Kaiser Bottom Fish OnlineFree trialNew StuffHow It WorksContact UsTerms of UseHome
Specializing in Canadian Stocks
SearchAdvanced Search
Welcome Guest User   (more...)
Home / Education
Education
 

SDLRC - Scientific Articles all years by Author - Fo+


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.
Searching this page for a specific term or authorIn your Firefox browser click Edit in the menu bar and then Find. In the Find box that shows up at the bottom of the web page enter your search term. Firefox will highlight all occurrences. This is particularly helpful when the author you are seeking was not the lead author by whom the compilation is sorted.
Sending or sharing a referenceThe left column (Posted/Published) has an embedded hyperlink for each reference. In Firefox, if you right click on it, you can obtain the link url for that reference's location within the page, which you can copy and paste into an email or any other document. You can also use the "share this link" option to tweet, facebook etc the link.
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 - Fo+
Posted/
Published
AuthorTitleSourceRegionKeywords
DS1860-0888
1895
Foa, E.Foa, E.Les Mines de Diamants du CapParis: Librairie Plon., 32P.Africa, South Africa, Cape ProvinceGeology
DS1993-1511
1993
Foden, J.Song, S.H., Foden, J.Geochemical evolution of lithospheric mantle beneath Southeast South Australia.The Xenolith window into the lower crust, abstract volume and workshop, p. 18AustraliaGeochemistry, Mantle
DS1997-1176
1997
Foden, J.Turner, S., Foden, J., Hawkesworth, C.State of the Arc'97 Island Arc magma genesis workshopGeol. Society of Australia Abstracts, No. 45, 115p. approx. 50.00AustraliaBook - table of contents, Island arc magma
DS2000-0705
2000
Foden, J.Neumann, N., Sandiford, M., Foden, J.Regional geochemistry and continental heat flow implications for the origin of the South Australian....Earth and Planetary Science Letters, Vol.183, No.1-2, Nov.30, pp.107-20.Australia, southHeat flow anomaly
DS2002-0464
2002
Foden, J.Foden, J., Song, Turner, Elburg, Smith, VandersteldtGeochemical evolution of lithospheric mantle beneath southeast South AustraliaChemical Geology, Vol.182, 2-4, Feb.15, pp.663-95.Southeast AustraliaGeochemistry
DS2002-0465
2002
Foden, J.Foden, J., Song-Suck-Hwan, Turner, S., Elburg, M., Smith, P.B., Van der StedtGeochemical evolution of lithospheric mantle beneath S.E. South AustraliaChemical Geology, Vol. 182, No. 2-4, pp. 663-95.AustraliaMagmatism
DS200612-0401
2006
Foden, J.Foden, J.Ultra depletion of the mantle and the development of boninite on the initiation of subduction.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 1, abstract only.MantleBoninites
DS200812-0360
2008
Foden, J.Foden, J., Tappert, R., Wills, K.The source and origin of the Mesozoic kimberlites in South Australia.9IKC.com, 3p. extended abstractAustraliaDeposit - Eurelia
DS200912-0748
2009
Foden, J.Tappert, R., Foden, J., Stachel, T., Muehlenbacher, K., Tappert, M., Wills, K.Deep mantle diamonds from South Australia: a record of Pacific subduction at the Gondwanan margin.Geology, Vol. 37, 1, pp. 43-46.Australia, South AustraliaDiamond genesis
DS200912-0749
2009
Foden, J.Tappert, R., Foden, J., Stachel, T., Muehlenbachs, K., Tappert, M., Wills, K.The diamonds of South Australia.Lithos, In press available 49p.AustraliaDiamond inclusions
DS200912-0750
2009
Foden, J.Tappert, R., Foden, J., Wills, K.The petrology of kimberlites in South Australia.Goldschmidt Conference 2009, p. A1315 Abstract.AustraliaDeposit - Eurelia
DS201112-1031
2011
Foden, J.Tappert, R., Foden, J., Muehlenbachs, K., Wills, K.Garnet peridotite xenoliths and xenocrysts from the Monk Hill kimberlite, South Australia: insights into the lithospheric mantle beneath the Adelaide fold belt.Journal of Petrology, Vol. 52, no. 10, pp. 1965-1986.AustraliaDeposit - Monk Hill
DS201904-0787
2019
Foden, J.Tappert, R., Foden, J., Heaman, L., Tappert, M.C., Zurevinski, S.E., Wills, K.The petrology of kimberlites from South Australia: linking olivine macrocrystic and micaceous kimberlites.Journal of Volacnology and Geothermal Research, Vol. 373, pp. 68-96.Australia, South Australiadeposit - Eurelia

Abstract: Kimberlites of Jurassic age occur in various parts of South Australia. Thirty-nine of these kimberlites, which are mostly new discoveries, were studied to characterize their structural setting, their petrography, and the composition of their constituent minerals. Although some of the kimberlites in South Australia occur on the Archean to Paleoproterozoic Gawler Block, most are part of a northwest-trending, semi-continuous kimberlite dike swarm located in the Adelaide Fold Belt. The kimberlites typically occur as dikes or sills, but diatremes are also present. In the Adelaide Fold Belt, diatremes are restricted to the hinge zones of regional-scale folds within thick sedimentary sequences of the Adelaidean Supergroup. Despite widespread and severe alteration, coherent and pyroclastic kimberlites can be readily distinguished. U-Pb and Sr/Nd isotopic compositions of groundmass perovskite indicate that all kimberlites belong to the same age group (177-197?Ma) and formed in a near-primitive mantle environment (87Sr/86Sr: 0.7038-0.7052, eNd: -0.07 to +2.97). However, the kimberlites in South Australia are compositionally diverse, and range from olivine-dominated varieties (macrocrystic kimberlites) to olivine-poor, phlogopite-dominated varieties (micaceous kimberlites). Macrocrystic kimberlites contain magnesium-rich groundmass phlogopite and spinel, and they are typically olivine macrocryst-rich. Micaceous kimberlites, in contrast, contain more iron- and titanium-rich groundmass phlogopite and less magnesian spinel, and olivine macrocrysts are rare or absent. Correlations between phlogopite and spinel compositions with modal abundances of olivine, indicate that the contrast between macrocrystic and micaceous kimberlites is primarily linked to the amount of mantle components that were incorporated into a compositionally uniform parental mafic silicate melt. We propose that assimilation of xenocrystic magnesite and incorporation of xenocrystic olivine from dunitic source rocks were the key processes that modified the parental silicate melt and created the unique hybrid (carbonate-silicate) character of kimberlites. Based on the composition of xenoliths and xenocrysts, the lithospheric mantle sampled by the South Australian kimberlites is relatively uniform, and extends to depths of 160-170?km, which is slightly below the diamond stability field. Only beneath the Eurelia area does the lithosphere appear thicker (>175?km), which is consistent with the presence of diamonds in some of the Eurelia kimberlites.
DS201709-1954
2017
Foden, J.D.Armistead, S.E., Collins, A.S., Payne, J.L., Foden, J.D., De Waele, B., Shaji, E., Santosh, M.A re-evaluation of the Kumta Suture in western peninsular India and its extension into Madagascar,Journal of Asian Earth Sciences, in press available, 47p.India, Africa, Madagascartectonis

Abstract: It has long been recognised that Madagascar was contiguous with India until the Late Cretaceous. However, the timing and nature of the amalgamation of these two regions remain highly contentious as is the location of Madagascar against India in Gondwana. Here we address these issues with new U-Pb and Lu-Hf zircon data from five metasedimentary samples from the Karwar Block of India and new Lu-Hf data from eight previously dated igneous rocks from central Madagascar and the Antongil-Masora domains of eastern Madagascar. New U-Pb data from Karwar-region detrital zircon grains yield two dominant age peaks at c. 3100 Ma and c. 2500 Ma. The c. 3100 Ma population has relatively juvenile eHf(t) values that trend toward an evolved signature at c. 2500 Ma. The c. 2500 Ma population shows a wide range of eHf(t) values reflecting mixing of an evolved source with a juvenile source at that time. These data, and the new Lu-Hf data from Madagascar, are compared with our new compilation of over 7000 U-Pb and 1000 Lu-Hf analyses from Madagascar and India. We have used multidimensional scaling to assess similarities in these data in a statistically robust way. We propose that the Karwar Block of western peninsular India is an extension of the western Dharwar Craton and not part of the Antananarivo Domain of Madagascar as has been suggested in some models. Based on eHf(t) signatures we also suggest that India (and the Antongil-Masora domains of Madagascar) were palaeogeographically isolated from central Madagascar (the Antananarivo Domain) during the Palaeoproterozoic. This supports a model where central Madagascar and India amalgamated during the Neoproterozoic along the Betsimisaraka Suture.
DS201709-2032
2017
Foden, J.D.Meredith, A.S., Collins, A.S., Williams, S.E., Pisarevsky, S., Foden, J.D., Archibald, D.B., Blades, M.L., Alessio, B.L., Armistead, S., Plavsa, D., Clark, C., Muller, R.D.A full plate global reconstruction of the Neoproterozoic.Gondwana Research, Vol. 50, pp. 84-134.Globalneoproterozoic

Abstract: Neoproterozoic tectonic geography was dominated by the formation of the supercontinent Rodinia, its break-up and the subsequent amalgamation of Gondwana. The Neoproterozoic was a tumultuous time of Earth history, with large climatic variations, the emergence of complex life and a series of continent-building orogenies of a scale not repeated until the Cenozoic. Here we synthesise available geological and palaeomagnetic data and build the first full-plate, topological model of the Neoproterozoic that maps the evolution of the tectonic plate configurations during this time. Topological models trace evolving plate boundaries and facilitate the evaluation of “plate tectonic rules” such as subduction zone migration through time when building plate models. There is a rich history of subduction zone proxies preserved in the Neoproterozoic geological record, providing good evidence for the existence of continent-margin and intra-oceanic subduction zones through time. These are preserved either as volcanic arc protoliths accreted in continent-continent, or continent-arc collisions, or as the detritus of these volcanic arcs preserved in successor basins. Despite this, we find that the model presented here still predicts less subduction (ca. 90%) than on the modern earth, suggesting that we have produced a conservative model and are likely underestimating the amount of subduction, either due to a simplification of tectonically complex areas, or because of the absence of preservation in the geological record (e.g. ocean-ocean convergence). Furthermore, the reconstruction of plate boundary geometries provides constraints for global-scale earth system parameters, such as the role of volcanism or ridge production on the planet's icehouse climatic excursion during the Cryogenian. Besides modelling plate boundaries, our model presents some notable departures from previous Rodinia models. We omit India and South China from Rodinia completely, due to long-lived subduction preserved on margins of India and conflicting palaeomagnetic data for the Cryogenian, such that these two cratons act as ‘lonely wanderers’ for much of the Neoproterozoic. We also introduce a Tonian-Cryogenian aged rotation of the Congo-São Francisco Craton relative to Rodinia to better fit palaeomagnetic data and account for thick passive margin sediments along its southern margin during the Tonian. The GPlates files of the model are released to the public and it is our expectation that this model can act as a foundation for future model refinements, the testing of alternative models, as well as providing constraints for both geodynamic and palaeoclimate models.
DS201904-0715
2019
Foden, J.D.Armistead, S.E., Collins, A.S., Redaa, A., Gilbert, S., Jepson, G., Gillespie, J., Blades, M.L., Foden, J.D., Razakamana, T.Structural evolution and medium temperature thermochronology of central Madagascar: implications for Gondwana amalgamation.Journal of the Geological Society of London, in press available 25p.Africa, Madagascarthermochronology

Abstract: Madagascar occupied an important place in the amalgamation of Gondwana, and preserves a record of several Neoproterozoic events that can be linked to orogenesis of the East African Orogen. We integrate remote sensing and field data to unravel complex deformation in the Ikalamavony and Itremo domains of central Madagascar. The deformation sequence comprises a gneissic foliation (S1), followed by south to south-west directed, tight to isoclinal, recumbent folding (D2). These are overprinted by north-trending upright folds that formed during a ~E-W shortening event. Together these produced type 1 and type 2 fold interference patterns throughout the Itremo and Ikalamavony domains. Apatite U-Pb and muscovite and biotite Rb-Sr thermochronometers indicate that much of central Madagascar was thermally reset to at least ~500oC at c. 500 Ma. Deformation in west-central Madagascar occurred between c. 750 Ma and c. 550 Ma, and we suggest this deformation formed in response to the c. 650 Ma collision of Azania with Africa along the Vohibory Suture in southwestern Madagascar. In eastern Madagascar, deformation is syn- to post-550 Ma, which formed in response to the final closure of the Mozambique Ocean along the Betsimisaraka Suture that amalgamated Madagascar with the Dharwar Craton of India.
DS202010-1826
2020
Foden, J.D.Armistead, S.E., Collins, A.S., Redaa, A., Jepson, G., Gillespie, J., Gilbert, S., Blades, M.L., Foden, J.D., RazakMnN, T.Structural evolution and medium temperature thermochronology of central Madagascar: implications for Gondwana amalagamation.Journal of the Geological Society, Vol. 177, pp. 784-798.Africa, Madagascargeothermometry

