpreted as the formation of Cabo Ortegal pyroxenites. Corresponding values of initial 187Os/188Os (0.111-0.117) are relatively unradiogenic, suggesting limited contributions of slab-derived Os to primitive arc melts such as those parental to these pyroxenites. This interpretation is consistent with radiogenic Os in arc lavas being mostly related to crustal assimilation. Paleoproterozoic to Archean Os model ages confirm that Cabo Ortegal pyroxenites record incipient volcanic arc magmatism on the continental margin of the Western African Craton, as notably documented by zircon UPb ages of 2.1 and 2.7 Ga. LuHf data collected on clinopyroxene and amphibole separates and whole-rock samples are characterized by uncorrelated 176Lu/177Hf and 176Hf/177Hf (0.2822-0.2855), decoupled from Nd-isotope compositions. This decoupling is ascribed to diffusional disequilibrium during melt-peridotite interaction, in good agreement with the results of percolation-diffusion models simulating the interaction of an arc melt with an ancient melt-depleted residue. These models notably show that HfNd isotopic decoupling such as recorded by Cabo Ortegal pyroxenites and peridotites (??Hf(i) up to +97) is enhanced during melt-peridotite interaction by slow diffusional re-equilibration and can be relatively insensitive to chromatographic fractionation. Finally, we discuss the hypothesis that arc-continent interaction may provide preferential conditions for such isotopic decoupling and propose that its ubiquitous recognition in peridotites reflects the recycling of sub-arc mantle domains derived from ancient, reworked SCLM.
DS202007-1161
2020
Tilhac, R.Lu, J., Tilhac, R., Griffin, W.L., Zheng, J.P., Xiong, Q., Oliveira, B., O'Reilly, S.Y.Lithospheric memory of subduction in mantle pyroxenite xenoliths from rift related basalts.Earth and Planetary Science Letters, Vol. 544, 116365 14p. PdfAustraliacarbonatite

Abstract: Petrological and geochemical studies have revealed the contribution of garnet pyroxenites in basalt petrogenesis. However, whether primary mantle melts are produced with such signature or acquired it subsequently remains somewhat controversial. We here integrate new major-, trace-element and Sr-Nd-Hf isotopic compositions of garnet pyroxenite xenoliths in Holocene alkali basalts from Lakes Bullenmerri and Gnotuk, Southeastern Australia, to relate their petrogenesis to mantle-wedge melt circulation and subsequent lithospheric evolution. Results show that the clinopyroxenites have lower MgO and Cr2O3 contents than the associated websterites, and range in compositions from depleted LREE patterns and highly radiogenic Nd and Hf isotopic signatures in relatively low-MgO samples (Type 1), to enriched REE patterns with negative HFSE anomalies, unradiogenic Nd and Hf isotopes, and extremely radiogenic Sr-isotopic ratios in samples with higher MgO (Type 2). Such compositional variabilities suggest that these pyroxenites represent segregates from melts derived from a recycled oceanic lithosphere with a potential contribution from pelagic sediments. Variable LREE contents and isotopic compositions between those of Type 1 and 2 clinopyroxenites are observed in amphibole-bearing samples (Type 3), which are interpreted as Type 1-like protoliths metasomatized by the basaltic and carbonatitic melts, possibly parental to Type 2 clinopyroxenites. The lithosphere beneath Southeastern Australia thus has received variable melt contributions from a heterogeneous mantle-wedge source, which notably includes a subducted oceanic slab package that has retained its integrity during subduction. On this basis, we suggest that the compositional heterogeneity and temporal evolution of the subsequent Southeastern Australian basaltic magmatism were probably affected by the presence of pyroxenite fragments in the basalt source and formed by the tectonic reactivation of this lithosphere during Cenozoic rifting. This interpretation is notably consistent with a trend of Nd-Pb isotopes towards EMII in Older Volcanic Provinces (OVP basalts) and limited Sr-Nd-Pb isotopic variations towards HIMU in the Newer Volcanic Provinces (NVP basalts, including the host lavas), which also exhibit low SiO2, high FeO and high CaO/Al2O3 commonly interpreted as due to pyroxenite contributions. Therefore, the identification of a subduction signature in these rift-related lavas attests to a "lithospheric memory" of earlier subduction episodes (as documented by the xenoliths), rather than a reflection of contemporaneous subduction tectonics.
DS200712-0388
2007
Till, C.B.Grove, T.L., Till, C.B.Processes controlling the relationship between volcanic fronts and the subducting slab revisited.Plates, Plumes, and Paradigms, 1p. abstract p. A358.MantleSubduction
DS201112-1046
2011
Till, C.B.Till, C.B., Grove, T.L., Withers, A.C.The beginnings of hydrous mantle wedge melting.Contributions to Mineralogy and Petrology, in press available 20p.MantleSubduction - Cascades
DS201212-0264
2012
Till, C.B.Grove, T.L., Till, C.B., Krawczynski, M.J.The role of H2O in subduction zone magmatism.Annual Review of Earth and Planetary Sciences, Vol. 40, pp. 413-439.MantleSubduction
DS201212-0730
2012
Till, C.B.Till, C.B., Grove, T.L., Withers, A.C.The beginnings of hydrous mantle wedge melting.Contributions to Mineralogy and Petrology, Vol. 163, 4,MantleMelting
DS201312-0339
2013
Till, C.B.Grove, T.L., Holbig, E.S., Barr, J.A., Till, C.B., Krawczynski, M.J.Inclusions in halite - evidence of mixing of evaporite xenoliths and kimberlites of Udachnaya -East pipe (Siberia).Contributions to Mineralogy and Petrology, Vol. 166, pp. 887-910.MantleMelting
DS201312-0340
2013
Till, C.B.Grove, T.L., Till, C.B., Krawcznski, M.J.The role of H2O in subduction zone magmatism.Annual Review of Earth and Planetary Sciences, Vol. 40, pp. 413-439.MantleMagmatism, water
DS201312-0342
2013
Till, C.B.Grove, T.L., Holbig, E.S., Barr, J.A., Till, C.B., Krawczynski, M.J.Melts of garnet lherzolite: experiments, models and comparison to melts of pyroxenite and carbonated lherzolite.Contributions to Mineralogy and Petrology, Vol. 166, pp. 887-910.South America, BrazilGeochronology (~91to 78)
DS201911-2529
2019
Till, C.B.Grove, T.L., Till, C.B.H2O rich mantle melting near the slab-wedge interface.Contributions to Mineralogy and Petrology, Vol. 174, 22p. PdfMantlesubduction, melting

Abstract: To investigate the first melts of the mantle wedge in subduction zones and their relationship to primitive magmas erupted at arcs, the compositions of low degree melts of hydrous garnet lherzolite have been experimentally determined at 3.2 GPa over the temperature range of 925-1150 °C. Two starting compositions with variable H2O contents were studied; a subduction-enriched peridotite containing 0.61% Na2O, 0.16 K2O% (wt%) with 4.2 wt% H2O added (Mitchell and Grove in Contrib Mineral Petrol 170:13, 2015) and an undepleted mantle peridotite (Hart and Zindler in Chem Geol 57:247-267, 1986) with 14.5% H2O added (Till et al. in Contrib Mineral Petrol 163:669-688, 2012). Saturating phases include olivine, orthopyroxene, clinopyroxene, garnet and rutile. Melting extent is tracked from near solidus (~?5 wt%) to 25 wt%, which is close to or beyond the point where clinopyroxene and garnet are exhausted. The beginning of melting is a peritectic reaction where 0.54 orthopyroxene?+?0.17 clinopyroxene?+?0.13 garnet react to produce 1.0 liquid?+?0.88 olivine. The melt production rate near the solidus is 0.1 wt% °C-1 and increases to 0.3 wt% °C-1 over the experimentally studied interval. These values are significantly lower than that observed for anhydrous lherzolite (~?1 wt% °C-1). When melting through this reaction is calculated for a metasomatized lherzolite source, the rare earth element characteristics of the melt are similar to melts of an eclogite, as well as those observed in many subduction zone magmas. Moreover, since rutile is stable up to?~?8 wt% melting, the first melts of a hydrous lherzolite source could also show strong high field strength element depletions as is observed in many subduction zone lavas. The silicate melts measured at the lowest temperatures and melting extents (
DS1970-0836
1973
Tillander, H.Tillander, H.Observations on Historical Shapes of Gem DiamondsAustralian Gemologist., Vol. 11, No. 11, PP. 3-6.GlobalGemology, Morphology
DS1975-0201
1975
Tillander, H.Tillander, H.The Hope Diamond and Its LineageHelsinki:, United StatesKimberlite, Kimberley, Janlib, Diamond
DS1960-0883
1967
Tilley, C.E.Tilley, C.E., Yoder, H.S.JR.The Pyroxenite Facies Conversion of Volcanic and Subvolcanic Melilite Bearing and Other Alkali Ultramafic Assemblages.Carnegie Institute Yearbook, FOR 1966, PP. 457-460.GlobalResearch
DS1988-0694
1988
Tillson Birmingham, N.Tillson Birmingham, N.The drama of diamondsTown and Country, Vol. 142, No. 5097, June pp. 136-139, 197-200GlobalPopular account
DS2003-1382
2003
Tilmann, F.Tilmann, F., Ni, J.Seismic imaging of the downwelling Indian lithosphere beneath central TibetScience, No. 5624, Nay 30, pp. 1424-26.China, Tibet, Asia, IndiaGeophysics - seismics
DS200412-1996
2003
Tilmann, F.Tilmann, F., Ni, J.Seismic imaging of the downwelling Indian lithosphere beneath central Tibet.Science, No. 5624, Nay 30, pp. 1424-26.China, Tibet, Asia, IndiaGeophysics - seismics
DS200912-0600
2009
Tilmann, F.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
DS200812-1173
2008
Tilmann, F.J.Tilmann, F.J., Dahm, T.Constraints on crustal and mantle structure of the oceanic plate south of Iceland from ocean bottom recorded Rayleigh waves.Tectonophysics, Vol. 447, 1-4, pp. 66-79.Europe, IcelandTectonics
DS1995-1910
1995
Tilsley, J.E.Tilsley, J.E.Sampling and due diligenceProspectors and Developers Association of Canada (PDAC) Short Course, March 4, pp. 77-96GlobalDue diligence, Sampling -Ore reserves
DS2002-0729
2002
TiltonHoernle, K., Tilton, Le Bas, Duggen, Garbe-SchonbergGeochemistry of oceanic carbonatites compared with continental carbonatites: mantle recycling of oceanic..Contributions to Mineralogy and Petrology, Vol. 142, No. 5, Feb. pp. 520-42.MantleGeochemistry, Carbonatite - crustal carbonate
DS1989-0648
1989
Tilton, G.Hoernie, K.A., Tilton, G., Le Bas, M.J., Staudigel, H.A plume origin for Fuerteventura (Canary Islands) carbonatitesEos, Vol. 70, No. 15, April 11, p. 503. (abstract.)GlobalCarbonatite
DS2002-0728
2002
Tilton, G.Hoenle, K., Tilton, G., LeBas, Duggen, GarbeSchonbergGeochemistry of oceanic carbonatites compared with continental carbonatites; mantle recycling of oceanic..Contribution to Mineralogy and Petrology, Vol.142, 5, pp.520-42.Mantle, OceanicCarbonatite - recycling crustal carbonate
DS1983-0600
1983
Tilton, G.R.Tilton, G.R., Grunenfelder, M.H.Lead Isotope Relationships in Billion Year Old Carbonatite Complexes Superior Province, Canadian Shield.Geological Society of America (GSA), Vol. 15, No. 6, P. 707. (abstract.).Canada, Ontario, SuperiorRelated Rocks, Geochronology, Killala, Firesand
DS1985-0671
1985
Tilton, G.R.Tilton, G.R., Frost, D.M., Kwon, SUNG TACK.Isotopic Relationships in Arkansaw Cretaceous Alkalic Complexes.Geological Society of America (GSA), Vol. 17, No. 3, P. 194. (abstract.).United States, Gulf Coast, Arkansas, Hot Spring County, Canada, QuebecIsotope
DS1986-0313
1986
Tilton, G.R.Grunenfelder, M.H., Tilton, G.R., Bell, K., Blenkinsop, J.Lead and strontium isotope relationship in the Oka carbonatitecomplex, QuebecGeochimica et Cosmochimica Acta, Vol. 50, pp. 461-468Quebec, UgandaMelilite, Carbonatite
DS1986-0476
1986
Tilton, G.R.Kwon, S.T., Tilton, G.R.lead isotopic studies of Canadian shield alkalic complexes:correlation with Sr isotopic evolutionGeological Society of America (GSA) Abstact Volume, Vol. 18, No. 6, p. 663. (abstract.)Ontario, ManitobaGeochronology, Alkaline rocks
DS1986-0805
1986
Tilton, G.R.Tilton, G.R., Kwon Sung Tacklead isotope studies of alkalic carbonatite and syenite complexesGeological Association of Canada (GAC) Annual Meeting, Vol. 11, p. 137. AbstractOntario, ArkansasCarbonatite, Geochronology
DS1987-0740
1987
Tilton, G.R.Tilton, G.R., Sung Tack Kwon, Frost, D.M.Isotopic relationships in Arkansaw Cretaceous alkalic complexesMantle metasomatism and alkaline magmatism, edited E. Mullen Morris and, No. 215, pp. 241-248ArkansasIsotope
DS1989-0839
1989
Tilton, G.R.Kwon, S.T., Tilton, G.R., Grunenfelder, M.H.Lead isotope relationships in carbonatites and alkalic complexes: anoverviewCarbonatites -Genesis and Evolution, Ed. K. Bell Unwin Hyman Publ, pp. 360-387Midcontinent, OntarioGeochronology, Lead
DS1990-0190
1990
Tilton, G.R.Ben Othman, D., Tilton, G.R., Menzies, M.A.lead, neodymium, and Strontium isotopic investigations of kaersutite and clinopyroxene from ultramafic nodules and their host basalts: the nature of the subcontinental mantleGeochimica et Cosmochimica Acta, Vol. 54, pp. 3449-3460California, Arizona, New MexicoMantle, Nodules -kaersutites
DS1990-1028
1990
Tilton, G.R.Meijer, A., Kwon, T.T., Tilton, G.R.U-Th-lead partioning behaviour during partial melting in the upper mantle-implications for the origin of high Mu-components and the lead paradoxJournal of Geophysical Research, Vol. 95, No. 1, Jan. 10, pp. 433-448GlobalMantle, lead paradox
DS1990-1317
1990
Tilton, G.R.Schreyer, W., Tilton, G.R., Schertl, H.P.Toward a P-T time path for the pyrope-coesite rocks of the Dora Mairamassif, western AlpsTerra, Abstracts of Crustal Dynamics: Pathways and Records held Bochum FRG, Vol. 2, December p. 32AlpsCoesite, Petrology
DS1990-1464
1990
Tilton, G.R.Tilton, G.R., Kwon, S-T.Isotopic evidence for crust-mantle evolution with emphasis on the CanadianshieldChem. Geol, Vol. 83, No. 3/4, June 25, pp. 149-183Canada, OntarioAlkaline complexes, Geochronology
DS1993-0029
1993
Tilton, G.R.Ames, L., Tilton, G.R., Zhou, G.Timing of collision of the Sino-Korean and Yangtse cratons: uranium-lead (U-Pb) (U-Pb) zircon dating of coesite-bearing eclogitesGeology, Vol. 21, No. 4, April pp. 339-342ChinaDabie Mountains, Diamonds
DS1994-1778
1994
Tilton, G.R.Tilton, G.R., Bell, K.Strontium neodymium lead relationships in Late Archean carbonatites and alkaline complexes: applications geochemical evolution.Geochimica et Cosmochimica Acta, August pp. 3145-3154.CanadaCarbonatite, Geochronology, Archean mantle
DS1998-1464
1998
Tilton, G.R.Tilton, G.R., Bryce, J.G., Mateen, A.lead, Strontium, and neodymium isotope dat a from 30 and 300 Ma collision zone carbonatites in northwest Pakistan #2Journal of Petrology, Vol. 39, No. 11-12, Nov-Dec. pp. 1865-74.PakistanCarbonatite, Geochronology
DS1998-1465
1998
Tilton, G.R.Tilton, G.R., Bryce, J.G., Mateen, A.lead, Strontium, neodymium isotope dat a from 30 and 300 Ma collision zone carbonatites in Northwest Pakistan #1Mineralogical Magazine, Goldschmidt abstract, Vol. 62A, p. 1521-2.PakistanCarbonatite, Geochronology
DS2001-0101
2001
Tilton, G.R.Bell, K., Tilton, G.R.neodymium lead and Strontium isotopic compositions of East African carbonatites: evidence for mantle mixing and plume....Journal of Petrology, Vol. 42, No. 10, Oct. pp. 1927-46.TanzaniaPlumes - inhomogeneity, mantle plumes, Carbonatite
DS1988-0695
1988
Tilton, J.E.Tilton, J.E.Changing patterns of mineral tradeColorado School of Mines Department of Mineral Economics, Working Paper No. 88-16, 15p. Database # 17619GlobalEconomics, Mineral trade
DS1988-0696
1988
Tilton, J.E.Tilton, J.E.The new view of minerals and economic growthColorado School of Mines Department of Mineral Economics, Working Paper No. 88-10, 32p. Database # 17620GlobalEconomics, Minerals Economic growth
DS1992-1554
1992
Tilton, J.E.Tilton, J.E.Mineral endowment, public policy and competitiveness: a survey of issuesColorado School of Mines, Department of Mineral Economics, Working Paper 92-4, 31pUnited StatesEconomics, Mineral endowment, public policy
DS1994-1779
1994
Tilton, J.E.Tilton, J.E.Environmental revolution: stage twoMining Engineering, Vol. 46, No. 7, July pp. 660-661United StatesLegal, Environmental laws
DS200412-1997
2004
Tilton, J.E.Tilton, J.E.Determining the optimal tax on mining.Natural Resources Forum, Vol. 28, 4, May, pp. 144-149.GlobalLegal - taxation
DS200512-0218
2005
Tilton, J.E.Davis, G., Tilton, J.E.The resource curse.Natural Resources Forum, Vol. 29, 3, August pp. 233-242.AfricaNews item - economics
DS1920-0350
1927
Tilton, J.L.Tilton, J.L.An Igneous Dike of Altered and Extremely Weathered Volcanicbreccia.West Virginia Geological Survey County Report, PP. 266-273.Appalachia, West VirginiaPendleton County, Related Rocks, Geology
DS1988-0697
1988
Timchenko, V.A.Timchenko, V.A., Borovkova, T.V., et al.Methods and results of deep geochemical mapping of closed areas when exploring for kimberlite bodies in western Yakutia.(Russian)Theory and Practice of geochemical exploration under modern conditions:text, pp. 93-94. abstractRussiaGeochemistry, Kimberlites
DS200812-1174
2008
Times onlineTimes onlineUntapped resources promise new scramble for Africa.Times Magazine, Sept. 17, 1p.Africa, ZimbabweNews item - legal
DS200812-1047
2007
Timina, T.Ju.Sharygin, V.V., Szabo, C., Kothay, K., Timina, T.Ju., Peto, MN., Torok, K., Vapnik, Y., Kuzmin, D.V.Rhonite in silica undersaturated alkali basalts: inferences on silicate melt inclusions in olivine phenocrysts.Vladykin Volume 2007, pp. 157-182.RussiaPetrology
DS202010-1880
2020
Timina, T.Y.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.
DS200612-1428
2006
Timina, T.Yu.Timina, T.Yu., Sharygin, V.V., Golovin, A.V.Melt evolution during the crystallization of basanites of the Tergesh pipe.Geochemistry International, Vol. 44, 8, pp. 752-770.RussiaBasanites, Foidites
DS201601-0047
2015
Timina, T.Yu.Tomilenko, A.A., Kuzmin, D.V., Bulbak, T.A., Timina, T.Yu., Sobolev, N.V.Composition of primary fluid and melt inclusions in regenerated olivines from hypabyssal kimberlites of the Malokuonapskaya pipe ( Yakutia).Doklady Earth Sciences, Vol. 465, 1, pp. 1168-1171.RussiaDeposit - Malokuonapskaya
DS1997-1127
1997
TimirshinSuvorov, V.D., Timirshin, Yruin, Parasotka, MatveevRatio of deep seated and near surface structures in the southern part Of the Yakutian kimberlite province.Russian Geology and Geophysics, Vol. 38, No. 5, pp. 1054-61.Russia, YakutiaGeophysics - seismics, Tectonics, structures
DS1995-1858
1995
Timirshin, K.V.Suvorov, V.D., Timirshin, K.V., Yurin, Yu.A., et al.Structure and evolution of the crust and uppermost mantle beneath Yakutian kimberlite Province -seismic dat a #1Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 592-593.Russia, YakutiaStructure, Geophysics -seismics
DS1997-1128
1997
Timirshin, K.V.Suvorov, V.D., Yurin, Yu.A., Timirshin, K.V., et al.Structure and evolution of the crust and uppermost mantle beneath Yakutian kimberlite province -seismics #2Russian Geology and Geophysics, Vol. 38, No. 2, pp. 518-527.Russia, YakutiaStructure, geodynamics, Geophysics - seismics
DS200712-1215
2007
Timm, J.Zack, T., Timm, J.An evaluation of reactive fluid flow and trace element mobility in subducting slabs.Chemical Geology, Vol. 237, 1-2, Feb. 15, pp. 5-22.MantleSubduction
DS201012-0788
2010
Timm, J.Timm, J., Layne, G.D., Haase, K.M., Barnes, J.D.Chlorine isotope evidence for crustal recycling into the Earth's mantle.Earth and Planetary Science Letters, Vol. 298, 1-2, Sept. 15, pp. 175-182.MantleSubduction
DS201112-0405
2011
Timm, J.Halama, R., Timm, J., Herms, P., Hauff, F., Schenk, V.A stable ( Li,O) and radiogenic (Sr, Nd) isotope perspective on metasomatic processes in a subducting slab.Chemical Geology, Vol. 281, 3-4, pp. 151-166.MantleSubduction
DS201112-1047
2011
Timm, J.Timm, J., Scambelluri, M., Frische, M., Barnes, J.D., Bach, W.Dehydration of subducting serpentinite: implications for halogen mobility in subduction zones and the deep halogen cycle.Earth and Planetary Science Letters, Vol. 308, 1-2, pp. 65-76.MantleSubduction
DS1995-1911
1995
Timmerman, M.J.Timmerman, M.J., Daly, J.S.samarium-neodymium (Sm-Nd) evidence for late Archean crust formation in the Lapland-Kola mobilebelt, Kola Peninsula, Russia NorwayPrecambrian Research, Vol. 72, No. 1-2, March pp. 97-108.Russia, NorwayGeochronology, Crust
DS202101-0021
2020
Timmerman, M.J.Krmicek, L., Romer, R.L., Timmerman, M.J., Ultych, J., Glodny, J.Long lasting ( 65Ma) regionally contrasting Late-to Post-orogenic variscan mantle-derived potassic magmatism in the Bohemian Massif.Journal of Petrology, Vol. 61, 7, doi.org/10.1093 /petrology/egaa072Europemagmatism

Abstract: The orogenic development after the continental collision between Laurussia and Gondwana, led to two contrasting associations of mantle-derived magmatic rocks on the territory of the Bohemian Massif: (i) a 340-310?Ma lamprophyre-lamproite orogenic association; and (ii) a 300-275?Ma lamprophyre association of anorogenic affinity. Major types of potassic mantle-derived magmatic rocks recognized in the orogenic and anorogenic associations include: (i) calc-alkaline to alkaline lamprophyres; (ii) alkaline ‘orthopyroxene minettes’ and geochemically related rocks grouped here under the new term lampyrite; and (iii) peralkaline lamproites. These three types significantly differ with respect to mineral, whole-rock and Sr-Nd-Pb-Li isotope composition and spatial distribution. The calc-alkaline lamprophyres occur throughout the entire Saxo-Thuringian and Moldanubian zones, whereas the different types of malte-derived potassic rocks are spatially restricted to particular zones. Rocks of the Carboniferous lamprophyre-lamproite orogenic association are characterized by variable negative eNd(i) and variably radiogenic Sr(i), whereas the rocks of the Permian lamprophyre association of anorogenic affinity are characterized by positive eNd(i) and relatively young depleted-mantle Nd-model ages reflecting increasing input from upwelling asthenospheric mantle. The small variation in the Pb isotopic composition of post-collisional potassic mantle-derived magmatic rocks (of both the orogenic and anorogenic series) implies that the Pb budget of the mantle beneath the Bohemian Massif is dominated by the same crust-derived material, which itself may include material derived from several sources. The source rocks of ‘orthopyroxene minettes’ are characterized by isotopically light (‘eclogitic’) Li and strongly radiogenic (crustal) Sr and may have been metasomatized by high-pressure fluids along the edge of a subduction zone. In contrast, the strongly Al2O3 and CaO depleted mantle source of the lamproites is characterized by isotopically heavy Li and high SiO2 and extreme K2O contents. This mantle source may have been metasomatized predominantly by melts. The mantle source of the lamprophyres may have undergone metasomatism by both fluids and melts.
DS201605-0908
2016
Timmerman, S.Timmerman, S.Silicic to saline fluid inclusions in Koffiefontein diamonds.DCO Edmonton Diamond Workshop, June 8-10Africa, South AfricaDeposit - Koffiefontein
DS201703-0434
2017
Timmerman, S.Timmerman, S., Koornneef, J.M., Chinn, I.L., Davies, G.R.Dated eclogitic diamond growth zones reveal variable recycling of crustal carbon through time.Earth and Planetary Science Letters, Vol. 463, pp. 178-188.Africa, BotswanaDeposit - Lethakane

Abstract: Monocrystalline diamonds commonly record complex internal structures reflecting episodic growth linked to changing carbon-bearing fluids in the mantle. Using diamonds to trace the evolution of the deep carbon cycle therefore requires dating of individual diamond growth zones. To this end Rb-Sr and Sm-Nd isotope data are presented from individual eclogitic silicate inclusions from the Orapa and Letlhakane diamond mines, Botswana. d13Cd13C values are reported from the host diamond growth zones. Heterogeneous 87Sr/86Sr ratios (0.7033-0.7097) suggest inclusion formation in multiple and distinct tectono-magmatic environments. Sm-Nd isochron ages were determined based on groups of inclusions with similar trace element chemistry, Sr isotope ratios, and nitrogen aggregation of the host diamond growth zone. Diamond growth events at 0.14±0.090.14±0.09, 0.25±0.040.25±0.04, 1.1±0.091.1±0.09, 1.70±0.341.70±0.34 and 2.33±0.022.33±0.02 Ga can be directly related to regional tectono-magmatic events. Individual diamonds record episodic growth with age differences of up to 2 Ga. Dated diamond zones have variable d13Cd13C values (-5.0 to -33.6‰ vs PDB) and appear to imply changes in subducted material over time. The studied Botswanan diamonds are interpreted to have formed in different tectono-magmatic environments that involve mixing of carbon from three sources that represent: i) subducted biogenic sediments (lightest d13Cd13C, low 87Sr/86Sr); ii) subducted carbonate-rich sediments (heavy d13Cd13C, high 87Sr/86Sr) and iii) depleted upper mantle (heavy d13Cd13C, low 87Sr/86Sr). We infer that older diamonds from these two localities are more likely to have light d13Cd13C due to greater subduction of biogenic sediments that may be related to hotter and more reduced conditions in the Archaean before the Great Oxidation Event at 2.3 Ga. These findings imply a marked temporal change in the nature of subducted carbon beneath Botswana and warrant further study to establish if this is a global phenomenon.
DS201705-0833
2017
Timmerman, S.Gress, M.U., Pearson, D.G., Timmerman, S., Chinn, I.L., Koornneef, J., Davies, G.R.Diamond growth beneath Letlhakane established by Re-Os and Sm-Nd systematics of individual eclogitic sulphide, garnet and clinopyroxene inclusions.European Geosciences Union General Assembly 2017, Vienna April 23-28, 1p. 5540 AbstractAfrica, BotswanaDeposit - Letlhakane

Abstract: The diamondiferous Letlhakane kimberlites are part of the Orapa kimberlite cluster (˜ 93.1 Ma) in north-eastern Botswana, located on the edge of the Zimbabwe Craton, close to the Proterozoic Magondi Mobile Belt. Here we report the first Re-Os ages of six individual eclogitic sulphide inclusions (3.0 to 35.7µg) from Letlhakane diamonds along with their rhenium, osmium, iridium and platinum concentrations, and carbon isotope, nitrogen content and N-aggregation data from the corresponding growth zones of the host diamonds. For the first time, Re-Os data will be compared to Sm-Nd ages of individual eclogitic silicate inclusions recovered from the same diamonds using a Triton Plus equipped with four 1013O amplifiers. The analysed inclusion set currently encompasses pairs of individual sulphides from two diamonds (LK040 sf4 & 5, LK113 sf1 & 2) and two sulphide inclusions from separate diamonds (LK048, LK362). Ongoing work will determine the Sm-Nd ages and element composition of multiple individual eclogitic garnets (LK113/LK362, n=4) and an eclogitic clinopyroxene (LK040) inclusion. TMA ages of the six sulphides range from 1.06 to 2.38 Ga (± 0.1 to 0.54 Ga) with Re and Os contents between 7 and 68 ppb and 0.03 and 0.3 ppb, respectively. The host diamond growth zones have low nitrogen abundances (21 to 43 ppm N) and high N-aggregation (53 to 90% IaB). Carbon isotope data suggests the involvement of crustal carbon (d13C between -19.3 to -22.7 ± 0.2 per mill) during diamond precipitation. Cathodoluminescence imaging of central plates from LK040 and LK113 displays homogenous internal structure with no distinct zonation. The two sulphide inclusions from LK040 define an 'isochron' of 0.92 ± 0.23 Ga (2SD) with initial 187Os/188Os = 1.31 ± 0.24. Sulphides from LK113 have clear imposed diamond morphology and indicate diamond formation at 0.93 ± 0.36 Ga (2SD) with initial 187Os/188Os = 0.69 ± 0.44. The variation in the initial 187Os/188Os does not justify including these inclusions (or any from other diamonds) on the same isochron and implies an extremely heterogeneous diamond crystallisation environment that incorporated recycled Os. C1-normalized osmium, iridium and platinum (PGE) compositions from the analysed sulphide inclusions display enrichment in Ir (3.4 to 33) and Pt (2.3 to 28.1) in comparison to eclogitic xenolith data from Orapa that are depleted relative to chondrite. The Re-Os isochrons determined in this study are within error of previously reported ages from the adjacent (˜40km) Orapa diamond mine (1.0 to 2.9 Ga) based on sulphide inclusions and a multi-point 990 ± 50 Ma (2SD) isochron for composite (n=730) silicate inclusions. Together with additional new Sm-Nd isochron age determinations from individual silicate inclusions from Letlhakane (2.3 ± 0.02 (n = 3); 1.0 ± 0.14 (n = 4) and 0.25 ± 0.04 Ga (n = 3), all 2SE) these data suggest a phase of Mesoproterozoic diamond formation as well as Neoarchean/Paleoproterozoic and Mesozoic diamond growth, in punctuated events spanning >2.0 Ga.
DS201708-1777
2017
Timmerman, S.Timmerman, S.Relation between fluid end-members and noble gases in South African diamonds.11th. International Kimberlite Conference, OralAfrica, South Africadiamond inclusions

Abstract: Fibrous diamond growth zones can contain abundant high density fluid inclusions (HDFs) and these provide the most direct information on the source and composition of diamond-forming fluids. Four different fluid end-members have been defined; silicic, low-Mg carbonatitic, high-Mg carbonatitic, and saline. Continuous arrays exist between the silicic and low-Mg carbonatitic end-member and between the saline and high-Mg carbonatitic end-member. Different processes have been proposed to explain the two major element compositional arrays, but the origin of and relation between the various fluid end-members is still uncertain. In this study we provide new constraints on the evolution and origin of these diamond-forming fluids by combining noble gas systematics with d13C, N concentrations, and fluid inclusion compositions.
DS201708-1778
2017
Timmerman, S.Timmerman, S.Formation of unusual yellow Orapa diamonds.11th. International Kimberlite Conference, PosterAfrica, Botswanadeposit - Orapa
DS201805-0982
2018
Timmerman, S.Timmerman, S., Jaques, A.L., Weiss, Y., Harris, J.W.N delta 13 inclusion profiles of cloudy diamonds from Koffiefontein: evidence for formation by continuous Rayleigh fractionation and multiple fluids.Chemical Geology, Vol. 483, pp. 31-46.Africa, South Africadeposit - Koffiefontein
DS201806-1233
2018
Timmerman, S.Koornneef, J.M., Berndsen, M., Hageman, L., Gress, M.U., Timmerman, S., Nikogosian, I., van Bergen, M.J., Chinn, I.L., Harris, J.W., Davies, G.R.Melt and mineral inclusions as messengers of volatile recycling in space and time. ( olivine hosted inclusions)Geophysical Research Abstracts www.researchgate.net, Vol. 20, EGU2018-128291p. AbstractAfrica, South Africadiamond inclusions

Abstract: Changing recycling budgets of surface materials and volatiles by subduction of tectonic plates influence the compositions of Earth’s major reservoirs and affect climate throughout geological time. Fluids play a key role in processes governing subduction recycling, but quantifying the exact fate of volatiles introduced into the mantle at ancient and recent destructive plate boundaries remains difficult. Here, we report on the role of fluids and the fate of volatiles and other elements at two very different tectonic settings: 1) at subduction settings, and 2) within the subcontinental lithospheric mantle (SCLM). We will show how olivine-hosted melt inclusions from subduction zones and mineral inclusions in diamond from the SCLM are used to reveal how changing tectonic settings influence volatile cycles with time. Melt inclusions from the complex Italian post-collisional tectonic setting are used to identify changing subduction recycling through time. The use of CO2 in deeply trapped melt inclusions instead of in lavas or volcanic gases provides a direct estimate of deep recycling, minimizing possible effects of contamination during transfer through the crust. The aim is to distinguish if increased recycling of sediments from the down-going plate at continental subduction settings results in increased deep CO2 recycling or if the increased CO2 flux results from crustal degassing of the overriding plate. Both processes likely affected climate through Earth history but could thus far not be discriminated. The study of mineral inclusions and their host diamonds from the SCLM can link changes in the cycling of carbon-rich fluids and the time and process through which the carbon redistribution took place. We use Sm-Nd isotope techniques to date the mineral inclusions and use the carbon isotope data of the host diamonds to investigate the growth conditions. I will present case-studies of peridotitic and eclogitic diamonds from three mines in Southern Africa.
DS201807-1531
2018
Timmerman, S.Timmerman, S., Chinn, I.L., Fisher, D., Davies, G.R.Formation of unusual Orapa yellow diamonds. Mineralogy and Petrology, 10.1007/ s710-018-0592 -9, 10p.Africa, Botswanadeposit - Orapa, Damtshaa, BK09, BK12,AK01

Abstract: Twenty eclogitic diamonds from Orapa Mine (Botswana) with an unusual yellow colour are characterised for their growth structure, N systematics, and C isotope composition, and the major element composition of their silicate inclusions. The diamonds show complex luminescence with green, blue and non-luminescent zones and occasional sector zonation. All parts of the diamonds have low total N concentrations (<50 at.ppm, with one exception of <125 at.ppm) and a limited range in C isotope composition (-5.7 to -10.6‰). Fourier Transform Infrared spectra show bands at 1334, 1332, 1282, and 1240 cm-1 typical for Ib-IaA diamonds. Relict unaggregated N defects (Nso and Ns+) are present and the preservation is likely caused by the low N concentrations and possible low mantle residence temperatures rather than young diamond formation (inclusion ages of 140, 1096, 1699 Ma; Timmerman et al. Earth Planet Sc Lett 463:178-188, 2017). Garnet and clinopyroxene inclusions extracted from 14 diamonds have an eclogitic composition with relatively low Ca contents and based on all characteristics, these diamonds form a distinct population from Orapa.
DS201807-1532
2018
Timmerman, S.Timmerman, S., Honda, M., Phillips, D., Jaques, A.L., Harris, J.W.Noble gas geochemistry of fluid inclusions in South Africa diamonds: implications for the origin of diamond forming fluids. ( fibrous)Mineralogy and Petrology, 10.1007/ s710-018- 0603-x 15p.Africa, South Africadeposit - Finsch, De Beers Pool, Koffiefontein

Abstract: Fibrous diamond growth zones often contain abundant high-density fluid (HDF) inclusions and these provide the most direct information on diamond-forming fluids. Noble gases are incompatible elements and particularly useful in evaluating large-scale mantle processes. This study further constrains the evolution and origin of the HDFs by combining noble gas systematics with d¹³C, N concentrations, and fluid inclusion compositions for 21 individual growth zones in 13 diamonds from the Finsch (n = 3), DeBeers Pool (n = 7), and Koffiefontein (n = 3) mines on the Kaapvaal Craton. C isotope compositions range from -2.8 to -8.6‰ and N contents vary between 268 and 867 at.ppm, except for one diamond with contents of <30 at.ppm N. Nine of the thirteen studied diamonds contained saline HDF inclusions, but the other four diamonds had carbonatitic or silicic HDF inclusions. Carbonatitic and silicic HDFs yielded low He concentrations, R/Ra (³He/4Hesample/³He/4Heair) values of 3.2–6.7, and low 4°Ar/³6Ar ratios of 390–1940. Noble gas characteristics of carbonatitic-silicic HDFs appear consistent with a subducted sediment origin and interaction with eclogite. Saline HDFs are characterised by high He concentrations, with R/Ra mostly between 3.9 and 5.7, and a wide range in 4°Ar/³6Ar ratios (389–30,200). The saline HDFs likely originated from subducted oceanic crust with low He but moderate Ar contents. Subsequent interaction of these saline HDFs with mantle peridotite could explain the increase in He concentrations and mantle-like He isotope composition, with the range in low to high 4°Ar/³6Ar ratios dependent on the initial ³6Ar content and extent of lithosphere interaction. The observed negative correlation between 4He contents and R/Ra values in saline HDFs indicates significant in situ radiogenic 4He production. Noble gas geochemistry of fluid inclusions in South African diamonds: implications for the origin of diamond-forming fluids.
DS201905-1081
2019
Timmerman, S.Timmerman, S., Jaques, A.L., Weiss, Y., Harris, J.W.N delta 13 C - inclusion profiles of cloudy diamonds from Koffiefontein: evidence for formation by continuous Rayleigh fractionation and multiple fluids.Chemical Geology, Vol. 483, pp. 31-46.Africa, South Africadeposit - Koffiefontein

Abstract: Six diamonds with a fibrous core, intermediate zone and monocrystalline outer zone (“cloudy diamonds”) from the Koffiefontein mine, South Africa, were investigated for N concentrations, carbon isotope compositions and micro-inclusion compositions along core to rim traverses. This study evaluates the nature of the change from fibrous to gem diamond growth and the relation between major element composition of high density fluid inclusions and N - d¹³C in fibrous growth zones. Three diamonds contain saline to carbonatitic fluid micro-inclusions with constant or increasing carbon isotope values which are inferred to have formed by varying amounts of Rayleigh fractionation in a closed system of a carbonate-bearing fluid. Continuous N - d¹³C fractionation trends from the fibrous to gem growth zone in two of the diamonds and equally low nitrogen aggregation states indicate formation of diamond shortly before kimberlite eruption from a single fluid without a time gap between fibrous and gem diamond growth. High major element/CO32- ratios in the growth media resulted in a constant major element composition of the fluid inclusions found in the studied fibrous diamonds. The transition from fibrous to gem diamond growth is likely caused by the precipitation of diamond reducing the degree of oversaturation of carbon in the fluid and hence decreasing the rate of diamond growth. Two other diamonds have inclusions that change from silicate minerals in the inner fibrous growth zones towards pure saline fluid compositions in the outer fibrous growth zones. This decrease in Si, Mg and Ca and increase in K and Cl in the inclusions is accompanied by a decrease in d¹³C values and N contents. These trends are suggested to be the result from gradually mixing in more saline fluids with lower d¹³C values. One diamond with silicic inclusions has significant N aggregation into B-centres, suggesting this fluid is different and that diamond formation occurred significantly (e.g. 1250 °C gives =10 Ma) before the kimberlite eruption.
DS201906-1354
2019
Timmerman, S.Timmerman, S., Krebs, M.Y., Pearson, D.G., Honda, M.Diamond forming media through time - trace element and noble gas systematics of diamonds formed over 3 billion years of Earth's history.Geochimica et Cosmochimica Acta, in press available 29p.Africa, South Africa, Botswanadeposit - Koffiefontein, Letlhakane, Orapa, Finsch, De Beers Pool