Abstract: Madagascar occupied an important place in the amalgamation of Gondwana and preserves a record of several Neoproterozoic events that are linked to orogenesis of the East African Orogen. In this study, we integrate remote sensing, field data and thermochronology to unravel complex deformation in the Ikalamavony and Itremo domains of central Madagascar. The deformation sequence comprises a gneissic foliation (S1), followed by south- to SW-directed, tight to isoclinal, recumbent folding (D2). These are overprinted by north-trending upright folds that formed during an approximately east-west shortening event (D3). Together these produced type 1 and type 2 fold interference patterns throughout the Itremo and Ikalamavony domains. We show that the Itremo and Ikalamavony domains were deformed together in the same orogenic system, which we interpret as the c. 630 Ma collision of Azania with Africa along the Vohibory Suture in southwestern Madagascar. In eastern Madagascar, deformation is syn- to post-550 Ma, and probably formed in response to final closure of the Mozambique Ocean along the Betsimisaraka Suture that amalgamated Madagascar with the Dharwar Craton of India. Apatite U-Pb and novel laser ablation triple quadrupole inductively coupled plasma mass spectrometry (LA-QQQ-ICP-MS) muscovite and biotite Rb-Sr thermochronology indicates that much of central Madagascar cooled through c. 500°C at c. 500 Ma.
DS202103-0367
2021
Foden, J.D.Armistad, S.E., Collins, A.S., Schmitt, R.S., Costa, R.L., De Waele, B., Razakamanana, T., Payne, J.L., Foden, J.D.Proterozoic basin evolution and tectonic geography of Madagascar: implications for an East Africa connection during the Paleoproterozoic. ( zircon analyses link Tanzania craton and India)Tectonics, doi/epdf/10. 10292020Tc006498 Africa, Madagascarcraton

Abstract: Madagascar hosts several Paleoproterozoic sedimentary sequences that are key to unravelling the geodynamic evolution of past supercontinents on Earth. New detrital zircon U-Pb and Hf data, and a substantial new database of ~15,000 analyses are used here to compare and contrast sedimentary sequences in Madagascar, Africa and India. The Itremo Group in central Madagascar, the Sahantaha Group in northern Madagascar, the Maha Group in eastern Madagascar, and the Ambatolampy Group in central Madagascar have indistinguishable age and isotopic characteristics. These samples have maximum depositional ages > 1700 Ma, with major zircon age peaks at c. 2500 Ma, c. 2000 Ma and c. 1850 Ma. We name this the Greater Itremo Basin, which covered a vast area of Madagascar in the late Paleoproterozoic. These samples are also compared with those from the Tanzania and the Congo cratons of Africa, and the Dharwar Craton and Southern Granulite Terrane of India. We show that the Greater Itremo Basin and sedimentary sequences in the Tanzania Craton of Africa are correlatives. These also tentatively correlate with sedimentary protoliths in the Southern Granulite Terrane of India, which together formed a major intra-Nuna/Columbia sedimentary basin that we name the Itremo-Muva-Pandyan Basin. A new Paleoproterozoic plate tectonic configuration is proposed where central Madagascar is contiguous with the Tanzania Craton to the west and the Southern Granulite Terrane to the east. This model strongly supports an ancient Proterozoic origin for central Madagascar and a position adjacent to the Tanzania Craton of East Africa.
DS201705-0854
2017
Foden, J.F.Merdith, A.S., Collins, A.S., Williams, S.E., Pisarevsky, S., Foden, J.F., Archibald, D., Blades, M.L., Alessio, B.L., Armistead, S., Plavsa, D., Clark, C., Muller, R.D.A full plate global reconstruction of the Neoproterozoic.Gondwana Research, in press available 155p.Gondwana, RodiniaGeodynamics

Abstract: Neoproterozoic tectonic geography was dominated by the formation of the supercontinent Rodinia, its break-up and the subsequent amalgamation of Gondwana. The Neoproterozoic was a tumultuous time of Earth history, with large climatic variations, the emergence of complex life and a series of continent-building orogenies of a scale not repeated until the Cenozoic. Here we synthesise available geological and palaeomagnetic data and build the first full-plate, topological model of the Neoproterozoic that maps the evolution of the tectonic plate configurations during this time. Topological models trace evolving plate boundaries and facilitate the evaluation of “plate tectonic rules” such as subduction zone migration through time when building plate models. There is a rich history of subduction zone proxies preserved in the Neoproterozoic geological record, providing good evidence for the existence of continent-margin and intra-oceanic subduction zones through time. These are preserved either as volcanic arc protoliths accreted in continent-continent, or continent-arc collisions, or as the detritus of these volcanic arcs preserved in successor basins. Despite this, we find that the model presented here still predicts less subduction (ca. 90%) than on the modern earth, suggesting that we have produced a conservative model and are likely underestimating the amount of subduction, either due to a simplification of tectonically complex areas, or because of the absence of preservation in the geological record (e.g. ocean-ocean convergence). Furthermore, the reconstruction of plate boundary geometries provides constraints for global-scale earth system parameters, such as the role of volcanism or ridge production on the planet's icehouse climatic excursion during the Cryogenian. Besides modelling plate boundaries, our model presents some notable departures from previous Rodinia models. We omit India and South China from Rodinia completely, due to long-lived subduction preserved on margins of India and conflicting palaeomagnetic data for the Cryogenian, such that these two cratons act as ‘lonely wanderers’ for much of the Neoproterozoic. We also introduce a Tonian-Cryogenian aged rotation of the Congo-São Francisco Craton relative to Rodinia to better fit palaeomagnetic data and account for thick passive margin sediments along its southern margin during the Tonian. The GPlates files of the model are released to the public and it is our expectation that this model can act as a foundation for future model refinements, the testing of alternative models, as well as providing constraints for both geodynamic and palaeoclimate models.
DS202104-0612
2020
Fodor, C.Varga, P., Fodor, C.About the energy and age of the plate tectonics.Terra Nova, 10.1111/ter.12518 7p. PdfMantleplate tectonics

Abstract: Recently, a number of research findings have come to light about the age of plate tectonics, and energies are needed to operate it. The aim of present study is to investigate whether the energy of plate tectonics process was different during the Phanerozoic (Pz) and in earlier eons, and if there is such a discrepancy, whether it can be justified by changes in the processes that able to move the plates. The study will track temporal changes in important components of plate tectonics such as length of mid-ocean ridges, subduction zones and relative oceanic crust coverage during Phanerozoic. Next, it will be examined how the knowledge gained in this way can be reconciled with the results of studies of previous eons. It was found that the temporal variation in kinetic energy of axial rotation due to changes in length of day (LOD) can be assumed as a determining energy which acts on the tectonic plates as in the Phanerozoic as earlier in Archean (Arch) and Proterozoic (Ptz).
DS1997-0354
1997
Fodor, D.Fodor, D.Investigations concerning the viability, the reduction and closure of Mines in Romania17th. World Mining Congress Oct. Mexico, pp. 609-630RomaniaEnvironment, Mine closure
DS200412-0094
2004
Fodor, I.Bardossy, G., Fodor, I.Evaluation of uncertainties and risks in geology. New mathematical approaches for their handling.Springer, 221p. approx. $ 130.TechnologyBook - evaluations
DS1970-0471
1972
Fodor, K.K.Aoki, K., Fodor, K.K., Dowty, E.Tremolite with High Richterite-molecule Content in Kimberlite from Buell Park, Arizona.American MINERALOGIST., Vol. 57, PP. 1889-1893.ArizonaKimberlite, Colorado Plateau, Rocky Mountains
DS1990-0476
1990
Fodor, R.V.Fodor, R.V., Sial, A.N., Mukasas, S.B., McKee, E.H.Petrology, isotope characteristics and K-Ar ages of the Maranhao northernBrasil, Mesozoic basalt provinceContributions to Mineralogy and Petrology, Vol. 104, No. 5, pp. 555-567BrazilGeochronology, Basalt
DS1990-0477
1990
Fodor, R.V.Fodor, R.V., Stal, A.N., Mukasa, S.B., McKee, E.H.Petrology, isotope characteristics, and K-Ar ages Of the Maranhao, Northern Brasil, Mesozoic basaltprovinceContributions to Mineralogy and Petrology, Vol. 104, No. 5, pp. 555-567BrazilBasalt, Maranhao
DS1991-0493
1991
Fodor, R.V.Fodor, R.V., Dobosi, G.Magma fractionation, replenishment and mixing as inferred from green ore clinopyroxenes in Pliocene basanite, southern SlovakiaGeological Society of America Annual Meeting Abstract Volume, Vol. 23, No. 5, San Diego, p. A 443Hungary, CzechoslovakiaBasanite, Petrology
DS1991-0494
1991
Fodor, R.V.Fodor, R.V., Gandhok, G.R., Sial, A.N.Vertical sampling of mantle beneath northeastern Brasil as represented by ultramafic xenoliths and megacrysis in Tertiary basaltsProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 101-102BrazilXenoliths, Mantle peridotite
DS1991-1579
1991
Fodor, R.V.Sial, A.N., Fodor, R.V., Long, L.E.Mantle xenoliths of northeast BrasilFifth International Kimberlite Conferences Field Excursion Guidebook, Servico Geologico do Brasil (CPRM) Special, pp. 3-16BrazilMantle, Xenoliths
DS1998-0436
1998
Fodor, R.V.Fodor, R.V., Mukasa, S.B., Sial, A.N.Isotopic and trace element indications of lithospheric and asthenospheric components Tertiary alkalic basaltsLithos, Vol. 43, No. 4, Sept. 1, pp. 197-218BrazilAlkaline rocks, Geochronology
DS2002-0466
2002
Fodor, R.V.Fodor, R.V., Sial, A.N., Gandhok, G.Petrology of spinel peridotite xenoliths from northeastern Brasil: lithosphere with a high geothermal gradient imparted by Fernando de Nornha plume.Journal of South American Earth Sciences, Vol.15,2,June pp. 183-98.BrazilGeothermometry, Hot spots
DS2002-0467
2002
Fodor, R.V.Fodor, R.V., Sial, A.N., Gandhok, G.Petrology of spinel peridotite xenoliths from northeastern Brasil: lithosphere with a high geothermal gradient imparted by Fernando de Noronha plume.Journal of South American Earth Sciences, Vol. 15, No. 2, pp. 199-214.BrazilTectonics, Xenoliths
DS2002-0468
2002
Fodor, R.V.Fodor, R.V., Sial, A.N., Gandhok, G.Petrology of spinel peridotite xenoliths from northeastern Brasil: lithosphere with a high geothermal gradient imparted by Fernando de Noronha plume.Journal of South American Earth Sciences, Vol.15,2,June pp. 199-214.Brazil, northeastMagmatism, hot spots, Geothermometry
DS1999-0221
1999
Foerster, A.Foerster, A., Merriam, D.F.Present heat flow along a profile across Western Canada sedimentary basin:the extent of hydrodynamic influenceGeothermics, Computer applications earth sciences, pp. 61-79.Western CanadaBasin - sedimentary
DS202104-0576
2021
Foerster, M.W.Foerster, M.W., Selway, K.Melting of subducted sediments reconciles geophysical images of subduction zones.Nature Communications, Vol. 12, 1, doi:10.10.1038/ s41467-021-21657-8 8p. PdfMantlegeophysics - seismic

Abstract: ediments play a key role in subduction. They help control the chemistry of arc volcanoes and the location of seismic hazards. Here, we present a new model describing the fate of subducted sediments that explains magnetotelluric models of subduction zones, which commonly show an enigmatic conductive anomaly at the trenchward side of volcanic arcs. In many subduction zones, sediments will melt trenchward of the source region for arc melts. High-pressure experiments show that these sediment melts will react with the overlying mantle wedge to produce electrically conductive phlogopite pyroxenites. Modelling of the Cascadia and Kyushu subduction zones shows that the products of sediment melting closely reproduce the magnetotelluric observations. Melting of subducted sediments can also explain K-rich volcanic rocks that are produced when the phlogopite pyroxenites melt during slab roll-back events. This process may also help constrain models for subduction zone seismicity. Since melts and phlogopite both have low frictional strength, damaging thrust earthquakes are unlikely to occur in the vicinity of the melting sediments, while increased fluid pressures may promote the occurrence of small magnitude earthquakes and episodic tremor and slip.
DS202108-1289
2021
Foerster, M.W.Hu, Z., Zeng, L., Foerster, M.W., Li, S., Zhao, L., Gao, L., Li, H., Yang, Y.Recycling of subducted continental crust: geochemical evidence from syn-exhumation Triassic alkaline mafic rocks of the southern Liaodong Peninsula, China.Lithos, 10.1016/j.lithos.2021.106353 13p. Chinaalkaline rocks

Abstract: Syn-exhumation mafic magmatism during continental collision provides insights into the crust-mantle reaction during deep subduction and the nature of orogenic lithospheric mantle in collisional orogens. In this study, we present a comprehensive data set of zircon U-Pb ages and whole-rock major-trace elements as well as Sr-Nd-Pb isotopes of alkaline mafic rocks from the southern Liaodong Peninsula, eastern China. Zircon U-Pb analyses yield Late Triassic age of 213 ± 3 to 217 ± 3 Ma, younger than the Middle Triassic ultrahigh-pressure metamorphic rocks of the Dabie-Sulu orogen. Thus, the alkaline mafic rocks are products of syn-exhumation magmatism during continental collision of the South and North China blocks. The rocks show shoshonitic affinities with high K2O (3.78-5.23 wt%) and K2O/Na2O (0.71-1.22). They are characterized by arc-like trace-element patterns with enriched LILE, Pb, and LREE, and depleted HFSE. They exhibit enriched Sr-Nd isotopic compositions with high initial 87Sr/86Sr isotopic ratios of 0.7058-0.7061 and negative eNd(t) values of -13.0 to -15.1. These results suggest involvement of recycled continental crust in their mantle source. The mantle source likely formed by the metasomatic reaction of subducted continental crust-derived melts with the overlying subcontinental lithospheric mantle during the Triassic continental collision. Decompressional melting of this metasomatized mantle formed syn-exhumation mafic magmas during the transition from convergent to extensional tectonics in the Late Triassic. Accordingly, mafic rocks from the southern Liaodong Peninsula provide a geochemical record of the subduction and recycling of continental crust into the mantle and melt-mantle reaction induced metasomatism within the orogen.
DS201807-1490
2018
Fofana, M.Fofana, M., Steyn, T.Monitoring the performance of DMS circuits using RhoVol technology.SAIMM Diamonds - source to use 2018 Conference 'thriving in changing times'. June 11-13., pp. 113-126.Africa, South Africadeposit - Venetia
DS202008-1391
2019
Fofana, M.Fofana, M., Steyn, T.Monitoring the performance of DMS circuits using RhoVol technology. ( DMC)The Journal of the Southern African Insitute of Mining and Metallurgy, Vol. 119, Feb. 6p. PdfAfrica, South AfricaDMC

Abstract: The petrology and bulk-rock sulphur isotopic compositions of kimberlite samples from four localities (Bultfontein, De Beers, Kimberley, Wesselton) of the archetypal Kimberley cluster, South Africa, were used to investigate the origin(s) of S in kimberlites and gain insights into the occurrence of recycled crustal material in the source of Mesozoic kimberlites. The samples, which show variable degrees of alteration, are all hypabyssal and were derived from coherent root-zones as well as dykes and sills. Typical sulphide minerals are Cu-Fe-Ni-sulphides with less common pyrite, galena, sphalerite, and djerfisherite. They occur in a variety of textural associations, for example as groundmass phases, secondary inclusions in olivine, inclusions in matrix phases (e.g., phlogopite), or in carbonate-serpentine segregations. Barite is the most commonly observed sulphate phase. Bulk-sample d34SVCDT values of sulphides in fresh kimberlites, which mostly do not contain barite, vary from - 2.0 to -5.7 ‰. Slightly altered kimberlite samples, in which sulphides were generally associated with serpentine, returned somewhat higher bulk-sulphide d34SVCDT (-3.8 to +1.1 ‰). One sample from the Wesselton Water Tunnel Sills complex contains abundant barite and pyrite in its groundmass, with the latter having d34SVCDT (+0.2 to +1.9 ‰) similar to altered kimberlites. Two further altered samples returned d34SVCDT values (-10.1 to -13.0 ‰) that suggest a contribution from the local country rocks (Dwyka shale: d34SVCDT from -10.2 to -10.5 ‰). All samples have near-zero ?33S values, suggesting that material displaying mass-independent fractionation has not played an important role. The negative d34SVCDT values of fresh kimberlites from Kimberley suggest the involvement of recycled crustal material in their source, which is consistent with radiogenic isotope compositions. Overall, it appears that most kimberlitic sulphide S isotopic compositions can be explained by the action of a few typical magmatic/hydrothermal processes. One of the most important performance indicators of a dense medium cyclone (DMC) circuit is the Tromp curve, and by extension the separation density and Ecart Probable (Ep) values. The densimetric profiles of DMC product streams have been traditionally acquired using heavy liquid sinkfloat analysis, which has certain disadvantages, such as the associated safety and health risks. More recently, non-toxic media such as lithium hetero-polytungstates (LST) have been used, with the desired densities being achieved by maintaining the solutions at specific temperatures. However, the high costs of these liquids can be prohibitive. The long turnaround time of the sink-float analysis is a further disadvantage for timeous interventions to the operating set-points of the DMC process. The RhoVol technology can generate the density distribution of a batch of particles in a rapid, accurate, repeatable, and safe manner. Additional data of interest, such as particle size and shape, are also measured and reported on a per-particle basis. Furthermore, samples can be sorted into discrete sorting bins based on any of the measured parameters of the particle, making further analyses of the material possible. This technology has applications across all commodities that use the DMC, particularly in the size fractions 25 +8 mm and 8 +3 mm. To date, laboratory results have proved very encouraging separation densities are within 5% of traditional sink-float results, and the technology is being introduced to diamond DMC plants.
DS2003-1351
2003
Fofanov, A.D.Svetov, S.A., Fofanov, A.D., Smolkin, V.F., Moshkina, E.V., Repnikova, E.A.Real structure and physical properties of chromites as an indicator of their genesisDoklady Earth Sciences, Kola PeninsulaBlank
DS200412-1954
2003
Fofanov, A.D.Svetov, S.A., Fofanov, A.D., Smolkin, V.F., Moshkina, E.V., Repnikova, E.A., Kevlich, V.I.Real structure and physical properties of chromites as an indicator of their genesis.Doklady Earth Sciences, Vol. 393A, 9, pp. 1272-1275.Russia, Kola PeninsulaSpinel mineralogy
DS200612-0822
2005
Fogel, M.Lindsay, J.F., Brasier, M.D., McLoughlin, N., Green, O.R., Fogel, M., Steele, A., Mertzman, S.A.The problem of deep carbon - an Archean paradox.Precambrian Research, Vol. 143,1-4, Dec. 15, pp. 1-22.AustraliaCarbon dykes, geochronology
DS201112-0713
2011
Fogel, M.L.Mysen, B.O., Kumamoto, K., Cody, G.D., Fogel, M.L.Solubility and solution mechanisms of C-O-H volatiles in silicate melt with variable redox conditions and melt composition at upper mantle temperatures and pressures.Geochimica et Cosmochimica Acta, Vol. 75, 9, pp. 6183-6199.MantleUHP
DS201312-0064
2013
Fogel, M.L.Bebout, G.E., Fogel, M.L., Cartigny, P.Nitrogen and its (biogeocosmo) chemical cycling: nitrogen: highly volatile yet surprisingly compatible.Elements, Vol. 9, pp. 333-338.TechnologyNitrogen
DS1991-0125
1991
Fogel, R.Blacic, J.D., Mathez, E.A., Maggiore, C., Mitchell, T.E., Fogel, R.Oxygen in diamond by the nuclear microprobe: analytical technique and initial resultsProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 20-22GlobalMicroprobe, Oxygen analyses
DS1993-0980
1993
Fogel, R.A.Mathez, E.A., Blacic, J.D., Maggiore, C., Mitchell, T.E., Fogel, R.A.The determination of the O content of diamond by microactivationAmerican Mineralogist, Vol. 78, No. 7-8, July-August pp. 753-761.South Africa, Botswana, ZaireKimberlites, Deposit -Monastery, Finsch, Orapa, Muji Mayi
DS1995-1178
1995
Fogel, R.A.Mathez, E.A., Fogel, R.A., Hutcheon, I.D., Marshintsev, V.Carbon isotopic composition and origin of SIC from kimberlites of Russia.Geochimica et Cosmochimica Acta, Vol. 59, No. 4, Feb. pp. 781-792.Russia, YakutiaGeochronology
DS1960-1102
1969
Fogelman, N.A.Fogelman, N.A.Mineralized Explosion Breccias of Cryptovolcanic SystemsDoklady Academy of Science USSR, Earth Science Section., Vol. 188, No. 1-6, PP. 121-123.RussiaKimberlite, Diatreme
DS1910-0045
1910
Fogg, F.P.Fogg, F.P.Genuine Diamond MinesNational Magazine, Vol. 32, SEPTEMBER PP. 604-615.United States, Gulf Coast, Arkansas, PennsylvaniaBlank
DS1996-0230
1996
Fogg, G.E.Carle, S.F., Fogg, G.E.Transition probability based indicator geostatisticsMath. Geol, Vol. 28, No. 4, May pp. 453-477GlobalGeostatistics, Kriging, co-kriging
DS1997-0162
1997
Fogg, G.E.Carle, S.F., Fogg, G.E.Modeling spatial variability width one and multidimensional continuous lag Markov chainsMath. Geol, Vol. 29, No. 7, pp. 891-918GlobalGeostatistics, Kriging, cokriging
DS200412-1952
2004
Fogson, R.E.Sutherland, F.L., Hollis, J.D., Birch, W.D., Fogson, R.E., Raynor, L.R.Cumulate rich xenolith suite in Late Cenozoic basaltic eruptives Hepburn Lagoon, Newlyn in relation to western Victorian lithospAustralian Journal of Earth Sciences, Vol. 51, 3, June pp. 319-338.AustraliaXenoliths
DS1993-0447
1993
Fohlmeister, I.F.Fohlmeister, I.F.Hotspots, mantle convection and plate tectonics towards a synthesisAmerican Geophysical Union, EOS, supplement Abstract Volume, October, Vol. 74, No. 43, October 26, abstract p. 598.MantleHotspots, Tectonics
DS2002-0469
2002
Fohlmeister, J.F.Fohlmeister, J.F., Renka, R.J.Distribution of mantle up welling determined from plate motions: a case for large scale Benard Convection.Geophysical Research Letters, Vol. 29, 10, DOI 10.1029/2001GL014625MantleHot spots, plumes
DS1900-0552
1907
Fohs, F.J.Fohs, F.J.Fluorspar Deposits of KentuckyKentucky Geological Survey Bulletin., No. 9, 296P.United States, Kentucky, Central StatesGemstones
DS1910-0046
1910
Fohs, F.J.Fohs, F.J.The Fluorspar, Lead and Zinc Deposits of Western KentuckyEconomic Geology, Vol. 5, PP. 377-386.United States, Kentucky, Central StatesBlank
DS1989-0266
1989
Foin, P.Chorowicz, J., Kim, J., Manoussis, S., Rudant, J-P., Foin, P.A new technique for recognition of geological and geomorphological patterns in digital terrain modelsRemote Sensing of the Environment, Vol. 29, pp. 229-239GlobalRemote sensing, Geomorphology
DS1987-0216
1987
Foit, F.F.Foit, F.F., Hooper, R.L., Rosenberg, P.E.An unusual pyroxene, melilite and iron oxide mineral assemblage in a coalfire buchite from Buffalo WyomingAmerican Mineralogist, Vol. 72, No. 1-2, Jan-Feb. pp. 137-147WyomingUSA, Melilite
DS200812-1028
2008
Fokin, A.A.Schwertfeger, H., Fokin, A.A., Schrteiner, P.R.'Diamonds are a chemists best friend'' (in German)Angewandte Chemie, Vol. 120, 6, pp. 1038-1053.TechnologyMineral chemistry
DS2002-1497
2002
Fokin, M.Sinha, A.K., Fokin, M.Mantle plumes and the breakup of supercontinent Rodinia16th. International Conference On Basement Tectonics '02, Abstracts, 1p.abst., 1p.abst.Virginia, North CarolinaGrenville Age basement rocks
DS200512-0567
2004
Fokin, P.A.Korotaev, M.V., Ershov, A.V., Fokin, P.A.Syncompressional lithosphere folding in the East European Craton.Moscow University Geology Bulletin, Vol. 59, 1, pp. 1-12.EuropeTectonics
DS2003-1410
2003
Fokkema, J.T.Van der Kruk, J., Wapenaar, C.P.A., Fokkema, J.T., Van den Berg, P.M.Three dimensional imaging of multicomponent ground penetrating radar dataGeophysics, Vol. 68, 4, pp. 1241-54.GlobalGeophysics - radar not specific to diamonds
DS200412-2036
2003
Fokkema, J.T.Van der Kruk, J., Wapenaar, C.P.A., Fokkema, J.T., Van den Berg, P.M.Three dimensional imaging of multicomponent ground penetrating radar data.Geophysics, Vol. 68, 4, pp. 1241-54.TechnologyGeophysics - radar not specific to diamonds
DS1981-0082
1981
Foland, K.A.Bergman, S.C., Foland, K.A., Spera, F.J.On the Origin of an Amphibole Rich Vein in a Peridotite Inclusion from the Lunar Crater Volcanic Fields, Nevada, United States (us)Earth and Planetary Science Letters, Vol. 56, PP. 343-361.United States, NevadaGreat Basin, Mineral Chemistry
DS1986-0247
1986
Foland, K.A.Foland, K.A., Henderson, C.M.B.Crustal contamination during genesis of the Mont. St. Hilairealkaline igneous complex, QuebecEos, Vol. 67, No. 16, April 22, p. 389. (abstract.)QuebecNepheline syenite, Alkaline rocks
DS1986-0290
1986
Foland, K.A.Gilbert, L.A., Foland, K.A.The Mont St. Hilaire plutonic complex: occurrence of excess 40Ar and short intrusion historyCanadian Journal of Earth Sciences, Vol. 23, No. 7, July pp. 948-958QuebecCarbonatite
DS1989-0435
1989
Foland, K.A.Foland, K.A., Chen, J.-F, Linder, J.S., Henderson, C.M.B., WhillansHigh resolution 40Ar/39Ar chronology of multiple intrusion igneouscomplexes, . Application to the Cretaceous Mount Brome complex, Quebec, CanadaContributions to Mineralogy and Petrology, Vol. 102, No. 2, pp. 127-137QuebecMount Brome, Igneous complex
DS1989-0622
1989
Foland, K.A.Henderson, C.M.R., Pendlebury, K., Foland, K.A.Mineralogy and petrology of the Red Hill alkaline igneous complex, NewHampshire, United States (US)Journal of Petrology, Vol. 30, No. 3, June pp. 627-666GlobalAlkaline rocks, Red Hill complex
DS1991-0262
1991
Foland, K.A.Chen Jiangfeng, Foland, K.A., Xing Fengming, Xu Xiang, Zhou TaixiMagmatism along the southeast margin of the Yangtse block: Precambrian collision of the Yangtse and Cathysia blocks of ChinaGeology, Vol. 19, No. 8, August, pp. 815-818ChinaTectonics, Ophiolites
DS1991-0745
1991
Foland, K.A.Hubacher, F.A., Foland, K.A.40Ar/39Ar ages for Cretaceous intrusions of the White Mountain magmaseries, northern New England and their tectonic implicationsGeological Society of America Abstracts, Vol. 23, No. 1, February p. 47Quebec, MaineTectonics, Geochronology
DS1992-0968
1992
Foland, K.A.Luttinen, A.V., Zhang, X., Foland, K.A.159 Ma Kjakebeinet lamproites ( Dronning Maud Land, Antarctica) and theirGeological Magazine, Vol. 139, 5, pp. 525-39.Antarctica, Dronning Maud LandLamproites, Tectonics
DS1994-0291
1994
Foland, K.A.Chen, J., Henderson, C.M.B., Foland, K.A.Open system, subvolcanic magmatic evolution: constraints on the petrogenesis Mount Brome alkaline C.Journal of Petrology, Vol. 35, No. 4, pp. 1127-1153.QuebecAlkaline complex, Deposit -Mount Brome
DS1994-0529
1994
Foland, K.A.Foland, K.A., Landoll, .J.D., Henderson, C.M.B.Some consequences of interaction between mantle magmas and crust in the formation of epizonal alkaline complexes.Geological Association of Canada (GAC) Abstract Volume, Vol. 19, p.MantleAlkaline rocks
DS1994-0976
1994
Foland, K.A.Landoll, J.D., Foland, K.A., Chen, J-F., Henderson, C.M.B.The role of crustal contamination in the formation of silica oversaturated rocks in the Montregian Hills province, Quebec.Geological Association of Canada (GAC) Abstract Volume, Vol. 19, p. posterQuebecAlkaline rocks, Montregian Hills
DS1996-0622
1996
Foland, K.A.Henderson, C.M.B., Foland, K.A.Barium and Titanium rich primary biotite from the Brome alkaline igneous complex, Montregian Hills: substitution ...Canadian Mineralogist, Vol. 34, pt. 6, pp. 1241-52.QuebecSpectroscopy, Mechanisms -substitution
DS1996-0804
1996
Foland, K.A.Landol, J.D., Foland, K.A.The formation of quartz syenite by crustal contamination at Mont Shefford and other MontregianCanadian Mineralogist, Vol. 34, pt. 2, April pp. 301-324.QuebecMetasomatism, Montregian Complexes
DS1997-1093
1997
Foland, K.A.Spped, R.C., Sharp, W.D., Foland, K.A.Late Paleozoic granitoid gneisses of northeastern Venezuela and the North america Gondwana collision zoneJournal of Geology, Vol. 105, No. 4, July, pp. 475-470VenezuelaTectonics
DS2002-1299
2002
Foland, K.A.Rahl, J.M.,McGrew, A.J., Foland, K.A.Transition from contraction to extension in the northeastern Basin and Range: new evidence from...Journal of Geology, Vol.110,1,pp. 179-94.NevadaTectonics, Copper Mountains area
DS200512-0201
2004
Foland, K.A.Dahl, P.S., Hamilton, M.A., Wooden, J.L., Tracy, R.J., Loehn, C.W., Jones, C.L., Foland, K.A.Do 2450-2480 mineral ages from Wyoming cratonic margins (USA) indicate incipient breakup of supercontinet Kenorland?Geological Society of America Annual Meeting ABSTRACTS, Nov. 7-10, Paper 142-8, Vol. 36, 5, p. 340.United States, WyomingGeochronology
DS200712-0212
2007
Foland, K.A.Dahl, P.S., Hamilton, M.A., Wooden, J.L., Foland, K.A., Frei, R., McCombc, J.A., Holm, D.K.2480 Ma mafic magmatism in the northern Black Hills, South Dakota: a new link connecting the Wyoming and Superior Cratons.Canadian Journal of Earth Sciences, Vol. 43, 10, pp. 1579-1600.United States, Wyoming, Canada, AlbertaMagmatism
DS1994-0093
1994
Folden, C.A.Balaban, A.T., Klein, D.J., Folden, C.A.Diamond graphite hybridsChem. P. Letters, Vol. 217, No. 3, Jan. 14, pp. 266-270. # MR402GlobalMineralogy, Graphite
DS202005-0721
2020
Foley, B.J.Bauer, A.M., Reimink, J.R., Chacko, T., Foley, B.J., Shirey, S.B., Pearson, D.G.Hafnium isotopes in zircons document the gradual onset of mobile-lid tectonics. ( Pilbara, Zimbabwe, Slave, Singhbhum, Rae, Wyoming, Jack HillsGeochemical Perspectives Letters, Vol. 14, pp. 1-6.GlobalTectonics