Abstract: Ten individual gem-quality monocrystalline diamonds of known peridotite/eclogite paragenesis from Southern Africa (Koffiefontein, Letlhakane, Orapa) were studied for trace element concentrations and He and Ar abundances and isotopic compositions. In addition, two samples, consisting of pooled fragments of gem-quality peridotitic diamonds from Finsch and DeBeers Pool respectively, were analysed for noble gases. Previous studies (Richardson et al., 1984; Pearson et al., 1998; Gress et al., 2017; Timmerman et al., 2017) provided age constraints of 0.09, 1.0-1.1, 1.7, 2.3, and 3.2-3.4?Ga on mineral inclusions in the studied diamonds, allowing us to study trace elements and noble gases over 3 Gyr of geological time. Concentrations of trace elements in the diamonds are very low - a few hundred ppt to several tens of ppbs - and are likely dependent on the amount of sub-micron inclusions present. Trace element patterns and trace element/3He ratios of the studied monocrystalline diamonds are similar to those in fibrous diamonds, suggesting that trace elements and stable noble gas isotopes reside within the same locations in diamond and track the same processes that are reflected in the trace element patterns. We cannot discern any temporal differences in these geochemical tracers, suggesting that the processes generating them have been occurring over at least the past 2.3?Ga. 3He/4He ratios decrease and 4He and 40Ar* contents increase with increasing age of peridotitic and some eclogitic diamonds, showing the importance of in-situ radiogenic 4He and 40Ar ingrowth by the decay of U-Th-Sm and K respectively. For most gem-quality monocrystalline diamonds, uncertainties in the 3He/4He evolution of the continental lithospheric mantle combined with large analytical uncertainties and possible spatial variability in U-Th-Sm concentrations limit our ability to provide estimates of diamond formation ages using 4He ingrowth. However, the limited observed 4He ingrowth (low U?+?Th/3He) together with a R/Ra value of 5.3 for peridotitic diamond K306 is comparable to the present-day sub-continental lithospheric mantle value and supports the young diamond formation age found by Re-Os dating of sulphides in the same diamond by Pearson et al. (1998). After correction for in-situ radiogenic 4He produced since diamond formation a large variation in 3He/4He remains in ~1?Ga old eclogitic diamonds that is suggested to result from the variable influence of subducted altered oceanic crust that has low 3He/4He. Hence, the 3He/4He isotope tracer supports an origin of the diamond-forming fluids from recycled oceanic crust for eclogitic diamonds, as indicated by other geochemical proxies.
DS201906-1355
2019
Timmerman, S.Timmerman, S., Yeow, H., Honda, M., Howell, D., Jaques, A.L., Krebs, M.Y., Woodland, S., Pearson, D.G., Avila, J.N., Ireland, T.R.U-Th/He systematics of fluid rich 'fibrous' diamonds - evidence for pre- and syn-kimberlite eruption ages.Chemical Geology, Vol. 515, pp. 22-36.Africa, Democratic Republic of Congo, Botswanadeposit - Jwaneng

Abstract: The physical characteristics and impermeability of diamonds allow them to retain radiogenic 4He produced in-situ from radioactive decay of U, Th and Sm. This study investigates the U-Th/He systematics of fibrous diamonds and provides a first step in quantification of the uncertainties associated with determining the in-situ produced radiogenic 4He concentration. Factors determining the total amount of measured helium in a diamond are the initial trapped 4He, the in-situ produced radiogenic 4He, a-implantation, a-ejection, diffusion, and cosmogenic 3He production. Alpha implantation is negligible, and diffusion is slow, but the cosmogenic 3He component can be significant for alluvial diamonds as the recovery depth is unknown. Therefore, samples were grouped based on similar major and trace element compositions to determine possible genetically related samples. A correlation between the 4He and U-Th concentrations approximates the initial 4He concentration at the axis-intersect and age as the slope. In this study, the corrections were applied to eight fibrous cubic diamonds from the Democratic Republic of the Congo and two diamonds from the Jwaneng kimberlite in Botswana. A correlation exists between the 4He and U-Th concentrations of the group ZRC2, 3, and 6, and of the group CNG2, 3, and 4 and both correlations deviate significantly from a 71?Ma kimberlite eruption isochron. The U-Th/He dating method appears a promising new approach to date metasomatic fluid events that result in fibrous diamond formation and this is the first evidence that some fibrous diamonds can be formed 10s to 100s Myr before the kimberlite eruption.
DS201908-1818
2019
Timmerman, S.Timmerman, S., Honda, M., Zhang, X., Jaques, A.L., Bulanova, G., Smith, C.B., Burnham, A.D.Contrasting noble gas compositions of peridotitic and eclogitic monocrystalline diamonds from the Argyle lamproite, Western Australia.Lithos, Vol. 344-345, pp. 193-206.Australiadeposit - Argyle

Abstract: He-Ne-Ar compositions were determined in diamonds from the Argyle lamproite, Western Australia, to assess whether subducted material affects the noble gas budget and composition of stable old sub-continental lithospheric mantle (SCLM). Twenty diamonds (both peridotitic and eclogitic) were characterized for their carbon isotopic compositions and N abundance and aggregation from which 10 eclogitic growth zones and 5 peridotitic growth zones were analysed for their He-Ne-Ar compositions. The eclogitic diamonds have d13C values of -4.7 to -16.6‰ indicating a subduction signature, whereas the peridotitic diamonds have mantle-like compositions of -4.0 to -7.8‰. Mantle residence temperatures based on N-in-diamond thermometry showed that the eclogitic diamonds were mainly formed at 1260-1270?°C or above 1300?°C near the base of the lithosphere, whereas the peridotitic diamonds generally formed at lower temperatures (mostly 1135-1230?°C). A noble gas subduction signature is present to various extents in the eclogitic diamonds and is inferred from a hyperbolic mixing relationship between R/Ra and 4He and d13C values concentrations with a predominance of low R/Ra values (<0.5; R/Ra?=?3He/4Hesample/3He/4Heair). In addition, low 40Ar/4He and 40Ar/36Ar ratios, high nucleogenic 21Ne/4He and low 3He/22Ne ratios are characteristic of subducted material and were found in the eclogitic diamonds. The peridotitic diamonds show generally higher R/Ra values (median 1.1?±?1.1) and lower 4He/40Ar ratios compared to eclogitic diamonds (median 0.1?±?0.8 R/Ra; with 7/10 samples having an average of 0.13?±?0.14 R/Ra). The studied peridotitic diamond growth zones showed a negative correlation between R/Ra and 4He concentrations over 2 orders of magnitude and limited variation in 3He, that can be largely explained by radiogenic 4He ingrowth. At low 4He concentrations the R/Ra value is around 2.8 for both paragenesis of diamonds and is significantly lower than present-day SCLM values, suggesting (1) a more radiogenic helium isotope composition beneath the Halls Creek Orogen than those for typical SCLM from other cratons and/or (2) that the peridotitic diamonds are formed from fluids that also had a subduction input. The high mantle residence temperature and low R/Ra value in the core and low temperature and higher R/Ra value in the rim of a single peridotitic diamond indicate multiple growth events and that part of the lherzolitic diamond population may be genetically related to the eclogitic diamonds. Combining the diamond mantle residence temperatures with noble gas compositions shows that noble gas subduction signatures are present at the base of the lithosphere below 180?km depth beneath Argyle and that fluid migration and interaction with the SCLM occurred over scales of at least 15?km, between 180 and 165?km depth.
DS201909-2098
2019
Timmerman, S.Timmerman, S., Honda, M., Burnham, A.D., Amelin, Y., Woodland, S., Pearson, D.G., Jaques, A.L., Le Losq, C., Bennett, V.C., Bulanova, G.P., Smith, C.B., Harris, J.W., Tohver, E.Primordial and recycled helium isotope signatures in the mantle transition zone. Science, Vol. 365, 6454, pp. 692-694.Mantlediamond genesis

Abstract: Isotope compositions of basalts provide information about the chemical reservoirs in Earth’s interior and play a critical role in defining models of Earth’s structure. However, the helium isotope signature of the mantle below depths of a few hundred kilometers has been difficult to measure directly. This information is a vital baseline for understanding helium isotopes in erupted basalts. We measured He-Sr-Pb isotope ratios in superdeep diamond fluid inclusions from the transition zone (depth of 410 to 660 kilometers) unaffected by degassing and shallow crustal contamination. We found extreme He-C-Pb-Sr isotope variability, with high 3He/4He ratios related to higher helium concentrations. This indicates that a less degassed, high-3He/4He deep mantle source infiltrates the transition zone, where it interacts with recycled material, creating the diverse compositions recorded in ocean island basalts.
DS200412-1998
2004
Timmermann, H.Timmermann, H., Stedra, V., Gerdes, A., Noble, S.R., Parrish, R.R., Dorr, W.The problem of dating high pressure metamorphism: a U Pb isotope and geochemical study on eclogites and related rocks of the MarJournal of Petrology, Vol. 45, 7, pp. 1311-1338.Europe, Czech RepublicEclogite, UHP
DS1993-0258
1993
Timmermans, T.J.Clark, J.A., Hendriks, M., Timmermans, T.J., Struck, C., Hilverda, K.J.Glacial isostatic deformation of the Great Lakes regionGeological Society of America Bulletin, Vol. 106, No. 1, January pp. 19-31.OntarioGeomorphology, Sea level changes, isostasy
DS1995-1912
1995
Timmons, B.J.Timmons, B.J.Exploration more than a beginning.... researchAmerican Institute of Mining, Metallurgical, and Petroleum Engineers (AIME) Preprint, No. 95-219, 5pGlobalExploration, Research -background
DS2000-0616
2000
Timmons, J.M.Marhsak, S., Karlstrom, K., Timmons, J.M.Inversion of Proterozoic extensional faults: an explanation for the pattern of Laramide and Rockies...Geology, Vol. 28, No.8, Aug. pp. 735-8.United States, CordilleraTectonics, Intracratonic deformation
DS201112-1048
2011
Timms, N.E.Timms, N.E., Kinny, P.D., Reddy, S.M., Evans, K., Clark, C., Healy, D.Relationship among titanium, rare earth elements, U-Pb ages and deformation microstructures in zircon: implications for Ti in zircon thermometry.Chemical Geology, Vol. 280, 1-2, pp. 33-46.Russia, SiberiaXenoliths
DS201711-2531
2017
Timms, N.E.Timms, N.E., Erickson, T.M., Zanetti, M.R., Pearce, M.A., Cayron, C., Cavosie, A.J., Reddy, S.M., Wittman, A., Carpenter, P.K.Cubic zirconia in >2370 C impact melt records Earth's hottest crust.Earth and Planetary Science Letters, Vol. 478, pp. 52-58.Canada, QuebecMistastin crater

Abstract: Bolide impacts influence primordial evolution of planetary bodies because they can cause instantaneous melting and vaporization of both crust and impactors. Temperatures reached by impact-generated silicate melts are unknown because meteorite impacts are ephemeral, and established mineral and rock thermometers have limited temperature ranges. Consequently, impact melt temperatures in global bombardment models of the early Earth and Moon are poorly constrained, and may not accurately predict the survival, stabilization, geochemical evolution and cooling of early crustal materials. Here we show geological evidence for the transformation of zircon to cubic zirconia plus silica in impact melt from the 28 km diameter Mistastin Lake crater, Canada, which requires super-heating in excess of 2370?°C. This new temperature determination is the highest recorded from any crustal rock. Our phase heritage approach extends the thermometry range for impact melts by several hundred degrees, more closely bridging the gap between nature and theory. Profusion of >2370?°C superheated impact melt during high intensity bombardment of Hadean Earth likely facilitated consumption of early-formed crustal rocks and minerals, widespread volatilization of various species, including hydrates, and formation of dry, rigid, refractory crust.
DS200712-0261
2007
TimofeevDobtresov, 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
DS201611-2100
2015
Timofeev, A.S.Chanturia, V.A., Dvoichenkova, G.P., Kovalchuk, O.E., Timofeev, A.S.Surface composition and role of hydrophilic diamonds in foam separation.Journal of Mining Science , Vol. 51, 5, pp. 1235-1241.RussiaMineral processing ** in Russian

Abstract: The article presents new test results on structural and chemical properties of mineral formations on the surface of natural hydrophilic diamonds using Raman, X-ray phase and Auger spectroscopy methods. Analysis of morphological features of nano formations involved scanning electron microscope Jeol-5610 and analyzer INCA. Based on the studies into phase composition of diamonds non-recovered in the circuit of kimberlite ore processing, two types of mineral formations are discovered on their surface: microformations as silicate nature globules less than 1 µm in size and silicate nano films more than 5 nm thick. The tests detect also presence of layered talc silicates that make diamond surface hydrophilic.
DS200712-0290
2006
Timofeev, M.Ekimov, E., Sidorov, V., Rakhmaninia, A., Melnik, N., Timofeev, M., Sadykov, R.Synthesis, structure and physical properties of boron doped diamond.Inorganic Materials, Vol. 42, 11, Nov. pp. 1198-1204.TechnologyDiamond mineralogy
DS201705-0819
2015
Timofeev, S.A.Chanturia, V.A., Dvoichenkova, G.P., Kovalchuk, O.E., Timofeev, S.A.Surface composition and role of hydrophillic diamonds in foam seperation.Journal of Mining Science, Vol. 51, 6, pp. 1235-1241.RussiaDiamond morphology

Abstract: The article presents new test results on structural and chemical properties of mineral formations on the surface of natural hydrophilic diamonds using Raman, X-ray phase and Auger spectroscopy methods. Analysis of morphological features of nano formations involved scanning electron microscope Jeol-5610 and analyzer INCA. Based on the studies into phase composition of diamonds non-recovered in the circuit of kimberlite ore processing, two types of mineral formations are discovered on their surface: microformations as silicate nature globules less than 1 µm in size and silicate nano films more than 5 nm thick. The tests detect also presence of layered talc silicates that make diamond surface hydrophilic.
DS2003-1295
2003
Timofeev, V.F.Smelov, A.P., Timofeev, V.F., Zaitsev, A.I.A geodynamic model for the formation of the north Asian craton in the Early8 Ikc Www.venuewest.com/8ikc/program.htm, Session 9, POSTER abstractChina, AsiaTectonics
DS200412-1855
2003
Timofeev, V.F.Smelov, A.P., Timofeev, V.F., Zaitsev, A.I.A geodynamic model for the formation of the north Asian craton in the Early Precambrian.8 IKC Program, Session 9, POSTER abstractChina, AsiaCraton studies Tectonics
DS200712-1002
2007
Timofeev, V.F.Smelov, A.P., Timofeev, V.F.The age of the North Asian cratonic basement: an overview.Gondwana Research, Vol. 12, 3, pp. 279-288.ChinaGeochronology
DS1984-0730
1984
Timofeyev, A.A.Timofeyev, A.A., Ilupin, I.P., Genshaft, I.S.Spatial Distribution of Ilmenites with Different Content Of magnesium in Yakutian Kimberlites.Doklady Academy of Sciences AKAD. NAUK SSSR., Vol. 278, No. 2, PP. 461-464.RussiaBlank
DS1984-0731
1984
Timofeyev, A.A.Timofeyev, A.A., Ilupin, I.P., Genshaft, Y.S.Spatial distribution of ilmenites with varying amounts of manganese in kimberlites from Yakutia.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR (Russian), Vol. 278, No. 2, pp. 461-464RussiaPetrology, Ilmenite
DS1984-0732
1984
Timofeyev, A.A.Timofeyev, A.A., Muzis, V.A.Consolidated Alluvial Sand Sampling While Prospecting for Kimberlite Bodies.Razved. Okhr. Nedr., No. 1, JANUARY PP. 28-30.RussiaProspecting, Sampling
DS1981-0437
1981
Timoshenko, I.L.Yelyanov, M.D., Timoshenko, I.L., Shevchenko, B.YE.The Weathering Mantle Section of CarbonatitesGeol. Zhurn., Vol. 41, No. 3, PP. 69-77.RussiaGeomorphology
DS200512-1089
2004
Timpa, S.A.Timpa, S.A., Rudnick, R.L.The dynamics of Archean lithosphere in northern Tanzania.Geological Society of America Annual Meeting ABSTRACTS, Nov. 7-10, Paper 57-2, Vol. 36, 5, p. 146.Africa, TanzaniaMozambique Belt, xenoliths, geochronology
DS1990-1465
1990
Tin Hlaing, U.Tin Hlaing, U.Myanmar diamonds from north to southThe Australian Gemologist, Vol. 17, No. 7, August p. 278GlobalNews item, Brief overview diamonds found
DS1987-0469
1987
Tindle, A.Menzies, M.A., Rogers, N., Tindle, A., Hawkesworth, C.J.Metasomatic and enrichment processes in lithospheric peridotites, an effectof asthenosphere-lithosphere interactionIn: Mantle Metasomatism, edited M.A. Menzies, C.J. Hawkesworth, Academic, pp. 313-364GlobalBlank
DS1992-1384
1992
Tindle, A.G.Sheraton, J.W., Black, L.P., Tindle, A.G.Petrogenesis of plutonic rocks in a Proterozoic granulite-facies terrane-the Bunger Hills, East AntarcticaChemical Geology, Vol. 97, No. 3-4, June 25, pp. 163-198AntarcticaBunger Hills
DS1991-1731
1991
Ting, W.Ting, W., Woolley, A.R.Fluid inclusion studies in apatite from Sukulu carbonatite complexes of East UgAnd a - a preliminary reportEuropean Current Research Fluid Inclusions, Firenze, Italy April 10-12, Abstracts, ECROFI XI, p. 221UgandaCarbonatite, Fluid inclusions
DS1994-1780
1994
Ting, W.Ting, W.A fluid inclusion study of the Sukulu carbonatite complex, UgandaPh.D. Thesis, Kingston Upon Thames University of, UgandaCarbonatite, Deposit -Sukulu
DS1994-1781
1994
Ting, W.Ting, W., Burke, E.A.J., Rankin, A.H., Woolley, A.R.The characterization and petrogenetic significance of CO2, H2O and CH4fluid inclusions in apatite SukuluEuropean Journal of Mineralogy, No. 6, pp. 787-804.UgandaCarbonatite, Deposit -Sukulu
DS1994-1782
1994
Ting, W.Ting, W., Rankin, A.H., Woolley, A.R.Petrogenetic significance of solid carbonate inclusions in apatite of the Sukulu carbonatite, Uganda.Lithos, Vol. 31, No. 3-4, January pp. 177-188.UgandaCarbonatite, Apatite, Deposit -Sukulu
DS1989-1500
1989
Tingey, D.G.Tingey, D.G.Late Oligocene and Miocene minette and olivine nephelinite dikes WasatchPlateau, Utah.Msc. Thesis Brigham Young University, 75p.UtahMinettes, Nephelinite dikes
DS1990-1466
1990
Tingey, D.G.Tingey, D.G., Christiansen, E.H., Best, M.G.Late Oligocene and Micocene minette and olivinene phelinite dikes, Wasatch Plateau, UtahGeological Society of America (GSA) Abstracts with programs, Cordilleran, Vol. 22, No. 3, p. 88UtahMinette
DS1991-1732
1991
Tingey, D.G.Tingey, D.G., Christansen, E.H., Best, M.G., Ruiz, J., Lux, D.R.Tertiary minette and melanephelinite dikes, Wasatch Plateau, Utah: recordsof mantle heterogeneities and changing tectonicsJournal of Geophysical Research, Vol. 96, No. B8, July 30, pp. 13, 529-13, 544UtahMinette, Melanephelinite
DS1992-1555
1992
Tingey, R.J.Tingey, R.J.The geology of AntarcticaOxford University Press, 704pAntarcticaStratigraphy, Book -ad
DS1986-0806
1986
Tingle, T.N.Tingle, T.N., Green, H.W., Finnerty, A.A.The solubility and diffusivity of carbon in olivine:implications for carbon in the earth's upper mantleProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, pp. 349-351New MexicoSan Carlos
DS1987-0741
1987
Tingle, T.N.Tingle, T.N., Green, H.W.II.Carbon solubility in olivine: implications for upper mantle evolutionGeology, Vol. 15, No. 4, April pp. 324-326GlobalMantle genesis, Carbon
DS1988-0698
1988
Tingle, T.N.Tingle, T.N., Green, H.W., Finnerty, A.A.Experiments and observations bearing on the solubility and diffusivity of carbon in olivine #1Journal of Geophysical Research, Vol. 93, No. B12, December 10, pp. 15, 289- 15, 304GlobalOlivine, Experimental petrology
DS1989-1501
1989
Tingle, T.N.Tingle, T.N., Green, H.W., Finnerty, A.A.Experiments and observations bearing on the solubility and diffusivity of carbon in olivine #2Geological Society of Australia Inc. Blackwell Scientific Publishing, No. 14, Vol. 2, pp. 922-934GlobalRequested not to be cited, Included for citation onl
DS1989-1502
1989
Tingle, T.N.Tingle, T.N., Mathez, E.A., Becker, C.H.Constraints on the origin of organic compounds on crack surfaces in mantlexenolithsEos, Vol. 70, No. 43, October 24, p. 1411. AbstractNew MexicoSan Carlos, Xenoliths
DS1990-1467
1990
Tingle, T.N.Tingle, T.N., Hochella, M.F., Becker, C.H.Reduced carbon in basalts and mantle xenolithsEos, Vol. 71, No. 17, April 24, p. 644 Abstract onlyGlobalBasalts, mantle xenoliths, Geochronology -carbon
DS1991-0799
1991
Tingle, T.N.Jin, Z.M, Green, H.W. II, Borch, R.S., Tingle, T.N.Unusual spinel garnet lherzolite xenoliths from basalts in eastern China:constraints on the late Tertiary thermal structure of the upper mantleProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 212-213ChinaLherzolite xenoliths -analyses, Geochemistry
DS1991-1733
1991
Tingle, T.N.Tingle, T.N., Hochela, M.F.Jr.Organic matter in basalts and mantle xenolithsGeological Society of America Annual Meeting Abstract Volume, Vol. 23, No. 5, San Diego, p. A 19GlobalMagma, Bioorganics
DS1991-1734
1991
Tingle, T.N.Tingle, T.N., Hochella, M.F.Jr.Reduced carbonaceous matter in basalts and mantle xenolithsProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 432-434Hawaii, Arizona, Mid-Atlantic Ridge, South Africa, MontanaOrganic matter, Geochronology -isotopes
DS1991-1735
1991
Tingle, T.N.Tingle, T.N., Mathez, E.A., Hochella, M.F.Jr.Carbonaceous matter in peridotites and basalts studied by XPS, SALI, SOURCE[ Geochimica et Cosmochimica ActaGeochimica et Cosmochimica Acta, Vol. 55, pp. 1345-1352South AfricaKimberlite -Jagersfontein, Spectroscopy
DS1992-1739
1992
Tingle, T.N.Zhen-Ming Jin, Green, H.W., Borch, R.S., Shu-Yan Jin, Tingle, T.N.Rare garnet and spinel garnet peridotite xenoliths -token of a modern back-arc geotherm beneath eastern ChinaInternational Symposium Cenozoic Volcanic Rocks Deep seated xenoliths China and its, Abstracts pp. 67-68ChinaXenoliths, Peridotite
DS1998-1466
1998
Tingle, T.N.Tingle, T.N.Accretion and differentiation of carbon in the Early EarthChemical Geology, Vol. 147, No. 1-2, May 15, pp. 3-10.MantleCarbon
DS1990-1468
1990
Tingley, H.V.S.Tingley, H.V.S.Using business due diligence to help evaluate minerals depositsMining Engineering, Vol. 42, No. 1, January pp. 35-36GlobalEconomics, Due diligence
DS1920-0172
1923
Tingley, R.H.Tingley, R.H.The Diamond Industry. a Survey of the World's Progress in The Mining and in the Use of Diamonds As Gems and in Industry.Comp. Air Magazine, Vol. 28, APRIL, PP. 459-462.GlobalMining Engineering
DS200512-0367
2005
Tinguely, C.Gregoire, M., Tinguely, C., Bell, D.R., Le Roex, A.P.Spinel lherzolite xenoliths from the Premier kimberlite ( Kaapvaal craton) South Africa: nature and evolution of the shallow upper mantle beneath Bushveld Complex.Lithos, Vol. 84, 3-4, Oct. pp. 185-205.Africa, South AfricaPetrology - Premier, melting, metasomatism
DS202008-1413
2020
Tinguely, C.Le Roex, A., Tinguely, C., Gregoire, M.Eclogite and garnet pyroxenite xenoliths from kimberlites emplaced along the southern margin of the Kaapvaal craton, southern Africa: mantle or lower crustal fragments?Journal of Petrology, https://doi.org/ 10.1093/petrology /egaa040 50p. PdfAfrica, South Africakimberlites

Abstract: Eclogite xenoliths, together with garnet pyroxenites and some mafic garnet granulites, found in kimberlites located along the southern margin of the Kaapvaal craton in southern Africa have been analysed by electron microprobe and mass spectrometry techniques to determine their geochemical characteristics. The majority of eclogites are bimineralic with garnet and omphacitic clinopyroxene in subequal proportions, with rutile as the main accessory phase; a few contain kyanite. Based on K2O in clinopyroxene and Na2O in garnet, the eclogites can be classified as Group II eclogites, and the majority are high-Ca in character. Garnet pyroxenites comprise garnet clinopyroxenites and garnet websterites. Major and trace element concentrations and isotope ratios of reconstituted bulk rock compositions of the eclogites and garnet pyroxenites allow constraints to be placed on depth of origin and likely protolith history. Calculated Fe–Mg exchange equilibration temperatures for the eclogites range from 815 to 1000?°C, at pressures of 1·7?±?0·4?GPa as determined by REE partitioning, indicating that they were sampled from depths of 50–55?km; i.e. within the lower crust of the Namaqua–Natal Belt. The garnet pyroxenites show slightly lower temperatures (686–835?°C) at similar pressures of equilibration. Initial 143Nd/144Nd and 87Sr/86Sr ratios (calculated to time of kimberlite emplacement) of both lithologies overlap the field for lower crustal samples from the Namaqua–Natal Belt. Further evidence for a crustal origin is found in the similar REE patterns shown by many of the associated garnet granulite xenoliths. Garnet pyroxenites are interpreted to have a similar origin as the associated eclogites but with the mafic protolith having insufficient Na (i.e. low modal plagioclase) to allow for development of omphacitic pyroxene. Metamorphism of the mafic protoliths to these eclogites and garnet pyroxenites is inferred to have occurred during crustal shortening and thickening associated with the collision of the Namaqua–Natal Belt with the Kaapvaal craton at 1–1·2?Ga.
DS202009-1639
2020
Tinguely, C.Le Roex, A., Tinguely, C., Gregoire, M.Eclogite and garnet pyroxenite xenoliths from kimberlites emplaced along the southern margin of the Kaapvaal Craton, southern Africa: mantle or lower crustal fragments?Journal of Petrology, pp. 1-32. pdf.Africa, South Africaeclogite, pyroxenite

Abstract: Eclogite xenoliths, together with garnet pyroxenites and some mafic garnet granulites, found in kimberlites located along the southern margin of the Kaapvaal craton in southern Africa have been analysed by electron microprobe and mass spectrometry techniques to determine their geochemical characteristics. The majority of eclogites are bimineralic with garnet and omphacitic clinopyroxene in subequal proportions, with rutile as the main accessory phase; a few contain kyanite. Based on K2O in clinopyroxene and Na2O in garnet, the eclogites can be classified as Group II eclogites, and the majority are high-Ca in character. Garnet pyroxenites comprise garnet clinopyroxenites and garnet websterites. Major and trace element concentrations and isotope ratios of reconstituted bulk rock compositions of the eclogites and garnet pyroxenites allow constraints to be placed on depth of origin and likely protolith history. Calculated Fe-Mg exchange equilibration temperatures for the eclogites range from 815 to 1000?°C, at pressures of 1•7?±?0•4?GPa as determined by REE partitioning, indicating that they were sampled from depths of 50-55?km; i.e. within the lower crust of the Namaqua-Natal Belt. The garnet pyroxenites show slightly lower temperatures (686-835?°C) at similar pressures of equilibration. Initial 143Nd/144Nd and 87Sr/86Sr ratios (calculated to time of kimberlite emplacement) of both lithologies overlap the field for lower crustal samples from the Namaqua-Natal Belt. Further evidence for a crustal origin is found in the similar REE patterns shown by many of the associated garnet granulite xenoliths. Garnet pyroxenites are interpreted to have a similar origin as the associated eclogites but with the mafic protolith having insufficient Na (i.e. low modal plagioclase) to allow for development of omphacitic pyroxene. Metamorphism of the mafic protoliths to these eclogites and garnet pyroxenites is inferred to have occurred during crustal shortening and thickening associated with the collision of the Namaqua-Natal Belt with the Kaapvaal craton at 1-1•2?Ga.
DS200912-0763
2008
Tinguely, C.E.Tinguely, C.E., Gregoire, M., LeRoex, A.P.Eclogite and pyroxenite xenoliths from off craton kimberlites near the Kaapvaal Craton, South Africa.Comptes Rendus Geoscience, Vol. 340, 12, pp. 811-812.Africa, South AfricaMineral chemistry
DS2002-1596
2002
Tinker, J.Tinker, J., De Wit, M.J., Grotzinger, J.Seismic stratigraphic constraints on Neoarchean Paleoproterozoic evolution of the western margin of the Kaapvaal Craton, South Africa.Geological Society of South Africa, Vol. 105, No. 2, pp. 107-34.South AfricaGeophysics - seismics, craton - margin
DS200412-0430
2004
Tinker, J.De Wit, M., Tinker, J.Crustal structure across the central Kaapvaal Craton from deep seismic reflection data.South African Journal of Geology, Vol. 107, 1/2, pp. 185-206.Africa, South AfricaGeophysics - seismics, tectonics, tomography
DS200412-1999
2004
Tinker, J.H.Tinker, J.H., De Wit, M.J., Royden, L.H.Old, strong continental lithosphere with weak Archean margin at 1.8 Ga, Kaapvaal Craton, South Africa.South African Journal of Geology, Vol. 107, 1/2, pp. 255-260.Africa, South AfricaGeochronology
DS1996-1432
1996
Tinker, M.A.Tinker, M.A., Wallace, T.C., et al.Geometry and state of stress of the Nazca plate beneath Bolivia and its implication for evolution of OroclineGeology, Vol. 24, No. 5, May, pp. 387-390BoliviaTectonics, Nazca plate
DS1997-0738
1997
Tinkham, D.Marshak, S., Tinkham, D., et al.Dome and keel provinces formed during Paleoproterozoic orogenic collapse -core complexes, diapirs ???Geology, Vol. 25, No. 5, May pp. 415-418Brazil, Quadrilatero FerriferoPenokean Orogen, Tectonics
DS1995-1913
1995
Tinsley, C.R.Tinsley, C.R.Boy, do I have a valuation for youAmerican Institute of Mining, Metallurgical, and Petroleum Engineers (AIME) Preprint, No. 95-149, 4pGlobalEconomics, Ore reserves
DS200712-0980
2006
Tiping, D.Shihong, T., Tiping, D., Jingwen, M., Yanhe, L., Zhongxin, Y.S, C, O, H isotope dat a and noble gas studies of the Maoniuping LREE deposit, Sichuan Province, China: a mantle connection for mineralization.Acta Geologica Sinica, Vol. 80, 4, pp. 540-549.ChinaAlkaline rocks, rare earths, carbonatite
DS1980-0226
1980
Tipnis, R.S.Mcarthur, M.L., Tipnis, R.S., Godwin, C.I.Early and Middle Ordovician Conodont Fauna from the Mountain Diatreme, Northern Mackenzie Mountains, District of Mackenzie.Geological Survey of Canada (GSC) PAPER., No. 80-1A, PP. 363-368.Canada, Northwest TerritoriesPaleontology
DS1991-1736
1991
Tipper, J.C.Tipper, J.C.A prototype general purpose dynamic visualization systemGeobyte, Vol. 6, No. 3, June pp. 11-15GlobalComputers, Program -images
DS1985-0672
1985
Tippett, C.R.Tippett, C.R.Glacial dispersal train of Paleozoic erratics central Baffin Island, northwest Territories.C.Canadian Journal of Earth Sciences, Vol. 22, pp. 1818-26.Northwest Territories, Baffin IslandGeomorphology, Glacial
DS1985-0673
1985
Tippett, C.R.Tippett, C.R.Glacial Dispersion Train of Paleozoic Erraticsm Central Baffin IslandCanadian Journal of Earth Sciences, Vol. 22, pp. 1818-26.Northwest Territories, Baffin IslandGeomorphology, Glacial
DS1960-1040
1968
Tippin, R.B.Tippin, R.B., Tveter, E.C.Heavy Liquid Recovery Systems in Mineral BeneficiationTransactions American Institute of Mining, Metallurgical, and Petroleum Engineers (AIME), Vol. 241, pp. 15-21.GlobalMineral Recovery, Hsl
DS201312-0915
2013
Tirel, C.Tirel, C., Brun, J-P, Burov, E., Wortel, M.J.R., Lebedev, S.A plate tectonics oddity: caterpillar walk exhumation of subducted continental crust.Geology, Vol. 41, 5, pp. 555-558.MantleSubduction
DS201901-0010
2018
Tirel, C.Brun, J-P., Sokoutis, D., Tirel, C., Gueydan, F., Beslier, M-O.Crustal versus mantle core complexes.Tectonophysics, Vol. 746, pp. 22-45.Mantlegeodynamics

Abstract: Deep crustal and mantle rocks are exhumed in core complex mode of extension in three types of structures: metamorphic core complexes, oceanic core complexes and magma poor passive margins. Using available analogue and numerical models and their comparison with natural examples, the present paper reviews the mechanical processes involved in these different types of extensional setting. Three main aspects are considered: i) the primary role of lithosphere rheology, ii) the lithosphere-scale patterns of progressive deformation that lead to the exhumation of deep metamorphic or mantle rocks and iii) the initiation and development of detachment zones. Crustal core complexes develop in continental lithospheres whose Moho temperature is higher than 750 °C with “upper crust-dominated” strength profiles. Contrary to what is commonly believed, it is argued from analogue and numerical models that detachments that accommodate exhumation of core complexes do not initiate at the onset of extension but in the course of progressive extension when the exhuming ductile crust reaches the surface. In models, convex upward detachments result from a rolling hinge process. Mantle core complexes develop in either the oceanic lithosphere, at slow and ultra-slow spreading ridges, or in continental lithospheres, whose initial Moho temperature is lower than 750 °C, with “sub-Moho mantle-dominated” strength profiles. It is argued that the mechanism of mantle exhumation at passive margins is a nearly symmetrical necking process at lithosphere scale without major and permanent detachment, except if strong strain localization could occur in the lithosphere mantle. Distributed crustal extension, by upper crust faulting above a décollement along the ductile crust increases toward the rift axis up to crustal breakup. Mantle rocks exhume in the zone of crustal breakup accommodated by conjugate mantle shear zones that migrate with the rift axis, during increasing extension.
DS200812-1175
2007
Tirmyaev, A.F.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
DS2000-0781
2000
Tirone, M.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
DS200912-0764
2009
Tirose, M.Tirose, M., Ganguly, J., Morgan, J.P.Modeled petrological geodynamics in the Earth's mantle.Geochemistry, Geophysics, Geosystems: G3, Vol. 10, Q04012.MantleThermometry
DS201904-0734
2019
Tisato, N.Faccenda, M., Ferreira, A.M.G., Tisato, N., Lithgow-Bertelloni, C., Stixrude, L., Pennacchioni, G.Extrinsic elastic anisotropy in a compositionally heterogeneous Earth's mantle.Journal of Geophysical Research: Solid Earth, https://doi,org/ 10.1029/2018JB016482Mantleanistropy