Abstract: The tectonic regime of the early Earth has proven enigmatic due to a scarcity of preserved continental crust, yet how early continents were generated is key to deciphering Earth’s evolution. Here we show that a compilation of data from 4.3 to 3.4 Ga igneous and detrital zircons records a secular shift to higher 176Hf/177Hf after ~3.8-3.6 Ga. This globally evident shift indicates that continental crust formation before ~3.8-3.6 Ga largely occurred by internal reworking of long-lived mafic protocrust, whereas later continental crust formation involved extensive input of relatively juvenile magmas, which were produced from rapid remelting of oceanic lithosphere. We propose that this secular shift in the global hafnium isotope record reflects a gradual yet widespread transition from stagnant-lid to mobile-lid tectonics on the early Earth.
DS201312-0044
2013
Foley, N.Ayuso, R., Tucker, R., Peters, S., Foley, N., Jackson, J., Robinson, S., Bove, M.Preliminary radiogenic isotope study on the origin of the Khanneshin carbonatite complex, Helmand Province, Afghanistan.Journal of Geochemical Exploration, Vol. 133, pp. 6-14.AfghanistanCarbonatite
DS201112-0615
2010
Foley, N.K.Long, K.R., Van Gosen, B.S., Foley, N.K., Cordier, D.The principal rare earth elements deposits of the United States - a summary of domestic deposits and a global perspective.U.S. Geological Survey, United StatesREE
DS1982-0210
1982
Foley, S.Foley, S.Petrology, Mineralogy and Geochemistry of Alkaline Intrusive Rocks from East Labrador.Msc., Memorial University Newfoundland., Canada, Quebec, LabradorBlank
DS1990-0478
1990
Foley, S.Foley, S.The origin of olivine lamproites- first results from the diamond stabilityfieldTerra, Abstracts of Experimental mineralogy, petrology and, Vol. 2, December abstracts p. 73AustraliaLamproite, Diamond genesis
DS1990-0601
1990
Foley, S.Green, D.H., Taylor, W.R., Foley, S.The earth's upper mantle as a source for volatilesUniversity of Western Australia Publishing, Proceedings on Conference on stable isotopes and, No. 23, pp. 17-34GlobalMantle, Geochemistry
DS1991-0495
1991
Foley, S.Foley, S.high pressure stability of the fluor and hydroxy end members of pargasite and K-richteriteGeochimica et Cosmochimica Acta, Vol. 55, pp. 2689-2694GlobalLamproite, Experimental petrology
DS1992-0471
1992
Foley, S.Foley, S.Petrological characterization of the source components of potassic magmas -geochemical and experimental constraints (review)Lithos, Vol. 28, No. 3-6. November pp. 187-204GlobalPetrology, Potassic magmas
DS1992-0472
1992
Foley, S.Foley, S.Vein-plus-wall-rock melting mechanism in the lithosphere and the origin of potassic alkaline magmasLithos, Vol. 28, No. 3-6. November pp. 435-453GlobalPotassic rocks
DS1994-0530
1994
Foley, S.Foley, S., Hofer, H., Brey, G.high pressure synthesis of Priderite and members of Lindsleyite-mathiasite and hawthornite-Yimengite seriesContributions to Mineralogy and Petrology, Vol. 117, No. 2, July, pp. 164-174.GlobalMineralogy, Priderite
DS1998-1621
1998
Foley, S.Zack, T., Foley, S., Rivers, T.Trace element partitioning between hydrous minerals ( phengite, zoisite, amphibole) and omphacite: hydrationMineralogical Magazine, Goldschmidt abstract, Vol. 62A, p. 1679-80.GlobalSubduction, Eclogites
DS2003-1380
2003
Foley, S.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
Foley, S.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
DS200412-1992
2003
Foley, S.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
DS200812-0361
2008
Foley, S.Foley, S.A trace element perspective on Archean crust formation and on the presence oor absence of Archean subduction.Geological Society of America Special Paper, 440, pp. 31-51.MantleSubduction
DS201112-0323
2011
Foley, S.Foley, S.Mantle migmatites and alkaline rock genesis.Peralk-Carb 2011, workshop held Tubingen Germany June 16-18, AbstractMantleGenesis - overview
DS201910-2310
2019
Foley, S.Yaxley, G., Foley, S.Mantle metasomatism, oxidation and kimberlite magma genesis.Goldschmidt2019, 1p. AbstractMantlediamond genesis

Abstract: High pressure experimental studies investigating the petrogenesis of kimberlites have focussed on the effects of CO2 and/or H2O on deep, partial melting of peridotite, or on locating the point of multiple saturation of peridotite phases on the liquidus of putative “primary” kimberlite melts in pressure-temperature space. These studies have failed to reach consensus regarding the source mineralogy or the pressure-temperature conditions of partial melting. An alternative hypothesis is that precursor melts to Group I kimberlites formed under conditions too reducing for carbonate stability, around the iron-wüstite (IW) buffer in the asthenospheric mantle below the cratonic lithosphere. The few experimental constraints on the nature of partial melts produced under these conditions suggest they are hydrous, highly olivine-normative and may contain a small dissolved carbonate component; they are not yet kimberlites at this early stage. Kimberlites have sampled large vertical sections of the cratonic lithospheric mantle in many locations, as garnet peridotite xenoliths. Studies of these xenoliths show that the cratonic mantle decreases in oxygen fugacity (ƒO2) with depth, reaching values ˜ IW near the base of the lithosphere at 6-7 GPa. However, many deep samples were metasomatically enriched and oxidised to ƒO2 values at which carbonate phases are stable [1,2]. Metasomatism in the deep cratonic mantle may also lead to enrichment in K2O, CaO, CO2 and H2O as modal metasomatic phases such as carbonates, phlogopite and clinopyroxene [3]. The asthenosphere-derived, reduced precursor melts to kimberlites may segregate from their source region and interact with this metasomatised lithosphere, dissolving these metasomatic components and evolving to high K/Na, CaO, CO2 and H2O-rich melts, which on modification during transport to the surface, may erupt as kimberlites.
DS202102-0188
2020
Foley, S.Fiorentini, M.L., O'Neill, C., Giuliani, A., Choi, E., Maas, R., Pirajno, F., Foley, S.Bushveld superplume drove Proterozoic magmatism and metallogenesis in Australia. Nature Scientific Reports, doi.org/10.1038/ s41598-020-76800-0 10p. PdfAustralia, Africa, South Africaalkaline magmatism

Abstract: Large-scale mantle convective processes are commonly reflected in the emplacement of Large Igneous Provinces (LIPs). These are high-volume, short-duration magmatic events consisting mainly of extensive flood basalts and their associated plumbing systems. One of the most voluminous LIPs in the geological record is the ~?2.06 billion-year-old Bushveld Igneous Complex of South Africa (BIC), one of the most mineralised magmatic complexes on Earth. Surprisingly, the known geographic envelope of magmatism related to the BIC is limited to a series of satellite intrusions in southern Africa and has not been traced further afield. This appears inconsistent with the inferred large size of the BIC event. Here, we present new radiometric ages for alkaline magmatism in the Archean Yilgarn Craton (Western Australia), which overlap the emplacement age of the BIC and indicate a much more extensive geographic footprint of the BIC magmatic event. To assess plume involvement at this distance, we present numerical simulations of mantle plume impingement at the base of the lithosphere, and constrain a relationship between the radial extent of volcanism versus time, excess temperature and plume size. These simulations suggest that the thermal influence of large plume events could extend for thousands of km within a few million years, and produce widespread alkaline magmatism, crustal extension potentially leading to continental break-up, and large ore deposits in distal sectors. Our results imply that superplumes may produce very extensive and diverse magmatic and metallogenic provinces, which may now be preserved in widely-dispersed continental blocks.
DS202104-0588
2021
Foley, S.Liu, Z., Shea, J., Foley, S., Bussweiler, Y., Rohrbach, A., Klemme, S., BerndtClarifying source assemblages and metasomatic agents for basaltic rocks in eastern Australia using olivine phenocryst compositions. Basanites, melilititesLithos, in press available, 74p. PdfAustraliametasomatism

Abstract: Many Cenozoic basaltic rocks in Eastern Australia exhibit an age-progressive trend from north to south, leading to the suggestion that one or more mantle plumes passed beneath the Australian plate. Trace element patterns indicate that the source regions have been metasomatised by infiltrating melts, but the source rock assemblages have never been closely identified. Here, trace element analyses of olivine and whole rock geochemistry for several occurrences in New South Wales (Bingara-Inverell, Dubbo, Barrington and Ebor) are combined to characterize the mineralogy of the source and identify the nature of the melts that caused the metasomatic enrichment. According to Ni/Mg against Mn/Fe and Zn/Fe ratios in olivines, Zn/Fe and FC3MS (FeOT/CaO-3*MgO/SiO2) parameters in whole rocks, tholeiite, alkali basalt, and basanite rich in olivine xenocrysts from Dubbo were derived from pyroxenite-dominated mixed source, mixed pyroxenite+peridotite source, and peridotite-dominated source, respectively. Similarly, basalts from Ebor and Bingara/Inverell are suggested to originate from a mixed pyroxenite+peridotite source based on their high FC3MS values. In contrast, the source of basanite and picrobasalt from Barrington was peridotite with little pyroxenite. High Li and Zn in olivines, high P2O5/TiO2 and Zr/Hf at low Ti/Eu in whole rocks illustrate that the pyroxenite sources of basanites from Bingara/Inverell, Barrington and Dubbo resulted from variable degrees of carbonatitic metasomatism. Partial melting of peridotite metasomatised by carbonatite melts at around the spinel-garnet peridotite transition depth produced basalts and basanites from Dubbo, Barrington, Ebor, Bingara/Inverell and Buckland (Queensland). Carbonatitic metasomatism is widespread in the eastern Australian mantle lithosphere, occurring seaboard of a ledge between thick lithosphere beneath the Australian continent that stretches from Queensland, through New South Wales to Victoria.
DS1984-0279
1984
Foley, S.F.Foley, S.F.Liquid Immiscibility and Melt Segregation in Alkaline Lamprophyres from Labrador.Lithos, Vol. 17, PP. 127-137.Canada, Quebec, LabradorSannite, Aillik Bay
DS1985-0194
1985
Foley, S.F.Foley, S.F.The Oxidation State of Lamproitic MagmasTschermaks. Min. Petrol, Vol. 34, No. 3-4, pp. 217-238GlobalLamproite
DS1985-0307
1985
Foley, S.F.Jaques, A.L., Foley, S.F.The origin of Aluminum rich spinel inclusions in leucite from The leucite lamproites of western AustraliaAmerican Mineralogist, Vol. 70, pp. 1143-1150Australia, Western AustraliaLamproite
DS1986-0248
1986
Foley, S.F.Foley, S.F.The genesis of lamproitic magmas in a reduced fluorine rich mantle #1Proceedings of the Fourth International Kimberlite Conference, Held, No. 16, pp. 173-175AustraliaLamproite
DS1986-0249
1986
Foley, S.F.Foley, S.F., Taylor, W.R., Green, D.H.The role of fluorine and oxygen fugacity in the genesis ofultrapotassicrocksContributions to Mineralogy and Petrology, Vol. 94, No. 2, pp. 183-192Wyoming, Spain, Arkansas, Utah, Germany, CaliforniaLamproite
DS1986-0519
1986
Foley, S.F.Malpas, J., Foley, S.F., King, A.F.Alkaline mafic and ultramafic lamprophyres from the Aillik Bayarea, LabradorCanadian Journal of Earth Sciences, Vol. 23, No.12, December pp. 1902-1918CanadaQuebec, Labrador
DS1986-0520
1986
Foley, S.F.Malpas, J., Foley, S.F., King, A.F.Alkaline mafic and ultramafic lamprophyres from the Allik Bay area, Labrador.Canadian Journal of Earth Sciences, Vol. 23, pp. 1902-18.Quebec, LabradorAlkalic rocks, Deposit - Allik Bay area
DS1987-0217
1987
Foley, S.F.Foley, S.F.Variability in continental basic alkaline magmatic activity as aconsequence of redox meltingTerra Cognita, Conference abstracts Oceanic and Continental Lithosphere:, Vol. 7, No. 4, Autumn, abstract only p. 613GlobalBlank
DS1987-0218
1987
Foley, S.F.Foley, S.F., Venturello, G., Green, D.H., Toscani, L.The ultrapotassic rocks: characteristics, classification and constraints for petrogenetic modelsEarth Science Reviews, Vol.24, pp. 81-134GlobalClassification, Petrogenesis
DS1988-0219
1988
Foley, S.F.Foley, S.F.The genesis of continental basic alkaline magmas: an interpretation interms of redox meltingJournal of Petrology, Special Volume 1988- Oceanic and Continental, pp. 139-162GlobalKimberlites, lamproites, range of rocks
DS1988-0730
1988
Foley, S.F.Venturelli, G., Mariani, E.S., Foley, S.F., Capedri, S., CrawfordPetrogeneis and conditions of crystallization of SpanishlamproiticrocksCanadian Mineralogist, Vol. 26, No. 1, March pp. 67-80GlobalLamproite
DS1989-0436
1989
Foley, S.F.Foley, S.F.Experimental constraints on phlogopite chemistry inlamproites. 1. effectof water activity and oxygenfugacityEuropean Journal of Mineralogy, Vol. 1, No. 3, pp. 411-426GlobalLamproite, Geochemistry
DS1989-0437
1989
Foley, S.F.Foley, S.F.Emplacement features of lamprophyre and carbonatitic lamprophyre dikes at Aillik Bay, LabradorGeological Magazine, Vol. 126, No. 1, January pp. 29-42LabradorLamprophyre, Carbonatite
DS1989-0438
1989
Foley, S.F.Foley, S.F.The genesis of lamproitic magmas in a reduced fluorine rich mantle #2Geological Society of Australia Inc. Blackwell Scientific Publishing, No. 14, Vol. 1, pp. 616-631Wyoming, AustraliaLeucite lamproite, Mantle Metasomatism
DS1989-0439
1989
Foley, S.F.Foley, S.F., Venturelli, G.High K2O rocks with high MgO, high SiO2 affinitiesIn: Boninites, Editor A.J. Crawford, Unwin and Hyman, pp. 72-88GlobalBoninites, Potassic alkaline rocks
DS1990-0479
1990
Foley, S.F.Foley, S.F.Experimental constraints on phlogopite chemistry in lamproites. 2. Effectof pressure temperature variationsEur. Journal of Mineralogy, Vol. 2, No. 3, pp. 327-341GlobalLamproite, Geochemistry
DS1990-0480
1990
Foley, S.F.Foley, S.F.A review and assessment of experiments on kimberlites, lamproites and lamprophyres as a guide to their originProceedings Indian Academy of Sciences, Vol. 99, No. 1, March pp. 57-80India, GlobalLamproites -review, Kimberlite, Experimental Petrology
DS1990-0481
1990
Foley, S.F.Foley, S.F., Wheller, G.E.Parallels in the origin of the geochemical signatures of island arc volcanics and continental potassic igneous rocks: the role of residualtitanatesChemical Geology, Vol. 85, No. 1/2, July 10, pp. 1-18Sunda-Banda Arc, Sunda ArcLamproites, Geochemistry, Leucitites, Potassic igneous rocks
DS1991-0195
1991
Foley, S.F.Bulatov, V., Brey, G.P., Foley, S.F.Origin of low Calcium, high chromium garnets by recrystallization of low pressure harzburgitesProceedings of Fifth International Kimberlite Conference held Araxa June, pp. 29-31GlobalExperimental petrology, Harzburgites -garnets
DS1991-0496
1991
Foley, S.F.Foley, S.F.Experimental studies of olivine lamproite at pressures in the diamond stability fieldProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 103-105AustraliaMineral chemistry, Experimental chemistry
DS1991-0497
1991
Foley, S.F.Foley, S.F.The origin of kimberlite, and lamproite in veined lithospheric mantleProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 109-111South AfricaGenesis -kimberlite, lamproite, Solid solution melting reactions
DS1991-0498
1991
Foley, S.F.Foley, S.F., Hoefer, H., Brey, G.P.The stability of priderite, lindsleyite-mathiasite andyimengite-hawthornite under lower continental lithosphere conditions:experiments at 35 to 50 KbarProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 106-108South Africa, Russia, AustraliaMicroprobe analyses, LIMA.
DS1993-0448
1993
Foley, S.F.Foley, S.F.An experimental study of olivine lamproite -1st result from the diamond stability fieldGeochemica et Cosmochimica Acta, Vol. 57, No. 2, January pp. 483-489GlobalLamproite, Petrology -experimental
DS1994-0531
1994
Foley, S.F.Foley, S.F.Geochemical and experimental studies of the origin of ultrapotassic igneousrock.(in German)Neues Jahr. Min. A., (in German), Vol. 167, No. 1, June pp. 1-55.GlobalGeochemistry -review, Ultrapotassic, alkaline rocks
DS1994-0532
1994
Foley, S.F.Foley, S.F., Jenner, G.A., Jackson, S.F., Fryer, B.J.Trace element partition coefficients phlogopite, clinopyroxene and matrixin alkaline lamprophyre.Mineralogical Magazine, Vol. 58A, pp. 280-281. AbstractNewfoundlandLamprophyre, Alkaline rocks -Notre Dame Bay
DS1995-0546
1995
Foley, S.F.Foley, S.F., Jenner, G.A., Konzett, J., Sweeney, R.J.Trace element partitioning in natural phlogopite and K richterite bearing xenoliths from southern Africa.Proceedings of the Sixth International Kimberlite Conference Extended Abstracts, p. 164-6.South AfricaXenoliths, Deposit -Bishoff dumps, Wesselton
DS1995-0547
1995
Foley, S.F.Foley, S.F., Van der Laan, S.R., Horn, I.Experimental melting reactions amphibole and phlogopite bearing mantle vein assemblages -trace elementsProceedings of the Sixth International Kimberlite Conference Extended Abstracts, p. 161-63.GlobalPetrology -experimenta, Mantle -alkaline magmas
DS1995-2154
1995
Foley, S.F.Zinngrebe, E., Foley, S.F., Vannucci, R., Bottazi, MatteyMetasomatism of peridotite by alkaline melt and cognate fluid:microchemical and ion probe evidence from low pressureProceedings of the Sixth International Kimberlite Conference Abstracts, pp. 700-702.Russia, Yakutia, Aldan ShieldMetasomatism, Deposit -Inagli complex
DS1996-0460
1996
Foley, S.F.Foley, S.F., Jackson, S.E., Jenner, G.A.Trace element partition coefficients for clinopyroxene and phlogopite in an alkaline lamprophyre from NewfoundlandGeochimica et Cosmochimica Acta, Vol. 60, No. 4, Feb. 1, pp. 629-638.NewfoundlandLamprophyre, Microscopy
DS1997-0605
1997
Foley, S.F.Klemme, S., Yaxley, G., Foley, S.F., Horn, I.Trace element composition of carbonatite melts in the earth's uppermantle.Geological Association of Canada (GAC) Abstracts, POSTER.MantleCarbonatite
DS1998-0034
1998
Foley, S.F.Andronikov, A.V., Foley, S.F., Melzer, S.Mantle xenoliths from the Jetty Peninsula area: samples of thermallyeroding lithosphere Lambert-Amery Rift.7th International Kimberlite Conference Abstract, pp. 20-22.AntarcticaTectonics, Magmatism - lherzolite
DS1998-0437
1998
Foley, S.F.Foley, S.F., Glaser, S.M., Andronikov, A.V.Non-cratonic garnet peridotites from rifted continental settings in ( Baikal Rift) and East Antarctica7th International Kimberlite Conference Abstract, pp. 217-219.Russia, Baikal, AntarcticaGarnet peridotites
DS1998-0438
1998
Foley, S.F.Foley, S.F., Musselwhite, D.S., Van der Laan, S.R.Melting processes in veined lithospheric mantle in cratonic and non-cratonic settings.7th International Kimberlite Conference Abstract, pp. 220-223.MantleMelt temperatures, Experimental petrology
DS1998-0673
1998
Foley, S.F.Jacob, D.E., Foley, S.F.Evidence for Archean ocean crust with Island Arc signature from diamondiferous eclogite xenoliths.7th International Kimberlite Conference Abstract, pp. 358-60.South Africa, Russia, YakutiaXenoliths, Deposit - Udachnaya, Finsch, Jagersfontein, Kaalvallei
DS1998-1400
1998
Foley, S.F.Stalder, R., Foley, S.F., Brey, G., Horn, I.Mineral aqueous fluid partitioning of trace elements at 900 1200 C and 3.0- 5.7 GPa: garnet, clinopyroxeneGeochimica et Cosmochimica Acta, Vol. 62, No. 10, pp. 1781-1801.MantleMetasomatism, Petrology - experimental
DS1998-1401
1998
Foley, S.F.Stalder, R., Foley, S.F., Brey, G.P., Forsythe, HornFirst results from a new experimental technique to determine fluid/solidtrace element partition coeffic.Neues Jahrbuch fnr Mineralogie Abh., Vol. 172, No. 1, pp. 117-132.GlobalPetrology - experimental, Diamond aggregates
DS1999-0253
1999
Foley, S.F.Glasser, S.M., Foley, S.F., Gunther, D.Trace element compositions of minerals in garnet and spinel peridotite xenoliths from the Vitim volcanicsLithos, Vol. 48, No. 1-4, Sept. pp. 263-86.Russia, Siberia, BaikalXenoliths, Volcanic field
DS1999-0328
1999
Foley, S.F.Jacob, D.E., Foley, S.F.Evidence for Archean ocean crust with low high field strength element signature - Diamondiferous eclogiticLithos, Vol. 48, No. 1-4, Sept. pp. 317-GlobalEclogites, xenoliths, Mineral chemistry
DS2000-0576
2000
Foley, S.F.Litasov, K.D., Foley, S.F., Litasov, Y.D.Magmatic modification and metasomatism of the subcontinental mantle beneath the Vitim volcanic fieldLithos, Vol. 54, No. 1-2, Oct. pp. 83-114.Russia, Siberia, VitiM.Xenoliths - peridotite, pyroxenite, Miocene picrobasalt, Metasomatism
DS2001-0034
2001
Foley, S.F.Andronikov, A.V. , Foley, S.F.Trace element and neodymium Strontium isotopic composition of ultramafic lamprophyres from the East Antarctic..Chemical Geology, Vol. 175, No. 3-4, June 1, pp.291-305.AntarcticaBeaver Lake area, Lamprophyres
DS2001-0322
2001
Foley, S.F.Foley, S.F., Petibon, C.M., Jenner, G.A., Kjarsgaard, B.High U Th partitioning by clinopyroxene from alkali silicate and carbonatite metasomatism: an origin for...Terra Nova, Vol. 13, pp. 104-9.TanzaniaNatrocarbonatite, uranium, thorium partitioning
DS2002-0110
2002
Foley, S.F.Barth, M.G., Foley, S.F., Horn, I.Partial melting in Archean subduction zones: constraints experimentally determined trace element ..Precambrian Research, Vol. 113, No. 3-4, pp. 323-40.MantleGeochemistry - partition coefficents, melting, Eclogites, tonalites
DS2002-0470
2002
Foley, S.F.Foley, S.F., Andronikov, A.V., Melzer, S.Petrology of ultramafic lamprophyres from the Beaver Lake area: their relation to breakup of Gondwanaland.Mineralogy and Petrology, Vol. 74, 2-4, pp. 361-84.eastern AntarcticaLamprophyres, Tectonics
DS2002-1412
2002
Foley, S.F.Schafer, F.N., Foley, S.F.The effect of crystal orientation on wetting behaviour of silicate melts on surfaces spinel peridotitesContribution to Mineralogy and Petrology, Vol.143,pp.254-61., Vol.143,pp.254-61.MantleCrystal anisotropy - experimental petrology
DS2002-1413
2002
Foley, S.F.Schafer, F.N., Foley, S.F.The effect of crystal orientation on wetting behaviour of silicate melts on surfaces spinel peridotitesContribution to Mineralogy and Petrology, Vol.143,pp.254-61., Vol.143,pp.254-61.MantleCrystal anisotropy - experimental petrology
DS2002-1765
2002
Foley, S.F.Zack, T., Foley, S.F., Rivers, T.Equilibrium and disequilibrium trace element partitioning in hydrous eclogites, Trescolmen, Central Alps.Journal of Petrology, Vol. 43, No. 10, Oct.pp. 1947-74.EuropeEclogites - not specific to diamonds
DS2002-1766
2002
Foley, S.F.Zack, T., Kronz, A., Foley, S.F., Rivers, T.Trace element abundances in rutiles from eclogites and associated garnet mica schistsChemical Geology, Vol. 184, 1-2, pp. 97-122.AlpsSubduction, Heavy minerals - not specific to diamonds
DS2003-0414
2003
Foley, S.F.Foley, S.F., Andronikov, A.V.The genesis of ultramafic lamprophyres8 Ikc Www.venuewest.com/8ikc/program.htm, Session 7, AbstractLabrador, GreenlandKimberlite petrogenesis
DS2003-0415
2003
Foley, S.F.Foley, S.F., Buhre, S., Jacob, D.E.Evolution of the Archean crust by delamination and shallow subductionNature, No. 6920, Jan 16, pp. 249-51.MantleSubduction
DS2003-0416
2003
Foley, S.F.Foley, S.F., Buhre, S., Jacob, D.E., Rehfeldt, T.Pyroxenite and dunite xenoliths as metamorphosed cumulates from the Archean lower8ikc, Www.venuewest.com/8ikc/program.htm, Session 2, POSTER abstractGlobalEclogites and Diamonds
DS2003-1102
2003
Foley, S.F.Prelevic, D., Foley, S.F., Romer, R., Cvetkovic, V.Serbian Tertiary ultrapotassic province petrology, geochemistry and geodynamic8 Ikc Www.venuewest.com/8ikc/program.htm, Session 7, POSTER abstractSerbiaAlkaline
DS2003-1358
2003
Foley, S.F.Tappe, S., Foley, S.F., Jenner, G.A., Ryan, B., Besserer, D., Kjarsgaard, B.A.Ultramafic lamprophyre dykes from Labrador and New Quebec: mineralogy and8 Ikc Www.venuewest.com/8ikc/program.htm, Session 7, AbstractQuebec, LabradorKimberlite petrogenesis
DS200412-0564
2003
Foley, S.F.Foley, S.F., Andronikov, A.V.The genesis of ultramafic lamprophyres.8 IKC Program, Session 7, AbstractCanada, Quebec, Labrador, Europe, GreenlandKimberlite petrogenesis
DS200412-0565
2004
Foley, S.F.Foley, S.F., Jenner, G.A.Trace element partitioning in lamproitic magmas - the Gaussberg olivine leucitite.Lithos, Vol. 75, 1-2, July, pp. 19-38.Europe, GermanyGeochemistry - fingerprinting, modelling origin, evolut
DS200412-1578
2004
Foley, S.F.Prelevic, D., Foley, S.F., Cvetkovic, V., Romer, R.L.Origin of minette by mixing of lamproite and dacite magmas in Veliki Majdan, Serbia.Journal of Petrology, Vol. 45, 4, pp. 759-752.Europe, SerbiaLamproite, micas, calcalkaline lamprophyres, superheat
DS200412-1579
2003
Foley, S.F.Prelevic, D., Foley, S.F., Romer, R., Cvetkovic, V.Serbian Tertiary ultrapotassic province petrology, geochemistry and geodynamic significance.8 IKC Program, Session 7, POSTER abstractEurope, SerbiaKimberlite petrogenesis Alkaline
DS200412-1754
2004
Foley, S.F.Schmickler, B., Jacob, D.E., Foley, S.F.Eclogite xenoliths from the Kuruman kimberlites, South Africa: geochemical fingerprinting of deep subduction and cumulate procesLithos, Vol. 75, 1-2, July pp. 173-207.Africa, South AfricaSubduction, Zero, petrogenetic processes
DS200412-1963
2003
Foley, S.F.Tappe, S., Foley, S.F., Jenner, G.A., Ryan, B.,Besserer, D., Kjarsgaard, B.A.Ultramafic lamprophyre dykes from Labrador and New Quebec: mineralogy and geochemistry.8 IKC Program, Session 7, AbstractCanada, Quebec, LabradorKimberlite petrogenesis
DS200512-0872
2005
Foley, S.F.Prelevic, D., Foley, S.F., Romer, R.L., Cvetkovic, V., Downes, H.Tertiary ultrapotassic volcanism in Serbia: constraints on petrogenesis and mantle source characteristics.Journal of Petrology, Vol. 46, 7, July pp. 1443-1487.Europe, SerbiaVolcanism
DS200512-1071
2005
Foley, S.F.Tappe, S., Foley, S.F., Jenner, G.A., Kjarsgaard, B.A.Integrating ultramafic lamprophyres into the IUGS classification of igneous rocks: rationale and implications.Journal of Petrology, Vol. 46, 9, Sept. pp. 1893-1900.Classification - lamprophyres
DS200512-1072
2003
Foley, S.F.Tappe, S., Foley, S.F., Pearson, D.G.African type kamafugites: a mineralogical and geochemical comparison with their Italian and Brazilian analogues.Periodico di Mineralogia, (in english), Vol. LXX11, 1. April, pp. 51-77.South America, Brazil, Africa, UgandaMelilite, katsilite, Toro Ankole Rift
DS200612-0402
2006
Foley, S.F.Foley, S.F.The contribution of ultramafic veins in alkaline and non-alkaline mafic magmatism.Geochimica et Cosmochimica Acta, Vol. 70, 18, 1, p. 1, abstract only.MantleMagmatism
DS200612-0403
2006
Foley, S.F.Foley, S.F., Andronikov, A.V., Jacob, D.E., Melzer, S.Evidence from Antarctic mantle peridotite xenoliths for changes in mineralogy, geochemistry and geothermal gradients beneath a developing rift.Geochimica et Cosmochimica Acta, Vol. 70, 12, June pp. 3096-3120.AntarcticaGeothermometry
DS200612-0631
2006
Foley, S.F.Jacob, D.E., Foley, S.F., Andonikov, A.V.Re-enrichment of cratonic lithospheric mantle beneath an evolving rift: mantle xenoliths from East Antarctica.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 285. abstract only.AntarcticaXenolith - geochemistry
DS200612-1178
2006
Foley, S.F.Rosenthal, A., Foley, S.F., Pearson, G.D., Nowell, G., Tappe, S.Ugand an kamafugites: re-melting of a variable enriched veined subcontinental lithospheric mantle.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 26, abstract only.Africa, UgandaGeochemistry - melting
DS200612-1411
2006
Foley, S.F.Tappe, S., Foley, S.F., Jenner, G.A., Heaman, L.M., Kjarsgaard, B.A., Romer,R.L., Stracke, A., Joyce, HoefsGenesis of ultramafic lamprophyres and carbonatites at Aillik Bay, Labrador: a consequence of incipient lithospheric thinning beneath the North Atlantic CratonJournal of Petrology, Vol. 47,7, pp. 1261-1315.Canada, LabradorCarbonatite
DS200712-0856
2007
Foley, S.F.Prelevic, D., Foley, S.F., Stracke, A., Romer, R.I., Conticelli, S.No need for involvement of a hidden mantle reservoir in the origin of lamproites from Mediterranean.Plates, Plumes, and Paradigms, 1p. abstract p. A809.EuropeLamproites - multi-component melts
DS200712-0883
2006
Foley, S.F.Rehfeldt, T., Foley, S.F., Jacob, D.E.Restoration of premetasomatic protolith compositions in mantle xenoliths.Geochimica et Cosmochimica Acta, In press availableMantleMetasomatism
DS200712-0884
2007
Foley, S.F.Rehfeldt, T., Foley, S.F., Jacob, D.E., Carlson, R.W.Characterizing Fe rich dunite xenoliths as cumulates of Phanerozoic and Archean flood basalt magmatism.Plates, Plumes, and Paradigms, 1p. abstract p. A827.Africa, South AfricaKimberley Cluster
DS200712-0885
2007
Foley, S.F.Rehfeldt, T., Jacob, D.E., Carlson, R.W., Foley, S.F.Fe rich dunite xenoliths from South African kimberlites: cumulates from Karoo flood basalts.Journal of Petrology, Vol. 48, 7, pp. 1387-1409.Africa, South AfricaMineral chemistry
DS200712-1068
2007
Foley, S.F.Tappe, S., Foley, S.F., Heaman, L.M., Romer, R.E., Stracke, A., Kjarsgaard, B.A., Jenner, G.A.Interactions between carbonate magmas and MARID metasomes: the case of Diamondiferous aillikites from the Torngat Mountains, Canada.Plates, Plumes, and Paradigms, 1p. abstract p. A1003.Canada, LabradorAillikite, magmatism
DS200712-1069
2007
Foley, S.F.Tappe, S., Foley, S.F., Stracke, A., Romer, R.L., Kjarsgaard, B.A., Heamna, L.M., Joyce, N.Craton reactivation on the Labrador sea margins 40Ar 39Ar age and Sr Nd Hf Pb isotope constraints from alkaline and carbonatite intrusives.Earth and Planetary Science Letters, Vol. 256, 3-4, pp. 433-454.CanadaCarbonatite
DS200812-0362
2008
Foley, S.F.Foley, S.F., Jacob, D.E.Trace element and isotopic effects of mantle metasomatism by carbonatitic and alkaline silicate melts in the lower cratonic mantle lithosphere.9IKC.com, 3p. extended abstractMantleMelting
DS200812-0363
2008
Foley, S.F.Foley, S.F., Yaxley, G.M., Rosenthal, A., Rapp, R.P., Jacob, D.E.Experimental melting of peridotites in the presence of CO2 and H2O at 40 - 60 kbar.9IKC.com, 3p. extended abstractTechnologyPeridotite - melting
DS200812-0920
2008
Foley, S.F.Prelevic, D., Foley, S.F.The origin of lamproites revisited: a Mediterranean perspective.Goldschmidt Conference 2008, Abstract p.A760.Europe, MediterraneanLamproite
DS200812-0921
2008
Foley, S.F.Prelevic, D., Foley, S.F.The origin of lamproites revisited: Mediterranean perspective.9IKC.com, 3p. extended abstractEurope, TurkeyLamproite
DS200812-0922
2008
Foley, S.F.Prelevic, D., Foley, S.F., Romer, R., Conticelli, S.Mediterranean Tertiary lamproites derived from multiple source components in Post collisional geodynamics.Geochimica et Cosmochimica Acta, 72p. in press availableEuropeLamproite
DS200812-0948
2008
Foley, S.F.Rehfeldt, T., Foley, S.F., Jacob, D.E., Carlson, R.W., Lowry, D.Contrasting types of metasomatism in dunite, wehrlite and websterite xenoliths from Kimberley, South Africa.Geochimica et Cosmochimica Acta, Vol. 73, 23, Dec. 1. pp. 5722-5756.Africa, South AfricaDeposit - Kimberley
DS200812-0949
2007
Foley, S.F.Rehfeldt, T., Jacob, D.E., Carlson, R.W., Foley, S.F.Fe rich dunite xenoliths from South African kimberlites: cumulates from Karoo flood basalts.Journal of Petrology, Vol. 48, pp. 1387-1409.Africa, South AfricaXenoliths
DS200812-0971
2008
Foley, S.F.Rosenthal, A., Foley, S.F., Pearson, D.G., Nowell, G.M., Tappe, S.Origin of kamafugite magmas in the East African Rift of western Uganda.9IKC.com, 3p. extended abstractAfrica, UgandaToro Ankole volcanic field
DS200812-1152
2008
Foley, S.F.Tappe, S., Foley, S.F., Kjarsgaard, B.A, Romer, R.L., Heaman, L.M., Stracke, A., Jenner, G.A.Origin of Diamondiferous Torngat ultramafic lamprophyres and the role of multiple MARID type and carbonatitic vein metasomatized cratonic mantle ...9IKC.com, 3p. extended abstractCanada, Quebec, LabradorGenesis of SiO2 poor potassic melts
DS200812-1153
2008
Foley, S.F.Tappe, S., Foley, S.F., Kjarsgaard, B.A., Romer, R.L., Heaman, L.M., Stracke, A., Jenner, G.A.Between carbonatite and lamproite - Diamondiferous Torngat ultramafic lamprohyres formed by carbonate fluxed melting of cratonic Marid type metasomes.Geochimica et Cosmochimica Acta, Vol. 72, 13, pp. 3258-3286.Canada, Labrador, QuebecTorngat
DS200912-0081
2009
Foley, S.F.Buhre, S., Jacob, D.E., Foley, S.F.Delayed continental crust formation on a hot Archean Earth.Goldschmidt Conference 2009, p. A171 Abstract.MantleMelting
DS200912-0223
2009
Foley, S.F.Foley, S.F.The renaissance of redox melting.Goldschmidt Conference 2009, p. A388 Abstract.MantleMelting
DS200912-0608
2008
Foley, S.F.Rahfeldt, T., Foley, S.F., Jacob, D.E., Carlson, R.W., Lowry, D.Contrasting types of metasomatism in dunite, wherlite and websterite xenoliths from Kimberley, South Africa.Geochimica et Cosmochimica Acta, Vol. 72, 5722-36.Africa, South AfricaDeposit - Kimberley
DS201012-0204
2010
Foley, S.F.Foley, S.F., Jacob, D.E., O'Neill, H.St.C.Trace element variations in olivine phenocrysts from Ugand an potassic rocks as clues to the chemical characteristics of parental magmas.Contributions to Mineralogy and Petrology, In press available, 20p.Africa, UgandaGeochemistry - East African Rift
DS201012-0205
2009
Foley, S.F.Foley, S.F., Yaxley, G.M., Rosenthal, A., Buhre, S., Kisseeva, E.S., Rapp, R.P., Jacob, D.E.The composition of near solidus melts of peridotite in the presence of CO2 and H2O between 40 and 60 kbar.Lithos, Vol. 112 S pp. 274-283.MantleMineral chemistry
DS201012-0212
2010
Foley, S.F.Fritschle, T., Prelevic, D., Foley, S.F.Mineral variations from Mediterranean lamproites: major element compositions and first indications from trace elements in phlogopites, olivines and clinopyroxenes.Geological Society of America Abstracts, 1p.Europe, Spain, Serbia, TurkeyLamproite
DS201012-0444
2010
Foley, S.F.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
DS201012-0597
2010
Foley, S.F.Prelevic, D., Akai, C., Romer, R.L., Foley, S.F.Lamproites as indicators of accretion and/or shallow subduction in the assembly of south western Anatolia, Turkey.Terra Nova, in press available,Europe, TurkeyLamproite
DS201012-0598
2010
Foley, S.F.Prelevic, D., Akal, C., Foley, S.F., Romer, R.L., Stracke, A., Van den Bogaard,P.Post collisional mantle dynamics of an orogenic lithosphere: lamproitic mafic rocks from SW Anatolia, Turkey.Geological Society of America Abstracts, 1p.Europe, TurkeyLamproite
DS201012-0599
2010
Foley, S.F.Prelevic, D., Stracke, A., Foley, S.F., Romer, R.I., Conticelli, R.S.Hf isotope compositions of Mediterranean lamproites: mixing of melts from asthenosphere and crustally contaminated mantle lithosphere.Lithos, Vol. 119, pp. 297-312.Europe, Italy, Macedonia, SerbiaLamproite
DS201012-0611
2010
Foley, S.F.Rapp, R.P., Norman, M.D., Laporte, D., Yaxley, G.M., Martin, H., Foley, S.F.Continent formation in the Archean and chemical evolution of the cratonic lithosphere: melt rock reaction experiments at 3-4 GPa and petrogenesisJournal of Petrology, Vol. 51, 6, pp. 1237-1266.MantleSanukitoids
DS201012-0621
2010
Foley, S.F.Rehfeldt, T., Foley, S.F., Jacob, D.E., Pearson, D.G.Trace elements in mantle olivine and orthopyroxene from the North Atlantic and Kaapvaal Cratons.Goldschmidt 2010 abstracts, abstractAfrica, South Africa, EuropeGeochemistry
DS201112-0324
2011
Foley, S.F.Foley, S.F.Reappraisal of redox melting in the Earth's mantle as a function of tectonic setting and time.Journal of Petrology, Vol. 52, 7-8, pp. 1363-1391.MantleMelting
DS201112-0325
2011
Foley, S.F.Foley, S.F., Eremets, M.I.Linking early atmospheric composition to volcanic degassing from a reduced mantle.Goldschmidt Conference 2011, abstract p.856.MantleOxidation, recycling, nitrogen
DS201112-0326
2011
Foley, S.F.Foley, S.F., Jacob, D.E., O'Neill, H.St.C.Trace element variations in olivine phenocrysts from Ugand an potassic rocks as clues to the chemical characteristics of parental magma.Contributions to Mineralogy and Petrology, Vol, 167, 1, July pp. 1-20.Africa, UgandaAlkaline rocks, magmatism
DS201112-0327
2011
Foley, S.F.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
DS201112-0328
2011
Foley, S.F.Foley, S.F., Prevelic, D., Link, K.Mantle migmatites and alkaline rock genesis.Peralk-Carb 2011... workshop June 16-18, Tubingen, Germany, Abstract p.45-47.Africa, TanzaniaMelt production
DS201112-0329
2011
Foley, S.F.Foley, S.F., Prevelic, D., Link, K.Mantle migmatites and alkaline rock genesis.Peralk-Carb 2011... workshop June 16-18, Tubingen, Germany, Abstract p.45-47.Africa, TanzaniaMelt production
DS201112-0824
2011
Foley, S.F.Prelevic, D., Akal, C., Foley, S.F., Romer, R.R.,Stracke, A., Van den Bogaard, P.Ultrapotassic mafic rocks as geochemical proxies for post collisional dynamics of orogenic lithospheric mantle: the case of southwestern Anatolia, Turkey.Peralk-Carb 2011, workshop held Tubingen Germany June 16-18, PosterEurope, TurkeyAlkalic
DS201212-0205
2012
Foley, S.F.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
DS201312-0017
2013
Foley, S.F.Ammannati, E., Foley, S.F., Avanzinelli, R., Jacob, D.E., Conticelli, S.Trace elements in olivine characterize the mantle source of subduction related potassic magmas.Goldschmidt 2013, AbstractMantleSubduction
DS201312-0271
2013
Foley, S.F.Foley, S.F., Prelevic, D., Rehfeldt, T., Jacob, D.E.Minor and trace elements in olivines as probes into early igneous and mantle melting.Earth and Planetary Science Letters, Vol. 363, pp. 181-191.MantleMetasomatism
DS201312-0280
2013
Foley, S.F.Fritschle, T., Prelevic, D., Foley, S.F., Jacob, D.E.Petrological characterization of the mantle source of Mediterranean lamproites: indications from major and trace elements of phlogopite.Chemical Geology, Vol. 353, pp. 267-279.Europe, SpainLamproite
DS201312-1017
2014
Foley, S.F.Ziaja, K., Foley, S.F., White, R.W., Buhre, S.Metamorphism and melting of picritic crust in the early Earth.Lithos, Vol. 189, pp. 173-184.MantlePicrite
DS201412-0086
2014
Foley, S.F.Bussweiler, Y., Foley, S.F., Prelevic, D., Jacob, D.E., Pearson, D.G., Stachel, T.Olivine as a petrogenetic and exploration indicator in Lac de Gras kimberlites.2014 Yellowknife Geoscience Forum, p. 20, 21 abstractCanada, Northwest TerritoriesDeposit - Ekati
DS201504-0187
2015
Foley, S.F.Bussweiler, Y., Foley, S.F., Prelevic, D., Jacob, D.E.The olivine macrocryst problem: new insights from minor and trace element compositions of olivine from Lac de Gras kimberlites, Canada.Lithos, Vol. 220-223, pp. 238-252.Canada, Northwest TerritoriesDeposit - Ekati field