Abstract: Several theoretical studies indicate that a substantial fraction of the measured seismic anisotropy could be interpreted as extrinsic anisotropy associated with compositional layering in rocks, reducing the significance of strain-induced intrinsic anisotropy. Here we quantify the potential contribution of grain-scale and rock-scale compositional anisotropy to the observations by (i) combining effective medium theories with realistic estimates of mineral isotropic elastic properties and (ii) measuring velocities of synthetic seismic waves propagating through modeled strain-induced microstructures. It is shown that for typical mantle and oceanic crust subsolidus compositions, rock-scale compositional layering does not generate any substantial extrinsic anisotropy (<1%) because of the limited contrast in isotropic elastic moduli among different rocks. Quasi-laminated structures observed in subducting slabs using P and S wave scattering are often invoked as a source of extrinsic anisotropy, but our calculations show that they only generate minor seismic anisotropy (<0.1-0.2% of Vp and Vs radial anisotropy). More generally, rock-scale compositional layering, when present, cannot be detected with seismic anisotropy studies but mainly with wave scattering. In contrast, when grain-scale layering is present, significant extrinsic anisotropy could exist in vertically limited levels of the mantle such as in a mid-ocean ridge basalt-rich lower transition zone or in the uppermost lower mantle where foliated basalts and pyrolites display up to 2-3% Vp and 3-6% Vs radial anisotropy. Thus, seismic anisotropy observed around the 660-km discontinuity could be possibly related to grain-scale shape-preferred orientation. Extrinsic anisotropy can form also in a compositionally homogeneous mantle, where velocity variations associated with major phase transitions can generate up to 1% of positive radial anisotropy.
DS201112-0360
2011
Tishin, P.Gertner, I., Tishin, P., Vrublevskii, V., Sazonov, A., Zvyagina, E., Kolmakov, Y.Neoproterozoic alkaline igneous rocks, carbonatites and gold deposits of the Yenisei Ridge, central Siberia: evidence of mantle plume activity and late collision...Resource Geology, Vol. 61, 4, pp. 316-343.Russia, SiberiaTectonics - carbonatites
DS200612-0449
2006
Tishin, P.A.Gertner, I.F., Glazunov, O.M., Vrublevskii, V.V., Krasnova, T.S., Tishin, P.A.Geochemical and isotopic constraints for the formation model of the Kingash ultramafic and mafic complex, eastern Sayan ridge, central Siberia.Vladykin: VI International Workshop, held Mirny, Deep seated magmatism, its sources and plumes, pp. 188-206.Russia, SiberiaGeochronology
DS201112-1095
2011
Tishin, P.A.Vrublevskii, V.V., Reverdatto, V.V., Izokh, A.E., Gertner, I.F., Yudin, D.S., Tishin, P.A.Neoproterozoic carbonatite magmatism of the Yenesei Ridge, central Siberia: 40AR39Ar geochronology of the Penchenga rock complex.Doklady Earth Sciences, Vol. 437, 2, pp. 443-448.Russia, SiberiaCarbonatite
DS201904-0765
2018
Tishkina, V.B.Pakhomova, V.A., Fedoseev, D.G., Kultenko, S.Y., Karabtsov, A.A., Tishkina, V.B., Solyanik, V.A., Kamynin, V.A.Synthetic moissanite coated with diamond film imitating rough diamond.Gems & Gemology, Vol. 54, 4, 4p.Russiamoissanite
DS201412-0166
2014
Tissandier, L.Dauphas, N., Roskosz, M., Alp, E.E., Neuville, D.R., Hu, M.Y., Sio, C.K., Tissot, F.L.H., Zhao, J., Tissandier, L., Medard, E., Cordier, C.Magma redox and structural controls on iron isotope variations in Earth's mantle and crust.Earth and Planetary Science Letters, Vol. 398, pp. 127-140.MantleRedox
DS201412-0166
2014
Tissot, F.L.H.Dauphas, N., Roskosz, M., Alp, E.E., Neuville, D.R., Hu, M.Y., Sio, C.K., Tissot, F.L.H., Zhao, J., Tissandier, L., Medard, E., Cordier, C.Magma redox and structural controls on iron isotope variations in Earth's mantle and crust.Earth and Planetary Science Letters, Vol. 398, pp. 127-140.MantleRedox
DS1997-0106
1997
Titaro, D.Bloom, L., Titaro, D.Building confidence in assaysSociety for Mining, Metallurgy and Exploration (SME) Preprint, No. 97-109, 3pGlobalSampling, assaying, Check assays
DS1996-0766
1996
Titayeva, N.A.Kogarko, L.N., Titayeva, N.A.Thorium isotope dat a on the In homogeneity of the mantle sources of alkali magmatism in the Cape Verde Island.Doklady Academy of Sciences, Vol. 342, No. 4, May pp. l52-154.GlobalAlkaline rocks, Mantle magmatism
DS1986-0366
1986
Titchmar, J.Hirsch, P.B., Hutchinson, J.L., Titchmar, J.Voidites in diamond- evidence for a crystalline phase containing nitrogenPhilosophical Magazine, Section A, Vol. 54, No. 2, August pp. L49-L54 ( letterGlobalDiamond morphology
DS2000-0355
2000
TitkovGorshkov, A. Bao, Titkov, Ryabchikov, Magazina, SivtsovComposition of mineral inclusions and formation of polycrystalline diamond aggregates ( Bort) Shengli pipeGeochemistry International, Vol. 38, No. 7, pp. 698-705.ChinaMineralogy - bort, Deposit - Shengli, Shenli
DS2002-0598
2002
TitkovGorshkov, A.I., Titkov, Vinokurov, Ryabchikov, BaoStudy of cubic diamond crystal from a placer in northern Chin a by analytical electron microscopy...Geochemistry International, Vol.40,3,pp.299-305., Vol.40,3,pp.299-305.ChinaDiamond - morphology, neutron activation analysis, Alluvials
DS2002-0599
2002
TitkovGorshkov, A.I., Titkov, Vinokurov, Ryabchikov, BaoStudy of cubic diamond crystal from a placer in northern Chin a by analytical electron microscopy...Geochemistry International, Vol.40,3,pp.299-305., Vol.40,3,pp.299-305.ChinaDiamond - morphology, neutron activation analysis, Alluvials
DS2002-0600
2002
TitkovGorshkov, A.I., Titkov, Vinolurov, Ryabchikov, BaoStudy of a cubic diamond crystal from a placer by analytical electron microscopy neuton activation anal.Gochemistry International, Vol.40, 3, pp.299-305.China, northernAlluvials - diamond morphology
DS1998-1467
1998
Titkov, S.Titkov, S., Gorshkov, Vinokov, Bershov, Solodov, SivtsovCarbonado from Yakutian diamond deposits (Russia): microinclusions, impurities and paragenetic centres.7th International Kimberlite Conference Abstract, pp. 914-6.Russia, YakutiaCarbonado, Deposit - Udachnaya
DS1995-0658
1995
Titkov, S.K.Gorshkov, A.I., Titkov, S.K., Sivtsov, A.V., BershovNative metals chromium, nickel and iron in cryptocrystalline diamonds (Carbonado) fromYakutia.Proceedings of the Sixth International Kimberlite Conference Extended, p. 187.Russia, YakutiaDiamond morphology, Carbonado
DS1990-0519
1990
Titkov, S.V.Garanin, V.K., Titkov, S.V.About etching patterns on diamond crystals from north European part of the USSR (technical note). (Russian)Izv. Akad. Nauk SSS*(in Russian), No. 9, September pp. 110-115RussiaDiamond morphology, Etching patterns
DS1994-1783
1994
Titkov, S.V.Titkov, S.V., Ivanov, A.I., et al.On radiation origin of green volume color of natural diamonds.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 335, No. 4, April pp. 498-502.RussiaDiamond morphology
DS1995-0147
1995
Titkov, S.V.Bershov, L.V., Mineyeva, R.M., Titkov, S.V.Paramagnetic centers in Yakutian diamonds: abundances and associationsGeochemistry International, Vol. 32, No. 12, Dec. pp. 91-103.Russia, YakutiaDiamond morphology, Diamond inclusions
DS1995-1260
1995
Titkov, S.V.Mineeva, R.M., Titkov, S.V., Marfunin, A.S., et al.EPR spectroscopy of Yakutian diamondsProceedings of the Sixth International Kimberlite Conference Abstracts, pp. 389.Russia, YakutiaDiamond morphology, Spectroscopy
DS1995-1265
1995
Titkov, S.V.Mineyeva, R.M., Speranskiy, A.V., Titkov, S.V., Bershov, L.V.A new type of paramagnetic centre based on nickel ions in natural diamondDoklady Academy of Sciences, Vol. 335A, No. 3, Nov., , pp. 143-147.RussiaDiamond morphology, Nickel
DS1995-1914
1995
Titkov, S.V.Titkov, S.V., Ivanov, A.I., et al.Irradiation as the cause of the bulk green color in natural diamondsDoklady Academy of Sciences, Vol. 337, No. 5, Dec., pp. 133-138.GlobalDiamond morphology, Radiation centres
DS1996-0548
1996
Titkov, S.V.Gorshov, A.N., Titkov, S.V., Marfunin, A.S.The first finds of native chromium, nickel and alpha iron in carbonado from the Diamond deposits of Yakutia.Geochemistry International, Vol. 33, No. 1, Jan. 1, pp. 59-63.Russia, YakutiaCarbonado, Native chromium, nickel, iron
DS1998-1284
1998
Titkov, S.V.Saparin, G.V., Obyden, S.K., Titkov, S.V.Use of cathodluminescence scanning electron microscope (SEM) with color TVdisplay for study natural diamonds -7th. Kimberlite Conference abstract, pp. 763-5.Russia, YakutiaDiamond morphology - structure, Luminescence - CL-scanning electron microscope (SEM).
DS1998-1468
1998
Titkov, S.V.Titkov, S.V., Bershov, Scandale, Saparin, ChukichevNickel structural impurities in natural diamonds7th International Kimberlite Conference Abstract, pp. 911-13.Russia, Yakutia, UralsDiamond morphology, Nickel inclusions
DS2001-1160
2001
Titkov, S.V.Titkov, S.V., Gorshkov, Vinokurov, Bershov, SolodovGeochemistry and genesis of carbonado from Yakutian diamond depositsGeochemistry International, Vol. 39, No. 3, pp. 228-36.Russia, YakutiaMicroinclusions, Carbonado
DS2002-1597
2002
Titkov, S.V.Titkov, S.V., Saparin, G.V., Obyden, C.K.A study of the evolution of grwoth sectors in natural diamond crystals using cathodluminescence microscopy.18th. International Mineralogical Association Sept. 1-6, Edinburgh, abstract p.151.RussiaDiamond - crystallography
DS2002-1598
2002
Titkov, S.V.Titkov, S.V., Saparin, G.V., Obyden, S.K.Evolution of growth sectors in natural diamond crystals as revealed by cathodluminescence topography.Geology of Ore Deposits, Vol. 44, 5, pp. 350-63.GlobalDiamond morphology
DS200412-0697
2004
Titkov, S.V.Gorshkov, A.I., Bershov, I.V., Titkov, S.V., Vinokurov, S.F.Mineral inclusions and impurities in diamonds from lamproites of the Argyle pipe, West Australia.Geochemistry International, Vol. 41, 12, pp. 1143-1151.AustraliaDeposit - Argyle, mineralogy
DS200412-1317
2004
Titkov, S.V.Mineeva, R.M., Speranskii, A.V., Titkov, S.V., Zhilicheva, O.M., Bershov, L.V., Bogatikov, O.A., KudryavtsevaSpectroscopic and morphological characteristics of diamonds from the Grib kimberlite pipe.Doklady Earth Sciences, Vol. 394, 1, Jan-Feb. pp. 96-99.Russia, Kola Peninsula, ArchangelDiamond morphology, deposit - Grib
DS200412-2000
2004
Titkov, S.V.Titkov, S.V., Gorshkov, A.I., Magazina, L.O., Sivtsov, A.V., Zakharchenko, O.D.Shapeless dark diamonds ( Yakutites) from placers of the Siberian platform and criteria of their impact origin.Geology of Ore Deposits, Vol. 46, 3, pp. 191-201.Russia, SiberiaDiamond morphology
DS200612-0480
2006
Titkov, S.V.Gorshkov, A.I., Titkov, S.V., Bao, Y.N., Ryabchikov, I.D., Magazina, L.O.Micro inclusions in diamonds of octahedral habit from kimberlites of Shandong province, eastern China.Geology of Ore Deposits, Vol. 48, 4, pp. 326-China, ShandongDiamond morphology, inclusions
DS200612-0481
2006
Titkov, S.V.Gorshkov, A.L., Titkov, S.V., Bao, Y.N., Ryabchikov, I.D., Magazina, L.O.Micro inclusions in diamonds of octahedral habit from kimberlites of Shandong Province, eastern China.Geology of Ore Deposits, Vol. 48, 4, pp 326-334.ChinaDiamond crystallography
DS200612-1429
2006
Titkov, S.V.Titkov, S.V., Gorshkov, A.I., Solodova, Ryabchikov, Magazina, Sivtsov, Gasanov, Sedova, SamosorovMineral Micro inclusions in cubic diamonds from the Yakutian deposits based on analytical electron microscopy data.Doklady Earth Sciences, Vol. 410, no. 7 July-August, pp. 1106-1108.Russia, YakutiaDiamond inclusions
DS200712-0728
2007
Titkov, S.V.Mineeva, R.M., Speransky, A.V., Titkov, S.V., Solodova, Y.P., Samosorov, G.G.Paramagnetic N1 centre in plastically deformed and differently colored crystals of natural diamond.Doklady Earth Sciences, Vol. 415, 5, pp. 782-785.TechnologyDiamond morphology
DS200712-1083
2006
Titkov, S.V.Titkov, S.V., Gorshkov, A.I., Zudin, N.G.Micro inclusions in dark gray diamond crystals of octahedral habit from Yakutian kimberlites.Geochemistry International, Vol. 44, 11, pp. 1121-1128.Russia, YakutiaDiamond morphology
DS200712-1084
2006
Titkov, S.V.Titkov, S.V., Solodova, Y.P., Gorshkov, A.I., Magaina, L.O., Sivtsov, A.V., Sedova, E.A., Gasanov, SamosorovInclusions in white gray diamonds of cubic habit from Siberia.Gems & Gemology, 4th International Symposium abstracts, Fall 2006, p.127-8. abstract onlyRussiaDiamond morphology
DS200812-1176
2008
Titkov, S.V.Titkov, S.V., Shigley, J.E., Breeding, C.M., Mineeva, R.M., Zudin, N.G., Sergeev, A.M.Natural color purple diamonds from Siberia. Mir field.Gems & Gemology, Vol. 44, 1, spring pp. 56-64.Russia, SiberiaDiamond - purple
DS200912-0501
2009
Titkov, S.V.Mineeva, R.M., Titkov, S.V., Speransky, A.V.Structural defects in natural plastically deformed diamonds: evidence from EPR spectroscopy.Geology of Ore Deposits, Vol. 51, 3, pp. 233-242.Russia, UralsSpectroscopy
DS201112-1049
2011
Titkov, S.V.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
DS201212-0731
2012
Titkov, S.V.Titkov, S.V., Krivovichev, S.V., Organova, N.I.Plastic deformation of natural diamonds by twinning: evidence from x-ray diffraction studies.Mineralogical Magazine, Vol. 76, 1, pp. 143-149.TechnologyDiamond morphology
DS201412-0932
2015
Titkov, S.V.Titkov, S.V., Mineeva, R.M., Zudina, N.N., Sergeev, A.M., Ryabchikov, I.D., Shiryaev, A.A., Speransky, A.V., Zhikhareva, V.P.The luminescent nature of orange coloration in natural diamonds: optical and EPR study.Physics and Chemistry of Minerals, Vol. 42, 2, pp. 131-141.TechnologyDiamond - spectroscopy
DS201502-0114
2015
Titkov, S.V.Titkov, S.V., Shiryaev, A.A., Zudina, N.N., Zudin, N.G., Solodova, Yu.P.Defects in cubic diamonds from the placers in the northeastern Siberian platform: results of IR microspectrometry.Russian Geology and Geophysics, Vol. 56, 1, pp. 354-365.RussiaDiamond morphology
DS201503-0180
2015
Titkov, S.V.Titkov, S.V., Mineeva, R.M., Zudina, N.N., Sergeev, A.M., Ryabchikov, I.D., Shiryaev, A.A., Speransky, A.V., Zhikhareva, V.P.The luminescent nature of orange coloration in natural diamonds: optical and EPR study.Physics and Chemistry of Minerals, Vol. 42, 2, pp. 131-144.TechnologyDiamond Colour
DS201608-1444
2016
Titkov, S.V.Titkov, S.V., Mineeva, R.M., Ryabchikov, I.D., Speransky, A.V.Sites of N1 nitrogen paramagnetic centers in natural diamond crystals: disssymmetrization of the structure as a result of plastic deformation.Doklady Earth Sciences, Vol. 468, 1., pp. 500-502.RussiaMorphology - brown diamonds
DS201801-0054
2017
Titkov, S.V.Reutsky, V.N., Shiryaev, A.A., Titkov, S.V., Wiedenbeck, M., Zudina, N.N.Evidence for large scale fractionation of carbon isotopes and of nitrogen impurity during crystallization of gem quality cubic diamonds from placers of North Yakutia.Geochemistry International, Vol. 55, 11, pp. 988-999.Russia, Yakutiaalluvials

Abstract: The spatial distribution of carbon and nitrogen isotopes and of nitrogen concentrations is studied in detail in three gem quality cubic diamonds of variety II according to Orlov’s classification. Combined with the data on composition of fluid inclusions our results point to the crystallization of the diamonds from a presumably oxidized carbonate fluid. It is shown that in the growth direction d13C of the diamond becomes systematically lighter by 2-3‰ (from -13.7 to -15.6‰ for one profile and from -11.7 to -14.1‰ for a second profile). Simultaneously, we observe substantial decrease in the nitrogen concentration (from 400-1000 to 10-30 at ppm) and a previously unrecognized enrichment of nitrogen in light isotope, exceeding 30‰. The systematic and substantial changes of the chemical and isotopic composition can be explained using the Burton-Prim-Slichter model, which relates partition coefficients of an impurity with the crystal growth rate. It is shown that changes in effective partition coefficients due to a gradual decrease in crystal growth rate describes fairly well the observed scale of the chemical and isotopic variations if the diamond-fluid partition coefficient for nitrogen is significantly smaller than unity. This model shows that nitrogen isotopic composition in diamond may result from isotopic fractionation during growth and not reflect isotopic composition of the mantle fluid. Furthermore, it is shown that the infra-red absorption at 1332 ?m-1 is an integral part of the Y-defect spectrum. In the studied natural diamonds the 1290 ?m-1 IR absorption band does not correlate with boron concentration.
DS1995-0660
1995
Titkov. S.V.Gorshov, A.I., Titkov. S.V., Pleshakov, A.M., et al.Inclusions of native metals and other mineral phases into carbonado From the Ubnagi region (Central Africa).Geology of Ore Deposits, Vol. 38, No. 2, pp. 131-136.Central African RepublicCarbonado, Mineralogy, microscopy, Ubangi area
DS201910-2298
2019
Titlov, S.V.Shiryaev, A.A., Kaminisky, F.V., Ludwig, W., Zolotov, D.A., Buzmakov, A.V., Titlov, S.V.Texture and genesis of polycrystalline varieties of diamond based on phase-contrast and diffraction contrast tomography.Geochemistry International, Vol. 57, 9, pp. 1015-1023.South America, Brazil, Africa, Central African Republic, Russiacarbonado

Abstract: Structural peculiarities of several types of cryptocrystalline diamond varieties: carbonado, impact-related yakutite and cryptocrystalline diamond aggregates from kimberlite were studied using Infrared spectroscopy, X-ray diffraction contrast (DCT—Diffraction Contrast Tomography) and phase contrast tomography (PCT). It is shown that the porosity of the carbonado and kimberlitic cryptocrystalline aggregates is similar being in range of 5-10 vol %, possibly indicating similar formation mechanism(s), whereas that of yakutite is essentially zero. Crystallographic texture is observed for some carbonado samples. It is suggested that at least partially the texture is explained by deformation-related bands. Infrared spectroscopy reveals presence of hydrous and, probably, of hydrocarbon species in carbonado.
DS200812-0002
2008
Titov, A.T.Afanasev, V.P., Nikolenko, E.I., Tychikov, N.S., Titov, A.T., Tolstov, A.V., Kornilova, V.P., Sobolev, N.V.Mechanical abrasion of kimberlite indicator minerals: experimental investigations.Russian Geology and Geophysics, Vol. 49, 2, pp. 91-97.TechnologyMineralogy
DS200812-0432
2008
Titov, A.T.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
DS1994-1784
1994
Titov, A.V.Titov, A.V., Vladimirov, A.G., Chupin, V.P., Mayorova, O.Evolution and crystallization conditions of shoshonite and latite melts Kyzylrabat volcanic structure, Pamirs.Doklady Academy of Science USSR, Earth Science Section, Vol. 328, No. 1, Nov. pp. 103-107.Russia, PamirShoshonite, Alkaline rocks
DS1996-1433
1996
Titov, K.Titov, K.Methodes magnetiques, electriques et electromagnetiques pour la prospectiondes kimberlites.Chron. de la Recherche Miniere, No. 522, pp. 3-9.GlobalGeophysics, Kimberlite prospecting
DS1994-1785
1994
Titov, K.V.Titov, K.V.Electrical and electromagnetic methods in exploration of kimberlite pipe son the Baltic shield.10th. Prospecting In Areas Of Glaciated Terrain, p. 186-187. AbstractRussia, Baltic shieldGeophysics -Electromagnetic, Exploration prospecting
DS2002-0492
2002
Tittgemeyer, M.Fuchs, K., Tittgemeyer, M., Ryberg, T., Wenzel, F., Mooney, W.Global significance of a Sub-Moho boundary layer (SMBL) deduced from high resolution seismic observations.International Geology Review, Vol. 44, 8, pp. 671-85.MantleGeophysics - seismics
DS202011-2067
2020
Titus, N.White-Gaynor, A.L., Nyblade, A.A., Durrheim, R., Raveloson, R., van der Meijde, M., Fadel, I., Paulssen, H., Kwadiba, M., Ntibinyane, O., Titus, N., Sitali, M.Lithospheric boundaries and upper mantle structure beneath southern Africa imaged by P and S wave velocity models.Geochemistry, Geophysics, Geosystems, 10.1029/GC008925 20p. PdfAfrica, South AfricaGeophysics, seismic

Abstract: We report new P and S wave velocity models of the upper mantle beneath southern Africa using data recorded on seismic stations spanning the entire subcontinent. Beneath most of the Damara Belt, including the Okavango Rift, our models show lower than average velocities (-0.8% Vp; -1.2% Vs) with an abrupt increase in velocities along the terrane's southern margin. We attribute the lower than average velocities to thinner lithosphere (~130 km thick) compared to thicker lithosphere (~200 km thick) immediately to the south under the Kalahari Craton. Beneath the Etendeka Flood Basalt Province, higher than average velocities (0.25% Vp; 0.75% Vs) indicate thicker and/or compositionally distinct lithosphere compared to other parts of the Damara Belt. In the Rehoboth Province, higher than average velocities (0.3% Vp; 0.5% Vs) suggest the presence of a microcraton, as do higher than average velocities (1.0% Vp; 1.5% Vs) under the Southern Irumide Belt. Lower than average velocities (-0.4% Vp; -0.7% Vs) beneath the Bushveld Complex and parts of the Mgondi and Okwa terranes are consistent with previous studies, which attributed them to compositionally modified lithosphere resulting from Precambrian magmatic events. There is little evidence for thermally modified upper mantle beneath any of these terranes which could provide a source of uplift for the Southern African Plateau. In contrast, beneath parts of the Irumide Belt in southern and central Zambia and the Mozambique Belt in central Mozambique, deep-seated low velocity anomalies (-0.7% Vp; -0.8% Vs) can be attributed to upper mantle extensions of the African superplume structure.
DS1990-1469
1990
Tiulenev, A.E.Tiulenev, A.E.Structural kimberlite controling carcass of the Siberian and China-KoreaPlatformInternational Mineralogical Association Meeting Held June, 1990 Beijing China, Vol. 1, extended abstract p. 105Russia, ChinaStructure, Lineaments
DS1988-0263
1988
Tiunov, A.A.Gorokhov, N.P., Tiunov, A.A., Kistanova, T.I., Sorokina, V.D.Use of phosphates in the flotation of pyrochlorefromcarbonatitepipes.(Russian)Tsvetn. Met. (Moscow), (Russian), No. 12, pp. 87-88RussiaCarbonatite, Mineral processing applic
DS1998-0365
1998
TiunovaDruzhinin, V.S., Karetin, Avtoneev, Gavrilova, TiunovaThe main structures of the crust and upper mantle of the Ural regionDoklady Academy of Sciences, Vol. 360, No. 4, pp. 597-601.Russia, UralsTectonics
DS200712-1085
2006
Tiwari, P.K.Tiwari, P.K., Surve, G., Mohan, G.Crustal complaints on the uplift mechanism of the western Gnats of India.Geophysical Journal International, Vol. 167, 3, Dec. 1, pp. 1309-1316.IndiaGeophysics - seismics
DS201012-0715
2010
Tiwari, R.N.Singh, R.K., Tiwari, R.N.Sectoral zoning in natural fluroites from carbonatite rocks of Ambadongar, Gujarat.Journal of the Geological Society of India, Vol. 76, 3, pp.IndiaCarbonatite
DS1984-0396
1984
Tiwari, R.S.Kashyap, S.P., Tiwari, R.S.Diamond Shaping Industry in Surat- Characteristics of Firms by Size- a Review.Econ. Politics, Vol. 19, No. 34, AUGUST 25TH. PP. M99-M103.GlobalDiamond Industry, Cutting
DS1984-0397
1984
Tiwari, R.S.Kashyap, S.P., Tiwari, R.S.Diamond Shaping Industry in SaratEconomic And Political Weekly, PP. M99-M103.IndiaCutting
DS200412-1334
2004
Tiwari, V.M.Mishra, D.C., Arora, K., Tiwari, V.M.Gravity anomalies and associated tectonic features over the Indian Peninsular Shield and adjoining Ocean basins.Tectonophysics, Vol. 379, 1-4, Feb. 13, pp. 61-76.IndiaGeophysics - gravity, crust
DS202005-0730
2020
Tiwari, V.M.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
Tiwari, V.M.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
DS202009-1638
2020
Tiwari, V.M.Kumar, N., Sigh, A.P., Tiwari, V.M.Gravity anomalies, isostasy and density structure of the Indian continental lithosphere.Episodes, Vol. 43, 1, pp. 609-621.Indiageophysics, gravity

Abstract: Gravity anomalies across the Indian region depict most of the geological and tectonic domains of the Indian continental lithosphere, which evolved through Archean cratonic nucleation, Proterozoic accretion, Phanerozoic India-Eurasia plate convergence, and modification through many thermal perturbations and rifting. Integrated analysis of gravity and geoid anomalies together with topographic and heat flow data led to deciphering the mechanism of isostatic compensation of topographic and geological loads, lithospheric structure, and composition. This study discusses the nature of gravity (free-air, Bouguer and Isostatic) and geoid anomalies in relation to the topography, geology, and tectonics, and presents a lithospheric density model across the peninsular India and Himalaya. Southern peninsular Indian region shows relatively low Bouguer gravity anomalies compared to the northern region. The mobile belts are generally observed to have relatively higher Bouguer gravity anomalies, e.g., Eastern Ghats Mobile Belt compared to the shield regions. The gravity lows are observed over topographic features like the Western Ghats and Himalaya, while some of the topographic highs like Aravalli show positive gravity anomaly. The Indian Ocean Geoid Low varies from -82 m over Dharwar Craton to -98 m over the Southern Granulite Terrain and finally reaches a significant low of -106 m in the Indian Ocean. Flexural isostatic compensation with variable Effective Elastic Thickness (EET) ~10 km to 50 km prevails over the stable continental region. The lithospheric thickness varies from 80 km along the coastal region to 120-130 km beneath the Saurashtra Plateau, the Southern Granulite Terrain, and the Eastern Indian Shield, and reaches to more than 200 km under the Himalayan orogenic belt in the north. From Dharwar Craton to Bundelkhand Craton in central India, the lithospheric thickness varies between 160 and 180 km.
DS1986-0807
1986
Tiwary, A.Tiwary, A., Twari, R.N.Petrography and petrogenesis of dikes intruded into the Katrolformation(Upper Jurassic). *HIN.Vijana Parshad Annual Patrika, *IND., Vol. 29, No. 2, April, pp. 131-147IndiaCarbonatite
DS1975-0881
1978
Tixeront, M.Tixeront, M., Lelann, F., Horn, R., Scolari, G.Ilmenite Prospection on the Continental Shelf of Senegal: Methods and Results.Marine Mining, Vol. 1, No. 3, PP. 171-187.GlobalDiamond Mining Recovery, Marine Placers, Alluvials
DS1975-1243
1979
Tixeront, M.Tixeront, M.French Activities in the Exploration for Placers on Continental Shelves.Resources Minerales Sous Marines, Scolari, G. Editor., French Geological Survey (BRGM) No. 7, PP. 167-184.South Africa, Southwest Africa, West Africa, NamibiaDiamond Mining Recovery, Alluvials, Marine Placers
DS1985-0702
1985
Tkach, V.Vishnevskiy, O.A., Kolesnik, Y.M., Vishnevskiy, A.S., Tkach, V.Pyrope with Crystalline Inclusions from Balta Deposits of The Central Bug Region, Dniester River Area.Dop. Akad. Nauk. Ukra. Ser. B., No. 4, PP. 9-14.Russia, UkraineKimberlite, Petrology, Inclusions
DS200712-0538
2007
Tkachenko, V.I.Khudolev, A.K., Kropachev, A.P., Tkachenko, V.I., Rublev, A.G., Sergeev, S.A., Matukov, D.I,LyahnitskayaMesoproterozoic to Neoproterozoic evolution of the Siberian Craton and adjacent microcontinents: an overview with constraints for a Laurentian Connection.SEPM Special Publication 86, pp. 209-226.RussiaCraton
DS200712-0539
2007
Tkachenko, V.I.Khudolev, A.K., Kropachev, A.P., Tkachenko, V.I., Rublev, A.G., Sergeev, S.A., Matukov, D.I,LyahnitskayaMesoproterozoic to Neoproterozoic evolution of the Siberian Craton and adjacent microcontinents: an overview with constraints for a Laurentian Connection.SEPM Special Publication 86, pp. 209-226.RussiaCraton
DS201908-1778
2019
Tkachev, S.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.
DS201602-0238
2015
Tkachev, S.N.Shumilova, T.G., Isaenko, S.I., Tkachev, S.N.Diamond formation through metastable liquid carbon.Diamond and Related Materials, in press availableTechnologyDiamond formation

Abstract: It is known that carbon melts at temperatures around 4000 K or higher, and, therefore, this will be for the first time, when liquid carbon state formation preserved within diamond is documented in a carbon-carbonate system at the PT-conditions around 8.0 GPa and 2000 K, that is essentially far from the carbon diagram liquid field, so the newly reported liquid carbon was formed by neither fusion nor condensation. Based on a preponderance of such a strong circumstantial evidence, as morphological features of globular glass-like carbon inclusions within the globular-textured host diamond crystals resulting from liquid segregation process under synthesis conditions, it is suggested, that the produced carbon state has general properties of liquid and is formed through agglomeration alongside with diffusion process of carbon within carbonate melt solvent, and, thus, can potentially open a novel route for liquid carbon production and manufacturing of advanced high-refractory alloys and high-temperature compounds at lower than commonly accepted standard temperatures. A new model of diamond formation via metastable liquid carbon is presented.
DS201603-0421
2016
Tkachev, S.N.Shumilova, T.G., Isaenko, S.I., Tkachev, S.N.Diamond formation through metastable liquid carbon.Diamond and Related Materials, Vol. 62, pp. 42-48.TechnologyCarbon

Abstract: It is known that carbon melts at temperatures around 4000 K or higher, and, therefore, this will be for the first time, when liquid carbon state formation preserved within diamond is documented in a carbon-carbonate system at the PT-conditions around 8.0 GPa and 2000 K, that is essentially far from the carbon diagram liquid field, so the newly reported liquid carbon was formed by neither fusion nor condensation. Based on a preponderance of such a strong circumstantial evidence, as morphological features of globular glass-like carbon inclusions within the globular-textured host diamond crystals resulting from liquid segregation process under synthesis conditions, it is suggested, that the produced carbon state has general properties of liquid and is formed through agglomeration alongside with diffusion process of carbon within carbonate melt solvent, and, thus, can potentially open a novel route for liquid carbon production and manufacturing of advanced high-refractory alloys and high-temperature compounds at lower than commonly accepted standard temperatures. A new model of diamond formation via metastable liquid carbon is presented.
DS201610-1893
2016
Tkachev, S.N.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.
DS1984-0536
1984
Tkachev, V.D.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
DS1985-0674
1985
Tkachev, V.D.Tkachev, V.D., Zaitsev, A.M., Tkachev, V.V.The Matrix Pressure Effect and Optical Activity of Inert Gases in Diamond.Doklady Academy of Sciences Nauk BSSR., Vol. 29, No. 5, PP. 412-414.RussiaCrystallography
DS1988-0699
1988
Tkachev, V.N.Tkachev, V.N., Iskandarkhodzhayev, T.A., Savitskaya, L.I., ShainThe Almalyk Permian strat a of the Adrasman volcanogenic structure.(Russian)Uzbekiston Geologiya Zhurnal., (Russian), No. 3, pp. 29-34RussiaNative element-diamond, Biostratigraphy
DS1985-0674
1985
Tkachev, V.V.Tkachev, V.D., Zaitsev, A.M., Tkachev, V.V.The Matrix Pressure Effect and Optical Activity of Inert Gases in Diamond.Doklady Academy of Sciences Nauk BSSR., Vol. 29, No. 5, PP. 412-414.RussiaCrystallography
DS2002-1599
2002
Tkalcic, H.Tkalcic, H., Romanowicz, B.Short scale heterogeneity in the lowermost mantle: insights from PcP-P and ScS-S data.Earth and Planetary Science Letters, Vol. 201, 1, July 15, pp. 57-68.MantleGeophysics - seismics
DS200612-0429
2006
Tkalcic, H.Garcia, R., Tkalcic, H., Chevrot, S.A new global PKP dat a set to study Earth's core and deep mantle.Physics of the Earth and Planetary Interiors, Vol. 159, 1-2, pp. 15-31.MantleGeophysics - seismics
DS200812-0555
2008
Tkalcic, H.Kennett, B.L.N., Tkalcic, H.Dynamic Earth: crustal and mantle heterogeneity.Australian Journal of Earth Sciences, Vol. 55, pp. 265-279.MantleGeodynamics, geophysics, seismic tomography
DS201012-0789
2010
Tkalcic, H.Tkalcic, H., Cormier, V.F., Kennett, B.L.N., He, K.Steep reflections from the Earth's core reveal small scale heterogeneity in the upper mantle.Physics of the Earth and Planetary Interiors, Vol. 178, pp. 80-91.MantleGeoiphysics - seismics
DS201312-0487
2013
Tkalcic, H.Kiseeva, E.S., Yaxley, G.M., Stepanov, A.S., Tkalcic, H., Litasov, K.D., Kamenetsky, V.S.Metapyroxenite in the mantle transition zone revealed from majorite inclusions in diamonds.Geology, Vol. 41, 8, pp. 883-886.MantleClassification - comparison majorites
DS201312-0916
2013
Tkalcic, H.Tkalcic, H., Young, M.K., Bodin, T., Ngo, S., Sambridge, M.The shuffling rotation of the Earth's inner core.Nature Geoscience, Vol. 6, pp. 497-502.MantleGeodynamics
DS201412-1011
2013
Tkalcic, H.Young, M.K., Tkalcic, H., Bodin, T., Sambridge, M.Global P wave tomography of Earth's lowermost mantle from partition modeling.Journal of Geophysical Research, Vol. 118, 10, pp. 5467-5486.MantleGeophysics - tomography
DS201502-0115
2015
Tkalcic, H.Tkalcic, H.Complex inner core of the Earth: the last frontier of global seismology.Reviews of Geophysics, Vol. 53, 1, pp. 59-94.MantleGeophysics - seismics
DS201905-1058
2019
Tkalcic, H.Makuuskina, A., Tauzin, B., Tkalcic, H., Thybo, H.The mantle transition zone in Fennoscandia: enigmatic high topography without deep mantle thermal anomaly.Geophysical Research Letters, Vol. 46, 7, pp. 3652-3662.Mantlegeothermometry

Abstract: High mountains in Norway have long puzzled scientists because it is challenging to explain their existence. Numerous explanations have been proposed including processes deep inside the Earth. Our results show that these processes must be located above 410-km depth. This observation is critical for the ongoing debate on the cause of the enigmatic mountains in Scandinavia. New data acquired between 2012 and 2017 by the collaborative ScanArray project between European institutions allow mapping of the mantle transition zone—the deepest layer possibly involved in the mountain support. We show that the mantle transition zone boundaries beneath Fennoscandia are close to reference depths and the zone has a standard thickness. As the depths to these boundaries are sensitive to temperatures, this indicates that the mantle transition zone in this area is unaffected by any ongoing deep process. Therefore, the explanation for the high topography in Norway must be found above the mantle transition zone. This study provides the first map of the mantle transition zone below Fennoscandia, which will be valuable for any further global studies of the mantle transition zone.
DS200912-0334
2009
Tliniemi, J.Janik, T., Kozlovskaya, E., Helikkinen, P., Tliniemi, J.Evidence for preservation of crustal root beneath the Proterozoic Lapland-Kola orogen ( northern Fennoscandian shield) derived from P and S wave models.Journal of Geophysical Research, Vol. 114. B 6, B06308.Europe, Finland, Kola PeninsulaGeophysics - seismics
DS1997-1160
1997
Tllton, G.R.Tllton, G.R., Mateen, A.lead, Strontium, neodymium isotope dat a from 30 and 300 Ma carbonatites in northwest Pakistan.Geological Association of Canada (GAC) Abstracts, PakistanCarbonatite, isotopes
DS1987-0045
1987
TltonBell, K., Blenkinsop, J., Kwon, Tlton, SageAge and radiogenic isotopic systematics of the Border carbonatite complexOntario, canada.Canadian Journal of Earth Sciences, Vol. 24, pp. 24-30.OntarioGeochronology, deposit - Borden
DS200512-1090
2005
Toa, A.Toa, A., Romanaowicza, B., Cap de Villeb, Y., Takeuchic, N.3 D effects of sharp boundaries at the borders of the African and Pacific superplumes: observation and modeling.Earth and Planetary Science Letters, Vol. 233, pp. 137-153.AfricaGeophysics - seismics, boundary
DS1997-1161
1997
Tobin, B.Tobin, B.Newfoundland and Labrador: exploring new frontiers for the next centuryThe Canadian Institute of Mining, Metallurgy and Petroleum (CIM). Bulletin, Vol. 90, No. 1013, Sept. pp. 42-44Newfoundland, LabradorExploration overview
DS1860-0191
1872
Tobin, T.W.Tobin, T.W.Notes from a Diamond Tour through South Africa Vaal RiverSoc. Arts Journal of (London), Vol. 20, PP. 351-354.Africa, South Africa, Cape ProvinceAlluvial placers, History
DS1988-0700
1988
Tobisch, O.T.Tobisch, O.T., Paterson, S.R.Analysis and interpretation of composite foliations in areas of progressivedeformationJournal of Structural Geology, Vol. 10, No. 7, pp. 745-754GlobalStructure, Deformation
DS2002-1600
2002
Tobler, J.Tobler, J.Black carbon bright fire.... story about Harry Winston and commentary by Ronald Winston.Nuvo, Spring, Pp. 45,47,48,50., Spring, pp. 45,47,48,50.GlobalHistory - profile Winston
DS2002-1601
2002
Tobler, J.Tobler, J.Black carbon bright fire.... story about Harry Winston and commentary by Ronald Winston.Nuvo, Spring, Pp. 45,47,48,50., Spring, pp. 45,47,48,50.GlobalHistory - profile Winston
DS2001-0482
2001
Tobsachall, H.J.Hoch, M., Rehkamper, M., Tobsachall, H.J.Strontium, neodymium, lead, Oxygen isotopes of minettes from Schirmacher Oasis: a case of mantle me tasomatism involving subduction....Journal of Petrology, Vol. 42, No. 7, July pp. 1387-1400.GlobalContinental material - subduction, Minettes
DS2002-1602
2002
Tocher, S.N.Tocher, S.N., McDonald, J.Geological report for Alberta diamond property Grande Cache areaMineral Assesment Files, Alberta Geological Survey, www.ags.gov.ab.ca, MIN 0106AlbertaAssessment - Grande Cache area
DS1996-0722
1996
Tod, J.Keating, P., Tod, J., Dumont, R.The National aeromagnetic databaseGeological Survey of Canada, LeCheminant ed, OF 3228, pp. 229-232.CanadaGeophysics -aeromagnetics
DS1990-0915
1990
Todd, D.Lei, Z., Todd, D.The development of China's mining industry and its relevance to the worldmarketCrs Perspectives, No. 33, July pp. 8-10ChinaEconomics, Markets
DS1994-1786
1994
Todd, D.Todd, D., Zhang LeiRegional policy ground in minerals exploitation. A Chinese exampleResources Policy, Vol. 20, No. 1, March pp. 5-14ChinaEconomics, Mineral development
DS200612-0460
2006
Todd, E.Gill, J.B., Tollstrup, D., Todd, E.Hf mobility and immobility in subduction zones.Geochimica et Cosmochimica Acta, Vol. 70, 18, 1, p. 17, abstract only.MantleSubduction
DS2001-0911
2001
Todd, J.Peterson, J., Todd, J.Wall control blasting practices at the Ekati diamond mineThe Canadian Mining and Metallurgical Bulletin (CIM Bulletin) ., Vol. 94, No. 1050, May pp. 67-73.Northwest TerritoriesMining, blasting, Deposit - Ekati
DS200612-0892
2006
Todd, J.McElroy, R., Nowicki, T., Dyck, D., Carlson, J., Todd, J., Roebuck, S., Crawford, B., Harrison, S.The geology of the PAnd a kimberlite Ekati mine, Canada.Emplacement Workshop held September, 5p. extended abstractCanada, Northwest TerritoriesDeposit - Panda geology
DS2003-0911
2003
Todd, J.K.McElroy, R.E., Nowicki, T.E., Dyck, D.R., Carlson, J.A., Todd, J.K., RoebuckThe geology of the PAnd a kimberlite, Ekati diamond mine, Canada8ikc, Www.venuewest.com/8ikc/program.htm, Session 1 POSTER abstractNorthwest TerritoriesKimberlite geology and economics, Deposit - Panda
DS1860-0526
1886
Todd, S.B.Todd, S.B.The South African Diamond Fields (1886) #1Rev. Colon. International (amsterdam), PP. 257-271.Africa, South AfricaHistory, Travelogue
DS1989-1136
1989
Todd, S.P.North, C.P., Todd, S.P., Turner, J.P.Alluvial fans and their tectonic controlsJournal of the Geological Society of London, Vol. 146, pt. 3, May pp. 507-508. Database # 17881GlobalOverview, Alluvial fans
DS1998-1336
1998
Todd, S.W.Shields, D.J., Todd, S.W.Using logistic regression to merge mineral reserve databasesNonrenewable Resources, Vol. 7, No. 1, pp. 53-61GlobalGeostatistics, ore reserves, GIS, models, deposits
DS1997-1070
1997
Todd, V.R.Snoke, A.W., Tullis, J., Todd, V.R.Princeton atlas of fault related rocksPrinceton University of Press, $ 125.00 see date 1998 availabilityGlobalBook - ad, Atlas - Fault related rocks
DS1994-1787
1994
Todd, W.Todd, W.A new method of blind hole boring in a mining environmentAmerican Institute of Mining, Metallurgical, and Petroleum Engineers (AIME) Preprint, Meeting held Albuquerque Feb. 14-17th, No. 94-81, 4pGlobalMining equipment
DS1995-1496
1995
Todeschuck, J.Pilkington, M., Todeschuck, J.Magnetic field statistics: comparison of continental and oceanic crustEos, Vol. 76, No. 46, Nov. 7. p.F174. Abstract.Mantle, crustGeophysics -magnetics
DS1992-1556
1992
Todeschuck, J.P.Todeschuck, J.P., et al.If geology is fractal, what do we do next?Geophysics: the leading edge of exploration, Vol. 11, No. 10, October pp. 29-35GlobalFractal, Scaling noises
DS1993-1240
1993
Todoeschuck, J.P.Pilkington, M., Todoeschuck, J.P.Fractal magnetization of continental crustGeophysical Research Letters, Vol. 20, No. 7, April 9, pp. 627-630.MantleGeophysics
DS1988-0381
1988
Todt, W.Kroner, A., Todt, W.Single zircon dating constraining the maximum age of theBarberton greenstone belt, Southern AfricaJournal of Geophysical Research, Vol. 93, No. B12, Dec. 10, pp. 15, 329-15, 338South AfricaGeochronology, Barberton Greenstone Belt
DS200512-0864
2005
Todt, W.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
Todt, W.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)
DS200612-1427
2006
Todt, W.Tichomirowa, M., Grosche, G., Gotze, J., Belyatsky, B.V., Savva, E.V., Keller, J., Todt, W.The mineral isotope composition of two Precambrian carbonatite complexes from the Kola Alkaline Province - alteration versus primary magmatic signatures.Lithos, In press available,Russia, Kola PeninsulaCarbonatite, geochronology, Tiksheozero, Siilinkarvi
DS1995-1562
1995
Todt, W.A.Reischmann, T., Brugmann, G.E., Jochum, K.P., Todt, W.A.Trace element and isotopic composition of baddeleyiteMineralogy and Petrology, Vol. 53, No. 1-3, pp. 155-164.GlobalMineralogy, Baddeleyite
DS201606-1118
2016
Toellner, T.S.Solomatova, N.V., Jackson, J.M., Sturhahn, W., Wicks, J.K., Zhao, J., Toellner, T.S., Kalkan, B., Steinhardt, W.M.Equation of state and spin crossover of ( Mg,Fe)O at high pressure, with implications for explaining topographic relief at the core mantle boundary.American Mineralogist, Vol. 101, 5, pp. 1084-1093.MantleCore, mantle boundary
DS201810-2313
2018
Toellner, T.S.Finkelstein, G.J., Jackson, J.M., Said, A., Alatas, A., Leu, B.M., Sturhahn, W., Toellner, T.S.Strongly anisotropic magnesiowustite in Earth's lower mantle. Journal of Geophysical Research Solid Earth, doi.org/10.1029/ 2017JB015349Mantlecore mantle boundary