Abstract: This study presents detailed petrographical and geochemical investigations on remarkably fresh olivines in kimberlites from the EKATI Diamond Mine- located in the Tertiary/Cretaceous Lac de Gras kimberlite field within the Slave craton of Canada. Olivine, constituting about 42 vol.% of the analyzed samples, can be divided into two textural groups: (i) macrocrystic olivines, > 100 µm sub-rounded crystals and (ii) groundmass olivines, < 100 µm subhedral crystals. Olivines from both populations define two distinct chemical trends; a “ "mantle trend" with angular cores, showing low Ca (< 0.1 wt.% CaO) and high Ni (0.3-0.4 wt.% NiO) at varying Mg# (0.86-0.93), contrasts with a "melt trend" typified by thin (< 100 µm) rims with increasing Ca (up to 1.0 wt.% CaO) and decreasing Ni (down to 0.1 wt.% NiO) contents at constant Mg# (~ 0.915). These findings are in agreement with recent studies suggesting that virtually all olivine is composed of xenocrystic (i.e. mantle-related) cores with phenocrystic (i.e. melt-related) overgrowths, thereby challenging the traditional view that the origin of kimberlitic olivine can be distinguished based on size and morphology. The two main trends can be further resolved into sub-groups refining the crystallization history of olivine; the mantle trend indicates a multi-source origin that samples the layered lithosphere below the Slave craton, whereas the melt trend represents multi-stage crystallization comprising a differentiation trend starting at mantle conditions and a second trend controlled by the crystallization of additional phases (e.g. chromite) and changing magma conditions (e.g. oxidation). These trends are also seen in the concentrations of trace elements not routinely measured in olivine (e.g. Na, P, Ti, Co, Sc, Zr). Trace element mapping with LA-ICP-MS reveals the distribution of these elements within olivine grains. The trace element distribution between the two trends appears to be consistent with phenocrystic olivine overgrowths mainly originating from dissolved orthopyroxene, showing enrichment in Zr, Ga, Nb, Sc, V, P, Al, Ti, Cr, Ca and Mn in the melt trend. In a sample of magmatic kimberlite from the Leslie pipe, the amount of xenocrystic and phenocrystic olivine is estimated to be around 23 vol.% and 19 vol.%, respectively. Subtraction of this xenocrystic olivine from the Leslie bulk composition, aimed at estimating the parental kimberlite melt, results in a minor decrease of Mg# (by about 0.01) and SiO2 content (by about 3 wt.%), whereas CaO increases (by about 3 wt.%).
DS201706-1109
2017
Foley, S.F.Wang, Y., Foley, S.F., Prelevic, D.Potassium rich magmatism from a phlogopite free source.Geology, Vol. 45, 5, pp. 467-470.Europe, Serbiamelting