Abstract: The juxtaposition of a liquid iron-dominant alloy against a mixture of silicate and oxide minerals at Earth's core-mantle boundary is associated with a wide range of complex seismological features. One category of observed structures is ultralow-velocity zones, which are thought to correspond to either aggregates of partially molten material or solid, iron-enriched assemblages. We measured the phonon dispersion relations of (Mg,Fe) O magnesiowüstite containing 76 mol % FeO, a candidate ultralow-velocity zone phase, at high pressures using high-energy resolution inelastic X-ray scattering. From these measurements, we find that magnesiowüstite becomes strongly elastically anisotropic with increasing pressure, potentially contributing to a significant proportion of seismic anisotropy detected near the base of the mantle.
DS1960-0557
1965
Toerien, D.K.Heath, D.C., Toerien, D.K.A Cryptovolcanic Structure on Hatzium Ii. 28, Southwest Africa.Geological Survey of South Africa Annual Report, Vol. 1, PP. 81-85.Southwest Africa, NamibiaGeology, Hatzium Dome
DS2003-1049
2003
Tofalo, O.R.Pazos, P.J., Sanchez Bettucci, L., Tofalo, O.R.The record of the Varanger glaciation at the Rio de la Plat a Craton, Vendian CambrianGondwana Research, Vol. 6, No. 1, pp. 65-78.Uruguay, South AmericaGeomorphology
DS1981-0199
1981
Toft, P.B.Haggerty, S.E., Toft, P.B., Tompkins, L.A.Diamonds in Graphitic SchistsEos, Vol. 62, No. 17, P. 416. (abstract.).GlobalGeology
DS1982-0242
1982
Toft, P.B.Haggerty, S.E., Toft, P.B.Magsat: Geological and Gravity Correlations in Northern South America and West Africa.Eos, Vol. 63, No. 45, Nov. 9TH., P. 909, (abstract.).South America, West AfricaGeophysics
DS1986-0808
1986
Toft, P.B.Toft, P.B., Haggerty, S.E.A remanent and induced magnetization model of magsat vector anomalies over the West African cratonGeophysical Research Letters, Vol. 13, No. 4, April pp. 341-344West AfricaTectonics, Geophysics
DS1988-0701
1988
Toft, P.B.Toft, P.B.Magsat anomalies over the main shield of the West African craton in relation to magnetization and evolution of the lithospherePh.D. Thesis, University of Massachusetts, 239p. University of MicrofilmsWest AfricaGeophysics -Magnetics, Kimberlite, eclogite
DS1988-0702
1988
Toft, P.B.Toft, P.B., Haggerty, S.E.Limiting depth of magnetization in cratonic lithosphereGeophysical Research Letters, Vol. 15, No. 5, May pp. 530-533West AfricaBlank
DS1989-1503
1989
Toft, P.B.Toft, P.B., Hills, D.V., Haggerty, S.E.Crustal evolution and the granulite to eclogite transition in xenoliths from kimberlites in the West African cratonTectonophysics, Vol. 161, No. 3/4, pp. 213-231GlobalEclogite
DS1992-1557
1992
Toft, P.B.Toft, P.B., Taylor, P.T., Arkanantha..., J., Haggerty, S.E.Interpretation of satellite magnetic-anomalies over the West Africancraton.Tectonophysics, Vol. 212, No. 1-2, Oct. 1, pp. 21-32.West AfricaGeophysics -magnetics, remote sensing, Craton
DS1993-1606
1993
Toft, P.B.Toft, P.B., Arkani-Hamed, J.Induced magnetization of the oceanic lithosphere and ocean-continent magnetization contrast inferred from Magsat anomaliesJournal of Geophysical Research, Vol. 98, No. B 4, April 10, pp. 6267-6282GlobalGeophysics -magnetics, Iceland Plateau, Magsat Anomalies
DS1993-1607
1993
Toft, P.B.Toft, P.B., Scowen, A.H., Arkani-Hamed, J., Francis, D.Demagnetization by hydration in deep crustal rocks in the Grenville Province of Quebec, Canada: implications for magnetic anomalies of continental collision zonesGeology, Vol. 21, No. 11, November pp. 999-1002QuebecTectonics, Geophysics -magnetics
DS1989-0330
1989
Toh, E.David, M., Toh, E.Grade control problems dilution and geostatistics:choosing the required quality and number of samples for grade controlThe Canadian Mining and Metallurgical Bulletin (CIM Bulletin), Vol. 82, No. 931, November pp. 53-60GlobalGeostatistics, Grade control
DS201012-0527
2010
Toh, S.Nakamuta, Y., Toh, S., Aoki, T.Transformation mechanism of graphite to diamonds in ureilites revealed by TEM observation.International Mineralogical Association meeting August Budapest, abstract p. 183.TechnologyUrelilite
DS201312-0627
2013
Toh, S.Nakamuta, Y., Toh, S.Transformation of graphite to lonsdaleite and diamond in the Goalpara ureilite directly observed by TEM.American Mineralogist, Vol. 98, pp. 574-581.TechnologyMeteorite
DS1989-1504
1989
Tohji, K.Tohji, K., Udagawa, Y.X-ray Raman scattering as a substitute for softX-rayextended X-ray absorption fine structurePhys. Rev. B., Condensed Matter, Vol. 39, No. 11, pp. 7590-7594GlobalDiamond morphology, Spectroscopy
DS2002-1603
2002
Tohver, E.Tohver, E., Vander Pluijm, Vander Voo, RizzottoPaleogeography of the Amazon Craton at 1.2 Ga: early Grenvillian collision with Llano segment of Laurentia.Earth and Planetary Science Letters, Vol.199,1-2,pp.185-200., Vol.199,1-2,pp.185-200.BrazilTectonics, Laurentia
DS2002-1604
2002
Tohver, E.Tohver, E., Vander Pluijm, Vander Voo, RizzottoPaleogeography of the Amazon Craton at 1.2 Ga: early Grenvillian collision with Llano segment of Laurentia.Earth and Planetary Science Letters, Vol.199,1-2,pp.185-200., Vol.199,1-2,pp.185-200.BrazilTectonics, Laurentia
DS2003-1383
2003
Tohver, E.Tohver, E., Mezger, K., Rizzoto, G.Implications of a two stage tectonic history of the SW Amazon Craton, the NovaGeological Society of America, Annual Meeting Nov. 2-5, Abstracts p.301.BrazilTectonics
DS200412-2001
2003
Tohver, E.Tohver, E., Mezger, K., Rizzoto, G.Implications of a two stage tectonic history of the SW Amazon Craton, the Nova Brasilandia metamorphic belt as a late MesoproterGeological Society of America, Annual Meeting Nov. 2-5, Abstracts p.301.South America, BrazilTectonics
DS200512-1091
2005
Tohver, E.Tohver, E., Van der Phuijm, B.A., Mezger, K., Scandolara, J.E., Essene, E.J.Two stage tectonic history of the SW Amazon Craton in the late Mesoproterozoic in the late Mesoproterozoic: identifying a cryptic suture zone.Precambrian Research, Vol. 137, 1-2, Apr.28, pp. 35-59.South America, BrazilParagua Craton, tectonics, geochronology
DS200512-1092
2004
Tohver, E.Tohver, E., Van der Pluijm, B., Mezger, B., Essene, E., Scandolara, J., Rizzotto, G.Significance of the Nova Brasilandia metasedimentary belt in western Brazil: redefining the Mesoproterozoic boundary of the Amazon Craton.Tectonics, Vol. 23, 6, TC 6004 1029/2003 TC001563South America, BrazilCraton - Amazon
DS200612-1430
2006
Tohver, E.Tohver, E., D'Agrella Filho, M.S., Trindade, R.I.F.Paleomagnetic record of Africa and South America for 1200 - 500 Ma interval, and evaluation of Rodinia and Gondwana assemblies.Precambrian Research, Vol. 147, 3-4, July 5, pp. 193-222.Africa, South AmericaGeochronology
DS200612-1431
2006
Tohver, E.Tohver, E., D'Agrella-Filho, M.S., Trinidade, R.I.F.Paleomagnetic record of Africa and South America for the 1200 - 500 Ma interval, and evaluation of Rodinia and Gondwana assemblies.Precambrian Research, In press, availableAfrica, South America, Democratic Republic of Congo, Arabia, Nubian ShieldCraton, Kalahari, Sao Francisco, paleomagnetism
DS200612-1432
2006
Tohver, E.Tohver, E., Teixeira, W., Van der Pluijum, B., Geraldes, M.C., Bettencourt, J.S., Rizzotto, G.Restored transect across the exhumed Grenville Orogen of Laurentia and Amazonia, with implications for crustal architecture.Geology, Vol. 34, 8, pp. 669-672.South America, BrazilGeochronology, Amazon Craton, tectonics
DS201909-2098
2019
Tohver, E.Timmerman, S., Honda, M., Burnham, A.D., Amelin, Y., Woodland, S., Pearson, D.G., Jaques, A.L., Le Losq, C., Bennett, V.C., Bulanova, G.P., Smith, C.B., Harris, J.W., Tohver, E.Primordial and recycled helium isotope signatures in the mantle transition zone. Science, Vol. 365, 6454, pp. 692-694.Mantlediamond genesis

Abstract: Isotope compositions of basalts provide information about the chemical reservoirs in Earth’s interior and play a critical role in defining models of Earth’s structure. However, the helium isotope signature of the mantle below depths of a few hundred kilometers has been difficult to measure directly. This information is a vital baseline for understanding helium isotopes in erupted basalts. We measured He-Sr-Pb isotope ratios in superdeep diamond fluid inclusions from the transition zone (depth of 410 to 660 kilometers) unaffected by degassing and shallow crustal contamination. We found extreme He-C-Pb-Sr isotope variability, with high 3He/4He ratios related to higher helium concentrations. This indicates that a less degassed, high-3He/4He deep mantle source infiltrates the transition zone, where it interacts with recycled material, creating the diverse compositions recorded in ocean island basalts.
DS200812-0892
2008
Toila, D.Petterson, M.G., Toila, D., Cronin, S.J., Addison, R.Communicating geoscience to indigenous people: examples from the Solomon Islands.Geological Society of London Special Publication, No. 305, pp. 141-161.Asia, Solomon IslandsAboriginal
DS1999-0378
1999
Toivo, K.Korsman, K., Toivo, K., Virransalo, P.The GGT SVEKA Transect: structure and evolution of the continental crust In the Paleoproterozoic SvecofennianInternational Geology Review, Vol. 41, No. 4, Apr. pp. 287-333.FinlandGeophysics - seismics, Geodynamics
DS201611-2095
2016
Tokar, K.Anzolini, C., Angel, R.J., Merlini, M., Derzsi, M., Tokar, K., Milani, S., Krebs, M.Y., Brenker, F.E., Nestola, F., Harris, J.W.Depth of formation of CaSi)3 - walstromite included in super -deep diamonds.Lithos, in press available 43p.South America, Brazil, Mato GrossoDeposit - Juina

Abstract: "Super-deep" diamonds are thought to crystallize between 300 and 800 km depth because some of the inclusions trapped within them are considered to be the products of retrograde transformation from lower mantle or transition zone precursors. In particular, single inclusion CaSiO3-walstromite is believed to derive from CaSiO3-perovskite, although its real depth of origin has never been proven. Our aim is therefore to determine for the first time the pressure of formation of the diamond-CaSiO3-walstromite pair by “single-inclusion elastic barometry” and to determine whether CaSiO3-walstromite derives from CaSiO3-perovskite or not. We investigated several single phases and assemblages of Ca-silicate inclusions still trapped in a diamond coming from Juina (Brazil) by in-situ analyses (single-crystal X-ray diffraction and micro-Raman spectroscopy) and we obtained a minimum entrapment pressure of ~ 5.7 GPa (~ 180 km) at 1500 K. However, the observed coexistence of CaSiO3-walstromite, larnite (ß-Ca2SiO4) and CaSi2O5-titanite in one multiphase inclusion within the same diamond indicates that the sample investigated is sub-lithospheric with entrapment pressure between ~ 9.5 and ~ 11.5 GPa at 1500 K, based on experimentally-determined phase equilibria. In addition, thermodynamic calculations suggested that, within a diamond, single inclusions of CaSiO3-walstromite cannot derive from CaSiO3-perovskite, unless the diamond around the inclusion expands by ~ 30% in volume.
DS200512-1238
2004
Tokarev, A.D.Zhamaletdinov, A.A., Shetsov, A.N., Tokarev, A.D.Normal model of electric conductivity of the Baltic Shield lithosphere and its geodynamic interpretation.Doklady Earth Sciences, Vol. 399, 8,pp. 1098-1102.Russia, Baltic ShieldGeophysics - seismics, tectonics
DS2002-1099
2002
Tokarvk, D.Mossman, D.J., Eigendorf, G., Tokarvk, D., Gauthier-Lafave, Guckert, MelezhikThe search for fullerenes in carbonaceous substances associated with the natural11th. Quadrennial Iagod Symposium And Geocongress 2002 Held Windhoek, Abstract p. 38.GabonFullerenes
DS1975-0535
1977
Tokieda, K.Ito, H., Tokieda, K., Suma, K., Kume, S.Paleomagnetism of South African KimberlitesNagoya University Afr. Studies Prelim. Report, 2ND., PP. 194-198.South AfricaPaleomagnetism
DS1975-0768
1978
Tokieda, K.Ito, H., Tokieda, K., Suwa, K. , Kume, S.Remanent Magnetism of Precambrian and Cretaceous Kimberlites in South Africa.Geophys. Journal of Roy. Astron. Soc., Vol. 55, No. 1, PP. 123-130.South AfricaPaleomagnetics, Geophysics, Kimberlite
DS1989-1508
1989
Tokonami, M.Toyoda, K., Tokonami, M.Instrumental proton activation analyses of rock reference samples and soil samples ofcarbonatite.*JPN.Kakuriken, Kenkyu Hokuru (Tohoku Daigaku), *JPN., Vol. 22, No. 1, pp. 117-122GlobalCarbonatite, Soil analysis
DS1994-1795
1994
Tokonami, M.Toyoda, K., Horiuchi, H., Tokonami, M.Dupal anomaly of Brazilian carbonatites: geochemical correlations with hotspots in South Atlantic.. mantleEarth and Planetary Science Letters, Vol. 126, No. 4, Sept. pp. 315-332.BrazilCarbonatite, Hotspots
DS200612-0811
2006
Toksoz, M.N.Li, C., Van der Hilst, R.D., Toksoz, M.N.Constraining P wave velocity variations in the upper mantle beneath southeast Asia.Physics of the Earth and Planetary Interiors, Vol. 154, 2, Feb. 16, pp. 180-195.Asia, ChinaGeophysics - seismics
DS200612-1395
2006
Toksoz, M.N.Sun, Y., Toksoz, M.N.Crustal structure of Chin a and surrounding regions from P wave traveltime tomography.Journal of Geophysical Research, Vol. 111, B3, B03310Asia, ChinaGeophysics - seismics
DS200812-1144
2008
Toksoz, M.N.Sun, Y., Toksoz, M.N., Pei, S., Zhao, D., Morgan, F.D., Rosca, A.S wave tomography of the crust and uppermost mantle in China.Journal of geophysical Research, Vol. 113, B11307.ChinaGeophysics - seismics
DS200712-1086
2007
Tokuda, N.Tokuda, N., Saito, T., Umezawa, H., Okushi, H., Yamasaki, S.The role of boron atoms in heavily boron-doped semiconducting homoepitaxial diamond growth. Study of surface morphology.Diamond and Related Materials, Vol. 16, 2, pp. 409-411. Ingenta 1070685096TechnologyDiamond morphology
DS1950-0240
1955
Tolansky, S.Tolansky, S.Pressure Crack Figures on Diamond Faces. I the Octahedral Face; Ii the Dodecahedral and Cubic Faces.Royal Society. Proceedings A., Vol. 230, No. 1182, PP. 287-293; PP. 294-301.GlobalDiamond Genesis
DS1950-0241
1955
Tolansky, S.Tolansky, S.Microstructures of DiamondLondon: National Association Gemmologists Press Ltd., GlobalDiamond Genesis, Kimberley
DS1950-0242
1955
Tolansky, S.Tolansky, S.The Microstructures of Diamond SurfacesLondon: N.a.g. Press, GlobalKimberlite, Kimberley, Janlib, Diamond
DS1950-0243
1955
Tolansky, S.Tolansky, S., Emara, S.H.An Occassional Mode of Growth in DiamondPhys. Soc. Proceedings B., Vol. 68, PP. 559-561.GlobalDiamond Genesis
DS1960-0302
1962
Tolansky, S.Tolansky, S.The History and Use of DiamondLondon: Methuen., 166P.GlobalKimberlite
DS1960-0752
1966
Tolansky, S.Tolansky, S.Birefringence of DiamondNature., Vol. 211, JULY 9TH., PP. 158-160.GlobalDiamond Genesis
DS1960-0884
1967
Tolansky, S.Tolansky, S., Komatsu, H.Abundance of Type Ii DiamondsScience., Vol. 157, PP. 1173-1175.GlobalDiamond Genesis
DS1960-1041
1968
Tolansky, S.Tolansky, S.Graphitized Natural DiamondDiamond Research, VOLUME FOR 1968, PP. 8-10.GlobalDiamond Genesis
DS1960-1042
1968
Tolansky, S.Tolansky, S.The Strategic DiamondEdinburgh: Oliver And Boyd., 119P.GlobalKimberley, Crystallography, Diamond Genesis
DS1960-1224
1969
Tolansky, S.Tolansky, S., Rawle-Cope, M.Abundance of Type Ii Diamonds Amongst Natural Micro-diamondsDiamond Research, VOLUME FOR 1969, PP. 2-6.GlobalDiamond Genesis, Classification, Morphology
DS1970-0435
1971
Tolansky, S.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
DS1970-0607
1972
Tolansky, S.Tolansky, S.Diamonds on the Moon?International Diamonds, Vol. 2, PP. 115-119.GlobalDiamond Genesis
DS1970-0608
1972
Tolansky, S.Tolansky, S.Intriguing Discoveries about Growth in DiamondsInternational DIAMOND ANNUAL, Vol. 2, PP. 274-276. ALSO: AUSTRALIAN Gemologist, Vol. 11GlobalGemology, Diamond Genesis, Natural
DS1970-0837
1973
Tolansky, S.Tolansky, S.Distribution of Type I and Type Ii in South African DiamondsDiamond Research, VOLUME FOR 1973, PP. 28-31.South AfricaDiamond Genesis, Classification
DS1970-0838
1973
Tolansky, S.Tolansky, S.Distribution of Type 1 and Type Ii in South African DiamondsDiamond Research, pp. 28-31.South AfricaDiamond Morphology
DS1970-0839
1973
Tolansky, S.Tolansky, S.Distribution of Type 1 and Type Ii South African DiamondsDiamond Research 1973, pp. 28-31.South AfricaDiamond Morphology
DS1989-0360
1989
Toledano, P.Dmitriev, V.P., Rochal, S.B., Gufan, Y.M., Toledano, P.Reconstructive transitions between ordered phases -the Martensitic FCC-HCP and the graphite diamondtransitionsPhys. Rev. L., Vol. 62, No. 2, May 22, pp. 2495-2498GlobalDiamond morphology, Graphite-diamond
DS1996-0984
1996
Toledo, M.C.Modenesi-Gauttieri, M.C., Toledo, M.C., MottaWeathering and the formation of hill slope deposits in the tropical highlands of ItatiaiaCatena, Vol. 27, No. 2, Aug. 1, pp. 81-104BrazilLaterite, Weathering
DS1995-1915
1995
Toledo, R.Toledo, R.Structural reform and privatization in PeruRaw Materials Report, Vol. 11, No. 3, pp. 29-37PeruLegal, Mining
DS201312-0175
2013
Toledo, V.Coopersmith, H., Toledo, V.Shefa Yamin - modern diamond and precious stone.Israel Geological Society, 1p. AbstractEurope, IsraelMount Carmel
DS201412-0144
2014
Toledo, V.Coopersmith, H., Toledo, V., Fritsch, E., Ward, J., De Wit, M., Spaggiari, R.Geology and exploration of gem deposits at Mt. Carmel, northern Israel: natural moissanite, sapphire, ruby and diamond.Geological Society of America Conference Vancouver Oct. 19-22, 2p. AbstractEurope, IsraelMoissanite
DS201412-0256
2014
Toledo, V.Fritsch, E., Toledo, V., Matlins, A.Record size natural moissanite crystals discovered in Isreal.Gems & Gemology, Vol 50, 2, summer 2p.Europe, IsraelMoissanite
DS201412-0933
2014
Toledo, V.Toledo, V., Ward, J., De Wet, M., Spaggiari, R., Coopersmith, H.Developing a geological model to guide placer exploration in the Kishon catchment, northern Israel.Shefa Yamin Exploration & Mining, 2p. Poster and 1 page abstractEurope, IsraelKishon Placers
DS201505-0246
2015
Toledo, V.Griffin, W.L., Gain, S.E.M., Toledo, V., O'Reilly, S.Y., Jacob, D., Pearson, N.J.Corundum, moissanite and super reducing conditions in the upper mantle beneath the lower ( southern) Galilee ( Israel).Israel Geological Society, 1p.posterEurope, IsraelMineralogy
DS201505-0247
2015
Toledo, V.Toledo, V., Apter, D.B., Ward, J.High pressure indicator minerals from the Rakefet magmatic complex ( RMC), Mt. Carmel, Israel.Israel Geological Society, 1p.posterEurope, IsraelMineralogy
DS201505-0248
2015
Toledo, V.Toledo, V., Ward, J., de Wit, M., Spaggiari, R., Coopersmith, H., Wald, R.A transient fluvial placer in the mid reach of the Kishon Valley northern Israel: initial results of follow up exploration.Israel Geological Society, 1p.posterEurope, IsraelExploration results
DS201603-0381
2016
Toledo, V.Griffin, W.L., Gain, S.E.M., Adams, D., Huang, J-X., Saunders, M.,Toledo, V., Pearson, N.J., O'Reilly, S.Y.Heaven on Earth: tistarite ( Ti203) and other nebular phases in corundum aggregates from Mt. Carmel volcanic rocks.Israel Geological Society, pp. 85-86. abstractEurope, IsraelMoissanite

Abstract: This ending talk, focused on the ongoing cooperative research of Prof. Griffin and his team at Macquarie University and Shefa Yamim, since January 2014, highlighting unique corundum species characteristics. Preliminary results of this research were presented in the IGS Annual Meeting of 2015, whereas this year Prof. Griffin has shared innovative findings only microscopically tracked within titanium-rich corundum aggregates. One of the more abundant minerals is Tistarite (Ti2O3), previously known only as a single grain in a primitive type of meteorite (!). An article has been submitted to a scientific journal detailing this first terrestrial occurrence. Several other minerals are common in meteorites, but unknown or extremely rare on Earth. About half of these minerals are unknown to science, and will be described as new minerals in the scientific literature. The first of these is a Titanium-Aluminium-Zirconium oxide, informally known as TAZ; it will be submitted to the International Mineralogical Association for recognition as a new mineral, ShefaTAZite. Using state of the art technologies such as Thermal Ionisation Mass Spectrometry (TIMS) and Electron Microscopy Facility (EMF) that has three scanning electron microscopes, all with EBSD capability, and a transmission electron microscope - Prof. Griffin revealed spectacular imagery of minerals and rare compounds associated with titanium rich corundum aggregates.
DS201603-0382
2016
Toledo, V.Griffin, W.L., Gain, S.E.M., Adams, D., Toledo, V., Pearson, N.J., O'Reilly, S.Y.Deep-Earth methane, mantle dynamics and mineral exploration: insights from northern Israel, southern Tibet and Kamchatka.Israel Geological Society, pp. 87-88. abstractEurope, Israel, TibetMoissanite
DS201603-0429
2016
Toledo, V.Wald, R., Toledo, V.Volcanic host rocks as sources of corundum recovered from Shefa Yamim's multi-commodity placer, northern Israel.Israel Geological Society, pp. 156-157. abstractEurope, IsraelKishon - corundum

Abstract: This talk focused on the proximal reach (closest to its source) of the Kishon River, covering the Yizre'el Valley and its margins. In this terrain Shefa Yamim's exploration area overlaps the PhD study area of Reli Wald, the company's geologist. The Yizre'el basin hosts a large volume of basalts, sourced mainly from fault planes, but also from volcanoes (vents). Combination of datasets gathered from intensive exploration of Shefa Yamim, including site specific geophysics (high resolution ground magnetometer) and three-dimensional (3D) geological and geophysical subsurface mapping of Reli Wald's PhD study, has enabled quantification of the basalt volume. Since the basalts are known as host rocks for corundum xenocrysts (both gem and industrial minerals), volume estimations become handy when analysing Shefa Yamim corundum species recoveries including the gem derivative sapphire. Corundum findings of the Mid Reach alluvial placer were explained by introducing the geological Miocene (geological period) volcanic setting of the hinterland (proximal reach), in terms of a supplier. Corundum crystals have crystallized in the uppermost mantle, been elevated by magmatic intrusions into the crust, and brought to surface by later, younger volcanism. Corundum findings thus emphasize rift-related setting and recurring magmatism in northern Israel whereas important questions regarding the connection between sapphire and corundum and the possibility for a deep subduction regime still await answers...
DS201610-1865
2016
Toledo, V.Griffin, W.L., Gain, S.E.M., Adams, D.T., Huang, J-X., Saunders, M., Toledo, V., Pearson, N.J., O'Reilly, S.Y.First terrestrial occurrence of tistarite ( Ti2O3): ultra-low oxygen fugacity in the upper mantle beneath Mount Carmel, Israel.Geology, Vol. 44, 10, pp. 815-818.Europe, IsraelMoissanite

Abstract: The minimum oxygen fugacity (fO2) of Earth's upper mantle probably is controlled by metal saturation, as defined by the iron-wüstite (IW) buffer reaction (FeO ? Fe + O). However, the widespread occurrence of moissanite (SiC) in kimberlites, and a suite of super-reduced minerals (SiC, alloys, native elements) in peridotites in Tibet and the Polar Urals (Russia), suggest that more reducing conditions (fO2 = 6-8 log units below IW) must occur locally in the mantle. We describe pockets of melt trapped in aggregates of corundum crystals ejected from Cretaceous volcanoes in northern Israel which contain high-temperature mineral assemblages requiring extremely low fO2 (IW < -10). One abundant phase is tistarite (Ti2O3), previously known as a single grain in the Allende carbonaceous chondrite (Mexico) and believed to have formed during the early evolution of the solar nebula. It is associated with other reduced phases usually found in meteorites. The development of super-reducing conditions in Earth's upper mantle may reflect the introduction of CH4 + H2 fluids from the deep mantle, specifically related to deep-seated volcanic plumbing systems at plate boundaries.
DS201709-1999
2017
Toledo, V.Huang, J-X., Xiong, Q., Griffin, W.L., Martin, L., Toledo, V., O'Reilly, S.Y.Moissanite in volcanic systems: super reduced conditions in the mantle.Goldschmidt Conference, abstract 1p.Mantlemoissanite

Abstract: Moissanite (SiC) occurs in mantle and mantle-generated rocks from different tectonic settings. SiC is stable only at low oxygen fugacity (ƒO2) ?IW. Israeli SiC is assiociated with corundum, Fe globules, native V and other phases in Cretaceous pyroclastic rocks from Mt Carmel and associated alluvial deposits[1]. The SiC grains contain inclusions of Si metal, FeSi2, FeTiSi2, FeAlSi2 and CaSi2+xSi2-x, which were liquids before being trapped during SiC crystallization. SiC has been found included in corundum, associated with Fe-Ti silicides, connecting the formation of SiC, reduced melts in corundum and conrundum itself. All grains are of the 6H polytype. d13C ranges from - 32.1 to -24.5‰ and d30Si from -0.68 to +1.42‰. These SiC grains are one product of the interaction of basaltic magma and mantle methane in a volcanic plumbing system. SiC crystallized from metallic melts that became immiscible during the reduction of the magma. Its low d13C may reflect Rayleigh fractionation under reduced conditions; the variation in Si isotopes may reflect fractionation between SiC and immiscible metallic melts. SiC samples from the Udachnaya and Mir kimberlite pipes contain inclusions of Si metal, FeSi2, FeSi, FeTiSi2, Si(N,O). The SiC has d13C ranging from -28.5 to -24.8‰, and d30Si from -1.72 to +1.42‰. SiC from harzburgites, chromitites and pyroxenites of the Tibetan Zedang ophiolites have inclusions of Si metal and unmixed Fe-Ni-Ti-Si alloy. Their d13C ranges from -30.6 to -24.7‰ and d30Si from -0.85 to +1.26‰. SiC samples from these different settings show very similar characteristics, implying that they may be formed in similar mantle conditions, where the flux of mantle methane gradually reduces magmas and interacts with them to produce different reduced phases at different stages.
DS201710-2280
2017
Toledo, V.Xiong, Q., Griffin, W.L., Huang, J-X., Gain, S.E.M., Toledo, V., Pearson, N.J., O'Reilly, S.Y.Super reduced assemblages in "ophiolitic" chromitites and peridotites: the view from Mount Carmel.European Journal of Mineralogy, Vol. 29, 4, pp. 557-570.Europe, Israelmineralogy

Abstract: Ultrahigh-pressure (UHP) materials (e.g., diamond, high-pressure polymorph of chromite) and super-reduced (SuR) phases (e.g., carbides, nitrides, silicides and native metals) have been identified in chromitites and peridotites of the Tibetan and Polar-Urals ophiolites. These unusual assemblages suggest previously unrecognized fluid- or melt-related processes in the Earth’s mantle. However, the origin of the SuR phases, and in particular their relationships with the UHP materials in the ophiolites, are still enigmatic. Studies of a recently recognized SuR mineral system from Cretaceous volcanics on Mt Carmel, Israel, suggest an alternative genesis for the ophiolitic SuR phases. The Mt Carmel SuR mineral system (associated with Ti-rich corundum xenocrysts) appears to reflect the local interaction of mantle-derived CH4 ± H2 fluids with basaltic magmas in the shallow lithosphere (depths of ~30-100 km). These interactions produced desilication of the magma, supersaturation in Al2O3 leading to rapid growth of corundum, and phase assemblages requiring local oxygen fugacity (fO2) gradually dropping to ~11 log units below the iron-wüstite (IW) buffer. The strong similarities between this system and the SuR phases and associated Ti-rich corundum in the Tibetan and Polar-Urals ophiolites suggest that the ophiolitic SuR suite probably formed by local influx of CH4 ± H2 fluids within previously subducted peridotites (and included chromitites) during their rapid exhumation from the deep upper mantle to lithospheric levels. In the final stages of their ascent, the recycled peridotites and chromitites were overprinted by a shallow magmatic system similar to that observed at Mt Carmel, producing most of the SuR phases and eventually preserving them within the Tibetan and Polar-Urals ophiolites.
DS201806-1225
2018
Toledo, V.Griffin, W.L., Huang, J-X., Thomassot, E., Gain, S.E.M., Toledo, V., O'Reilley, S.Y.Super reducing conditions in ancient and modern volcanic systems: sources and behaviour of carbon-rich fluids in the lithospheric mantle. Mt. Carmel moissaniteMineralogy and Petrology, in press available, 14p.Europe, Israelmetasomatism

Abstract: Oxygen fugacity (fO2) is a key parameter of Earth’s mantle, because it controls the speciation of the fluids migrating at depth; a major question is whether the sublithospheric mantle is metal-saturated, keeping fO2 near the Iron-Wustite (IW) buffer reaction. Cretaceous basaltic pyroclastic rocks on Mt. Carmel, Israel erupted in an intraplate environment with a thin, hot lithosphere. They contain abundant aggregates of hopper-shaped crystals of Ti-rich corundum, which have trapped melts with phenocryst assemblages (Ti2O3, SiC, TiC, silicides, native V) requiring extremely low fO2. These assemblages are interpreted to reflect interaction between basaltic melts and mantle-derived fluids dominated by CH4 + H2. Similar highly reduced assemblages are found associated with volcanism in a range of tectonic situations including subduction zones, major continental collisions, intraplate settings, craton margins and the cratons sampled by kimberlites. This distribution, and the worldwide similarity of d13C in mantle-derived SiC and associated diamonds, suggest a widespread process, involving similar sources and independent of tectonic setting. We suggest that the common factor is the ascent of abiotic (CH4 + H2) fluids from the sublithospheric mantle; this would imply that much of the mantle is metal-saturated, consistent with observations of metallic inclusions in sublithospheric diamonds (e.g. Smith et al. 2016). Such fluids, perhaps carried in rapidly ascending deep-seated magmas, could penetrate high up into a depleted cratonic root, establishing the observed trend of decreasing fO2 with depth (e.g. Yaxley et al. in Lithos 140:142-151, 2012). However, repeated metasomatism (associated with the intrusion of silicate melts) will raise the FeO content near the base of the craton over time, developing a carapace of oxidizing material that would prevent the rise of CH4-rich fluids into higher levels of the subcontinental lithospheric mantle (SCLM). Oxidation of these fluids would release CO2 and H2O to drive metasomatism and low-degree melting both in the carapace and higher in the SCLM. This model can explain the genesis of cratonic diamonds from both reduced and oxidized fluids, the existence of SiC as inclusions in diamonds, and the abundance of SiC in some kimberlites. It should encourage further study of the fine fractions of heavy-mineral concentrates from all types of explosive volcanism.
DS201808-1749
2018
Toledo, V.Griffin, W.L., Huang, J-X., Thomassot, E., Gain, S.E.M., Toledo, V., O'Reilly, S.Y.Super-reducing conditions in ancient and modern volcanic systems: sources and behaviour of carbon-rich fluids in the lithospheric mantle ( Mt. Carmel).Mineralogy and Petrology, doi.org/10.1007/s00710-018-0575-x 14p.Mantlemoissanite
DS201810-2323
2018
Toledo, V.Griffin, W.L., Gain, S.E.M., Huang, J.X., Belousova, E.A., Toledo, V., O'Reilly, S.Y.Permian to quaternary magmatism beneath the Mt. Carmel area, Israel: zircons from volcanic rocks and associated alluvial deposits.Lithos, Vol. 314-315, pp. 307-322.Europe, Israel zircons

Abstract: Xenocrystic zircons from Cretaceous pyroclastic vents on Mt. Carmel, N. Israel, document two major periods of earlier mafic magmatism: Permo-Triassic (285-220?Ma) and Jurassic (200-160?Ma). Related alluvial deposits also contain these zircon populations. However, most alluvial zircons are Cretaceous (118-80?Ma) or younger, derived from Miocene to Pliocene volcanic episodes. The Permo-Triassic-Jurassic zircons are typically large and glassy; they have irregular shapes and a wide variety of internal zoning patterns. They appear to have grown in the interstitial spaces of coarse-grained rocks; many show evidence of recrystallization, including brecciation and rehealing by chemically similar zircon. Grains with relict igneous zoning have mantle-like d18O (5.5?±?1.0‰), but brecciation leads to lower values (mean 4.8‰, down to 3.1‰). Hf-isotope compositions lie midway between the Chondritic Uniform Reservoir (CHUR) and Depleted Mantle (DM) reservoirs; Hf model ages suggest that the source region separated from DM in Neoproterozoic time (1500-1000?Ma). Most Cretaceous zircons have 176Hf/177Hf similar to those of the older zircons, suggesting recrystallization and/or Pb loss from older zircons in the Cretaceous thermal event. The Permo-Jurassic zircons show trace-element characteristics similar to those crystallized from plume-related magmas (Iceland, Hawaii). Calculated melts in equilibrium with them are characterized by strong depletion in LREE and P, large positive Ce anomalies, variable Ti anomalies, and high and variable Nb, Ta, Th and U, consistent with the fractionation of monazite, zircon, apatite and Ti-bearing phases. We suggest that these coarse-grained zircons crystallized from late differentiates of mafic magmas, ponded near the crust-mantle boundary (ca 30?km depth), and were reworked repeatedly by successively younger igneous/metasomatic fluids. The zircon data support a published model that locates a fossil Neoproterozoic plume head beneath much of the Arabia-Levant region, which has been intermittently melted to generate the volcanic rocks of the region. The Cretaceous magmas carry mantle xenoliths derived from depths up to 90?km, providing a minimum depth for the possible plume head. Post-Cretaceous magmatism, as recorded in detrital zircons, shows distinct peaks at 30?Ma, 13?Ma, 11.4?±?0.1?Ma (a major peak; n?=?15), 9-10?Ma and 4?Ma, representing the Lower and Cover Basalts in the area. Some of these younger magmas tapped the same mantle source as the Permian-Jurassic magmatism, but many young zircons have Hf-isotope compositions extending up to DM values, suggesting derivation of magmas from deeper, more juvenile sources.
DS201902-0275
2018
Toledo, V.Griffin, W.L., Gain, S.E.M., Bindi, L., Toledo, V., Camara, F., Saunders, M., O'Reilly, S.Y.Carmeltazite, ZrAl2Ti4011, a new mineral trapped in corundum from volcanic rocks of Mt Carmel, northern Israel.Minerals ( mdpi.com), Vol. 8, 12, 11p. PdfEurope, Israelmineralogy

Abstract: The new mineral species carmeltazite, ideally ZrAl2Ti4O11, was discovered in pockets of trapped melt interstitial to, or included in, corundum xenocrysts from the Cretaceous Mt Carmel volcanics of northern Israel, associated with corundum, tistarite, anorthite, osbornite, an unnamed REE (Rare Earth Element) phase, in a Ca-Mg-Al-Si-O glass. In reflected light, carmeltazite is weakly to moderately bireflectant and weakly pleochroic from dark brown to dark green. Internal reflections are absent. Under crossed polars, the mineral is anisotropic, without characteristic rotation tints. Reflectance values for the four COM wavelengths (Rmin, Rmax (%) (? in nm)) are: 21.8, 22.9 (471.1); 21.0, 21.6 (548.3), 19.9, 20.7 (586.6); and 18.5, 19.8 (652.3). Electron microprobe analysis (average of eight spot analyses) gave, on the basis of 11 oxygen atoms per formula unit and assuming all Ti and Sc as trivalent, the chemical formula (Ti3+3.60Al1.89Zr1.04Mg0.24Si0.13Sc0.06Ca0.05Y0.02Hf0.01)S=7.04O11. The simplified formula is ZrAl2Ti4O11, which requires ZrO2 24.03, Al2O3 19.88, and Ti2O3 56.09, totaling 100.00 wt %. The main diffraction lines, corresponding to multiple hkl indices, are (d in Å (relative visual intensity)): 5.04 (65), 4.09 (60), 2.961 (100), 2.885 (40), and 2.047 (60). The crystal structure study revealed carmeltazite to be orthorhombic, space group Pnma, with unit-cell parameters a = 14.0951 (9), b = 5.8123 (4), c = 10.0848 (7) Å, V = 826.2 (1) Å3, and Z = 4. The crystal structure was refined to a final R1 = 0.0216 for 1165 observed reflections with Fo > 4s(Fo). Carmeltazite exhibits a structural arrangement similar to that observed in a defective spinel structure. The name carmeltazite derives from Mt Carmel (“CARMEL”) and from the dominant metals present in the mineral, i.e., Titanium, Aluminum and Zirconium (“TAZ”). The mineral and its name have been approved by the IMA Commission on New Minerals, Nomenclature and Classification (2018-103).
DS201903-0514
2019
Toledo, V.Griffin, W.L., Gain, S.E.M., Huang, J-X., Saunders, M., Shaw, J., Toledo, V., O'Reilly, S.Y.A terrestrial magmatic hibonite-grossite-vanadium assemblage: desilication and extreme reduction in a volcanic plumbing system, Mount Carmel, Israel.American Mineralogist, Vol. 104, pp. 207-219.Europe, Israelmelting

Abstract: Hibonite (CaAl12O19) is a constituent of some refractory calcium-aluminum inclusions (CAIs) in carbonaceous meteorites, commonly accompanied by grossite (CaAl4O7) and spinel. These phases are usually interpreted as having condensed, or crystallized from silicate melts, early in the evolution of the solar nebula. Both Ca-Al oxides are commonly found on Earth, but as products of high-temperature metamorphism of pelitic carbonate rocks. We report here a unique occurrence of magmatic hibonitegrossite-spinel assemblages, crystallized from Ca-Al-rich silicate melts under conditions [high-temperature, very low oxygen fugacity (fO2)] comparable to those of their meteoritic counterparts. Ejecta from Cretaceous pyroclastic deposits on Mt Carmel, N. Israel, include aggregates of hopper/skeletal Ti-rich corundum, which have trapped melts that crystallized at fO2 extending from 7 log units below the iron-wustite buffer (?IW = -7; SiC, Ti2O3, Fe-Ti silicide melts) to ?IW = -9 (native V, TiC, and TiN). The assemblage hibonite + grossite + spinel + TiN first crystallized late in the evolution of the melt pockets; this hibonite contains percentage levels of Zr, Ti, and REE that reflect the concentration of incompatible elements in the residual melts as corundum continued to crystallize. A still later stage appears to be represented by coarse-grained (centimeter-size crystals) ejecta that show the crystallization sequence: corundum + Liq ? (low-REE) hibonite ? grossite + spinel ± krotite ? Ca4Al6F2O12 + fluorite. V0 appears as spheroidal droplets, with balls up to millimeter size and spectacular dendritic intergrowths, included in hibonite, grossite, and spinel. Texturally late V0 averages 12 wt% Al and 2 wt% Mn. Spinels contain 10-16 wt% V in V0-free samples, and <0.5 wt% V in samples with abundant V 0. Ongoing paragenetic studies suggest that the fO2 evolution of the Mt Carmel magmatic system reflects the interaction between OIB-type mafic magmas and mantle-derived CH4+H2 fluids near the crust-mantle boundary. Temperatures estimated by comparison with 1 atm phase-equilibrium studies range from ca. 1500 °C down to 1200-1150 °C. When fO2 reached ca. ?IW = -7, the immiscible segregation of Fe,Ti-silicide melts and the crystallization of SiC and TiC effectively desilicated the magma, leading to supersaturation in Al2O3 and the rapid crystallization of corundum, preceding the development of the hibonite-bearing assemblages. Reports of Ti-rich corundum and SiC from other areas of explosive volcanism suggest that these phenomena may be more widespread than presently realized, and the hibonite-grossite assemblage may serve as another indicator to track such activity. This is the first reported terrestrial occurrence of krotite (CaAl2O4), and of at least two unknown Zr-Ti oxides.
DS201906-1276
2019
Toledo, V.Bindi, L., Camara, F., Griffin, W.L., Huang, J-X., Gain, S.E.M., Toledo, V., O'Reilly, S.Y.Discovery of the first natural hydride. Mt. CarmelAmerican Mineralogist, Vol. 104, pp. 611-614.Europe, Israelcrystallography

Abstract: Although hydrogen is the most abundant element in the solar system, the mechanisms of exchange of this element between the deep interior and surface of Earth are still uncertain. Hydrogen has profound effects on properties and processes on microscopic-to-global scales. Here we report the discovery of the first hydride (VH2) ever reported in nature. This phase has been found in the ejecta of Cretaceous pyroclastic volcanoes on Mt Carmel, N. Israel, which include abundant xenoliths containing highly reduced mineral assemblages. These xenoliths were sampled by their host magmas at different stages of their evolution but are not genetically related to them. The xenoliths are interpreted as the products of extended interaction between originally mafic magmas and CH4+H2 fluids, derived from a deeper, metal-saturated mantle. The last stages of melt evolution are recorded by coarse-grained aggregates of hibonite (CaAl12O19) + grossite (CaAl4O7) + V-rich spinels ± spheroidal to dendritic inclusions of metallic vanadium (V0), apparently trapped as immiscible metallic melts. The presence of V0 implies low oxygen fugacities and suggests crystallization of the aggregates in a hydrogen-rich atmosphere. The presence of such reducing conditions in the upper mantle has major implications for the transport of carbon, hydrogen and other volatile species from the deep mantle to the surface.
DS201910-2258
2019
Toledo, V.Gain, S.E., Griffin, W.L., Saunders, M., Shaw, J.A., Toledo, V.A showcase of analytical techniques: native vanadium in hibonite and chromium in corundum: ultra-high contents under reducing conditions. Two posters Shefa Gems Microscopy and Microanalysis ( M&M)Co. Conference, Sept. 9, posters 1 p. eachEurope, Israeldeposit - Kishon