Abstract: The generation of strongly potassic melts in the mantle is generally thought to require the presence of phlogopite in the melting assemblage. In the Mediterranean region, trace element and isotope compositions indicate that continental crustal material is involved in the generation of many potassium-rich lavas. This is clearest in ultrapotassic rocks like lamproites and shoshonites, for which the relevant chemical signals are less diluted by extensive melting of peridotite. Furthermore, melting occurs here in young lithosphere, so the continental crust was not stored for a long period of time in the mantle before reactivation. We have undertaken two types of experiments to investigate the reaction between crust and mantle at 1000-1100 °C and 2-3 GPa. In the first, continental crustal metasediment (phyllite) and depleted peridotite (dunite) were juxtaposed as separate blocks, whereas in the second, the same rock powders were intimately mixed. In the first series, a clear reaction zone dominated by orthopyroxene was formed between dunite and phyllite but no hybridized melt could be found, whereas analyzable pools of hybridized melt occurred throughout the charges in the second series. Melt compositions show high abundances of Rb (100-220 ppm) and Ba (400-870 ppm), and consistent ratios of Nb/Ta (10-12), Zr/Hf (34-42), and Rb/Cs (28-34), similar to bulk continental crust. These experiments demonstrate that melts with as much as 5 wt% K2O may result from reaction between melts of continent-derived sediment and depleted peridotite at shallow mantle depths without the need for phlogopite or any other potassic phase in the residue.
DS201707-1323
2017
Foley, S.F.Forster, M.W., Orelevic, D., Schmuck, H.R., Buhre, S., Veter, M., Mertz-Kraus, R., Foley, S.F., Jacob, D.E.Melting and dynamic metasomatism of mixed harzburgite + glimmerite mantle source: implications for the genesis of orogenic potassic magmas.Chemical Geology, Vol. 455, pp. 182-191.Mantlemetasomatism