Abstract: The Microscopy and Microanalysis (M&M) conference in Portland Oregon, USA is one of the biggest microscopy conferences in the world and this year it hosted its largest meeting in history with over 3,300 participants, up to 20 parallel sessions and over 600 posters. The two posters were presented by Sarah E.M. Gain who is from the University of Western Australia where she trains and supports researchers in Microscopy, Characterisation and Microanalysis. Sarah discussed some of the unique gem material collected from Shefa Gems’ exploration activity in the Kishon Mid Reach and Rakefet Magmatic Complex, analysed using a range of microscopy and microanalysis techniques. She also discussed the scientific importance of this material.The first poster looked at hibonite (a Ca-Al-oxide) with inclusions of vanadium metal. The second poster looked at, Cr corundum (ruby), which is unusual due to the extremely high Cr levels and the inclusions of Cr metal.
DS202012-2217
2020
Toledo, V.Griffin, W.L., Gain, S.E.M., Saunders, M., Bindi, L., Alard, O., Toledo, V., O'Reilly, S.Y.Parageneses of TiB2 in corundum xenoliths from Mt. Carmel, Israel: siderophile behavior of boron under reducing conditions.American Mineralogist, Vol. 105, pp. 1609-1621. pdfEurope, Israeldeposit - Mt. Carmel

Abstract: Titanium diboride (TiB2) is a minor but common phase in melt pockets trapped in the corundum aggregates that occur as xenoliths in Cretaceous basaltic volcanoes on Mt. Carmel, north Israel. These melt pockets show extensive textural evidence of immiscibility between metallic (Fe-Ti-C-Si) melts, Ca-Al-Mg-Si-O melts, and Ti-(oxy)nitride melts. The metallic melts commonly form spherules in the coexisting oxide glass. Most of the observed TiB2 crystallized from the Fe-Ti-C silicide melts and a smaller proportion from the oxide melts. The parageneses in the melt pockets of the xenoliths require fO2 = ?IW-6, probably generated through interaction between evolved silicate melts and mantle-derived CH4+H2 fluids near the crust-mantle boundary. Under these highly reducing conditions boron, like carbon and nitrogen, behaved mainly as a siderophile element during the separation of immiscible metallic and oxide melts. These parageneses have implications for the residence of boron in the peridotitic mantle and for the occurrence of TiB2 in other less well-constrained environments such as ophiolitic chromitites.
DS202101-0001
2020
Toledo, V.Bindi, L., Camara, F., Gain, S.E.M., Griffin, W.L., Huang, J-X., Saunders, M., Toledo, V.Kishonite, VH2 and oreillyite, Cr2N, two new minerals from the conundrum xenocrysts of Mt. Carmel, northern Israel.Minerals MDPI, Vol. 10, 1118, doi:10.3390/ min10121118 10p. PdfEurope, Israeldeposit - Mt. Carmel

Abstract: Here, we describe two new minerals, kishonite (VH2) and oreillyite (Cr2N), found in xenoliths occurring in pyroclastic ejecta of small Cretaceous basaltic volcanoes exposed on Mount Carmel, Northern Israel. Kishonite was studied by single-crystal X-ray diffraction and was found to be cubic, space group Fm3¯m, with a = 4.2680(10) Å, V = 77.75(3) Å3, and Z = 4. Oreillyite was studied by both single-crystal X-ray diffraction and transmission electron microscopy and was found to be trigonal, space group P3¯1m, with a = 4.7853(5) Å, c = 4.4630(6) Å, V = 88.51 Å3, and Z = 3. The presence of such a mineralization in these xenoliths supports the idea of the presence of reduced fluids in the sublithospheric mantle influencing the transport of volatile species (e.g., C, H) from the deep Earth to the surface. The minerals and their names have been approved by the Commission of New Minerals, Nomenclature and Classification of the International Mineralogical Association (No. 2020-023 and 2020-030a).
DS202101-0013
2020
Toledo, V.Griffin, W.L., Gain, S.E.M., Saunders, M., Bindi, L., Alard, O., Toledo, V., O'Reilly, S.Y.Parageneses of TIB2 in corundum xenoliths from Mt. Carmel, Israel: siderophile behaviour of boron under reducing conditions.American Mineralogist , in press available 33p. PdfEurope, Israeldeposit - Mt. Carmel

Abstract: Titanium diboride (TiB2) is a minor but common phase in melt pockets trapped in the corundum aggregates that occur as xenoliths in Cretaceous basaltic volcanoes on Mt. Carmel, north Israel. These melt pockets show extensive textural evidence of immiscibility between metallic (Fe-Ti-C-Si) melts, Ca-Al-Mg-Si-O melts, and Ti-(oxy)nitride melts. The metallic melts commonly form spherules in the coexisting oxide glass. Most of the observed TiB2 crystallized from the Fe-Ti-C silicide melts and a smaller proportion from the oxide melts. The parageneses in the melt pockets of the xenoliths require fO2 = ?IW-6, probably generated through interaction between evolved silicate melts and mantle-derived CH4+H2 fluids near the crust-mantle boundary. Under these highly reducing conditions boron, like carbon and nitrogen, behaved mainly as a siderophile element during the separation of immiscible metallic and oxide melts. These parageneses have implications for the residence of boron in the peridotitic mantle and for the occurrence of TiB2 in other less well-constrained environments such as ophiolitic chromitites.
DS1989-0019
1989
Toledo-Groke, M.C.Alcover Neto, A., Toledo-Groke, M.C.Preliminary characterization of the supergene evolution of the carbonatite rocks of the Juquia (sp) Alkaline carbonatite complex with phosphateenrichmentXiii International Geochemical Exploration Symposium, Rio 89 Brazilian, p. 219. AbstractBrazilCarbonatite, Geochemistry
DS201811-2555
2019
Toleu, S.F.Bouyo, M.H., Penaye, J., Mount, H., Toleu, S.F.Eclogite facies metabasites from the Paleoproterozoic Nyong Group, SW Cameroon: mineralogical evidence and implications for a high pressure metamorphism related to a subduction zone at the NW margin of the Archean Congo craton.Journal of African Earth Sciences, Vol. 149, pp. 215-234.Africa, Cameroonsubduction

Abstract: High- to ultrahigh-pressure metamorphic assemblages consisting of garnet-omphacitic clinopyroxene bearing mafic rocks have been identified within the Paleoproterozoic Nyong Group in SW Cameroon, at the northwestern margin of the Archean Congo craton. These rocks were investigated in detail and for the first time evidence for eclogite facies metamorphism at ca 25?kbar and 850?°C is provided. A clockwise P-T path with nearly isothermal decompression (ITD) is deduced from mineral zoning and textural relationships characterized by mineral recrystallization and multi-layered coronitic overgrowths of plagioclase and clinopyroxene surrounding garnet porphyroblasts. These P-T conditions imply a burial depth greater than 90?km, at lower geothermal gradient of ca 10?°C/km. The geochemical signature of ten representative rock samples show that two groups of eclogite facies rocks genetically originate from mostly basaltic and basaltic andesite compositions, with a characteristic upper mantle-derived tholeiitic trend. Moreover, their chondrite and MORB normalized REE and trace element concentrations are characterized by nearly flat REE patterns with very little to no Eu anomaly, (La/Sm)N?=?1 and Zr/Nb?=?10, as well as a gradual depletion from LREE to HREE with also very little to no Eu anomaly, but (La/Sm)N < 1, Zr/Nb > 10 and negative anomalies in Th, K, Nb, Ta, Sr, Zr and Ti consistent with mid-ocean ridge basalt (MORB) contaminated by a subduction component or by a crustal component. Previous available geochronological data coupled with our new petrological, mineralogical and geochemical findings clearly indicate that the eclogite facies metabasites from the Eburnean Nyong Group between 2100 and 2000 Ma represent one of the oldest subducted oceanic slab or trace of a suture zone so far recorded within the West Central African Fold Belt (WCAFB). The geodynamic implications of these eclogites suggest a subduction-related process followed by a rapid exhumation of their protoliths, therefore, providing critical information corroborating that plate tectonic processes operated during the Paleoproterozoic.
DS1910-0596
1919
Tolkowsky, M.Tolkowsky, M.Diamond DesignLondon: Spoon Ltd., GlobalKimberlite, Kimberley, Janlib, Diamond
DS201811-2602
2018
Tollefsen, E.Ranta, E., Stockmann, G., Wagner, T., Fusswinkel, T., Sturkell, E., Tollefsen, E., Skelton, A.Fluid-rock reactions in the 1.3 Ga siderite carbonatite of the Gronnedal-Ika alkaline complex, southwest Greenland.Contributions to Mineralogy and Petrology, Vol. 173, 26p. Doi.org/10.1007/s00410-018-1505-yEurope, Greenlandcarbonatite

Abstract: Petrogenetic studies of carbonatites are challenging, because carbonatite mineral assemblages and mineral chemistry typically reflect both variable pressure-temperature conditions during crystallization and fluid-rock interaction caused by magmatic-hydrothermal fluids. However, this complexity results in recognizable alteration textures and trace-element signatures in the mineral archive that can be used to reconstruct the magmatic evolution and fluid-rock interaction history of carbonatites. We present new LA-ICP-MS trace-element data for magnetite, calcite, siderite, and ankerite-dolomite-kutnohorite from the iron-rich carbonatites of the 1.3 Ga Grønnedal-Íka alkaline complex, Southwest Greenland. We use these data, in combination with detailed cathodoluminescence imaging, to identify magmatic and secondary geochemical fingerprints preserved in these minerals. The chemical and textural gradients show that a 55 m-thick basaltic dike that crosscuts the carbonatite intrusion has acted as the pathway for hydrothermal fluids enriched in F and CO2, which have caused mobilization of the LREEs, Nb, Ta, Ba, Sr, Mn, and P. These fluids reacted with and altered the composition of the surrounding carbonatites up to a distance of 40 m from the dike contact and caused formation of magnetite through oxidation of siderite. Our results can be used for discrimination between primary magmatic minerals and later alteration-related assemblages in carbonatites in general, which can lead to a better understanding of how these rare rocks are formed. Our data provide evidence that siderite-bearing ferrocarbonatites can form during late stages of calciocarbonatitic magma evolution.
DS2002-1126
2002
TollefsrudNeumann, E.R., Dunworth, Sundvolt, TollefsrudB1 basaltic lavas in Vestfold Jeloya area, central Oslo rift: derivation from initial melts formed ... enrichedLithos, Vol.61, 1-2, pp. 21-53.Norway, EuropeMantle plume - progressive partial melting, Clinopyroxenites, wehrlites, websterites
DS1975-1244
1979
Tollo, K.P.Tollo, K.P., Haggerty, S.E.Composition and Textural Relations of Discrete Ilmenite And rutile Nodules from the Orapa Ak 1 Kimberlite Pipe, Botswana.Eos, Vol. 60, No. 18, PP. 418-419. (abstract.).BotswanaPetrography
DS1981-0408
1981
Tollo, R.P.Tollo, R.P., Haggerty, S.E., Mcmahon, B.M.Ilmenite Rutile Intergrowths in Kimberlites: Mineral Chemistry, Phase Relations and Possible Implications.Eos, Vol. 62, No. 17, P. 414. (abstract.).South Africa, BotswanaJagersfontein, Orapa
DS1982-0602
1982
Tollo, R.P.Tollo, R.P.Petrography and Mineral Chemistry of Ultramafic and Related inclusions from the Orapa A/k 1 Kimberlite Pipe, Botswana.Amherst: Ph.d. Thesis, University Massachusetts, Published As Uni, 203P.BotswanaXenoliths, Petrology, Mineralogy
DS1983-0127
1983
Tollo, R.P.Beckett, J.R., Tollo, R.P.A Revised Geothermometer for Coexisting Ilmenite and Clinopyroxene from Kimberlitic Nodule Suites.Geological Society of America (GSA), Vol. 15, No. 6, P. 524. (abstract.).GlobalGeothermometry, Genesis, Xenoliths
DS1987-0742
1987
Tollo, R.P.Tollo, R.P., Haggerty, S.E.Niobium, chromium rutile in the Orapa kimberlite BotswanaCanadian Mineralogist, Vol. 25, pp. 251-264BotswanaMineralogy, Nodules
DS1989-1505
1989
Tollo, R.P.Tollo, R.P., Gottfried, D.Early Jurassic quartz normative magmatism of the eastern North Americanprovince: evidence for independent magmas and distinct sourcesNew Mexico Bureau of Mines Bulletin., Continental Magmatism Abstract Volume, Held, Bulletin. No. 131, p. 270 Abstract held June 25-July 1United States, Appalachia, MidcontinentTectonics, Magma
DS200412-2002
2004
Tollo, R.P.Tollo, R.P., Corriveau, l., McLelland, J., Bartholomew, M.J.Proterozoic tectonic evolution of the Grenville Orogen in North America.Geological Society of America Memoir, MWR 197,pp. 1-18. ISBN 0-8137-1197-5 geosociety.orgCanada, Ontario, United States, MexicoBook - tectonics, geodynamics
DS200612-0460
2006
Tollstrup, D.Gill, J.B., Tollstrup, D., Todd, E.Hf mobility and immobility in subduction zones.Geochimica et Cosmochimica Acta, Vol. 70, 18, 1, p. 17, abstract only.MantleSubduction
DS201112-0831
2010
TolmachevaProskurnin, 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
DS201412-0473
2014
Tolmacheva, E.Korikovsky, S., Kotov, A., Salnikova, E., Aranovich, L., Korpechkov, D., Yakovleva, S., Tolmacheva, E., Anisimova, I.The age of the protolith of metamorphic rocks in the southeastern Lapland granulite belt, southern Kola Peninsula: correlation with the Belomorian mobile belt in the context of the problem of Archean eclogites.Petrology, Vol. 22, 2, pp. 91-108.Russia, Kola PeninsulaEclogite
DS200812-1078
2008
Tolmacheva, E.V.Skublov, S.G., Lobach Zhuchenko, S.B., Guseva, N.S., Gembitckaya, I.M., Tolmacheva, E.V.REE distribution in zircons from lamproites in Panozero complex of sanukitoids (Karelia, NW Russia).Goldschmidt Conference 2008, Abstract p.A875.Russia, KareliaLamproite
DS200912-0697
2009
Tolmacheva, E.V.Skublov, S.G., Lobach-Zhuchenko, S.B., Guseva, N.S., Gembitskaya, I.M., Tolmacheva, E.V.Rare earth and trace element distribution in zircons from miaskite lamproites of the Panozero complex, central Karelia.Geochemistry International, Vol. 47, 9., Sept. pp. 901-913.RussiaLamproite
DS201712-2686
2017
Tolmacheva, E.V.Gladkochub, D.P., Donskaya, T.V., Sklyarov, E.V., Kotov, A.B., Vladykin, N.V., Pisarevsky, S.A., Larin, A.M., Salnikova, E.B., Saveleva, V.B., Sharygin, V.V., Starikova, A.E., Tolmacheva, E.V., Velikoslavinsky, S.D., Mazukabzov, A.M., Bazarova, E.P., KovaThe unique Katugin rare metal deposit ( southern Siberia): constraints on age and genesis.Ore Geology Reviews, in press available, 18p.Russia, Siberiadeposit - Katugin

Abstract: We report new geological, mineralogical, geochemical and geochronological data about the Katugin Ta-Nb-Y-Zr (REE) deposit, which is located in the Kalar Ridge of Eastern Siberia (the southern part of the Siberian Craton). All these data support a magmatic origin of the Katugin rare-metal deposit rather than the previously proposed metasomatic fault-related origin. Our research has proved the genetic relation between ores of the Katugin deposit and granites of the Katugin complex. We have studied granites of the eastern segment of the Eastern Katugin massif, including arfvedsonite, aegirine-arfvedsonite and aegirine granites. These granites belong to the peralkaline type. They are characterized by high alkali content (up to 11.8?wt% Na2O?+?K2O), extremely high iron content (FeO*/(FeO*?+?MgO)?=?0.96-1.00), very high content of most incompatible elements - Rb, Y, Zr, Hf, Ta, Nb, Th, U, REEs (except for Eu) and F, and low concentrations of CaO, MgO, P2O5, Ba, and Sr. They demonstrate negative and CHUR-close eNd(t) values of 0.0…-1.9. We suggest that basaltic magmas of OIB type (possibly with some the crustal contamination) represent a dominant part of the granitic source. Moreover, the fluorine-enriched fluid phases could provide an additional source of the fluorine. We conclude that most of the mineralization of the Katugin ore deposit occurred during the magmatic stage of the alkaline granitic source melt. The results of detailed mineralogical studies suggest three major types of ores in the Katugin deposit: Zr mineralization, Ta-Nb-REE mineralization and aluminum fluoride mineralization. Most of the ore minerals crystallized from the silicate melt during the magmatic stage. The accessory cryolites in granites crystallized from the magmatic silicate melt enriched in fluorine. However, cryolites in large veins and lens-like bodies crystallized in the latest stage from the fluorine enriched melt. The zircons from the ores in the aegirine-arfvedsonite granite have been dated at 2055?±?7?Ma. This age is close to the previously published 2066?±?6?Ma zircon age of the aegirine-arfvedsonite granites, suggesting that the formation of the Katugin rare-metal deposit is genetically related to the formation of peralkaline granites. We conclude that Katugin rare-metal granites are anorogenic. They can be related to a Paleoproterozoic (~2.05?Ga) mantle plume. As there is no evidence of the 2.05?Ga mantle plume in other areas of southern Siberia, we suggest that the Katugin mineralization occurred on the distant allochtonous terrane, which has been accreted to Siberian Craton later.
DS201312-0917
2013
Tolmacheva, T.Yu.Tolmacheva, T.Yu., Alekseev, A.S., Reimers, A.N.Conodonts in xenoliths from kimberlite pipes of the southeastern White Sea region ( Arkhangelsk Oblast): key to Ordovician stratigraphic and paleogeographic reconstructions of the East European Platform.Doklady Earth Sciences, Vol. 451, 1, pp. 687-691.Russia, Archangel, Kola PeninsulaGeochronology
DS1990-1470
1990
Tolmacheva, Y.V.Tolmacheva, Y.V., Velkoslavinskii, S.D.On the supposed moissonite finding in early Precambrian formations of the Aldanian shield.(Russian)Doklady Academy of Sciences Nauk. SSSR, (Russian), Vol. 314, No. 5, pp. 1215-1217RussiaMineralogy, Moissonite
DS1992-1558
1992
Tolmacheva, Ye..Tolmacheva, Ye.., Velikoslavinsky, S.D.On a presumed find of moissanite in the Lower Precambrian rocks of the Aldan Shield.Doklady Academy of Sciences USSR, Earth Science Section, Vol. 314, No. 1-6, July 1992, pp. 97-100.Russia, AldanMoissanite, Mineralogy
DS1993-0768
1993
Tolochko, V.V.Kadik, A.A., Zharkova, Ye.V., Tolochko, V.V.Redox conditions during the generation of diamond-bearing kyanite eclogitein the Udachnaya kimberlite pipe, Yakutia.Doklady Academy of Sciences USSR, Earth Science Section, Vol. 321, No. 8, August 1993, pp. 217-221.Russia, Commonwealth of Independent States (CIS), YakutiaGenesis, Deposit -Udachnaya
DS201812-2892
2018
Tolosana-Delgado, R.Tolosana-Delgado, R., von Eynatten, H., Krippner, A., Meinhold, G.A multivariate discrimination scheme of detrital garnet chemistry for use in sedimentary provenance analysis.Sedimentary Geology, Vol. 375, pp. 14-26.Europe, Norway, Austria, Africa, Ugandamineral chemistry

Abstract: Garnet chemistry provides a well-established tool in the discrimination and interpretation of sediment provenance. Current discrimination approaches, however, (i) suffer from using less variables than available, (ii) subjective determination of discrimination fields with strict boundaries suggesting clear separations where in fact probabilities are converging, and (iii) significant overlap of compositional fields of garnet from different host-rock groups. The new multivariate discrimination scheme is based on a large database, a hierarchical discrimination approach involving three steps, linear discriminant analysis at each step, and the five major host-rock groups to be discriminated: eclogite- (A), amphibolite- (B) and granulite- (C) facies metamorphic rocks as well as ultramafic (D) and igneous rocks (E). The successful application of statistical discrimination approaches requires consideration of the a priori knowledge of the respective geologic setting. This is accounted for by the use of prior probabilities. Three sets of prior probabilities (priors) are introduced and their advantages and disadvantages are discussed. The user is free to choose among these priors, which can be further modified according to the specific geologic problem and the level of a priori knowledge. The discrimination results are provided as integrated probabilities of belonging to the five major host-rock groups. For performing calculations and results a supplementary Excel® spreadsheet is provided. The discrimination scheme has been tested for a large variety of examples of crystalline rocks covering all of the five major groups and several subgroups from various geologic settings. In most cases, garnets are assigned correctly to the respective group. Exceptions typically reflect the peculiarities of the regional geologic situation. Evaluation of detrital garnets from modern and ancient sedimentary settings of the Western Gneiss Region (Norway), Eastern Alps (Austria) and Albertine Rift (Uganda) demonstrates the power to reflect the respective geologic situations and corroborates previous results. As most garnet is derived from metamorphic rocks and many provenance studies aim at reconstructing the tectonic and geodynamic evolution in the source area, the approach and the examples emphasize discrimination of metamorphic facies (i.e., temperature-pressure conditions) rather than protolith composition.
DS1992-0823
1992
Tolstikhi, I.N.Kanenskiy, I.L., Tolstikhi, I.N.High HE3/He 4 ratios in diamonds -constraints on alluvium age.(Russian)Geochemistry International (Geokhimiya), (Russian), No. 4, April pp. 561-569RussiaGeochemistry, helium, Helium in diamond inclusions
DS1992-0817
1992
Tolstikhim, I.N.Kamenskiy, I.L., Tolstikhim, I.N.High 3He/4He in diamond and constraints on the age of alluviuMGeochemistry International, Vol. 29, No. 11, 94-102GlobalDiamond inclusions, Helium, age determination
DS1998-0950
1998
Tolstikhin, I.Marty, B., Tolstikhin, I., Zimmermann, J.L.Plume derived rare gases in 380 Ma carbonatites from the Kola region And the argon isotopic composition...Earth and Planetary Science Letters, Vol.164, No.1-2, Dec.15, pp.179-92.Russia, Kola PeninsulaMantle chemistry, geochronology, Carbonatite
DS200512-1093
2005
Tolstikhin, I.Tolstikhin, I., Hofmann, A.W.Early crust on top of the Earth's core.Physics of the Earth and Planetary Letters, Vol. 148, 2-4, Feb. pp. 109-130.MantleGeochemistry, core mantle boundary, rare gases, REE
DS200912-0794
2009
Tolstikhin, I.Verchovsky, A., Tolstikhin, I.N and C isotopic compositons in high 3He Kola plume rocks.Goldschmidt Conference 2009, p. A1378 Abstract.Russia, Kola PeninsulaCarbonatite
DS1990-0143
1990
Tolstikhin, I.N.Azbel, I.Ya., Tolstikhin, I.N.Geodynamics, magmatism and degassing of the earthGeochimica et Cosmochimica Acta, Vol. 54, pp. 139-154GlobalMantle dynamics, Mantle genesis
DS1994-1308
1994
Tolstikhin, I.N.O'Nions, R.K., Tolstikhin, I.N.Behaviour of residence times of lithophile and rare gas tracers in The upper mantle.Earth and Planet. Science Letters, Vol. 124, No. 1-4, June pp. 131-138.Mantlerare earth elements (REE).
DS1994-1788
1994
Tolstikhin, I.N.Tolstikhin, I.N., O'Nions, R.K.The earth's missing xenon: a combination of early degassing and of rare gas loss from the atmosphereChemical Geology, Vol. 115, No. 1-2, July 1, pp. 1-6MantleXenon, Geochemistry
DS1997-0630
1997
Tolstikhin, I.N.Kramers, J.D., Tolstikhin, I.N.Two terrestrial lead isotope paradoxes, forward transport modelling, coreformation... history crustChemical Geology, Vol. 139, pp. 75-110MantleAccretion, crustal growth, Core formation continental crust
DS2002-1605
2002
Tolstikhin, I.N.Tolstikhin, I.N., Kamensky, Marty, Nivin, Vetrin et al.Rare gas isotopes and parent trace elements in ultrabasic alkaline carbonatite complexes, Kola Peninsula.Geochimica et Cosmochimica Acta, Vol. 66, No. 5, pp. 881-901.Russia, Kola PeninsulaMantle plume component, Geochemistry
DS200612-1433
2005
Tolstikhin, I.N.Tolstikhin, I.N., Kramers, J.D., Hofmann, A.W.A chemical Earth model with whole mantle convection: the importance of a core mantle boundary layer 'D' and its early formation.Chemical Geology, Vol. 226, 3-4, pp. 79-99.MantleConvection, model
DS202006-0946
2020
TolstovPonomarchuk, 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 d13C 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 d13C carbonates from -25 to -59‰ are characterized. The formation of abnormally low d13C in carbonates is determined by the biogenic oxidation of methane from d13Cmet to -70‰.
DS200712-0594
2007
Tolstov, A.Lapin, A., Tolstov, A., Antonov, A.Sr and Nd isotopic compositions of kimberlites and associated rocks of the Siberian Craton.Doklady Earth Sciences, Vol. 413, 3, pp. 557-560.RussiaGeochronology
DS200712-0595
2007
Tolstov, A.Lapin, A., Tolstov, A., Antonov, A.Sr and Nd isotopic compositions of kimberlites and associated rocks of the Siberian Craton.Doklady Earth Sciences, Vol. 413, 3, pp. 557-560.RussiaGeochronology
DS1990-0886
1990
Tolstov, A.V.Kravchenko, S.M., Belyakov, A.Yu., Kubyshev, A.I., Tolstov, A.V.Scandium rare earth yttrium niobium ores - a new economic resourceInternational Geology Review, Vol. 32, No. 3, March pp. 280-284BrazilCarbonatite, Rare earths Araxa
DS1998-1548
1998
Tolstov, A.V.Vladykin, N.V., Lelyukh, M.I., Tolstov, A.V.Lamproites of the Anabar region, northern rimming of the SiberianPlatform7th International Kimberlite Conference Abstract, pp. 946-8.Russia, SiberiaLamproites, chemistry, Deposit - Pinabarie
DS2003-1430
2003
Tolstov, A.V.Vladykin, N.V., Lelyukh, M.I., Tolstov, A.V., Serov, V.P.Petrology of kimberlite lamproite carbonatite rock association, east Prianabar'e (8 Ikc Www.venuewest.com/8ikc/program.htm, Session 7, POSTER abstractRussiaBlank
DS200412-2062
2003
Tolstov, A.V.Vladykin, N.V., Lelyukh, M.I., Tolstov, A.V., Serov, V.P.Petrology of kimberlite lamproite carbonatite rock association, east Prianabar'e ( Russia).8 IKC Program, Session 7, POSTER abstractRussiaKimberlite petrogenesis
DS200512-0007
2004
Tolstov, A.V.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
DS200812-0002
2008
Tolstov, A.V.Afanasev, V.P., Nikolenko, E.I., Tychikov, N.S., Titov, A.T., Tolstov, A.V., Kornilova, V.P., Sobolev, N.V.Mechanical abrasion of kimberlite indicator minerals: experimental investigations.Russian Geology and Geophysics, Vol. 49, 2, pp. 91-97.TechnologyMineralogy
DS200812-0632
2007
Tolstov, A.V.Lapin, A.V., Tolstov, A.V., Vasilenko, V.B.Petrochemical characteristics of the kimberlites in the Middle Markha region with application to the problem of the geochemical heterogeneity of kimberlites.Geochemistry International, Vol. 45, 12, Dec. pp. 1197-1209.Russia, YakutiaGeochemistry - comparison Zolotitsa and Grib
DS200812-0689
2008
Tolstov, A.V.Lupin, A.V., Tolstov, A.V.Geochemical types of kimberlites and their mantle sources.Deep Seated Magmatism, its sources and plumes, Ed. Vladykin, N.V., 2008 pp. 147-168.MantleGeochemistry
DS200812-1207
2008
Tolstov, A.V.Vasilenko, V.B., Tolstov, A.V., Minin, V.A., Kuznetsova, L.G., Surkov, N.V.Normative quartz as an indicator of the mass transfer intensity during the postmagmatic alteration of the Botuobinskaya pipe kimberlites ( Yakutia).Russian Geology and Geophysics, Vol. 49,no. 12, pp. 894-907.Russia, YakutiaDeposit - Botuobinskaya
DS200912-0426
2009
Tolstov, A.V.Lapin, A.V., Tolstov, A.V.Geochemical types of kimberlites and their mantle sources.alkaline09.narod.ru ENGLISH, May 10, 2p. abstractRussia, Kola Peninsula, ArchangelDeposits
DS200912-0765
2009
Tolstov, A.V.Tolstov, A.V., Minin, V.A., Vasilenko, V.B., Kuznetsova, L.G., Razumov, A.N.A new body of highly Diamondiferous kimberlites in the Nakyn field of the Yakutian kimberlite province.Russian Geology and Geophysics, Vol. 50, 3, pp. 162-173.RussiaMineral chemistry
DS201012-0814
2010
Tolstov, A.V.Vasilenko, V.B., Tolstov, A.V., Kuznetsova, L.G., Minin, V.A.Petrochemical evaluation of the diamond potentials of Yakutian kimberlite fields.Geochemistry International, Vol. 48, 4, pp. 346-354.RussiaMineralogy
DS201212-0006
2012
Tolstov, A.V.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
DS201212-0439
2012
Tolstov, A.V.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
DS201212-0751
2012
Tolstov, A.V.Vasilenko, V.B., Kuznetsova, L.G., Minin, V.A., Tolstov, A.V.Behavior of major and rare earth elements during the postmagmatic alteration of kimberlites.Russian Geology and Geophysics, Vol. 53, pp. 62-76.RussiaAlteration
DS201507-0320
2015
Tolstov, A.V.Lazereva, E.V., Zhmodik, S.M., Dobretsov, N.L., Tolstov, A.V., Shcherbov, B.L., Karmanov, N.S., Gerasimov, E.Yu., Bryanskaya, A.V.Main minerals of abnormally high grade ores of the Tomtor deposit ( Arctic Siberia).Russian Geology and Geophysics, Vol. 56, pp. 844-873.RussiaDeposit - Tomtor
DS201510-1805
2015
Tolstov, A.V.Sobolev, N.V., Sobolev, A.V., Tomilenko, A.A., Batanova, V.G., Tolstov, A.V., Logvinova, A.M., Kuzmin, D.V.Unique compositional pecularities of olivine phenocrysts from the post flood basalt Diamondiferous Malokuonapskaya kimberlite pipe, Yakutia.Doklady Earth Sciences, Vol. 463, 2, pp. 828-832.RussiaDeposit - Malokuonapskaya
DS201612-2326
2016
Tolstov, A.V.Panina, L.I., Rokosova, E.Yu., Isakova, A.T., Tolstov, A.V.Lamprophyres of the Tomto Massif: a result of mixing between potassic and sodic alkaline mafic magmas.Petrology, Vol. 24, 6, pp. 608-625.RussiaAlkalic
DS201710-2266
2017
Tolstov, A.V.Sobolev, N.V., Schertle, H-P., Neuser, R.D., Tomilenko, A.A., Kuzmin, D.V., Loginova, A.M., Tolstov, A.V., Kostrovitsky, S.I., Yakovlev, D.A., Oleinikov, O.B.Formation and evolution of hypabyssal kimberlites from the Siberian craton: part 1 - new insights from cathodluminescence of the carbonates. Anabar and Olenek areaJournal of Asian Earth Sciences, Vol. 145, pt. B, pp. 670-678.Russia, Siberiadeposit - Kuranakh, Kharamay
DS201712-2715
2017
Tolstov, A.V.Panina, L.I., Rokosova, E.Yu., Isakova, A.T., Tolstov, A.V.Mineral composition of alkaline lamprophyres of the Tomto massif as reflection of their genesis.Russian Geology and Geophysics, Vol. 58, pp. 887-902.Russiamonchiquites
DS201808-1722
2018
Tolstov, A.V.Agashev, A.M., Nakai, S., Serov, I.V., Tolstov, A.V., Garanin, K.V., Kovalchuk, O.E.Geochemistry and origin of the Mirny field kimberlites, Siberia.Mineralogy and Petrology, doi.org/10.1007/s00710-018-06174 12p.Russia, Siberiadeposit - Mirny

Abstract: Here we present new data from a systematic Sr, Nd, O, C isotope and geochemical study of kimberlites of Devonian age Mirny field that are located in the southernmost part of the Siberian diamondiferous province. Major and trace element compositions of the Mirny field kimberlites show a significant compositional variability both between pipes and within one diatreme. They are enriched in incompatible trace elements with La/Yb ratios in the range of (65-00). Initial Nd isotope ratios calculated back to the time of the Mirny field kimberlite emplacement (t?=?360 ma) are depleted relative to the chondritic uniform reservoir (CHUR) model being 4 up to 6 ?Nd(t) units, suggesting an asthenospheric source for incompatible elements in kimberlites. Initial Sr isotope ratios are significantly variable, being in the range 0.70387-0.70845, indicating a complex source history and a strong influence of post-magmatic alteration. Four samples have almost identical initial Nd and Sr isotope compositions that are similar to the prevalent mantle (PREMA) reservoir. We propose that the source of the proto-kimberlite melt of the Mirny field kimberlites is the same as that for the majority of ocean island basalts (OIB). The source of the Mirny field kimberlites must possess three main features: It should be enriched with incompatible elements, be depleted in the major elements (Si, Al, Fe and Ti) and heavy rare earth elements (REE) and it should retain the asthenospheric Nd isotope composition. A two-stage model of kimberlite melt formation can fulfil those requirements. The intrusion of small bodies of this proto-kimberlite melt into lithospheric mantle forms a veined heterogeneously enriched source through fractional crystallization and metasomatism of adjacent peridotites. Re-melting of this source shortly after it was metasomatically enriched produced the kimberlite melt. The chemistry, mineralogy and diamond grade of each particular kimberlite are strongly dependent on the character of the heterogeneous source part from which they melted and ascended.
DS201906-1348
2019
Tolstov, A.V.Skublov, S.G., Tolstov, A.V., Baranov, L.N., Melnik, A.E., Levashova, E.V.First data on the geochemistry and U-Pb age of zircons from the kamaphorites of the Tomtor alkaline ultrabasic massif, Arctic Yakutia. ( carbonatite)Geochemistry, in press available 11p.Russia, Yakutiadeposit - Tomtor

Abstract: Zircon from Tomtor syenites and kamaphorites was dated following the U-Pb method (SHRIMP-II), and the distribution of trace and rare-earth elements (REE) was studied at the same zircon point using an ion microprobe. The main zircon population from syenites was dated at 402?±?7 Ma, while the age range of single zircon grains was 700-660 M?. Different-aged zircon groups from syenites exhibited the characteristics of magmatic zircon, but their concentrations of REE and other trace elements differed markedly. The REE distribution in 700-660-M? zircon is consistent with that of the typical zircon from syenites (Belousova et al., 2002), while the heavy rare-earth elements (HREE), P, Ti, and Y concentrations of ca. 400-Ma zircon differ from those of older zircon. This is the first isotope-geochemical study of zircon from kamaphorites, and the U-Pb age of ca. 400 M? is within the error limits with of the main zircon population from syenites. The considerable enrichment of REE, C?, Ti, Sr, Y, Nb, and Ba in zircon from kamaphorites may be partly due to the presence of burbankite microinclusions. The trace-element distribution pattern of zircon from kamaphorites is very similar to the geochemical characteristics of zircon from Tiksheozero carbonatites (Tichomirowa et al., 2013). The new age dates for Tomtor syenites and kamaphorites, consistent with 700-660 M? and ca. 400 M? events, support the zircon (Vladykin et al., 2014) and pyrochlore (Antonov et al., 2017) age dates determined following the U-Pb method and those of biotite obtained following the 40Ar-39Ar method (Vladykin et al., 2014).
DS202005-0719
2020
Tolstov, A.V.Agashev, A.M., Chervyakovskaya, M.V., Serov, I.V., Tolstov, A.V., Agasheva, E.V., Votyakov, S.L.Source rejuvenation vs. re-heating: constraints on Siberian kimberlite origin from U-Pb and Lu-Hf isotope compositions and geochemistry of mantle zircons. ( Silurian, Devonian, Triassic, Jurassic)Lithos, Vol. 364-365, 10p. PdfRussia, Siberiadeposit - Druzhba, Choumurdakh

Abstract: We have studied a suite of mantle zircons from several differently aged pipes of the Siberian kimberlite province via UPb and LuHf isotope analyses and trace element compositions. The UPb ages we obtained confirmed four main episodes (Silurian, Devonian, Triassic and Jurassic) of kimberlite activity on the Siberian craton. The Druzhba pipe had two populations of zircons dating from the Silurian and Devonian, respectively. The geochemical features of our suite of mantle zircons show low concentrations of U, Th and heavy rare earth elements (REEs), positive Ce anomalies, and weak or absent Eu anomalies, which is in accord with the mantle-derived nature of the zircon. Despite having broadly similar geochemistry, zircons from differently aged kimberlites had some clear differences arising from variations in the composition of the protokimberlite metasomatic melt and from peculiarities of fractional crystallization. The Th/U ratios were highest in the Silurian zircons and sharply decreased toward the Devonian. The Triassic zircons had elevated and highly variable Ce/Nb ratios with low and nearly constant Th/U ratios. Zircons from Siberian kimberlites with different UPb ages showed systematic variations in their initial Hf isotope compositions. The oldest Silurian kimberlite field, Chomurdakh, had two zircon populations: Silurian zircons, with ?Hft values in the range of +2.8 to +5.9 units, and Devonian zircons, with ?Hft values in the range of +1.6 to +2.0 units. Zircons from the Devonian field kimberlites were in the range of +5.6 to +9.6 ?Hft units. The Triassic kimberlitic zircons had the most juvenile Hf isotope composition, at +9.3 to +11.2 ?Hft units, while the Jurassic zircons had +6.9 ?Hft units. The combination of the UPb and LuHf isotope data suggests a periodic rejuvenation of the lithospheric mantle roots by low-volume melts from the asthenospheric mantle, resulting shortly after in kimberlite emplacements. Some Devonian and Jurassic kimberlites may have been melted by re-heating the Silurian and Triassic age sources, respectively, about 60 Myr after they were formed.
DS202012-2251
2020
Tolstov, A.V.Skublov, S.G., Tolstov, A.V., Baranov, L.N., Melnik, A.E., Levashova, E.V.First data on the geochemistry and U-Pb age of zircons from the kamaphorites of the Tomtor alkaline-ultrabasic massif, Arctic Yakutia.Geochemistry , in press available, 11p. PdfRussia, Yakutiadeposit - Tomtor

Abstract: Zircon from Tomtor syenites and kamaphorites was dated following the U-Pb method (SHRIMP-II), and the distribution of trace and rare-earth elements (REE) was studied at the same zircon point using an ion microprobe. The main zircon population from syenites was dated at 402?±?7 Ma, while the age range of single zircon grains was 700-660 M?. Different-aged zircon groups from syenites exhibited the characteristics of magmatic zircon, but their concentrations of REE and other trace elements differed markedly. The REE distribution in 700-660-M? zircon is consistent with that of the typical zircon from syenites (Belousova et al., 2002), while the heavy rare-earth elements (HREE), P, Ti, and Y concentrations of ca. 400-Ma zircon differ from those of older zircon. This is the first isotope-geochemical study of zircon from kamaphorites, and the U-Pb age of ca. 400 M? is within the error limits with of the main zircon population from syenites. The considerable enrichment of REE, C?, Ti, Sr, Y, Nb, and Ba in zircon from kamaphorites may be partly due to the presence of burbankite microinclusions. The trace-element distribution pattern of zircon from kamaphorites is very similar to the geochemical characteristics of zircon from Tiksheozero carbonatites (Tichomirowa et al., 2013). The new age dates for Tomtor syenites and kamaphorites, consistent with 700-660 M? and ca. 400 M? events, support the zircon (Vladykin et al., 2014) and pyrochlore (Antonov et al., 2017) age dates determined following the U-Pb method and those of biotite obtained following the 40Ar-39Ar method (Vladykin et al., 2014).
DS201112-0727
2010
Tolstykh, M.L.Naumov, V.B., Tolstykh, M.L., Grib, E.N., Leonov, V.L., Kononkova, N.N.Chemical composition, volatile components, and trace elements in melts of the Karymskii volcanic centre, Kamchatka and Golovnin a volcano, Kunashir Island....Vladykin, N.V., Deep Seated Magmatism: its sources and plumes, pp. 104-127.RussiaMineral inclusions
DS1991-1737
1991
Tolstykh, N.D.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
DS1996-1434
1996
Tolwinski, B.Tolwinski, B., Nahan, P.B.An application of L-TOPS to project evaluationSociety for Mining, Metallurgy and Exploration (SME)-American Institute of Mining, Metallurgical, and Petroleum Engineers (AIME) Preprint, 96-77GlobalGeostatistics, Ore reserves
DS1988-0278
1988
Tom, H.Guptill, S.C., Cotter, D., Gibson, R., Liston, R., Tom, H., Trainor, T.A process for evaluating geographic information systemsUnited States Geological Survey (USGS) Open File, No. 88-0105, 55p. $ 21.25GlobalGIS, Technology Group
DS1988-0495
1988
Tom LeongNam, Tom Leong, Burns, R.C., Keddy, R.J.Radiation detector from a mass of small diamond particlesPatent: S. African 87 06994 A June 29, 1988 16p. (De Beers), GlobalDiamond Application
DS2001-0850
2001
TomaOhtani, E., Toma, Litasov, Kubo, SuzukiStability of dense hydrous magnesium silicate phases and water storage capacity in transition zone -Physical Earth and Planetary Interiors, Vol. 124, No. 1-2, pp. 105-117.MantleSlab melting, water
DS2002-0798
2002
Toma, M.Kabo, T., Ohtani, E., Kondo, T., Kato, T., Toma, M., Hosoya, T., Sano, A.Metastable garnet in oceanic crust at the top of the lower mantleNature, No. 6917, Dec. 19, pp. 803-5.MantleGarnet mineralogy
DS1997-0715
1997
Tomable, A.R.Magang, D.N., Tomable, A.R., Ntsimanyana, M.Mining potential of BotswanaMiga Conference Held Denver June 3-5, 37pBotswanaMining, Overview
DS1997-0716
1997
Tomable, A.R.Magang, D.N., Tomable, A.R., Ntsimanyana, M.Mining potential of BotswanaMiga Conference Held Denver June 3-5, 37p.BotswanaMining, Overview
DS200812-1177
2007
Toman, S.Toman, S.Sit up and listen.... interview with Ian Smillie Chair of the Diamond Development Initiative.Canadian Diamonds, Fall, pp. 26-31.Canada, GlobalDiamond Development Inititative
DS1970-0363
1971
Tomanoskaya, YU.I.Milashev, V.A., Tomanoskaya, YU.I.Phenomena of Alkaline-ultrabasic Magmatism in the Littoral PLeningrad: Niiga., PP. 127-133.RussiaBlank
DS1970-0148
1970
Tomanovskaya, YU.I.Milashev, V.A., Tomanovskaya, YU.I.Kimberlitic Volcanism in the Northeast Siberian Platform And the Prospects of the Region As a Source of Diamonds.Leningrad: Nauka., USSRRussiaBlank
DS1970-0364
1971
Tomanovskaya, YU.I.Milashev, V.A., Tomanovskaya, YU.I.Problems of Definition of the Term Kimberlite and ClassificaLeningrad: Niiga., PP. 57-61.RussiaBlank
DS1981-0409
1981
Tomanovskaya, YU.I.Tomanovskaya, YU.I.On the Skarn Forming Processes in the Kimberlite Rocks of The Siberian PlatformSoviet Geology And Geophysics, Vol. 22, No. 9, PP. 42-47.RussiaPicritic, Anabar, Sukhanskaya, Basin, Anteclise, Garnet, Kimberlite
DS2002-1198
2002
Tomascak, P.B.Owens, B.E., Tomascak, P.B.Mesoproterozoic lamprophyres in the Labrieville Massif, Quebec: clues to the origin of alkalic onorthosites?Canadian Journal of Earth Science, Vol.39,6 June,pp. 983-97.QuebecPetrology - lamprophyres
DS2003-1195
2003
Tomascak, P.B.Rudnick, R.L., McDonough, W.F.,Tomascak, P.B., Zack, T.Lithium isotopic composition of eclogites - implications for subduction zone processes8 Ikc Www.venuewest.com/8ikc/program.htm, Session 4, AbstractSierra LeoneMantle geochemistry, Deposit - Koidu
DS2003-1539
2003
Tomascak, P.B.Zack, T., Tomascak, P.B., Rudnick, R.L., Dalpe, C., McDonough, W.F.Extremely light Li in orogenic eclogites: the role of isotope fractionation duringEarth and Planetary Science Letters, Vol. 208, 3-4, pp. 279-90.MantleEclogites
DS200412-1702
2003
Tomascak, P.B.Rudnick, R.L., McDonough, W.F.,Tomascak, P.B., Zack, T.Lithium isotopic composition of eclogites - implications for subduction zone processes.8 IKC Program, Session 4, AbstractAfrica, Sierra LeoneMantle geochemistry Deposit - Koidu
DS200412-2194
2003
Tomascak, P.B.Zack, T., Tomascak, P.B., Rudnick, R.L., Dalpe, C., McDonough, W.F.Extremely light Li in orogenic eclogites: the role of isotope fractionation during dehydration in subducted oceanic crust.Earth and Planetary Science Letters, Vol. 208, 3-4, pp. 279-90.MantleEclogite
DS200512-1078
2004
Tomascak, P.B.Teng, F.Z., McDonough, W.F., Rudnick, R.L., Dalpe, C., Tomascak, P.B., Chappell, B.W., Gao, S.Lithium isotopic composition and concentration of the upper continental crust.Geochimica et Cosmochimica Acta, Vol. 68, 20, pp. 4167-4178.MantleGeochemistry, geochronology
DS200812-1162
2008
Tomascal, P.B.Teng, F-Z., Rudnick, R.L., McDonough, W.F., Gao, S., Tomascal, P.B., Liu, Y.Lithium isotopic composition and concentration of the deep continental crust.Chemical Geology, Vol. 255, 1-2, Sept. 30, pp. 47-59.MantleGeochronology
DS2003-1540
2003
Tomascek, P.R.Zack, T., Tomascek, P.R., Rudnick, R.L., Dalpe, C., McDonough, W.F.Extremely light Li in orogenic eclogites: the role of isotope fractionation duringEarth and Planetary Science Letters, Vol. 208, 3-4, March 30, pp.279-90.SwitzerlandSubduction - not specific to diamonds
DS200412-2195
2003
Tomascek, P.R.Zack, T., Tomascek, P.R., Rudnick, R.L., Dalpe, C., McDonough, W.F.Extremely light Li in orogenic eclogites: the role of isotope fractionation during dehydration in subducted oceanic crust.Earth and Planetary Science Letters, Vol. 208, 3-4, March 30, pp.279-90.Europe, SwitzerlandSubduction - not specific to diamonds
DS1991-1386
1991
Tomashpol'skiyPuktiel, 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
DS201212-0051
2012
Tomassi, A.Baptiste, V., Tomassi, A., Demouchy, S.Deformation and hydration of the lithospheric mantle beneath the Kaapvaal craton, South Africa.Lithos, Vol. 149, pp. 31-50.Africa, South AfricaPeridotite and water content
DS2001-0568
2001
TombaleKampunzu, A.B., Atekwana, McCourt, Tombale, RanganaiInteraction between Kaapvaal and Zimbabwe Cratons during the Neoarchean and implications for transition..Slave-Kaapvaal Workshop, Sept. Ottawa, 3p. abstractSouth Africa, ZimbabweArchean and post Archean plate tectonic styles, Limpopo Shashe belt
DS2003-0687
2003
Tombale, A.R.Kampunzu, A.B., Tombale, A.R., Zhai, M., Bagai, Z., Majaule, T., Modisi, M.P.Major and trace element geochemistry of plutonic rocks from Francistown, NELithos, Vol. 71, 2-4, pp. 431-460.ZimbabweTectonics
DS200412-0949
2003
Tombale, A.R.Kampunzu, A.B., Tombale, A.R., Zhai, M., Bagai, Z., Majaule, T., Modisi, M.P.Major and trace element geochemistry of plutonic rocks from Francistown, NE Botswana: evidence for a Neoarchean continental actiLithos, Vol. 71, 2-4, pp. 431-460.Africa, ZimbabweTectonics
DS200812-1178
2008
Tombale, A.R.Tombale, A.R.Botswana diamond centre: the second diamond revolution ( presentation by Botswana Diamond Hub Coordinator) down stream marketsBotswana Resource Conference held July 23-24., ppt presentation 18 slidesAfrica, BotswanaDiamond polishing and cutting, market
DS1986-0809
1986
Tombs, G.A.Tombs, G.A., Schos, B.Examination of surface features of Argyle diamonds from WesternAustraliaThe Australian Gemologist, (Proceedings 20th. International Gemmological Conference, Vol. 16, No. 2, May pp. 41-44AustraliaDiamond morphology
DS1990-1471
1990
Tombs, G.A.Tombs, G.A.Argyle diamondsThe Australian Gemologist, Vol. 17, No. 8, November pp. 321-324AustraliaDiamonds -, Mineralogy
DS201112-1110
2011
Tome, C.N.Wenk, H-R., Cottaar, S., Tome, C.N., McNamara, A., Romanowicz, B.Deformation in the lowermost mantle: from physical polycrystal plasticity to seismic anisotropy.Earth and Planetary Science Letters, Vol. 306, 1-2, pp. 33-45.MantleD- anisotropy, perovskite
DS1990-1472
1990
Tomeoka, K.Tomeoka, K., Ozima, M., Zashu, S., Sato, S., Yazu, S.X-ray micro-analysis of micro-inclusions in a Zaire coated diamond21st. Lunar And Planetary Science Conference, March 12-16, Houston, March 16 presentationDemocratic Republic of CongoDiamond morphology, X-ray microscopy
DS201608-1452
2016
Tomilanko, A.A.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
DS2001-0880
2001
TomilenkoPalyanov, Y.N., Shatsky, V.S., Sokol, A.G., TomilenkoCrystallization of metamorphic diamond: an experimental modelingDoklady, Vol. 381, No. 8, pp. 935-8.GlobalDiamond - morphology, Metamorphism
DS2001-1105
2001
TomilenkoSonin, V.M., Zhimulev, Fedorov, Tomilenko, ChepurovEtching of diamond crystals in a dry silicate melt at high pressure-temperature parameters.Geochemistry International, Vol. 39, No. 3, pp. 268-74.GlobalDiamond - experimental petrology, Morphogenesis
DS1993-0256
1993
Tomilenko, A.A.Chupin, V.P., Tomilenko, A.A., Chupin, S.V.Origin of granulite complexes: results of study of melt, fluid inclusions zircon and rock form minerals.Russian Geology and Geophysics, Vol. 34, No. 12, pp. 103-116.GlobalExperimental petrology, Zircon
DS1994-0300
1994
Tomilenko, A.A.Chepurov, A.I., Tomilenko, A.A., et al.Fluid inclusions in diamonds from alluvial deposits of Yakutia.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 336, No. 5, June pp. 662-665.Russia, YakutiaDiamond inclusions, Alluvials
DS1995-1916
1995
Tomilenko, A.A.Tomilenko, A.A., Chepurov, A.I., Palyanov, Yu.N., et al.Volatile components in the upper mantleProceedings of the Sixth International Kimberlite Conference Abstracts, pp. 628-630.Russia, YakutiaSpectroscopy, Deposit -Udachnaya, Obnazhenaya, Mir
DS1996-0269
1996
Tomilenko, A.A.Chepurov, A.I., Tomilenko, A.A., Shebanin, A.P., SobolevFluid inclusions in diamonds from Yakutian placersDoklady Academy of Sciences, Vol. 339, No. 8, Jan., pp. 128-132.Russia, YakutiaDiamond inclusions, Alluvials
DS1997-1162
1997
Tomilenko, A.A.Tomilenko, A.A., Chepurov, Turkin, Shebanin, SobolevFluid inclusions in synthetic diamond crystalsDoklady Academy of Sciences, Vol. 353, No. 2, Feb-Mar, pp. 247-50.GlobalDiamond - synthetics, crystallography
DS1998-1469
1998
Tomilenko, A.A.Tomilenko, A.A., Chepurov, A.I., et al.Hydrocarbon inclusions in synthetic diamondsEuropean Journal of Mineralogy, Vol. 10, No. 6, pp. 1135-41.GlobalDiamond inclusions, Diamonds - synthetic
DS2000-0913
2000
Tomilenko, A.A.Sokol, A.G., Tomilenko, A.A., Palyanov, Borzdov, et al.Fluid regime of diamond crystallization in carbonate carbon systemsEuropean Journal of Mineralogy, Vol. 12, pp. 367-75.GlobalDiamond - morphology, crystal, Petrology - experimental
DS2001-1161
2001
Tomilenko, A.A.Tomilenko, A.A., et al.Variation in the fluid phase composition in the process of natural diamondcrystallization.Doklady Academy of Sciences, Vol. 379, No. 5, June-July pp. 571-4.GlobalDiamond - morphology
DS2002-1606
2002
Tomilenko, A.A.Tomilenko, A.A., Shatsky, V.S., Kovyazin, S.V., Ovchinnikov, Y.I.Melt and fluid inclusions in anorthosite xenolith from the Udachnaya kimberlite pipe, Yakutia.Doklady Earth Sciences, Vol. 387A,9, pp. 1060-62.Russia, YakutiaInclusions, Deposit - Udachnaya
DS2002-1607
2002
Tomilenko, A.A.Tomilenko, A.A., Shatsky, V.S., Kovyazin, S.V., Ovchinnilkov, Yu.I.Melt and fluid inclusions in anorthosite xenolith from the Udachnaya kimberlite pipe, Yakutia.Doklady, Vol. 387A, Nov-Dec. No. 9, pp. 1060-62.Russia, YakutiaGeochemistry - inclusions
DS2003-1089
2003
Tomilenko, A.A.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
DS200412-1494
2004
Tomilenko, A.A.Palyanov, Yu.N.,Sokol, A.G., Tomilenko, A.A., Sobolev, N.V.Conditions of diamond formation under carbonate silicate interaction.Lithos, ABSTRACTS only, Vol. 73, p. S83. abstractTechnologyDiamond nucleation
DS200412-1560
2003
Tomilenko, A.A.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
DS200412-1882
2004
Tomilenko, A.A.Sonin, V.M., Zhimulev, E.I., Tomilenko, A.A., Chepurov, S.A., Chepurov, A.I.Chromatographic study of diamond etching in kimberlitic melts in the context of diamond natural stability.Geology of Ore Deposits, Vol. 46, 3, pp. 182-190.TechnologyDiamond morphology
DS200412-2228
2004
Tomilenko, A.A.Zhimulev, E.I., Sonin, V.M., Fedorov, I.I., Tomilenko, A.A., Pkhilenko, L.N., Chepurov, A.I.Diamond stability with respect to oxidation in experiments with minerals from mantle xenoliths at high P T parameters.Geochemistry International, Vol. 42, 6, pp. 520-525.MantleDiamond morphology, etching
DS200512-0817
2005
Tomilenko, A.A.Palyanov, Y.N., Sokol, A.G., Tomilenko, A.A., Sobolev, N.V.Conditions of diamond formation through carbonate silicate interaction.European Journal of Mineralogy, Vol. 17, 2, pp. 207-214.Diamond genesis
DS200512-1022
2004
Tomilenko, A.A.Sokol, A.G., Palynaov, Y.N., Palyanova, G.A., Tomilenko, A.A.Diamond crystallization in fluid and carbonate fluid systems under mantle P-T conditions: 1. fluid composition.Geochemistry International, Vol. 42, 9, pp. 830-838.MantleGeochemistry - diamond crystallography
DS200612-1271
2005
Tomilenko, A.A.Shatsky, V.S., Palyanov, Y.N., Sokol, A.G., Tomilenko, A.A., Sobolev, N.V.Diamond formation in UHP dolomite marbles and garnet pyroxene rocks of the Kokchetav Massif, northern Kazakstan: natural and experimental evidence.International Geology Review, Vol. 47, 10, pp. 999-1010.RussiaUHP
DS200812-0905
2008
Tomilenko, A.A.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
DS200912-0711
2009
Tomilenko, A.A.Sokol, A.G., Palyanova, G.A., Palyanov, Y.N., Tomilenko, A.A., Melenevsky, V.N.Fluid regime and diamond formation in the reduced mantle: experimental constraints.Geochimica et Cosmochimica Acta, Vol. 73, 19, pp. 5820-5834.MantleDiamond genesis, crystallography
DS200912-0766
2009
Tomilenko, A.A.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
DS200912-0863
2009
Tomilenko, A.A.Zhimulev, E.I., Sonin, V.M., Chepurov, A.I., Tomilenko, A.A.Chromatographic study of formation conditions of rhombododecahedral diamond crystals.Geology of Ore Deposits, Vol. 51, 3, pp. 243-246.TechnologyDiamond morphology
DS201112-0182
2011
Tomilenko, A.A.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
DS201112-0940
2011
Tomilenko, A.A.Sharapov, V.N., Mazurov, M.P., Tomilenko, A.A., Faleev, V.A.Mass transfer in garnet ultramafic xenoliths subject to partial melting under hot reduced gas flows.Russian Geology and Geophysics, Vol. 52, pp. 165-177.Russia, YakutiaDeposit - Udachnaya Vostochnaya
DS201112-1050
2011
Tomilenko, A.A.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
DS201212-0683
2012
Tomilenko, A.A.Sobolev, N.V., Sobolev, A.V., Tomilenko, A.A., Kovyazin, S.V., Kuzmin, D.V.Pyrope lherzolite assemblage of Ti bearing olivine macrocryst from Udachanya ultrafresh kimberlite, Yakutia, Russia.emc2012 @ uni-frankfurt.de, 1p. AbstractRussiaDeposit - Udachnaya
DS201312-0154
2013
Tomilenko, A.A.Chepurov, A.I., Zhimulev, E.I., Agafonov, L.V., Sonin, V.M., Chepurov, A.A., Tomilenko, A.A.The stability of ortho- and clinopyroxenes, olivine and garnet in kimberlitic magma.Russian Geology and Geophysics, Vol. 54, 4, pp. 406-415.RussiaMineral chemistry
DS201412-0863
2014
Tomilenko, A.A.Sobolev, N.V., Sobolev, A.V., Tomilenko, A.A., Kovyazin, S.V., Batanova, V.G., Kuzmin, D.V.Paragenesis and origin of olivine macrocrysts from Udachnaya-East hypabyssal kimberlite, Yakutia, Russia.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
DS201412-1013
2014
Tomilenko, A.A.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
DS201502-0104
2015
Tomilenko, A.A.Sobolev, N.V., Sobolev, A.V., Tomilenko, A.A., Kovyazin, S.V., Batanova, V.G., Kuzmin, D.V.Paragenesis and complex zoning of olivine macrocrysts from unaltered kimberlite of the Udachnaya-East pipe, Yakutia: relationship with the kimberlite formation conditions and evolution.Russian Geology and Geophysics, Vol. 56, 1, pp. 260-279.Russia, YakutiaDeposit - Udachnaya-East
DS201507-0334
2015
Tomilenko, A.A.Sharapov, V.N., Chudnenko, K.V., Tomilenko, A.A.The physicochemical dynamics of carbonatization of the rocks of lithospheric mantle beneath the Siberian Platform.Russian Geology and Geophysics, Vol. 56, pp. 696-708.RussiaCarbonatite
DS201510-1805
2015
Tomilenko, A.A.Sobolev, N.V., Sobolev, A.V., Tomilenko, A.A., Batanova, V.G., Tolstov, A.V., Logvinova, A.M., Kuzmin, D.V.Unique compositional pecularities of olivine phenocrysts from the post flood basalt Diamondiferous Malokuonapskaya kimberlite pipe, Yakutia.Doklady Earth Sciences, Vol. 463, 2, pp. 828-832.RussiaDeposit - Malokuonapskaya
DS201601-0047
2015
Tomilenko, A.A.Tomilenko, A.A., Kuzmin, D.V., Bulbak, T.A., Timina, T.Yu., Sobolev, N.V.Composition of primary fluid and melt inclusions in regenerated olivines from hypabyssal kimberlites of the Malokuonapskaya pipe ( Yakutia).Doklady Earth Sciences, Vol. 465, 1, pp. 1168-1171.RussiaDeposit - Malokuonapskaya
DS201608-1445
2016
Tomilenko, A.A.Tomilenko, A.A., Bulbak, T.A., Khomenko, M.O., Kuzmin, D.V., Sobolev, N.V.The composition of volatile components in olivines from Yakutian kimberlites of various ages: evidence from gas chromatography - mass spectrometry.Doklady Earth Sciences, Vol. 469, 1, pp. 690-694.RussiaDeposit - Olivinvaya, Malokuonapskaya, Udachnaya-East

Abstract: The composition of volatiles from fluid and melt inclusions in olivine phenocrysts from Yakutian kimberlite pipes of various ages (Olivinovaya, Malokuonapskaya, and Udachnaya-East) were studied for the first time by gas chromatography-mass spectrometry. It was shown that hydrocarbons and their derivatives, as well as nitrogen-, halogen-, and sulfur-bearing compounds, played a significant role in the mineral formation. The proportion of hydrocarbons and their derivatives in the composition of mantle fluids could reach 99%, including up to 4.9% of chlorineand fluorine-bearing compounds.
DS201709-2064
2017
Tomilenko, A.A.Tomilenko, A.A., Dublansky, Yu.V., Kuzmin, D.V., Sobolev, N.V.Isotope compositions of C and O of magmatic calcites from the Udachnaya-East pipe kimberlite, Yakutia.Doklady Earth Sciences, Vol. 475, 1, pp. 828-831.Russia, Yakutiadeposit - Udachnaya-East

Abstract: It has been demonstrated for the first time that the isotopic compositions of carbon (d13C) in magmatic calcites from the Udachnaya–East pipe kimberlite groundmass varies from–2.5 to–1.0‰ (V-PDB), while those of oxygen (d18O) range from 15.0 to 18.2‰ (V-SMOW). The obtained results imply that during the terminal late magmatic and postmagmatic stages of the kimberlite pipe formation, the carbonates in the kimberlite groundmass became successively heavier isotopically, which indicates the hybrid nature of the carbonate component of the kimberlite: it was formed with contributions from mantle and sedimentary marine sources.
DS201710-2266
2017
Tomilenko, A.A.Sobolev, N.V., Schertle, H-P., Neuser, R.D., Tomilenko, A.A., Kuzmin, D.V., Loginova, A.M., Tolstov, A.V., Kostrovitsky, S.I., Yakovlev, D.A., Oleinikov, O.B.Formation and evolution of hypabyssal kimberlites from the Siberian craton: part 1 - new insights from cathodluminescence of the carbonates. Anabar and Olenek areaJournal of Asian Earth Sciences, Vol. 145, pt. B, pp. 670-678.Russia, Siberiadeposit - Kuranakh, Kharamay
DS201710-2269
2017
Tomilenko, A.A.Tomilenko, A.A., Kuzmin, D.V., Bulbak, T.A., Sobolev, N.V.Primary melt and fluid inclusions in regenerated crystals and phenocrysts of olivine from kimberlites of the Udachnaya-East pipe, Yakutia: the problem of the kimberlite melt.Doklady Earth Sciences, Vol. 475, 2, pp. 949-952.Russiadeposit - Udachnaya-East

Abstract: The primary melt and fluid inclusions in regenerated zonal crystals of olivine and homogeneous phenocrysts of olivine from kimberlites of the Udachnaya-East pipe, were first studied by means of microthermometry, optic and scanning electron microscopy, electron and ion microprobe analysis (SIMS), inductively coupled plasma mass-spectrometry (ICP MSC), and Raman spectroscopy. It was established that olivine crystals were regenerated from silicate-carbonate melts at a temperature of ~1100°C.
DS201809-2011
2018
Tomilenko, A.A.Chepurov, A.A., Sonin, V.M., Chepurov, A.I., Tomilenko, A.A.The effects of the concentration of olivine xenocrysts on the viscosity of kimberlite melts: experimental evidence.Journal of Volcanology and Seismology, Vol. 12, 2, pp. 140-149.Russiadeposit- Nyurbinskaya

Abstract: The study of viscosity in sub-liquidus heterogeneous media, which includes kimberlite magma at the pressures and temperatures that prevail in the mantle, is an urgent task. We have conducted experiments in the serpentine-olivine, serpentine-CaCO3?olivine, and native kimberlite-olivine systems at a pressure of 4 GPa and temperatures of 1400?1600°? in a BARS high-pressure device using the technique of a falling Pt pellet. The samples were examined after experiments to find fine-grained chilled mass of crystals where the Pt pellet was observed at the time of chilling. The concentration of the solid phase was varied in the experiments between 10 and 50 wt %. We showed that when 50 wt % of olivine grains has been introduced, it was not possible to detect the motion of the Pt pellet, while when the concentration of olivine xenocrysts reached 10 wt %, the Pt pellet very rapidly descended to the bottom of the reaction volume. Viscosity was calculated using the Stokes method. We found that the viscosity of a homogeneous kimberlite melt at 4 GPa and 1600°? is below 2 Pa s, with the viscosity of a melt that contained up to 10 wt % of the solid phase being approximately constant. A kimberlite melt that contained 30 wt % of the solid phase had a viscosity on the order of 100 Pa s, while with 50 wt % of the solid phase the relative viscosity of an ultrabasic system increased to reach values over 1000 Pa s.
DS201811-2613
2018
Tomilenko, A.A.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.
DS201907-1559
2019
Tomilenko, A.A.Logvinova, A.M., Shatskiy, A., Wirth, R., Tomilenko, A.A., Ugapeva, S.S., Sobolev, N.V.Carbonatite melt in type Ia gem diamond.Lithos, in press available, 17p.Russiadeposit - Sytykanskaya

Abstract: Monocrystalline type Ia diamonds with octahedral growth morphology prevail among lithospheric diamonds, including precious stones. Unlike less common ‘fibrous’ diamonds that grew from alkali-rich carbonate-bearing melts and fluids, the growth medium of ‘monocrystalline’ type Ia diamonds remains debatable. Here we report the first finding of an optically visible (~30?µm in size) carbonate inclusion in the center of a gem type Ia octahedral diamond from the Sytykanskaya kimberlite pipe, Yakutia. We found that the inclusion consists of submicron size carbonate phases represented by K2Ca(CO3)2 bütschliite (~15?vol%), Na2Mg(CO3)2 eitelite (~5?vol%), and dolomite (~80?vol%). Although neither bütschliite nor eitelite can coexist with dolomite under mantle P-T conditions, these phases readily appear all together in the quenched products of carbonatite melt under mantle pressures. Thus, at the moment of capture, the inclusion material was a carbonatite melt with the following composition 10(K0.75Na0.25)2CO3·90(Ca0.57Mg0.43)CO3. The content of alkali carbonates at the level of 10?mol% indicates that the melt was formed at a temperature of =1300?°C. The high K/Na and Ca/(Ca?+?Mg) ratios in this melt indicate its derivation by partial melting of recycled marine sediments (pelites). Considering an age of the last subduction event beneath the Siberian craton, our new finding implies that subducting slabs drag carbonated material of the continental crust beneath ancient cratons, where it experiences partial melting to form a potassic dolomitic melt responsible for the formation of most diamonds, since the Late Archean.
DS201909-2060
2019
Tomilenko, A.A.Logvinova, A.M., Shatskiy, A., Wirth, R., Tomilenko, A.A., Ugapeva, S.S., Sobolev, N.V.Carbonatite melt in type Ia gem diamond. Lithos, Vol. 342-343, pp. 463-467.Russiadeposit - Sytykanskaya

Abstract: Monocrystalline type Ia diamonds with octahedral growth morphology prevail among lithospheric diamonds, including precious stones. Unlike less common ‘fibrous’ diamonds that grew from alkali-rich carbonate-bearing melts and fluids, the growth medium of ‘monocrystalline’ type Ia diamonds remains debatable. Here we report the first finding of an optically visible (~30?µm in size) carbonate inclusion in the center of a gem type Ia octahedral diamond from the Sytykanskaya kimberlite pipe, Yakutia. We found that the inclusion consists of submicron size carbonate phases represented by K2Ca(CO3)2 bütschliite (~15?vol%), Na2Mg(CO3)2 eitelite (~5?vol%), and dolomite (~80?vol%). Although neither bütschliite nor eitelite can coexist with dolomite under mantle P-T conditions, these phases readily appear all together in the quenched products of carbonatite melt under mantle pressures. Thus, at the moment of capture, the inclusion material was a carbonatite melt with the following composition 10(K0.75Na0.25)2CO3·90(Ca0.57Mg0.43)CO3. The content of alkali carbonates at the level of 10?mol% indicates that the melt was formed at a temperature of =1300?°C. The high K/Na and Ca/(Ca?+?Mg) ratios in this melt indicate its derivation by partial melting of recycled marine sediments (pelites). Considering an age of the last subduction event beneath the Siberian craton, our new finding implies that subducting slabs drag carbonated material of the continental crust beneath ancient cratons, where it experiences partial melting to form a potassic dolomitic melt responsible for the formation of most diamonds, since the Late Archean.
DS201911-2565
2019
Tomilenko, A.A.Soboelev, N.V., Logvinova, A.M., Tomilenko, A.A., Wirth, R., Bulbak, T.A., Lukyanova, L.I., Fedorova, E.N., Reutsky, V.N., Efimova, E.S.Mineral and fluid inclusions in diamonds from the Urals placers, Russia: evidence for solid molecular N2 and hydrocarbons in fluid inclusions.Geochimica et Cosmochimica Acta, Vol. 266, pp. 197-212.Russia, Uralsdiamond inclusions

Abstract: The compositions of mineral inclusions from a representative collection (more than 140 samples) of diamonds from the placer deposits in the Ural Mountains were studied to examine their compositional diversity. The overwhelming majority of rounded octahedral and dodecahedral stones typical of placers contain eclogitic (E-type) mineral inclusions (up to 80%) represented by garnets with Mg# 40-75 and Ca# 10-56, including the unique high calcic “grospydite” composition, omphacitic pyroxenes containing up to 65% of jadeite, as well as kyanite, coesite, sulfides, and rutile. Peridotitic (P-type) inclusions are represented by olivine, subcalcic Cr-pyrope, chrome diopside, enstatite and magnesiochromite that are typical for diamonds worldwide. Comparing the chemical composition of olivine, pyrope and magnesiochromite in diamonds of the Urals, north-east of the Siberian platform placers and Arkhangelsk province kimberlites show striking similarity. There are significant differences only in the variations of carbon isotopic composition of the diamonds from the placers of the Urals and north-east of the Siberian platform. One typical rounded dodecahedral diamond was found to contain abundant primary oriented submicrometer-sized (<3.0?µm) octahedral fluid inclusions identified by transmission electron microscopy, which caused the milky color of the entire diamond crystal. The electron energy-loss spectrum of a singular inclusion has a peak at ~405?eV, indicating that nitrogen is present. The Raman spectra with peaks at 2346-2350?cm-1 confirmed that nitrogen exists in the solid state at room temperature. This means that fossilized pressure inside fluid inclusions may be over 6.0 GPa at room temperature, so the diamond may be considered sublithospheric in origin. However, identification of unique fluid inclusions in one typical placer diamond allows one to expand the pressure limit to at least more than 8.0 GPa. The volatile components of four diamonds from the Urals placers were analyzed by gas chromatography-mass spectrometry (GC-MS). They are represented (rel. %) by hydrocarbons and their derivatives (14.8-78.4), nitrogen and nitrogenated compounds (6.2-81.7), water (2.5-5.5), carbon dioxide (2.8-12.1), and sulfonated compounds (0.01-0.96). It is shown that high-molecular-weight hydrocarbons and their derivatives, including chlorinated, nitrogenated and sulfonated compounds, appear to be stable under upper mantle P-T conditions. A conclusion is drawn that Urals placer diamonds are of kimberlitic origin and are comparable in their high E-type/P-type inclusion ratios to those from the northeastern Siberian platform and in part to diamonds of the Arkhangelsk kimberlite province.
DS201912-2768
2019
Tomilenko, A.A.Alvaro, M., Mazzucchelli, M.L., Angel, R.J., Murri, M., Campmenosi, N., Scambelluri, M., Nestola, F., Korsakov, A., Tomilenko, A.A., Marone, F., Morana, M.Fossil subduction recorded by quartz from the coesite stability field. GeobarometryGeology, in press, 5p. PdfRussia, Yakutiadeposit - Mir

Abstract: Metamorphic rocks are the records of plate tectonic processes whose reconstruction relies on correct estimates of the pressures and temperatures (P-T) experienced by these rocks through time. Unlike chemical geothermobarometry, elastic geobarometry does not rely on chemical equilibrium between minerals, so it has the potential to provide information on overstepping of reaction boundaries and to identify other examples of non-equilibrium behavior in rocks. Here we introduce a method that exploits the anisotropy in elastic properties of minerals to determine the unique P and T of entrapment from a single inclusion in a mineral host. We apply it to preserved quartz inclusions in garnet from eclogite xenoliths hosted in Yakutian kimberlites (Russia). Our results demonstrate that quartz trapped in garnet can be preserved when the rock reaches the stability field of coesite (the high-pressure and high-temperature polymorph of quartz) at 3 GPa and 850 °C. This supports a metamorphic origin for these xenoliths and sheds light on the mechanisms of craton accretion from a subducted crustal protolith. Furthermore, we show that interpreting P and T conditions reached by a rock from the simple phase identification of key inclusion minerals can be misleading.
DS202008-1379
2020
Tomilenko, A.A.Chepurov, A.I., Tomilenko, A.A., Sonin, V.M., Zhimulev, E.I., Bulbak, T.A., Cheperov, A.A., Sobolev, N.V.Interaction of an Fe-Ni melt with anthracene ( C14H10) in the presence of olivine at 3 Gpa: fluid phase composition.Doklady Earth Sciences, Vol. 492, pp. 333-337.MantleUHP, diamond

Abstract: The first results on the interaction between an Fe-Ni melt and anthracene (?14?10) in the presence of olivine at 3 GPa and 1500°? and on the study of the component composition of the fluid generated in this process are presented. The stability of aliphatic hydrocarbons in the implemented conditions is confirmed experimentally. It is established that, under these conditions, crystallization of high-magnesian olivines occurs (Fo = 97-98 mol %). The composition of the fluid is similar to the composition of the fluid from inclusions in synthetic diamonds. The conditions implemented in the experiment might have occurred at the early stages of the Earth’s evolution.
DS202008-1449
2020
Tomilenko, A.A.Sokol, I.A., Sokol, A.G., Zaikin, P.A., Tomilenko, A.A., Bulbak, T.A.Hydrogenation of graphite, diamond, carbonates and iron carbides as the source of hydrocarbons in the upper mantle.Goldschmidt 2020, 1p. AbstractMantlehydrogen

Abstract: Formation of hydrocarbons by reactions of hydrogenbearing fluids with carbon [1] (13C soot, graphite, or diamond), carbonate-bearing pelites [2] and iron carbides (Fe3C and Fe7C3) [3] was simulated at 5.5-7.8 GPa and 1100- 1400°C, fH2 in Pt and Au capsules being controlled at the Mo+MoO2+H2O or Fe+FeO+H2O equilibria. For the first time, formation of hydrocarbons from inorganic compounds was proved by the reaction of 13C with hydrogen, which yielded isotopically pure alkanes. The greatest amounts of HCs (CH4/C2H6 < 1, CH4/C3H8 and CH4/C4H10 = 10) formed at 1400°C in the 10-hr run. The amount of HCs synthesized at 1200°C was twice smaller. The rate of HCs formation was slowest in runs with diamond. At 1200 °C, light alkanes (C1˜C2>C3>C4) formed either by direct hydrogenation of Fe3C or Fe7C3, or by hydrogenation of graphite/diamond in the presence of Fe3C, Fe7C3. The CH4/C2H6 ratio in the fluids decreased from 5 to 0.5 with decreasing iron activity and the C fraction increased in the series: Fe-Fe3C?Fe3C- Fe7C3?Fe7C3-graphite?graphite-Fe3C-magnesite and Fe3C-H2O-CO2 systems at 1200 °C yielded magnesiowüstite and wüstite, respectively, and both produced C-rich Fe7C3 and mainly light alkanes (C1˜C2>C3>C4). In the experiments containing pelites methaneimine (CH3N) was found to be the main N-bearing compound. The experiments have provided the first unambiguous evidence that volatile-rich and reduced mantles of terrestrial planets (at fO2 near or below IW) provided favorable conditions for abiotic generation of complex hydrocarbon systems that predominantly contain light alkanes. The conditions favorable for HC formation exist in earth mantle, where slab-derived H2O-, CO2- and carbonate-bearing fluids interact with metal-saturated mantle.
DS202010-1880
2020
Tomilenko, A.A.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.
DS2003-1315
2003
Tomileno, A.A.Sonin, V.M., Zhimulev, .I., Chepurov, A.I., Afanesev, V.P., Tomileno, A.A.Etching of diamond crystals in the system silicate melt C O H S fluid under a highGeochemistry International, Vol. 41, 7, pp. 688-93.GlobalDiamond - morphology
DS200412-1881
2003
Tomileno, A.A.Sonin, V.M., Zhimulev, .I., Chepurov, A.I., Afanesev, V.P., Tomileno, A.A.Etching of diamond crystals in the system silicate melt C O H S fluid under a high pressure.Geochemistry International, Vol. 41, 7, pp. 688-93.TechnologyDiamond - morphology
DS201603-0379
2015
Tomioka, N.Goncharov, A.F., Lobanov, S.S., Tan, X., Hohensee, G.T., Cahill, D.G., Lin, J-F., Thomas, S-M., Okuchi, T., Tomioka, N., Helffrich, G.Experimental study of thermal conductvity at high pressures: implication for the deep Earth's interior.Physics of the Earth and Planetary Interiors, Vol. 247, pp. 11-16.MantleExperimental Petrology

Abstract: Lattice thermal conductivity of ferropericlase and radiative thermal conductivity of iron bearing magnesium silicate perovskite (bridgmanite) - the major mineral of Earth’s lower mantle- have been measured at room temperature up to 30 and 46 GPa, respectively, using time-domain thermoreflectance and optical spectroscopy techniques in diamond anvil cells. The results provide new constraints for the pressure dependencies of the thermal conductivities of Fe bearing minerals. The lattice thermal conductivity of ferropericlase Mg0.9Fe0.1O is 5.7(6) W/(m * K) at ambient conditions, which is almost 10 times smaller than that of pure MgO; however, it increases with pressure much faster (6.1(7)%/GPa vs 3.6(1)%/GPa). The radiative conductivity of a Mg0.94Fe0.06SiO3 bridgmanite single crystal agrees with previously determined values for powder samples at ambient pressure; it is almost pressure-independent in the investigated pressure range. Our results confirm the reduced radiative conductivity scenario for the Earth’s lower mantle, while the assessment of the heat flow through the core-mantle boundary still requires in situ measurements at the relevant pressure-temperature conditions.
DS201605-0909
2016
Tomioka, N.Tomioka, N., Miyahara, M., Ito, M.Discovery of natural MgSi03 tetragonal garnet in a shocked chronitic meteorite.Science Advances, on line doi: 10.1126 1501725TechnologyMeteorite

Abstract: MgSiO3 tetragonal garnet, which is the last of the missing phases of experimentally predicted high-pressure polymorphs of pyroxene, has been discovered in a shocked meteorite. The garnet is formed from low-Ca pyroxene in the host rock through a solid-state transformation at 17 to 20 GPa and 1900° to 2000°C. On the basis of the degree of cation ordering in its crystal structure, which can be deduced from electron diffraction intensities, the cooling rate of the shock-induced melt veins from ~2000°C was estimated to be higher than 103°C/s. This cooling rate sets the upper bound for the shock-temperature increase in the bulk meteorite at ~900°C.
DS2001-0028
2001
TomiolaAndo, J., Shibata, Okajima, Kanagawa, Furosho, TomiolaStriped iron zoning of olivine induced discloaction creep in deformed peridotitesNature, No. 6866, Dec. 20, pp. 893-4.MantlePeridotites
DS1992-1559
1992
Tomisch, B.N.V.Tomisch, B.N.V.Ore reserves: considerations for project financeAustralian Institute of Mining and Metallurgy (AusIMM) Bulletin, No. 7, December pp. 17-23AustraliaGeostatistics, Ore reserves
DS201412-0609
2014
Tomita, T.Mysen, B., Tomita, T., Ohtani, E., Suzuki, A.Speciation of and D/H partioning between fluids and melts in silicate D-O-H-C-N systems determined in-situ at upper mantle temperatures, pressures, and redox conditions.American Mineralogist, Vol. 99, pp. 578-588.MantleMelting
DS1950-0431
1958
Tomkieff, S.I.Tomkieff, S.I.Siberian Diamonds #2The Loupe., Vol. 8, No. 3, MAY-JUNE P. 2.RussiaBlank
DS201112-0311
2011
Tomkins, A.G.Evans, K.A., Tomkins, A.G.The relationship between subduction zone redox budget and arc magma fertility.Earth and Planetary Science Letters, Vol. 308, 3-4, pp. 401-409.MantleSubduction
DS201810-2372
2018
Tomkins, A.G.Rielli A., Tomkins, A.G., Nebel, O., Raveggi, M., Jeon, H., Martin, L., Laure, A., Janaina, N.Sulfur isotope and PGE systematics of metasomatised mantle wedge.Earth and Planetary Science Letters, Vol. 497, 1, pp. 181-192.Mantlemetasomatism

Abstract: At convergent margins fluids liberated from subducting slabs metasomatise the overlying mantle wedge, enriching it in volatiles, incompatible elements and possibly ore-forming metals. Despite the genetic link between this process, the genesis of arc magmas, and formation of porphyry Cu-Au deposits, there is currently little understanding of the behaviour of chalcophile and siderophile elements during subduction-related mantle metasomatism. In this study, we report sulfur isotopic compositions and PGE concentrations of sulfides in a suite of garnet peridotites from the Western Gneiss Region of Norway, sampling mantle wedge from ~100 to ~250 km depth. Sulfides hosted in metasomatised samples have deviated from typical mantle values, ranging between -10.0 and +5.4‰, indicating derivation of sulfur from subducted crust. Sulfides in pervasively metasomatised samples have atypical PGE signatures, with strong enrichment in Os and Ru relative to Ir, whereas channelised fluid flow produced sulfides extremely enriched in Pd, up to 700 times the concentration found in non-metasomatised samples. These signatures are reconcilable with a high oxidation state of the metasomatising agents and demonstrate that subduction can recycle chalcophile and siderophile elements into and within the mantle, along with sulfur. We further show that because the solubility of Os and Ru in fluids is redox sensitive, and Pd is more soluble than the I-PGE, ratios such as Os/Ir, Ru/Ir plotted against Pd/Ir can be used to trace the metasomatic oxidation of mantle samples, mantle-derived magmas and porphyry Cu±Au deposits. This geochemical insight is used to show that Au-rich porphyry Cu deposits are derived from more oxidised mantle wedge than Au-poor porphyry deposits.
DS2002-0121
2002
Tomlin, K.P.Bauer, R.L., Tomlin, K.P., Curtis, D.J.Reworking of the southeastern margin of the Archean Wyoming Province during the Trans Hudson and Medicine B16th. International Conference On Basement Tectonics '02, Abstracts, 2p., 2p.Wyoming, southeastOrogeny - Trans Hudson, Medicine Bow, Laramie Mountains
DS200712-1087
2007
Tomlinon, E.L.Tomlinon, E.L., McMillan, P.F., Zhang, M., Jones, A.P., Redfern, S.A.T.Quartz bearing C-O-H fluid inclusions diamond: retracing the pressure-temperature path in the mantle using calibrated high temperature IR spectroscopy.Geochimica et Cosmochimica Acta, on line in press available, 10p.Africa, Democratic Republic of CongoDeposit - Mbuji Mayi - mineralogy
DS1998-1440
1998
TomlinsonTainton, K., Seggie, A., Bayly, B., Tomlinson, QuadlingRegional variation in mantle heat flow within the Tanzanian Craton7th International Kimberlite Conference Abstract, pp. 880-2.TanzaniaGeotherm - garnets, Deposit - Mwadui
DS1999-0725
1999
TomlinsonTainton, K.M., Seggie, Bayly, Tomlinson, QuadlingGarnet therombarometry: implications for mantle heat flow within the Tanzanian Craton.7th International Kimberlite Conference Nixon, Vol. 2, pp. 852-60.TanzaniaCraton mineral chemistry, Deposit - Mwadui, Kisumbi, Negezi, Mhunse, Nzega
DS200412-2003
2004
Tomlinson, E.Tomlinson, E., Jones, A., Milledge, J.High pressure experimental growth of diamond using C K2CO3-KCl as an analogue for Cl bearing carbonate fluid.Lithos, Vol. 77, 1-4, Sept. pp. 287-294.TechnologyDiamond growth, potassium carbonate, potassium chloride
DS200512-1094
2005
Tomlinson, E.Tomlinson, E., De Schrijver, I., De Corte, K., Jones, A.P., Moens, L., Vanhaecke, F.Trace element compositions of submicroscopic inclusions in coated diamond: a tool for understanding diamond petrogenesis.Geochimica et Cosmochimica Acta, Vol. 69, 19, Oct. 1, pp. 4719-4732.Africa, Democratic Republic of CongoSilicate melt inclusions, Group 1, diamond inclusions
DS201012-0728
2010
Tomlinson, E.Smith, E., Kopylova, M., Dubrovinsky, L., Tomlinson, E.X-ray diffraction study of the mineral and fluid inclusions in fibrous diamond.38th. Geoscience Forum Northwest Territories, Abstract pp.124-125.Canada, Northwest Territories, Ontario, Africa, Democratic Republic of CongoMineral inclusions - Panda, Jericho
DS201910-2264
2019
Tomlinson, E.Hoare, B., Tomlinson, E., Balz, K.Fossil geotherms frozen in diamond require very deep ( >300 km) Early Kalahari cratonic lithosphere.Goldschmidt2019, 1p. AbstractAfrica, South Africageothermometry

Abstract: In the Archaean, global surface heat flow was substantially higher than today because of greater internal radiogenic heat production and primordial heat content within the Earth. Nonetheless, the lithospheric roots of Archaean cratons were apparently surprisingly cool, recording similarly low ambient temperatures to those inferred today, allowing e.g. for the stabilisation of diamond. This finding is seemingly in conflict with a generally ‘hotter’ Archaean mantle, as is widely postulated, but the paradox could be explained if the sub-cratonic lithospheric mantle was substantially thicker in the Archaean than today. Here, we report a re-investigation of the thermal structure of the Archaean Kalahari lithosphere using published and unpublished petrological data of diamond inclusions indicated to be of Archaean age. Our thermobarometric calculations agree with earlier findings that the Archaean cratonic mantle root was surprisingly cool. Importantly, the shape of the inclusion-derived P-T array deviates from the modern geotherm recorded by peridotite xenoliths. Specifically, diamond inclusions define a systematically steeper geothermal gradient than is observed in cratonic xenoliths. We find that Archaean diamond inclusion and modern xenolith P-T data cannot be reconciled by a single steady-state geotherm. The P-T conditions recorded in diamond inclusions are incompatible with the current characteristically low present-day heat-production of the overlying crust. Instead, the steeper geotherm implies high heat production in the crust during diamond formation and the distinctive geothermal gradient recorded in the studied diamond inclusions could reflect ancient mantle conditions. We modelled a suite of ‘fossil’ geotherms, with increased radiogenic heat production within the crust during the Archaean. Solutions providing very good fits with the diamond inclusion geotherm all require that the Archaean lithosphere must have extended to far greater depths than is preserved today. The required depth ranges from ~ 300 km to ~ 450 km depth, for a modern (~ 1350°C) and a significantly hotter (~ 1600°C) mantle potential temperature, respectively. In either case, it is clear that the Kalahari lithosphere must have experienced significant (at least 100 km) basal erosion subsequent to its formation.
DS200712-1088
2007
Tomlinson, E.I.Tomlinson, E.I., Beard, A.D., Harris, J.W.A snapshot of mantle metasomatism?Plates, Plumes, and Paradigms, 1p. abstract p. A1029.Canada, Northwest TerritoriesPanda
DS200812-1179
2008
Tomlinson, E.I.Tomlinson, E.I., Muller, W., Hinton, R.W., Klein Ben-David, O., Pearson, D.G., Harris, J.W.Metasomatic processes recorded in fibrous diamonds.Goldschmidt Conference 2008, Abstract p.A950.Canada, Northwest TerritoriesDeposit - Panda
DS2003-1384
2003
Tomlinson, E.L.Tomlinson, E.L., Jones, A.P., Milledge, H.J.Multiple fluids in diamond coat and their role in diamond growth8ikc, Www.venuewest.com/8ikc/program.htm, Session 3, POSTER abstractGlobalDiamonds - inclusions
DS200612-1434
2006
Tomlinson, E.L.Tomlinson, E.L., Jones, A.P., Harris, J.W.Co-existing fluid and silicate inclusions in mantle diamond.Earth and Planetary Science Letters, Vol. 250, 3-4, pp. 581-595.MantleDiamond inclusions
DS200712-1089
2006
Tomlinson, E.L.Tomlinson, E.L., Jones, A.P., Harris, J.W.Co-existing fluid and silicate inclusions in mantle diamond.Earth and Planetary Science Letters, Vol. 250, 3-4, Oct. 30, pp. 581-595.MantleDiamond inclusions
DS200912-0767
2009
Tomlinson, E.L.Tomlinson, E.L., Muller, W., EIMFA snapshot of mantle metasomatism: trace element analysis of coexisting fluid (LA ICP-MS) and silicate (SIMS) inclusions in fibrous diamonds.Earth and Planetary Science Letters, Vol. 279, 3-4, pp. 361-372.MantleGeochronology, metasomatism
DS201112-1051
2011
Tomlinson, E.L.Tomlinson, E.L., Howell, D., Jones, A.P., Frost, D.J.Characteristics of HPHT diamond grown at sub-lithosphere conditions (10-20 GPa).Diamond and Related Materials, Vol. 20, 1, Jan. pp. 11-17.TechnologyUHP
DS201612-2340
2016
Tomlinson, E.L.Stead, C.V., Tomlinson, E.L., Kamber, B.S., Babechuk, M.G., McKenna, C.A.REE determination in olivine by LA-Q-ICP-MS: an analytical strategy and applications.Geostandards and Geoanalytical Research, in press availableTechnologyREE mass fractions

Abstract: Olivine offers huge, largely untapped, potential for improving our understanding of magmatic and metasomatic processes. In particular, a wealth of information is contained in rare earth element (REE) mass fractions, which are well studied in other minerals. However, REE data for olivine are scarce, reflecting the difficulty associated with determining mass fractions in the low ng g-1 range and with controlling the effects of LREE contamination. We report an analytical procedure for measuring REEs in olivine using laser ablation quadrupole-ICP-MS that achieved limits of determination (LOD) at sub-ng g-1 levels and biases of ~ 5-10%. Empirical partition coefficients (D values) calculated using the new olivine compositions agree with experimental values, indicating that the measured REEs are structurally bound in the olivine crystal lattice, rather than residing in micro-inclusions. We conducted an initial survey of REE contents of olivine from mantle, metamorphic, magmatic and meteorite samples. REE mass fractions vary from 0.1 to double-digit ng g-1 levels. Heavy REEs vary from low mass fractions in meteoritic samples, through variably enriched peridotitic olivine to high mass fractions in magmatic olivines, with fayalitic olivines showing the highest levels. The variable enrichment in HREEs demonstrates that olivine REE patterns have petrological utility.
DS201709-2065
2017
Tomlinson, E.L.Tomlinson, E.L., Kamber, B.C., Hoare, C.V., Stead, C.V., Ildefonse, B.An exsolution origin for Archaean mantle garnet.Goldschmidt Conference, abstract 1p.Mantlegarnet

Abstract: It is now well established that the cratonic sub-continental lithospheric mantle (SCLM) represents a residue of extensively melted fertile peridotite. The widespread occurrence of garnet in the Archaean SCLM remains a paradox because many experiments agree that garnet is exhausted beyond c. 20% melting. It has been suggested that garnet may have formed by exsolution from Al-rich orthopyroxene [1,2,3]. However, the few examples of putative garnet exsolution in cratonic samples remain exotic and have not afforded a link to garnet that occurs as distinct grains in granular harzburgite. We present crystallographic (EBSD), petrographic and chemical (SEM-EDS and LA-ICP-MS) data for an exceptionally well-preserved orthopyroxene megacryst juxtaposed against granular harzburgite. Garnet lamellae within the megacryst show crystallographic continuity and have a strong fabric relative to the host orthopyroxene, strongly indicating that the megacryst formed by exsolution. Garnet lamellae are sub-calcic Cr-pyropes with sinusoidal rare earth element patterns, while the orthopyroxene host is high-Mg enstatite; the reconstructed precursor is clinoestatite. The megacryst shows evidence for disintegrating into granular peridotite, and garnet and orthopyroxene within the granular peridotite are texturally and chemically identical to equivalent phases in the megacryst. Collectively, this evidence supports a common origin for the granular and exsolved portions of the sample. The compositions of the exsolved Cr pyrope and enstatite are typical of harzburgites and depleted lherzolites from the SCLM. Furthermore, garnet inclusions within orthopyroxene in several granular peridotites exhibit the same fabric as those in the exsolved megacryst. We hypothesise that clinoenstatite was a common phase in cratonic SCLM and that exsolution is the likely origin of many sub-calcic garnets in depleted peridotites.
DS201805-0983
2018
Tomlinson, E.L.Tomlinson, E.L., Kamber, B.S., Hoare, B.C., Stead, C.V., Ildefonse, B.An exsolution origin for Archean mantle garnet. C-SCLM KaapvaalGeology, Vol. 46, 2, pp. 123-126.Africa, South Africacraton

Abstract: It is well established that the cratonic subcontinental lithospheric mantle (C-SCLM) represents a residue of extensively melted peridotite. The widespread occurrence of garnet in C-SCLM remains a paradox because experiments show that it should be exhausted beyond ~20% melting. It has been suggested that garnet may have formed by exsolution from Al-rich orthopyroxene; however, the few documented examples of garnet exsolution in cratonic samples are exotic and do not afford a direct link to garnet in granular harzburgite. We report crystallographic, petrographic, and chemical data for an exceptionally well preserved orthopyroxene megacryst containing garnet lamellae, juxtaposed against granular harzburgite. Garnet lamellae are homogeneously distributed within the host orthopyroxene and occur at an orientation that is unrelated to orthopyroxene cleavage, strongly indicating that they formed by exsolution. Garnet lamellae are subcalcic Cr-pyrope, and the orthopyroxene host is high-Mg enstatite; these phases equilibrated at 4.4 GPa and 975 °C. The reconstructed precursor is a high-Al enstatite that formed at higher pressure and temperature conditions of ~6 GPa and 1750 °C. The megacryst shows evidence for disintegrating into granular peridotite, and garnet and orthopyroxene within the granular peridotite are texturally and chemically identical to equivalent phases in the megacryst. Collectively, this evidence supports a common origin for the granular and exsolved portions of the sample. We hypothesize that high-Al enstatite was a common phase in the C-SCLM and that exsolution during cooling and stabilization of the C-SCLM could be the origin of most subcalcic garnets in depleted peridotites.
DS201905-1049
2019
Tomlinson, E.L.Kamber, B.S., Tomlinson, E.L.Petrological, mineralogical and geochemical pecularities of Archaean cratons.Chemical Geology, Vol. 511, 1, pp. 122-151.Globalcraton

Abstract: The most outstanding features of Archaean cratons are their extraordinary thickness and enduring longevity. Seismically, Archaean cratonic fragments are sharply-bounded deep roots of mechanically strong, cold lithospheric mantle, clearly distinguishable from non-cratonic lithosphere. Rhenium-depletion of deep cratonic xenolith whole rocks and sulphide inclusions in diamond indicate that melting was broadly coeval with formation of the overlying proto-cratonic crust, which was of limited mechanical strength. A very important process of proto-cratonic development was vertical crustal reorganisation that eventually yielded a thermally stable, cratonised crust with a highly K-U-Th-rich uppermost crust and much more depleted deeper crust. Clastic sedimentary rocks available for geochemical study are predominantly found in the youngest parts of supracrustal stratigraphies and over-represent the highly evolved rocks that appeared during cratonisation. Vertical crustal reorganisation was driven by crustal radiogenic heat and emplacement of proto-craton-wide, incubating and dense supracrustal mafic and ultramafic volcanic rocks. Statistical analysis of these cover sequences shows a preponderance of basalt and a high abundance of ultramafic lavas with a dearth of picrite. The ultramafic lavas can be grouped into Ti-enriched and Ti-depleted types and high pressure and temperature experimental data indicate that the latter formed from previously depleted mantle at temperatures in excess of 1700?°C. Most mantle harzburgite xenoliths from cratonic roots are highly refractory, containing very magnesian olivine and many have a high modal abundance of orthopyroxene. High orthopyroxene mode is commonly attributed to metasomatic silica-enrichment or a non-pyrolitic mantle source but much of the excess silica requirement disappears if melting occurred at high pressures of 4-6?GPa. Analysis of experimental data demonstrates that melting of previously depleted harzburgite can yield liquids with highly variable Si/Mg ratios and low Al2O3 and FeO contents, as found in komatiites, and complementary high Cr/Al residues. In many harzburgites, there is an intimate spatial association of garnet and spinel with orthopyroxene, which indicates formation of the Al-phase by exsolution upon cooling and decompression. New and published rare earth element (REE) data for garnet and orthopyroxene show that garnet has inherited its sinusoidal REE pattern from the orthopyroxene. The lack of middle-REE depletion in these refractory residues is consistent with the lack of middle- over heavy-REE fractionation in most komatiites. This suggests that such pyroxene or garnet (or precursor phases) were present during komatiite melting. In the Kaapvaal craton, garnet exsolution upon significant cooling occurred as early as 3.2?Ga and geobarometry of diamond inclusions from ancient kimberlites also supports cool Archaean cratonic geotherms. This requires that some mantle roots have extended to 300 to possibly 400?km and that early cratons must have been much larger than 500?km in diameter. We maintain that the Archaean-Proterozoic boundary continues to be of geological significance, despite the recognition that upper crustal chemistry, as sampled by sedimentary rocks, became more evolved from ca. 3?Ga onwards. The boundary coincides with the disappearance of widespread komatiite and marks the end of formation of typical refractory cratonic lithosphere. This may signify a fundamental change in the thermal structure of the mantle after which upwellings no longer resulted in very high temperature perturbations. One school of thought is that the thermal re-ordering occurred at the core-mantle boundary whereas others envisage Archaean plumes to have originated at the base of the upper mantle. Here we speculate that Archaean cratonic roots may contain remnants of older domains of non-convecting mantle. These domains are potential carriers of isotope anomalies and their base could have constituted a mechanical and thermal boundary layer. Above laterally extensive barriers, emerging proto-cratons were protected from the main mantle heat loss. The eventual collapse of these mechanical barriers terminated very high temperature upwellings and dismembered portions of the barrier were incorporated into the cratonic mantle during the final Neoarchaean ‘superplume’ event. The surviving cratons may therefore preserve biased evidence of geological processes that operated during the Archaean.
DS2003-1288
2003
Tomlinson, I.Skinner, E.M.W., Apterm D.B., Morelli, C., Tomlinson, I., Smithson, K.N.Kimberlites of the Man Craton8 Ikc Www.venuewest.com/8ikc/program.htm, Session 8, POSTER abstractGuinea, Sierra Leone, LiberiaBlank
DS200412-1845
2003
Tomlinson, I.Skinner, E.M.W., Apter, D.B., Morelli, C., Tomlinson, I., Smithson, K.N.Kimberlites of the Man Craton.8 IKC Program, Session 8, POSTER abstractAfrica, Guinea, Sierra Leone, LiberiaDiamond exploration
DS1998-1470
1998
Tomlinson, K.Y.Tomlinson, K.Y., Stevenson, R.K., Henry, P.The Red Lake GS: evidence of plume related magmatism at 3 Ga and evidence of an older enriched sourcePrecambrian Research, Vol. 89, No. 1-2, May pp. 59-76Ontario, Superior ProvinceGreenstone Belt, Plumes, magmas
DS2001-1162
2001
Tomlinson, K.Y.Tomlinson, K.Y., Condie, K.C.Archean mantle plumes: evidence from greenstone belt geochemistryGeological Society of America, Special Paper, Special Paper. 352, pp. 341-58.MantlePlumes, Geochemistry
DS201112-0979
2011
Tomlinson, L.Smith, E.M., Kopylova, M.G., Dubrovinsky, L., Navon, O., Ryder, J.E., Tomlinson, L.Transmission X-ray diffraction as a new tool for diamond fluid inclusion studies.Mineralogical Magazine, Vol. 75, 5, Oct. pp. 2657-2675.Africa, Democratic Republic of Congo, Canada, Ontario, Wawa, Northwest Territories, NunavutDeposit - Mbuji-Mayi, Wawa, Panda, Jericho
DS2003-1505
2003
Tomlinson, N.Wyatt, B.A., Mitchell, M., Shee, S.R., Griffin, W.L., Tomlinson, N., White, B.The Brockman Creek kimberlite, east Pilbara, Australia8 Ikc Www.venuewest.com/8ikc/program.htm, Session 8, POSTER abstractAustraliaDeposit - Brockman Creek
DS200412-2152
2003
Tomlinson, N.Wyatt, B.A., Mitchell, M., Shee, S.R., Griffin, W.L., Tomlinson, N., White, B.The Brockman Creek kimberlite, east Pilbara, Australia.8 IKC Program, Session 8, POSTER abstractAustraliaDiamond exploration Deposit - Brockman Creek
DS1994-1789
1994
Tommasi, A.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
DS1994-1844
1994
Tommasi, A.Vauchez, A., Tommasi, A., Ehydio-Silva, M.Self indentation of a heterogeneous continental lithosphereGeology, Vol. 22, No. 11, November pp. 967-970.BrazilCraton, Sao Francisco
DS1998-1525
1998
Tommasi, A.Vauchez, A., Tommasi, A., Barruol, G.Rheological heterogeneity, mechanical anisotropy and deformation of the continental lithosphere.Tectonophysics, Vol. 296, No. 1-2, . Oct. 30, pp. 61-86.MantleTectonics, Lithosphere
DS1999-0739
1999
Tommasi, A.Tommasi, A., Tikoff, B., Vauchez, A.Upper mantle tectonics: three dimensional deformation, olivine, crystallographic fabrics and seismic propertyEarth and Planetary Science Letters, Vol. 169, 1-2, Apr.30, pp.173-86.MantleGeophysics - seismics, Tectonics
DS2001-1163
2001
Tommasi, A.Tommasi, A., Vauchez, A.Continental rifting parallel to ancient collisional belts: an effect of the mechanical anisotropy of mantleEarth and Planetary Science Letters, Vol. 185, No. 1-2, Feb.15, pp.199-210.MantleLithosphere - rifts, Tectonics
DS2002-0113
2002
Tommasi, A.Bascou, J., Tommasi, A., Mainprice, D.Plastic deformation and development of clinopyroxene lattic preferred orientations in eclogites.Journal of Structural Geology, Vol.24,8,pp. 1357-68.GlobalEclogites - omphacite lattics, Mineralogy
DS2003-0464
2003
Tommasi, A.Gibert, B., Sepold, U., Tommasi, A., Mainprice, D.Thermal diffusivity of upper mantle rocks: influence of temperature, pressure and theJournal of Geophysical Research, Vol. 108, 8, ECV 1 , DOI 10.1029/2002JB002108MantleGeothermometry
DS200412-0661
2003
Tommasi, A.Gibert, B., Sepold, U., Tommasi, A., Mainprice, D.Thermal diffusivity of upper mantle rocks: influence of temperature, pressure and the deformation fabric.Journal of Geophysical Research, Vol. 108, 8, ECV 1 , DOI 10.1029/2002 JB002108MantleGeothermometry
DS200512-0679
2005
Tommasi, A.Mainprice, D., Tommasi, A., Couvy, H., Cordier, P., Frost, D.J.Pressure sensitivity of olivine slip systems and seismic anisotropy of Earth's upper mantle.Nature, No. 7027, Feb. 17, pp. 731-2.MantleOlivine
DS200512-0994
2005
Tommasi, A.Simpson, F., Tommasi, A.Hydrogen diffusivity and electrical anisotropy of a peridotite mantle.Geophysical Journal International, Vol. 160, 3, pp. 1092-1102.MantleGeophysics
DS200512-0995
2005
Tommasi, A.Simpson, F., Tommasi, A.Hydrogen diffusivity and electrical anisotropy of a peridotite mantle.Geophysical Journal International, Vol. 160, 3, pp. 1092-1102.MantlePeridotite
DS200512-1088
2004
Tommasi, A.Tikoff, B., Russo, R., Teyssier, C., Tommasi, A.Mantle driven deformation of orogenic zones and clutch tectonics.Geological Society of London Special Paper, No. 226, pp. 41-64.MantleTectonics
DS200712-0604
2007
Tommasi, A.Le Roux, V., Bodinier, J-L., Tommasi, A., Alard, O., Dautria, J-M., Vauchez, A., Riches, A.J.V.The lherz spinel lherzolite: refertilized rather than pristine mantle.Earth and Planetary Science Letters, Vol. 259, 3-4, pp. 599-612.MantleLherzolite chemistry
DS200712-0605
2007
Tommasi, A.Le Roux, V., Bodinier, J-L., Tommasi, A., Alard, O., Dautria, J-M., Vauchez, A., Riches, A.J.V.The lherz spinel lherzolite: refertilized rather than pristine mantle.Earth and Planetary Science Letters, Vol. 259, 3-4, pp. 599-612.MantleLherzolite chemistry
DS200812-0640
2008
Tommasi, A.Le Roux, V., Tommasi, A., Vauchez, A.Feedback between melt percolation and deformation in an exhumed lithosphere asthenosphere boundary.Earth and Planetary Science Letters, Vol. 274, pp. 410-413.MantleMelting
DS200812-0702
2008
Tommasi, A.Mainprice, D., Tommasi, A., Ferre, D., Carrez, P., Cordier, P.Predicted glide systems and crystal preferred orientations of polycrystalline silicate Mg perovskite at high pressure: implications for seismic anisotropyEarth and Planetary Science Letters, Vol. 271, 1-4, pp. 135-144.MantlePerovskite - lower mantle
DS200812-0794
2008
Tommasi, A.Neves, S.P., Tommasi, A., Vauchez,A., Hassani, R.Intraplate continental deformation: influence of a heat producing layer in the lithospheric mantle.Earth and Planetary Science Letters, Vol. 274, pp. 392-400.MantleMetasomatism
DS200812-1180
2008
Tommasi, A.Tommasi, A., Vauchez, A., Ionov, D.A.Deformation, static recrystallization, and reactive melt transport in shallow subcontinental mantle xenoliths ( Tok Cenozoic volcanic field, SE Siberia).Earth and Planetary Science Letters, Vol. 272, 1-2, pp. 65-77.Russia, SiberiaXenoliths
DS201212-0007
2012
Tommasi, A.Agrusta, R., Tommasi, A.Lithosphere thinning by small scale convection in a plume fed low viscosity layer beneath a moving plate.emc2012 @ uni-frankfurt.de, 1p. AbstractMantlePlume
DS201212-0052
2012
Tommasi, A.Baptiste, V., Tommasi, A., Demouchy, S.Deformation and hydration of the lithospheric mantle beneath the Kaapvaal craton, South Africa.emc2012 @ uni-frankfurt.de, 1p. AbstractAfrica, South AfricaMetasomatism
DS201212-0208
2012
Tommasi, A.Frets, E., Tommasi, A., Garrido, C.J., Padron-Navarta, J.A., Amri, I., Targuisti, K.Deformation processes and rheology of pyroxenites under lithospheric mantle conditions.Journal of Structural Geology, Vol. 39, pp. 138-157.Europe, Africa, MoroccoWebsterite, Beni-Bousera
DS201212-0299
2012
Tommasi, A.Higgie, K., Tommasi, A.Deformation in a shallow partially molten mantle: constraints from natural systems.emc2012 @ uni-frankfurt.de, 1p. AbstractMantleMelting
DS201312-0919
2013
Tommasi, A.Tommasi, A., Baptiste, V., Soustelle, V., Le Roux, V., Mainprice, D., Vauchez, A.Heterogeneity and anisotropy in the lithospheric mantle.Goldschmidt 2013, AbstractMantleGeophysics
DS201412-0253
2014
Tommasi, A.Frets, E.C., Tommasi, A., Garrido, C.J., Vauchez, A., Mainprice, D., Targuisti, K., Amri, I.The Beni Boussera peridotite ( Rif belt, Morocco): an oblique slip low angle shear zone thinning the subcontinental mantle lithosphere.Journal of Petrology, Vol. 55, 2, pp. 283-313.Africa, MoroccoPeridotite
DS201602-0187
2015
Tommasi, A.Agrusta, R., Tommasi, A., Arcay, D., Gonzalez, A., Gerya, T.How partial melting affects small-scale convection in a plume-fed sublithospheric layer beneath fast-moving plates.Geochemistry, Geophysics, Geosystems: G3, Vol. 16, 11, Nov. pp. 3924-3945.MantleConvection

Abstract: Numerical models show that small-scale convection (SSC) occurring atop a mantle plume is a plausible mechanism to rejuvenate the lithosphere. The triggering of SSC depends on the density contrast and on the rheology of the unstable layer underlying the stagnant upper part of the thermal boundary layer (TBL). Partial melting may change both properties. We analyze, using 2-D numerical simulations, how partial melting influences the dynamics of time-dependent SSC instabilities and the resulting thermo-mechanical rejuvenation of an oceanic plate moving atop of a plume. Our simulations show a complex behavior, with acceleration, no change, or delay of the SSC onset, due to competing effects of the latent heat of partial melting, which cools the plume material, and of the buoyancy increase associated with both melt retention and depletion of residue following melt extraction. The melt-induced viscosity reduction is too localized to affect significantly SSC dynamics. Faster SSC triggering is promoted for low melting degrees (low plume temperature anomalies, thick lithosphere, or fast moving plates), which limit both the temperature reduction due to latent heat of melting and the accumulation of depleted buoyant residue in the upper part of the unstable layer. In contrast, high partial melting degrees lead to a strong temperate decrease due to latent heat of melting and development of a thick depleted layer within the sublithospheric convecting layer, which delay the development of gravitational instabilities. Despite differences in SSC dynamics, the thinning of the lithosphere is not significantly enhanced relatively to simulations that neglect partial melting.
DS201704-0650
2016
Tommasi, A.Varas-Reu, M.I., Garrido, C.J., Marchesi, C., Bodinier, J-L., Frets, E., Bosch, D., Tommasi, A., Hidas, K., Targuisti, K.Refertilization processes of the subcontinental lithospheric mantle: the record of the Beni Bousera orogenic peridotite ( Rif Belt, northern Morocco).Journal of Petrology, Vol. 57, 11-12, pp. 2251-2270.Africa, MoroccoDeposit - Beni Bousera

Abstract: Correlations between major and minor transition elements in tectonically emplaced orogenic peridotites have been ascribed to variable degrees of melt extraction and melt-rock reaction processes, leading to depletion or refertilization. To elucidate how such processes are recorded in the subcontinental lithospheric mantle, we processed a large geochemical dataset for peridotites from the four tectono-metamorphic domains of the Beni Bousera orogenic massif (Rif Belt, northern Morocco). Our study reveals that variations in bulk-rock major and minor elements, Mg-number and modal mineralogy of lherzolites, as well as their clinopyroxene trace element compositions, are inconsistent with simple partial melting and mainly resulted from different reactions between melts and depleted peridotites. Up to 30% melting at <3 GPa and cryptic metasomatism can account for the geochemical variations of most harzburgites. In Grt-Sp mylonites, melting and melt-rock reactions are masked by tectonic mixing with garnet pyroxenites and subsolidus re-equilibration. In the rest of the massif, lherzolites were mostly produced by refertilization of a refractory protolith (Mg-number = 91, Ol = 70%, Cpx/Opx = 0.4) via two distinct near-solidus, melt- rock reactions: (1) clinopyroxene and orthopyroxene precipitation and olivine consumption at melt/rock ratios <0.75 and variable mass ratio between crystallized minerals and infiltrated melt ®, which are recorded fairly homogeneously throughout the massif; (2) dissolution of orthopyroxene and precipitation of clinopyroxene and olivine at melt/rock ratios <1 and R = 0.2-0.3, which affected mainly the Arie` gite-Seiland and Seiland domains. The distribution of secondary lherzolites in the massif suggests that the first refertilization reaction occurred prior to the differentiation of the Beni Bousera mantle section into petro-structural zones, whereas the second reaction was associated with the development of the tectono-metamorphic domains. Our data support a secondary, refertilization-related origin for most lherzolites in orogenic peridotite massifs.
DS201908-1787
2019
Tommasi, A.Liu, S., Tommasi, A., Vauchez, A., Mazzucchelli, M.Crust mantle coupling during continental convergence and break-up: constraints from peridotite xenoliths from the Bororema province, northeast Brazil.Tectonophysics, Vol. 766, pp. 249-269.South America, Brazilgeophysics - seismic

Abstract: We studied a suite of mantle xenoliths carried by Cenozoic volcanism in the Borborema Province, NE Brazil. These xenoliths sample a subcontinental lithospheric mantle affected by multiple continental convergence and rifting events since the Archean. Equilibrium temperatures indicate a rather hot geotherm, implying a ca. 80?km thick lithosphere. Most xenoliths have coarse-granular and coarse-porphyroclastic microstructures, recording variable degrees of annealing following deformation. The high annealing degree and equilibrated pyroxene shapes in coarse-granular peridotites equilibrated at ~900?°C indicate that the last deformation event that affected these peridotites is several hundreds of Ma old. Coarse-porphyroclastic peridotites equilibrated at 950-1100?°C probably record younger (Cretaceous?) deformation in the deep lithospheric mantle. In addition, a few xenoliths show fine-porphyroclastic microstructures and equilibrium temperatures =1200?°C, which imply recent deformation, probably related to the dykes that fed the Cenozoic volcanism. Chemical and microstructural evidence for reactive percolation of melts is widespread. Variation in textural and chemical equilibrium among samples implies multiple melt percolation events well spaced in time (from Neoproterozoic or older to Cenozoic). Crystal preferred orientations of olivine and pyroxenes point to deformation controlled by dislocation creep with dominant activation of the [100](010) and [001]{0kl} slip systems in olivine and pyroxenes, respectively, for all microstructures. Comparison of xenoliths' seismic properties to SKS splitting data in the nearby RCBR station together with the equilibrated microstructures in the low-temperature xenoliths point to coupled crust-mantle deformation in the Neoproterozoic (Brasiliano) continental-scale shear zones, which is still preserved in the shallow lithospheric mantle. This implies limited reworking of the lithospheric mantle in response to extension during the opening of the Equatorial Atlantic in the Cretaceous, which in the present sampling is restricted to the base of the lithosphere.
DS201012-0012
2010
Tommasi, A.M.Arndt, N.T., Guitreau, M., Boullier, A-M., Le Roex, A., Tommasi, A.M., Cordier, P., Sobolev, A.Olivine, and the origin of kimberlite.Journal of Petrology, Vol. 51, 3, pp. 573-602.TechnologyKimberlite genesis
DS1992-0656
1992
Tommasini, S.Halliday, A.N., Davies, G.R., Lee, D-C, Tommasini, S., Paslick, C.R.Lead isotope evidence for young trace element enrichment in the oceanic upper mantleNature, Vol. 359, No. 6396, October 15, pp. 623-626MantleGeochronology
DS200512-0716
2005
Tommasini, S.Melluso, L., Morra, V., Bortsu, P., Tommasini, S., Renna, MR, Duncan, R., Franciosi, L., D'Amelio, F.Geochronology and petrogenesis of the Cretaceous Antampombato Ambatovy Complex and associated dyke swarm, Madagascar.Journal of Petrology, Vol. 46, 10, pp. 1963-1996.Africa, MadagascarGeochronology - dike
DS200912-0057
2009
Tommasini, S.Boari, E., Tommasini, S., Laurenzi, M.A., Conticelli, S.Transition from ultrapotassic kamafugitic to sub-alkaline magmas: Sr Nd and Pb isotope, trace element and 40Ar 39Ar age dat a from the Middle LatinJournal of Petrology, Vol. 50,no. 7,. pp. 1327-1357.Europe, ItalyKamafugite
DS201112-1052
2011
Tommasini, S.Tommasini, S., Avanzinelli, R., Conticelli, S.The Th/La and Sm/La a conundrum of the Tethyan realm lamproites.Earth and Planetary Science Letters, Vol. 301, 3-4, pp. 469-478.EuropeLamproite
DS1900-0223
1903
Tompkins, D.A.Tompkins, D.A.History of Mecklenburg County and the City of Charlotte From 1740 to 1903.Charlotte: Observer Printing House., Vol. 2, PP. 109-131.United States, North Carolina, AppalachiaHistory
DS1998-1471
1998
Tompkins, L.Tompkins, L., Taylor, W., Ramsay, R., Armstrong, R.The mineralogy and geochemistry of the Kamafugitic Tres Barras intrusion, Mat a da Corda, Minas Gerais, Brasil.7th International Kimberlite Conference Abstract, pp. 920-2.Brazil, Minas GeraisLeucitites, kamafugites, Deposit - Tres Barras
DS1981-0199
1981
Tompkins, L.A.Haggerty, S.E., Toft, P.B., Tompkins, L.A.Diamonds in Graphitic SchistsEos, Vol. 62, No. 17, P. 416. (abstract.).GlobalGeology
DS1981-0410
1981
Tompkins, L.A.Tompkins, L.A., Haggerty, S.E.The Koidu Kimberlite, Sierra Leone: Preliminary Analytical Results.National Diamond Mining Company Sierra Leone., 28P. UNPUBL. SEPTEMBER.West Africa, Sierra LeoneChemical, Analyses, Mineral Chemistry, Ilmenite, Chlorite, Eclogite
DS1982-0243
1982
Tompkins, L.A.Haggerty, S.E., Tompkins, L.A.Opaque Mineralogy and Chemistry of Ilmenite Nodules in West africa Kimberlites: Subsolidus Equilibrium and Controls on Crystallization Trends.Proceedings of Third International Kimberlite Conference, TERRA COGNITA, ABSTRACT VOLUME., Vol. 2, No. 3, PP. 224-225, (abstract.).West Africa, Liberia, Sierra Leone, Mali, GuineaKimberlite, Heavy Minerals, Sampling
DS1982-0603
1982
Tompkins, L.A.Tompkins, L.A., Haggerty, S.E.Unique Kimberlitic Chlorites from Sierra LeoneGeological Society of America (GSA), Vol. 14, No. 7, P. 632, (abstract.).Sierra Leone, West AfricaKimberlite, Petrography
DS1982-0604
1982
Tompkins, L.A.Tompkins, L.A., Haggerty, S.E.The Koidu Kimberlite Complex, Sierra LeoneProceedings of Third International Kimberlite Conference, TERRA COGNITA, ABSTRACT VOLUME., Vol. 2, No. 3, P. 210, (abstract.).Sierra Leone, West AfricaKimberlite, Yengema, Pipe, Dike, Petrology, Mineralogy, Texture
DS1983-0276
1983
Tompkins, L.A.Haggerty, S.E., Tompkins, L.A.Subsoildus Reactions in Kimberlitic Ilmenites: Exsolutions, reduction and the Redox State of the Mantle- Appendix.Annales Scientifiques De L' Universite De Clermont-ferrand Ii, No. 74, PP. 141-148.West Africa, Liberia, Sierra Leone, Russia, South AfricaAnalyses
DS1983-0277
1983
Tompkins, L.A.Haggerty, S.E., Tompkins, L.A.Redox State of Earth's Upper Mantle from Kimberlite IlmeniteNature., Vol. 303, No. 5915, PP. 295-300.West Africa, Liberia, United StatesMineral Chemistry
DS1983-0601
1983
Tompkins, L.A.Tompkins, L.A.The Koidu Kimberlite Complex Sierra Leone, West AfricaMsc. Thesis, University Massachusetts, 230P.West Africa, Sierra LeoneMineral Chemistry, Chlorite, Kimberlite Mineralogy, Petrology
DS1983-0602
1983
Tompkins, L.A.Tompkins, L.A., Haggerty, S.E.The Koidu Kimberlite Complex, Sierra Leone: Geological Setting, Petrology and Mineral Chemistry- Appendix.Annales Scientifiques De L' Universite De Clermont-ferrand Ii, No. 74, PP. 99-122.West Africa, Sierra LeoneAnalyses, Mineral Chemistry
DS1983-0603
1983
Tompkins, L.A.Tompkins, L.A., Hargraves, R.B., Haggerty, S.E.Magnetic Mineralogy and Palaeomagnetism of the Koidu Kimberlite Complex Sierra Leone, West Africa.Eos, Vol. 64, No. 18, PP. 216-217. (abstract.).West Africa, Sierra LeoneMineral Chemistry
DS1984-0331
1984
Tompkins, L.A.Haggerty, S.E., Tompkins, L.A.Subsolidus Reactions in Kimberlitic Ilmenites: Exsolution, Reduction and the Redox State of the Mantle.Proceedings of Third International Kimberlite Conference, Vol. 1, PP. 335-357.South Africa, West Africa, Sierra Leone, LiberiaMineral Chemistry, Related Rocks
DS1984-0733
1984
Tompkins, L.A.Tompkins, L.A., Bailey, S.W., Haggerty, S.E.Kimberlitic Chlorites from Sierra Leone, West Africa: Unusual Chemistries and Structural Polytypes.American Mineralogist., Vol. 69, PP. 237-249.West Africa, Sierra LeoneMineral Chemistry, Nodules
DS1984-0734
1984
Tompkins, L.A.Tompkins, L.A., Haggerty, S.E.The Koidu Kimberlite Complex, Sierra Leone: Geological Setting, Petrology and Mineral Chemistry.In: Kimberlites. I. Kimberlites And Related Rocks, Kornprobs, PP. 83-105.West Africa, Sierra LeoneDiatreme, Kimberlite, Genesis, Carbonatite, Related Rocks, Craton
DS1985-0675
1985
Tompkins, L.A.Tompkins, L.A., Haggerty, S.E.Groundmass Oxide Minerals in the Koidu Kimberlite Dikes, Sierra Leone, West Africa.Contributions to Mineralogy and Petrology, Vol. 91, No. 3, PP. 245-263.West Africa, Sierra LeonePetrology
DS1987-0743
1987
Tompkins, L.A.Tompkins, L.A.Exploration for kimberlites in the Southwest Goias region,Brasil: mineral chemistry of stream sediment samplesJournal of Geochemical Exploration, Vol. 27, pp. 1-28BrazilGeochemistry, Analyses, ilmenite
DS1989-1506
1989
Tompkins, L.A.Tompkins, L.A., Gonzaga, G.M.Diamonds in Brasil and a proposed model for the origin and distribution Of diamonds in the Coromandel region,Minas Gerais, BrasilEconomic Geology, Vol. 84, No. 3, May pp. 591-602BrazilDiamond genesis, Diamond occurrences, distr
DS1990-0631
1990
Tompkins, L.A.Haggerty, S.E., Hargraves, R.B., Tompkins, L.A.Oxide mineralogy and magmatic properties of the Koidukimberlite Sierra Leone, West-AfricaGeophysical Journal, I, Vol. 100, No. 2, February pp. 275-Sierra LeoneGarnet analsyses -Mineralogy, Koidu Complex
DS1991-1738
1991
Tompkins, L.A.Tompkins, L.A.Kimberlite structural environments and diamonds in BrasilProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 426-428BrazilCraton, Amazonico, Rio-Negro-Jurena Mobile Belt, Paramirim craton, Juina, Sao Francisco
DS1991-1739
1991
Tompkins, L.A.Tompkins, L.A.The Japeccanga pipeFifth International Kimberlite Conferences Field Excursion Guidebook, Servico Geologico do Brasil (CPRM) Special, pp. 45-48BrazilGeology, Kimberlite
DS1991-1740
1991
Tompkins, L.A.Tompkins, L.A., Ramsay, R.R.The Boa Esperanca and Cana Verde pipes, Corrego d'Anta, Minas Gerais, BrasilProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 429-431Brazil, Inga, Quartel, Portugal, Minas Gerais, Boa EsperancaBambui province, lineament, structure, craton, Mineral chemistry
DS1992-1560
1992
Tompkins, L.A.Tompkins, L.A.Kimberlite structural environments and diamond productivity in BrasilRussian Geology and Geophysics, Vol. 33, No. 10, 8p.BrazilStructure, Diamondiferous kimberlites
DS1994-1438
1994
Tompkins, L.A.Ramsay, R.R., Tompkins, L.A.The geology, heavy mineral concentrate mineralogy, diamond prospectivity Of the Boa Esperanca and Cana Verde pipes.Proceedings of Fifth International Kimberlite Conference, Vol. 2, pp. 329-345.Brazil, Minas Gerais, Mato GrossoGeochemistry, Deposit -Boa Esperanca, Cana Verde
DS1994-1751
1994
Tompkins, L.A.Taylor, W.R., Tompkins, L.A., Haggerty, S.E.Comparative geochem. of West African kimberlites: evidence micaceous kimberlite endmember sublithosphericGeochimica et Cosmochimica Acta, Vol. 58, 19, pp. 4017-37.GlobalGeochemistry, Deposit -Koidu
DS1994-1752
1994
Tompkins, L.A.Taylor, W.R., Tompkins, L.A., Haggerty, S.E.Comparative geochemistry of West African kimberlites: evidence for amicaceous kimberlite endmember sublith.Geochimica et Cosmochimica Acta, Vol. 58, No. 19, pp. 4017-4037.West Africa, Sierra LeoneGeochemistry, Kimberlites -micaceous
DS1994-1790
1994
Tompkins, L.A.Tompkins, L.A.Tectono structural environments of primary diamond source rocks in Brasil:a review.Proceedings of Fifth International Kimberlite Conference, Vol. 2, pp. 259-267.BrazilTectonics, Diamond host rocks -review
DS1995-1555
1995
Tompkins, L.A.Reddicliffe, T., Taylor, W., Ong, N., Tompkins, L.A.The igneous rocks from the Coanjula microdiamond deposit, NorthernTerritory, Australia.Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 460-461.AustraliaMicrodiamonds, Deposit -Coanjula
DS1998-1472
1998
Tompkins, L.A.Tompkins, L.A., Meyer, S.P., Han, Z., Hu, S.Petrology and geochemistry of kimberlites from Liaoning and ShandongProvinces, China.7th International Kimberlite Conference Abstract, pp. 917-9.China, Liaoning, ShandongChangma, comparison, Deposit - Fuxian, Mengyin
DS1999-0740
1999
Tompkins, L.A.Tompkins, L.A., Meyer, Han, Hu, Armstrong, TaylorPetrology and chemistry of kimberlites from Shandong and Liaoning Provinces7th International Kimberlite Conference Nixon, Vol. 2, pp. 872-87.China, Shandong, FuxianMineral chemistry, trace, multi, analyses, thermometry, Deposit - Mengyin, Fuxian
DS2003-1385
2003
Tompkins, L.A.Tompkins, L.A., Taylor, W.A., Cowan, D.R.Diamond prospectivity of the Altjawarra Craton, Australia8ikc, Www.venuewest.com/8ikc/program.htm, Session 5, POSTER abstractAustraliaTarget area selection
DS2000-0276
2000
TomshinErnst, R.E., Buchan, K.L., Hamilton, Okrugin, TomshinIntegrated paleomagnetism and uranium-lead (U-Pb) geochronology of mafic dikes of Eastern Anabar Shield Region: LaurentiaJournal of Geology, Vol. 108, pp. 381-401.Russia, SiberiaMesoproterozoic paleolatitude comparison Laurentia, Geophysics - magnetics
DS1995-1385
1995
Tomshin, M.D.Oleinikov, O.B., Tomshin, M.D.Basite magmatism of the Yakut kimberlite provinceProceedings of the Sixth International Kimberlite Conference Abstracts, pp. 406.Russia, YakutiaMagmatism, Basite
DS1998-1473
1998
Tomshin, M.D.Tomshin, M.D., Fomin, A.S., Oleinikov, B.V.Basites of the Vilyui Markha zone Siberian Platform7th International Kimberlite Conference Abstract, pp. 923-5.Russia, SiberiaBilyuisk paleorift system, Dike swarm, magmatism
DS201012-0698
2010
Tomshin, M.D.Shiryae, A.A., Griffin, W.L., Tomshin, M.D., Okrugin, A.Natural silicon carbide from kimberlites: polytypes, trace elements, inclusions and speculations on its origin.International Mineralogical Association meeting August Budapest, abstract p. 181.TechnologyMoissanite
DS201012-0790
2010
Tomshin, M.D.Tomshin, M.D.Magmatites of the Ebe Khaya dike belt as a possible primary source of placer diamonds in the northeastern part of the Siberian platform..Doklady Earth Sciences, Vol. 431, 1, pp. 285-287.Russia, SiberiaAlluvials
DS201802-0269
2017
Tomshin, M.D.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.
DS1990-1146
1990
Tomura, K.Ozima, M., Zashu, M., Tomura, K.Crustal origin of carbonado (diamond) noble gas evidenceEos, Vol. 71, No. 43, October 23, p. 1708 AbstractGlobalCarbonado, Diamond -noble gas
DS1991-1281
1991
Tomura, K.Ozima, M., Zashu, S., Tomura, K., Matushi, Y.Constraints from mobile gas contents on the origin of carbonado diamondsNature, Vol. 351, No. 6326, June 6, pp. 472-474GlobalDiamond inclusions, Carbonado -gas
DS200612-0346
2006
Tomurkhuu, D.Dorjnamjaa, D., Tomurkhuu, D., Davaadorj, T.The geotectonic evolution and metallogeny of Mongolia during the Precambrian Phanerozoic time.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 1, abstract only.Asia, MongoliaTectonics
DS1997-1163
1997
Tomurtogoo, O.Tomurtogoo, O.A new tectonic scheme of the Paleozoides in MongoliaProceedings 30th. IGC., Vol. 7, pp. 75-82GlobalTectonics
DS1997-1164
1997
Ton, S.Y.M.Ton, S.Y.M., Wong, A., Wortel, M.J.R.Slab detachment in continental collision zones: an analysis of controllingparameters.Geophy. Res. Letters, Vol. 24, No. 16, Au. 15, pp. 2095-98.MantleSubduction
DS2001-0253
2001
TonariDiBattistini, G., Montanini, Vernia, Venturelli, TonariPetrology of melilite bearing rocks from the Montefiascone volcanic complex Roman magmatic provinceLithos, Vol. 59, No. 1-2, Oct. pp. 1-24.ItalyUltrapotassic volcanism
DS1998-0852
1998
Tonarini, S.Leeman, W.P., Tonarini, S.Fluids in subduction zone magmatism: implications of boron geochemistryMineralogical Magazine, Goldschmidt abstract, Vol. 62A, p. 873-4.MantleGeochemistry - boron, Subduction
DS200512-1095
2005
Tonarini, S.Tonarini, S., Agostini, S., Innocent, F., Manetti, P.d11B as tracer of slab dehydration and mantle evolution in western Anatolia Cenozoic magmatism.Terra Nova, Vol. 17, 3, pp. 259-264.MantleMagmatism - not specific to diamonds
DS200612-1446
2006
Tonarini, S.Turner, S., Tonarini, S., Bindeman, L., Leeman, W.P., Schaefer, B.F.Boron and oxygen isotopic evidence for recycling of subducted components through the Earth's mantle since 2.5 Ga.Geochimica et Cosmochimica Acta, Vol. 70, 18, 1, p. 28, abstract only.MantleSubduction
DS200712-0266
2007
Tonarini, S.D'Orazio, M., Innocenti, F., Tonarini, S.Carbonatites in a subduction system: the Pleistocene alvikite.Lithos, Vol. 98, 1-4, pp. 313-334.Europe, ItalyCarbonatite
DS1990-0289
1990
Tondello, E.Casarin, M., Granozzi, G., Tondello, E., Vittadin, A.A molecular cluster approach to the electronic structure of anomalous muonium in diamondChem. Phys, Vol. 148, No. 2-3, December 1, pp. 183-192GlobalDiamond morphology, MuoniuM.
DS201707-1359
2017
Tondo, M.J.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
Tondo, M.J.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.
DS1995-1917
1995
TongTong, LiElement abundances of China's continental crust and its sedimentary layer and upper continental crustChinese Journal of GeocheM., Vol. 14, No. 1, pp. 26-32ChinaContinental crust
DS200612-1242
2006
Tong, L.Schneider, J., Jahn, B-M., Okamoto, K., Tong, L., Lizuka, Y., Xu, Z.Rb Sr and Sm Nd isotope analyses of CCSD eclogites ( Sulu, China): a test for the closure temperature concept.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 12, abstract only.ChinaUHP, geochronology
DS201112-1053
2011
Tong, L.Tong, L., Jahn, B-M., Zheng, Y-F.Diverse P-T paths of the northern Dabie complex in central Chin a and its reworking in the early Cretaceous.Journal of Asian Earth Sciences, Vol. 42, 4, pp. 633-640.Asia, ChinaUHP
DS200412-1432
2004
Tong, Y.Ni, Z., Zhai, M., Wang, R., Tong, Y., Shu, G., Hai, X.Discovery of Late Paleozoic retrograded eclogites from the middle part of the northern margin of North Chin a Craton.Chinese Science Bulletin, Vol. 49, 6, pp. 600-606. Ingenta 1042070211ChinaEclogite
DS202009-1658
2020
Tong, Y.Shang, S.Y., Tong, Y., Zhang, S.X., Huang, F.L.Study on phase transformation mechanism of various carbon sources in detonation synthesis of diamond.Fullerenes, nanotubes and carbon nanostructures, Vol. 28, 11, pp. 877-885.globalsynthetics

Abstract: In this paper, the phase transformation mechanism of various carbon sources in the synthesis of diamond by direct detonation method was studied. Through designing comparison experiment and the X-ray diffraction (XRD) characterization technique, an experimental study was conducted on the detonation process with the external of the combined carbon source and free carbon source, and without the participation of the external carbon source. The laws of phase transformation of the various carbon sources are obtained, in which the surplus carbon in the explosives participates in the formation of diamonds through the collision growth of droplet-like carbon, the added bonded carbon does not participate in the synthesis of diamond, and the added free carbon forms diamonds through the Martensitic transformation.
DS1991-0123
1991
Tong ChenBishop, P.K., Burston, M.W., Tong Chen, Lerner, D.N.A low cost dedicated multi-level groundwater sampling systemQuart. Journal of Engineering Geology, Vol. 24, pp. 311-324GlobalGroundwater, Sampling
DS200412-1320
2004
Tongwei, Z.Mingjie, Z., Zianbin, W., Gang, L., Tongwei, Z., Wenrui, B.Compositions of upper mantle fluids beneath eastern China: implications for mantle evolution.Acta Geologica Sinica, Vol. 78, 1, pp. 125-130.ChinaGeochemistry
DS1995-0820
1995
Tonika, J.Hopggod, A.M., Bowes, D.R., Tonika, J.Application of structural sucession to characterization of the Bohemian Forest tectonic domain... Hercynides.Neues Jahrbuch fnr Mineralogie Abh, Vol. 169, No. 2, pp. 119-156GlobalStructure, Tectonics
DS1998-1474
1998
Tonn, R.Tonn, R.Seismic reservoir characterization of Montney Sand in the Peace River Archarea, Canada.The Leading Edge, May pp. 643-5.AlbertaMontney Sand - not specific to diamonds, Geophysics - seismics
DS1996-1435
1996
Tontti, M.Tontti, M., Gautneb, H., Grenne, T., et al.Map of ore deposits in central FennoscandiaFinland Geological Survey Map, 1: 1, 000, 000FinlandMetallogeny, Deposits
DS200912-0841
2009
Tonui, E.Young, E.D., Tonui, E., Manning, C.E., Schauble, E., Macris, C.A.Spinel olivine magnesium isotope thermometry in the mantle and implications for the MG isotopic composition of Earth.Earth and Planetary Science Letters, Vol. 288, 3-4, pp. 524-533.MantleGeothermometry
DS201012-0881
2009
Tonui, E.Young, E.D., Tonui, E., Manning, C.E., Schauble, E., Macris, C.A.Spinel olivine magnesium isotope thermometry in the mantle and implications for the Mg isotopic composition of Earth.Earth and Planetary Science Letters, Vol. 288, pp. 524-533..MantleGeochemistry
DS1990-1473
1990
Tooker, M.Tooker, M., Schewchenko, N., Bonham-Carter, G.F., Renze, A.N.Plotter- a fortran program using UNIRAS for plotting SPANS and EASI/PACEimagesGeological Survey of Canada Open File, No. 2255, 43p. Report and 1 diskette $ 23.00GlobalComputer, Program -PLOTTER.
DS1986-0810
1986
Toombs, G.A.Toombs, G.A., Sechos, B.Examination of the surface features of Argyle diamonds, from WesternAustraliaAustralian Gemologist, Vol. 16, No. 2, pp. 41-44AustraliaCrystallography, Morphology
DS1960-1117
1969
Tooms, J.S.Gregory, G.P., Tooms, J.S.Geochemical Prospecting for KimberlitesCol. Sch. Mines Quarterly, Vol. 64, No. 1, JANUARY PP. 265-304.United States, Gulf Coast, ArkansasGeochemistry, Evaluation, Prairie Creek, Mineral Chemistry, Soil
DS1995-1918
1995
Toon, O.Toon, O., Zahnle, K.All impacts great and smallGeotimes, Vol. 40, No. 3, March pp. 21-23GlobalImpacts
DS200712-1090
2007
Tooyama, C.Tooyama, C., Muramatsu, Y., Yamamotto, J., Kaneoka, I.Determin ation of 33 elements in kimberlites from South Africa and Chin a by ICP-MS.Plates, Plumes, and Paradigms, 1p. abstract p. A1030.Africa, South Africa, ChinaShandon, Liaoning
DS200412-1894
2004
Top, Z.Srinivasan, A., Top,Z., Sclosser, P., Hohmann, R., Iskandarani, M., Olson, D.B., Lupton, J.E., Jenkins, W.J.Mantle 3 He distribution and deep circulation in the Indian Ocean.Journal of Geophysical Research, Vol. 109, 6, 10.1029/2003 JC002028Indian OceanMineralogy
DS1991-1813
1991
Topel, J.Voll, G., Topel, J., Pattison, DR.M., Seifert, F.Equilibrium and kinetics in contact metamorphismSpringer-Verlag Pub, 424p. approx. $ 190.00 United StatesGlobalmetamorphism, Book -ad
DS1990-0408
1990
Topley, C.G.D'Lemos, R.S., Strachan, R.A., Topley, C.G.The Cadomian OrogenyGeological Society of London Special Publication, No. 51, 410pFrance, Wales, Iberia, Spain, Nova ScotiaTectonics, Avalon Terrane, Structure, shear zones, Amorican Massif, Proterozoic
DS2001-1055
2001
Toplis, M.J.Seyler, M., Toplis, M.J., Lorand, JP, Luquet, CannalClinopyroxene microtextures reveal incompletely extracted melts in abyssalperidotites.Geology, Vol. 29, No. 2, Feb. pp. 155-8.MantlePeridotites
DS2003-0944
2003
Toplis, M.J.Meyzen, C.M., Toplis, M.J., Humler, E., Ludden, J.N., Mevel, C.A discontinuity in mantle composition beneath the southwest Indian ridgeNature, No. 6924, Feb. 13, pp. 731-33.IndiaMantle - boundary
DS201012-0080
2010
Toplis, M.J.Burnard, P., Toplis, M.J., Medynski, S.Low solubility of He and Ar carbonatitic liquids: implications for decoupling noble gas and lithophile isotope systems.Geochimica et Cosmochimica Acta, Vol. 74, 5, pp. 1672-1683.MantleCarbonatite
DS201705-0860
2017
Toplis, M.J.Nedelec, A., Monnereau, M., Toplis, M.J.The Hadean-Archean transition at 4Ga: from magma trapping in the mantle to volcanic resurfacing of the Earth.Terra Nova, in press availableMantleMagmatism

Abstract: The Hadean-Archaean transition is poorly known because of the dearth of Hadean rocks. A new conceptual model is presented based on variations in mantle potential temperature (Tp) with time. The critical issue is the depth of melting with respect to a negatively buoyant magma sink between 410 and 330 km (14-11 GPa). Hadean plume magmatism begins below the magma sink, leading to generation of a refractory upper mantle reservoir and the minor production of boninite-like magmas near the surface. With cooling, the onset of melting migrates above the magma sink, a situation likely occurring since 3.9 Ga and corresponding to Tps of ~1870°C or less. Therefore, a burst of mafic to ultramafic volcanism was produced at 3.9-3.8 Ga. This extensive volcanism may have triggered gravitational instabilities and favoured the recycling of the Hadean crust into the mantle. Results of this model are discussed in the light of existing isotopic data.
DS201709-1962
2017
Toplis, M.J.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.
DS202012-2206
2020
Toplis, M.J.Borisova, A.Y., Bindeman, I.N., Toplis, M.J., Zagrtdenov, N.R., Guignard, J., Safonov, O.G., Bychkov, A.Y., Shcheka, S., Melnik, O.E., Marcelli, M., Fehrenbach, J.Zircon survival in shallow asthenosphere and deep lithosphere.American Mineralogist, Vol. 105, pp. 1662-1671. pdfMantlemelting

Abstract: Zircon is the most frequently used mineral for dating terrestrial and extraterrestrial rocks. However, the system of zircon in mafic/ultramafic melts has been rarely explored experimentally and most existing models based on the felsic, intermediate and/or synthetic systems are probably not applicable for prediction of zircon survival in terrestrial shallow asthenosphere. In order to determine the zircon stability in such natural systems, we have performed high-temperature experiments of zircon dissolution in natural mid-ocean ridge basaltic and synthetic haplobasaltic melts coupled with in situ electron probe microanalyses of the experimental products at high current. Taking into account the secondary fluorescence effect in zircon glass pairs during electron microprobe analysis, we have calculated zirconium diffusion coefficient necessary to predict zircon survival in asthenospheric melts of tholeiitic basalt composition. The data imply that typical 100 micron zircons dissolve rapidly (in 10 hours) and congruently upon the reaction with basaltic melt at mantle pressures. We observed incongruent (to crystal ZrO2 and SiO2 in melt) dissolution of zircon in natural mid-ocean ridge basaltic melt at low pressures and in haplobasaltic melt at elevated pressure. Our experimental data raise questions about the origin of zircons in mafic and ultramafic rocks, in particular, in shallow oceanic asthenosphere and deep lithosphere, as well as the meaning of the zircon-based ages estimated from the composition of these minerals. Large size zircon megacrysts in kimberlites, peridotites, alkali basalts and other magmas suggest the fast transport and short interaction between zircon and melt.The origin of zircon megacrysts is likely related to metasomatic addition of Zr into mantle as any mantle melting episode should obliterate them.
DS201112-0543
2011
Toporski, J.Korsakov, A.V., Golovin, A.V., Dieing, T., Toporski, J.Fluid inclusions in rock forming minerals of ultrahigh pressure metamorphic rocks ( Kokchetav massif, northern Kazakhstan).Doklady Earth Sciences, Vol. 437, 2, pp. 473-478.Russia, KazakhstanUHP
DS200612-1289
2006
TORShomali, Z.H., Roberts, R.G., Pedersen, L.B., TORLithospheric structure of the Tornquist Zone resolved by nonlinear P and S teleseismic tomography along the TOR array.Tectonophysics, Vol. 416, 1-4, April 5, pp. 133-149.Europe, Baltic ShieldGeophysics - seismics
DS200612-1491
2006
TORVoss, P., Mosegaard, K., Gregersen, S., TORThe Tornquist Zone, north east inclining lithospheric transition at the south western margin of the Baltic Shield: revealed through a nonlinear teleseismic tomographic inversion.Tectonophysics, Vol. 416, 1-4, April 5, pp. 151-166.Europe, Baltic ShieldGeophysics - seismics
DS201112-0072
2011
Torabi, G.Bayat, F., Torabi, G.Alkaline lamprophyric province of central Iran.Isalnd Arc, Vol. 20, 3, pp. 386-400.Europe, IranCamptonite
DS201012-0418
2010
Toraman, E.Kusky, T.M., Toraman, E., Raharimahefa, T., Rasoazanamparany, C.Active tectonics of the Alatra Ankay graben system, Madagascar: possible extension of Somalian African diffusive plate boundary?Gondwana Research, Vol. 18, 2-3, pp. 274-294.Africa, MadagascarTectonics
DS201112-0358
2011
Torano, J.Gent, M., Menendez, M., Torano, J., Torno, S.A review of indicator minerals and sample processing methods for geochemical exploration. Mentions kimberlitesJournal of Geochemical Exploration, Vol. 110, 2, pp. 47-60.TechnologyIM, density, magnetic
DS1995-1226
1995
Toravik, T.H.Meert, J.G., Toravik, T.H.Superplumes and the breakup of RodiniaEos, Vol. 76, No. 46, Nov. 7. p.F588. Abstract.GondwanaPlumes, Geodynamics, tectonics
DS200612-1487
2005
Torbeeva, T.S.Vladykin, N.V., Torbeeva, T.S.Lamproites of the Tomtor massif ( eastern Anabar area).Russian Geology and Geophysics, Vol. 46, 10 pp. 1024-1036.RussiaPetrology - lamproites
DS1960-1043
1968
Tordi, C.Tordi, C.Traite de Prospection et Exploitation de Gisements Detritiques de Diamant En Afrique Occidentale.Amic Anc. Elev. Tech. Mines Al Esalaam Bulletin., No. 119, PP. 268-274.West AfricaProspecting, Alluvials, Diamonds
DS1989-0554
1989
Tordiffe, E.A.W.Grobler, N.J., Van der Westhuizen, W.A., Tordiffe, E.A.W.The Sodium Group, South Africa: reference section for Late Archean- early Proterozoic cratonic cover sequencesAustralian Journal of Earth Sciences, Vol. 36, pp. 41-64. Database # 17953South AfricaProterozoic, Kaapvaal Craton
DS1992-1561
1992
Torgensen, T.Torgensen, T.Crustal fluid flow: continuous or episodic?Eos, Vol. 72, No. 3, Jan. 15, pp. 18, 19GlobalMantle, Crustal fluid flow, hydrology, water
DS1990-1474
1990
Torgersen, T.Torgersen, T.Crustal scale fluid transport. Magnitude and mechanismsEos, Vol. 71, No. 1, January 2, pp. 1, 4, 13GlobalMantle, Crustal transport
DS1991-1741
1991
Torgersen, T.Torgersen, T.Crustal scale fluid transport: magnetitude and mechanisMGeophysical Research Letters, Vol. 18, No. 5, May pp. 917-918GlobalCrust, Fluid flow
DS1995-1919
1995
Torgersen, T.Torgersen, T., Drenkard, S., Stute, M., et al.Mantle helium in ground waters of eastern North America: time and space constraints on sourcesGeology, Vol. 23, No. 8, August pp. 675-678GlobalHot spots, Tectonics
DS200812-1181
2007
Torii, Y.Torii, Y., Yoshioka, S.Physical conditions producing slab stagnation: constraints of the Clapeyron slope, mantle viscosity retreat and dip angles.Tectonophysics, Vol. 445, 3-4, pp. 200-209.MantleSlab
DS200812-0547
2008
Toriumi, M.Katayama, I., Komiya, T., Toriumi, M.Annealing time scale of the cratonic lithosphere of southern Africa inferred from the shape of inclusion minerals.International Geology Review, Vol. 50, 1, pp. 84-88.Africa, South AfricaCraton, inclusions
DS202004-0525
2019
Torne, M.Kumar, A., Fernandez, M., Jimenez-Munt, I., Torne, M., Verges, J., Afonso, J.C.LitMod2D_2.0: an improved integrated geophysical petrological modeling took for the physical interpretation of upper mantle anomalies.Geochemistry, Geophysics, Geosystems, 10.1029/2019GC008777. 19p.Mantlegeophysics

Abstract: LitMod2D integrates geophysical and petrological data sets to produce the thermal, density, and seismic velocity structure of the lithosphere and upper mantle. We present a new LitMod2D_2.0 package with improvements focused on (i) updated anelastic attenuation correction for anharmonic seismic velocities, (ii) chemical composition in the sublithospheric mantle, and (iii) incorporation of sublithospheric mantle anomalies. Sublithospheric mantle anomalies can be defined with different chemical composition, temperature, seismic velocities, and a combination of them, allowing the application of LitMod2D_2.0 to regions affected by mantle upwelling, subduction, delamination, and metasomatism. We demonstrate the potential application of LitMod2D_2.0 to such regions and the sensitivity of thermal and compositional anomalies on density and seismic velocities through synthetic models. Results show nonlinearity between the sign of thermal and seismic velocity anomalies, and that S wave velocities are more sensitive to temperature whereas P wave velocities are to composition. In a synthetic example of subduction, we show the sensitivity of sublithospheric mantle anomalies associated with the slab and the corner flow on surface observables (elevation, geoid height, and gravity anomalies). A new open-source graphic user interface is incorporated in the new package. The output of the code is simplified by writing only the relevant physical parameters (temperature, pressure, material type, density, and seismic velocities) to allow the user using predefined post-processing codes from a toolbox (flexure, mineral assemblages, synthetic passive seismological data, and tomography) or designing new ones. We demonstrate a post-processing example calculating synthetic seismic tomography, Rayleigh surface-wave dispersion curves, and P wave receiver functions from the output file of LitMod2D_2.0.
DS1860-0395
1882
Tornebohm, A.E.Tornebohm, A.E.Mikroskopiska Bergartsstudier. Xvii. Melilitbasalt Fran AlnoGeol. Foren. Forhandl., Vol. 6, No. 6, PP. 240- 251.Europe, Sweden, ScandinaviaMelilitite
DS201112-0358
2011
Torno, S.Gent, M., Menendez, M., Torano, J., Torno, S.A review of indicator minerals and sample processing methods for geochemical exploration. Mentions kimberlitesJournal of Geochemical Exploration, Vol. 110, 2, pp. 47-60.TechnologyIM, density, magnetic
DS1950-0432
1958
Torny, A.Torny, A.Sterne im Sand, Digger, Durst und DiamantenC. Bertelsmann., 282P.South Africa, Southwest Africa, Russia, NamibiaDiamonds, Kimberley, Fiction, True Adventure
DS200812-0926
2008
Toro, J.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
Toro, J.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
DS1975-0641
1977
Toro, R.D.Toro, R.D.Variacion Vertical Y Lateral de Ocho Perfiles Aluvionales De la Quebrada Grande, Afluente Del Rio Guaniamo, Comprendidos Entre Los Campos Mineros la Bicicleta YFifth. Congreso Venezolano, PP. 954-988.South America, VenezuelaGeochemistry, Alluvial Prospecting
DS2002-0095
2002
Torok, K.Bali, E.O., Szabo, C., Vaselli, O., Torok, K.Significance of silicate melt pockets in upper mantle xenoliths from Bakony Balaton Highland volcanic fieldLithos, Vol.61, 1-2, March, pp. 79-102.HungaryXenoliths - silicates ( not specific to diamond)
DS200812-1047
2007
Torok, K.Sharygin, V.V., Szabo, C., Kothay, K., Timina, T.Ju., Peto, MN., Torok, K., Vapnik, Y., Kuzmin, D.V.Rhonite in silica undersaturated alkali basalts: inferences on silicate melt inclusions in olivine phenocrysts.Vladykin Volume 2007, pp. 157-182.RussiaPetrology
DS1997-0804
1997
Torokhov, M.Mitrofanov, F., Torokhov, M., Iljina, M.Ore deposits of the Kola Peninsula, northwestern RussiaFinland Geological Survey Guidebook, No. 45, 46pRussia, Kola PeninsulaMetallogeny, Kola Peninsula
DS200512-1096
2005
Toronto StarToronto StarAfter the gold... diamond mining booms in northwest.. buried treasure. Brief descriptions of Diavik and Ekati.Toronto Star, August 1, p. D1, D2.Canada, Northwest TerritoriesNews item - Diavik, Ekati
DS200912-0768
2009
Toronto StarToronto StarHigh end Harry Winston sees red, but dollar stores (Dollerama) deliver more green.Toronto Star, Sept. 1, p. B2.GlobalNews item - Harry Winston
DS201112-1054
2011
Toronto StarToronto StarNorthern diamonds in the rough. Jericho history and future.Toronto Star, April 23, 2p.Canada, NunavutNews item - Shear
DS1998-1475
1998
Toronto Stock ExchangeToronto Stock Exchange, Ontario Securities CommissionSetting new standards: proposed standards for public mineral exploration and mining companiesTse/osc Publ, 110pCanada, OntarioBook - table of contents, Legal - mining rules, disclosure, qualified person
DS200712-1091
2007
Torppa, O.A.Torppa, O.A., Karhu, J.A.Ancient subduction recorded in the isotope characteristics of ~1.8 Ga Fennoscandian carbonatites.Plates, Plumes, and Paradigms, 1p. abstract p. A1032.Europe, Fennoscandia, FinlandCarbonatite
DS201312-0564
2013
Torpy, A.MacRae, C.M., Wilson, N.C., Torpy, A.hyper spectral cathodluminescence.Mineralogy and Petrology, in pressTechnologyCL spectra
DS1989-1507
1989
Torrens, H.S.Torrens, H.S.Hawking history- a vital future for geology's pastModern Geology, Vol. 13, No. 1, pp. 83-94GlobalHistory, Tectonics
DS201910-2284
2019
Torrent, J.Menendez, I., Campeny, M., Quevedo-Gonzalez, L., Mangas, J., Llovet, X., Tauler, E., Barron, V., Torrent, J., Mendez-Ramos, J.Distribution of REE-bearing minerals in felsic magmatic rocks and palesols from Gran Canaria, Spain: intraplate oceanic islands as a new example of potential, non-conventional sources of rare earth elements.Journal of Geochemical Exploration, Vol. 204, pp. 270-288.Europe, SpainREE

Abstract: Gran Canaria is a hotspot-derived, intraplate, oceanic island, comprising a variety of alkaline felsic magmatic rocks (i.e. phonolites, trachytes, rhyolites and syenites). These rocks are enriched in rare-earth elements (REE) in relation to the mean concentration in the Earth's crust and they are subsequently mobilised and redistributed in the soil profile. From a set of 57 samples of felsic rocks and 12 samples from three paleosol profiles, we assess the concentration and mobility of REE. In the saprolite that developed over the rhyolites, we identified REE-bearing minerals such as primary monazite-(Ce), as well as secondary phases associated with the edaphic weathering, such as rhabdophane-(Ce) and LREE oxides. The averaged concentration of REE in the alkaline bedrock varies from trachytes (449?mg?kg-1), to rhyolites (588?mg?kg-1) and to phonolites (1036?mg?kg-1). REE are slightly enriched in saprolites developed on trachyte (498?mg?kg-1), rhyolite (601?mg?kg-1) and phonolite (1171?mg?kg-1) bedrocks. However, B-horizons of paleosols from trachytes and phonolites showed REE depletion (436 and 994?mg?kg-1, respectively), whereas a marked enrichment was found in soils developed on rhyolites (1584?mg?kg-1). According to our results, REE resources on Gran Canaria are significant, especially in Miocene alkaline felsic magmatic rocks (declining stage) and their associated paleosols. We estimate a total material volume of approximately 1000?km3 with REE concentrations of 672?±?296?mg?kg-1, yttrium contents of 57?±?30?mg?kg-1, and light and heavy REE ratios (LREE/HREE) of 17?±?6. This mineralisation can be considered as bulk tonnage and low-grade ore REE deposits but it remains necessary to develop detailed mineral exploration on selected insular zones in the future, without undermining environmental and socioeconomic interests.
DS201312-0319
2013
Torres, M.G.Gomide, C.S., Brod, J.A., Junqueira-Brod, T.C., Buhn, B.M., Santos, R.V., Barbosa, E.S.R., Cordeiro, P.F.O., Palmieri, M., Grasso, C.B., Torres, M.G.Sufur isotopes from Brazilian alkaline carbonatite complexes.Chemical Geology, Vol. 341, pp. 38-49.South America, BrazilDeposit - Tapira, Salitre, Serra Negra, Catalao, Jacupiringa
DS2002-1459
2002
Torres Alvarado, I.S.Sheth, H.C., Torres Alvarado, I.S., Verma, S.P.What is the 'Calc alkaline rock series'?International Geology Review, Vol. 44, 8, pp. 686-701.GlobalAlkaline - classification
DS2000-0890
2000
Torres-Alvarado, I.S.Sheth, H.C., Torres-Alvarado, I.S., Verma, S.P.Beyond subduction and plumes: a unified tectonic petrogenetic model for the Mexican volcanic belt.International Geology Review, Vol.42,12,Dec. pp. 1116-32.MexicoSubduction - not specific to diamond
DS1995-1671
1995
TorresanSchlee, Karl, TorresanImaging the sea floorUnited States Geological Survey (USGS) Bulletin, No. 2079, 30pOceanRemote sensing, side scan sonar, sea beaM., Tectonics, crust
DS1990-0911
1990
Torres-RuizLeblanc, M., Curras, J., Gervilla, F., Temagoult, A., Torres-RuizLherzolite related mineralizationsTerra, Abstracts of International Workshop Orogenic Lherzolites and Mantle Processes, Vol. 2, December abstracts p. 133AlpsLherzolite, Mineralogy
DS1997-1165
1997
Torries, T.F.Torries, T.F.Evaluating mineral projects: applications and misconceptionsSociety for Mining, Metallurgy and Exploration (SME)., 172p. approx. $ 50.00 United StatesGlobalBook - ad, Evaluations, economics, projects, discoveries
DS1997-1166
1997
Torries, T.F.Torries, T.F.NPV or IRR? Why not both?Internal rate of return/ net present valuecomparisonSociety for Mining, Metallurgy and Exploration (SME) Preprint, No. 97-34, 6pUnited StatesEconomics, Geostatistics, ore reserves
DS1998-1476
1998
Torries, T.F.Torries, T.F.NPV or IRR? Why not both?Mining Eng, Vol. 50, No. 10, Oct. pp. 69-73GlobalEconomics - investment, capital, Discoveries, exploration
DS201012-0791
2010
Torro, L.Torro, L., Villanova, C., Castillo, M., Campeny, M., Goncalves, O.A., Melgarejo, J.C.Nb and REE minerals from the Virulundo carbonatite Namibe, Angola.International Mineralogical Association meeting August Budapest, abstract p. 578.Africa, AngolaCarbonatite
DS201212-0732
2012
Torro, L.Torro, L., Villanova, C., Castillo, M., Campeny, M., Goncalves, A.O., Melgarejo, J.C.Niobium and rare earth minerals from the Virulundo carbonatite, Namibe, Angola.Mineralogical Magazine, Vol. 76, 2, pp. 393-409.Africa, AngolaDeposit - Virulundo
DS1999-0567
1999
Torske, 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
DS1998-1204
1998
TorsvikRakotosolofo, N.A., Torsvik, Ashwal, De Wit, EideMadagascar during the Late Paleozoic and MesozoicJournal of African Earth Sciences, Vol. 27, 1A, p. 148. AbstractMadagascarTectonics
DS201212-0071
2012
Torsvik, H.Biggin, A.J., Steinberger, B., Aubert, J., Suttle, N., Holme, R., Torsvik, H., Van der Meer, D.G., Van Hinsbergen, J.J.Possible links between long term geomagnetic variations and whole mantle convection processes.Nature Geoscience, Vol. 5, pp. 526-533.MantleConvection
DS1998-1477
1998
Torsvik, T.Torsvik, T., Tucker, Ashwal, Eide, Rakotosolofo, De WitMadagascar: Cretaceous volcanism and the Marian hot spotJournal of African Earth Sciences, Vol. 27, 1A, p. 197. AbstractMadagascarvolcanism., Plume
DS200612-1013
2006
Torsvik, T.O'Neill, C., Lenardic, A., Moresi, L., Torsvik, T., Lee, C.T.The nature of subduction on the early Earth.Geochimica et Cosmochimica Acta, Vol. 70, 18, 1, p. 458, abstract only.MantleSubduction
DS201607-1383
2016
Torsvik, T.Torsvik, T.Linking African ( Gondwanan) kimberlites to deep Earth processes.IGC 35th., Session A Dynamic Earth 1p. AbstractAfricaKimberlite
DS201801-0070
2018
Torsvik, T.Tappe, S., Smart, K., Torsvik, T., Massuyeau, M., de Wit, M.Geodynamics of kimberlites on a cooling Earth: clues to plate tectonic evolution and deep volatile cycles.Earth and Planetary Science Letters, Vol. 484, pp. 1-14.Mantlekimberlite, origin, magmatism

Abstract: Kimberlite magmatism has occurred in cratonic regions on every continent. The global age distribution suggests that this form of mantle melting has been more prominent after 1.2 Ga, and notably between 250-50 Ma, than during early Earth history before 2 Ga (i.e., the Paleoproterozoic and Archean). Although preservation bias has been discussed as a possible reason for the skewed kimberlite age distribution, new treatment of an updated global database suggests that the apparent secular evolution of kimberlite and related CO2-rich ultramafic magmatism is genuine and probably coupled to lowering temperatures of Earth's upper mantle through time. Incipient melting near the CO2- and H2O-bearing peridotite solidus at >200 km depth (1100-1400?°C) is the petrologically most feasible process that can produce high-MgO carbonated silicate melts with enriched trace element concentrations akin to kimberlites. These conditions occur within the convecting asthenospheric mantle directly beneath thick continental lithosphere. In this transient upper mantle source region, variable CHO volatile mixtures control melting of peridotite in the absence of heat anomalies so that low-degree carbonated silicate melts may be permanently present at ambient mantle temperatures below 1400?°C. However, extraction of low-volume melts to Earth's surface requires tectonic triggers. Abrupt changes in the speed and direction of plate motions, such as typified by the dynamics of supercontinent cycles, can be effective in the creation of lithospheric pathways aiding kimberlite magma ascent. Provided that CO2- and H2O-fluxed deep cratonic keels, which formed parts of larger drifting tectonic plates, existed by 3 Ga or even before, kimberlite volcanism could have been frequent during the Archean. However, we argue that frequent kimberlite magmatism had to await establishment of an incipient melting regime beneath the maturing continents, which only became significant after secular mantle cooling to below 1400?°C during post-Archean times, probably sometime shortly after 2 Ga. At around this time kimberlites replace komatiites as the hallmark mantle-derived magmatic feature of continental shields worldwide. The remarkable Mesozoic-Cenozoic ‘kimberlite bloom’ between 250-50 Ma may represent the ideal circumstance under which the relatively cool and volatile-fluxed cratonic roots of the Pangea supercontinent underwent significant tectonic disturbance. This created more than 60% of world's known kimberlites in a combination of redox- and decompression-related low-degree partial melting. Less than 2% of world's known kimberlites formed after 50 Ma, and the tectonic settings of rare ‘young’ kimberlites from eastern Africa and western North America demonstrate that far-field stresses on cratonic lithosphere enforced by either continental rifting or cold subduction play a crucial role in enabling kimberlite magma transfer to Earth's surface.
DS1995-1920
1995
Torsvik, T.HTorsvik, T.H, Meert, J.G.Superchrons and supercontinentsEos, Vol. 76, No. 46, Nov. 7. p.F172. Abstract.MantleRodinia, Gondwana, Pangea
DS1994-0683
1994
Torsvik, T.H.Gurnis, M., Torsvik, T.H.Rapid drift of large continents during the late Precambrian and Paleozoic:paleomagnetic constraints.Geology, Vol. 22, No. 11, November pp. 1023-1026.Laurentia, Baltic StatesGeodynamics, Polar wandering
DS1995-0487
1995
Torsvik, T.H.Eide, E.A., Torsvik, T.H.Paleozoic continental collision and mantle flushing: coupled surface-mantle processes and Klaman interval.Eos, Vol. 76, No. 46, Nov. 7. p.F172. Abstract.MantleRodinia, Gondwana, Pangea
DS1995-1921
1995
Torsvik, T.H.Torsvik, T.H., Lohmann, K.G., Sturt, B.A.Vendian glaciation and their relation to the dispersal of Rodinia:paleomagnetic constraints.Geology, Vol. 23, No. 8, August pp. 727-730.NorwaySupercontinent -Rodinia, Geomorphology
DS1996-0940
1996
Torsvik, T.H.Meert, J.G., Torsvik, T.H., Eide, E.E.Paleomagnetic investigation of the NeoProterozoic Fen Carbonatite Complex:contraints on rifting...Geological Society of America, Abstracts, Vol. 28, No. 7, p. A-494.NorwayTectonics - Neoproterozoic, Laurentia, Baltica
DS1996-1436
1996
Torsvik, T.H.Torsvik, T.H., Smethurst, M.A., Meert, J.G., Van de VooContinental breakup and collision in the Neoproterozoic and Paleozoic - atale of Baltica and Laurentia.Earth Science Reviews, Vol. 40, pp. 229-258.Baltica, Laurentia, Rodinia, PangeaSupercontinent, Tectonics
DS1997-1167
1997
Torsvik, T.H.Torsvik, T.H., Djomani, Y.P., Dawson, J.B.The age and tectonic significance of dolerite dykes in western NorwayJournal of Geological Society of London, Vol. 154, No. 6, Nov. pp. 961-974.NorwayTectonics, Dikes
DS1998-1359
1998
Torsvik, T.H.Smelthurst, M.A., Khramov, A.N., Torsvik, T.H.The Neoproterozoic and Paleozoic paleomagnetic dat a for the Siberianplatform: from Rodinia to Pangea.Earth Science Reviews, Vol. 43, pp. 1-24.Russia, SiberiaTectonics, Paleomagnetism
DS1999-0468
1999
Torsvik, T.H.Meert, J.G., Torsvik, T.H., Eide, E.A., Dahlgren, S.Tectonic significance of the Fen Province: constraints from geochronology and PaleomagnetismJournal of Geology, Vol. 106, No. 5, Sept. pp. 553-64.NorwayTectonics, Dikes
DS1999-0741
1999
Torsvik, T.H.Torsvik, T.H., Smethurst, M.A.Plate tectonic modelling: virtual reality with GMAPComputers and Geosciences, Vol. 25, pp. 395-402.GlobalTectonics - paleogeography, Program - GMAP
DS2000-0955
2000
Torsvik, T.H.Torsvik, T.H., Tucker, R.D., Ashwal, Carter, JamtveitLate Cretaceous India Madagascar fit and timing of break up related magmatisnTerra Nova, Vol. 12, No. 5, Oct. pp. 220-4.India, Madagascar, GondwanaGeochronology, Gondwana, tectonics
DS2001-1164
2001
Torsvik, T.H.Torsvik, T.H., Ashwal, L.D., Tucker, R.D., Eide, E.A.Neoproterozoic geochronology and paleogeochronology of the Seyschelles microcontinent: the India link.Precambrian Research, Vol. 110, pp. 47-60.IndiaPaleomagetisM., Geochronology