Abstract: Tectonically young, orogenic settings are commonly the sites of post-collisional silica-rich ultrapotassic magmas with extreme K2O-contents of up to 9 wt% and K2O/Na2O > 2. Many experimental studies investigating the generation of these melts have concentrated on melting of homogenous phlogopite bearing peridotites, whereas geochemical signatures indicate the involvement of at least two types of source rocks: ultra-depleted and K and trace elements-enriched ones. We report the results of melting experiments at 1–2 GPa of mixed glimmerite and harzburgite, in which these rock types make up two halves each capsule. Melting begins in the glimmerite, and its metasomatic effects on the harzburgite are apparent at 1100 °C even before melt pools are visible. The first melts are Na-rich, seen in zoning of olivines and as growth of clinopyroxene in the harzburgite, but change at higher degrees of melting to produce a typical lamproite-like melt with K2O > 10 wt%. A major advantage of this study is the preservation of distinct melts in different parts of the capsule, which reflect a process of dynamic metasomatism: within the harzburgite matrix, the infiltrating melt derived from melting of the glimmerite changes consistently with the distance of travel through the harzburgite, enabling quantification of the metasomatic effects as an increase in SiO2 and K2O. This results principally from assimilation of orthopyroxene, which increases the Ol/Opx ratio of the residual harzburgite. The effects of quench olivine growth are recognizable and can be quantified due to a step-change in composition at the glimmerite/harzburgite border: the large total surface area of olivine and small melt fraction mean that the amount of quench olivine is high within the harzburgite, but negligible in the almost completely molten glimmerite. Melts of the glimmerite contain up to 8–10 wt% K2O and 53 wt% SiO2, which increase to 55–56 wt% after interaction with the harzburgite. Mediterranean lamproites resemble melts of glimmerite, whereas melts that have interacted with harzburgite are more similar to less potassic, but more SiO2-rich shoshonites of the Mediterranean region.
DS201707-1381
2017
Foley, S.F.Wang, Y., Prelevic, D., Buhre, S., Foley, S.F.Constraints on the sources of post-collisional K rich magmatism: the roles of continental clastic sediemtns and terrigenous blueschists.Chemical Geology, Vol. 455, pp. 192-207.Mantlemagmatism

Abstract: The possible role of continental sediments in the generation of potassium-enriched lavas of the Alpine-Himalayan belt depends on their melting behaviour either during subduction or during post-collisional relaxation. Although usually classed as orogenic lavas, these volcanic rocks may result from re-melting of newly formed mantle lithosphere 30–40 million years after collision ends, and can thus be considered as the first stage of intraplate volcanism. The potassic component in these volcanics is characterized by a high Th/La signature for which there are two competing explanations: melting of subducted continental clastic sediments, and the involvement of lawsonite blueschists in the protoliths to the melting assemblages. Here, we report on a series of high-pressure experiments at 1–3 GPa and 900 to 975 °C on the melting behaviour of natural phyllite from Serbia, which serves as a proxy for Balkan upper continental crust. Hydrous granitic melts are present in all runs (68 wt% SiO2, ~ 4–5 wt% K2O, Mg# < 54 and ~ 5 wt% H2O). Garnet, quartz/coesite, plagioclase, K-feldspar, biotite/phengite, clinopyroxene and sillimanite/kyanite, and accessory phases including zircon, rutile, ilmenite, apatite and monazite occur in the charges. LA-ICP-MS analyses establish that the melts are extremely enriched in LILE (except for Sr), Th and U, but depleted in Nb and Zr, with LREE higher than HREE. Accessory phases accommodate several trace elements, especially HFSE and REE. Partition coefficients for some trace elements between residue and crustal melts are close to 1, contrasting strongly with melts of peridotite. Our dataset indicates that the direct melting of upper continental crust alone would generate siliceous, high-K magmas with enriched LILE, Th and U, but cannot explain the high Th/La fingerprint of K-rich lavas of the Alpine-Himalayan orogenic belt. We demonstrate that the Alpine-Himalayan orogenic volcanics attribute their unusual trace element geochemistry to the involvement of lawsonite blueschists that are imbricated together with extremely depleted fore-arc peridotites to form new lithosphere in the source region. There is no need or evidence for deep subduction in which a succession of additional reactions would only serve to modify and dilute the high Th/La signature.
DS201708-1639
2017
Foley, S.F.Foley, S.F.The carbon cycle in the continental lithosphere and the generation of alkaline mafic melts in cratonic and rift ridges.11th. International Kimberlite Conference, OralMantlecarbon
DS201711-2533
2017
Foley, S.F.Veter, M., Foley, S.F., Mertz-Kraus, R., Groschopf, N.Trace elements in olivine of ultramafic lamprophyres controlled by phlogopite rich mineral assemblages in the mantle source.Lithos, Vol. 292-293, pp. 81-95.Mantlelamprophyres

Abstract: Carbonate-rich ultramafic lamprophyres (aillikites) and associated rocks characteristically occur during the early stages of thinning and rifting of cratonic mantle lithosphere, prior to the eruption of melilitites, nephelinites and alkali basalts. It is accepted that they require volatile-rich melting conditions, and the presence of phlogopite and carbonate in the source, but the exact source rock assemblages are debated. Melts similar to carbonate-rich ultramafic lamprophyres (aillikites) have been produced by melting of peridotites in the presence of CO2 and H2O, whereas isotopes and trace elements appear to favor distinct phlogopite-bearing rocks. Olivine macrocrysts in aillikites are usually rounded and abraded, so that it is debated whether they are phenocrysts or mantle xenocrysts. We have analyzed minor and trace element composition in olivines from the type aillikites from Aillik Bay in Labrador, Canada. We characterize five groups of olivines: [1] mantle xenocrysts, [2] the main phenocryst population, and [3] reversely zoned crystals interpreted as phenocrysts from earlier, more fractionated, magma batches, [4] rims on the phenocrysts, which delineate aillikite melt fractionation trends, and [5] rims around the reversely zoned olivines. The main phenocryst population is characterized by mantle-like Ni (averaging 3400 µg g- 1) and Ni/Mg at Mg# of 88-90, overlapping with phenocrysts in ocean island basalts and Mediterranean lamproites. However, they also have low 100 Mn/Fe of 0.9-1.3 and no correlation between Ni and other trace elements (Sc, Co, Li) that would indicate recycled oceanic or continental crust in their sources. The low Mn/Fe without high Ni/Mg, and the high V/Sc (2-5) are inherited from phlogopite in the source that originated by solidification of lamproitic melts at the base of the cratonic lithosphere in a previous stage of igneous activity. The olivine phenocryst compositions are interpreted to result from phlogopite and not high modal pyroxene in the source. The presence of kimberlites and ultramafic lamprophyres of Mesozoic age in Greenland indicates the persistence of a steep edge to the cratonic lithosphere at a time when this had been removed from the western flank in Labrador.
DS201801-0014
2017
Foley, S.F.Foley, S.F., Fischer, T.P.An essential role for continental rifts and lithosphere in the deep carbon cycle.Nature Geoscience, Vol. 10, 12, pp. 897-902.Mantlecarbon

Abstract: The continental lithosphere is a vast store for carbon. The carbon has been added and reactivated by episodic freezing and re-melting throughout geological history. Carbon remobilization can lead to significant variations in CO2 outgassing and release in the form of magmas from the continental lithosphere over geological timescales. Here we use calculations of continental lithospheric carbon storage, enrichment and remobilization to demonstrate that the role for continental lithosphere and rifts in Earth’s deep carbon budget has been severely underestimated. We estimate that cratonic lithosphere, which formed 2 to 3 billion years ago, originally contained about 0.25 Mt C km -3. A further 14 to 28 Mt C km -3 is added over time from the convecting mantle and about 43 Mt C km -3 is added by plume activity. Re-melting focuses carbon beneath rifts, creating zones with about 150 to 240 Mt C km -3, explaining the well-known association of carbonate-rich magmatic rocks with rifts. Reactivation of these zones can release 28 to 34 Mt of carbon per year for the 40 million year lifetime of a continental rift. During past episodes of supercontinent breakup, the greater abundance of continental rifts could have led to short-term carbon release of at least 142 to 170 Mt of carbon per year, and may have contributed to the high atmospheric CO2 at several times in Earth's history.
DS201808-1754
2018
Foley, S.F.Jaques, A.L., Foley, S.F.Insights into the petrogenesis of the West Kimberley lamproites from trace elements in olivine.Mineralogy and Petrology, doi.org/10.1007/s00710-018-0612-9 19p.Australialamproites

Abstract: The Miocene lamproites of the West Kimberley region, Western Australia include olivine-leucite lamproites (=10 wt% MgO) containing olivine and leucite microphenocrysts, and diamondiferous olivine lamproites (20-30 wt% MgO) containing olivine phenocrysts and larger (1-10 mm) olivine as mantle xenocrysts and dunite micro-xenoliths. Olivine phenocrysts and thin (<100 µm) magmatic rims define trends of decreasing Cr and Ni, and increasing Ca and Mn, with decreasing olivine Mg#, consistent with fractional crystallisation of olivine (and minor chromite). Many phenocrysts are zoned, and those with cores of similar Mg# and trace element abundances to the mantle xenocrysts may be xenocrysts overgrown by later olivine crystallised from the lamproite magma. Magmatic olivines Mg#91-92 are estimated to have been in equilibrium with olivine lamproite magma(s) containing ~22-24 wt% MgO. The xenocrystic mantle olivines Mg90-92.5 in the olivine lamproites are inferred from trace element abundances to be mostly derived from garnet peridotite with equilibration temperatures estimated from the Al-in-olivine thermometer (Bussweiler et al. 2017) to be ~1000-1270 °C at depths of 115-190 km. Olivines from the deeper lithosphere are less depleted (lower Mg#, higher Na, Al, P, Ti, Zr etc) than those at shallower depths, a feature suggested to reflect the combined effects of metasomatic re-enrichment of the craton roots (Ti, Fe, Zr etc) and increasing temperature with depth of origin (Na, Al, Ca). The West Kimberley lamproite olivines are not enriched in Li, as might be expected if their source regions contained continental sedimentary material as has been previously inferred from lamproite large-ion-lithophile trace elements, and Sr and Pb isotopes.
DS201809-2063
2018
Foley, S.F.Liu, Y-S., Foley, S.F., Chien, C.F., He, D., Zong, K.Q.Mantle recycling of sedimentary carbonate along the northern margin of the North Chin a craton.Goldschmidt Conference, 1p. AbstractChinacarbonatite

Abstract: Sedimentary carbonate rocks, which exist extensively in the oceanic realm, are subducted to differing degrees during the closure of oceanic basins. However, very few observational data exist to provide details on the mechanisms of transport of carbonate materials from the surface to mantle depths and back to the Earth’s surface. Here we presented a series of diamond-bearing carbonatite xenoliths, carbonatite intrusions and carbonatite veins along the northern margin of the North China Craton (NCC). These carbonatites show geochemical features of recycled limestone (similar trace element patterns and high 87Sr/86Sr ratios of 0.705-0.709), indicating that they had a sedimentary limestone precursor. However, the presence of diamond, reduced minerals (e.g., moissanite), mantle-derived silicate minerals (eg., Cpx and Opx), and high Ni content and 143Nd/144Nd ratio indicate their staying for a time in the mantle. Combining with the zircon age spectrums of the carbonatite xenoliths and intrusions and the extensive high-87Sr/86Sr (up to 0.708) carbonatite metasomatism in the lithospheric mantle along the northern margin of NCC, we suggest that the limestone precursor could have been derived from the Paleo-Asian Ocean, and these carbonatites mark the subduction of a carbonate platform of the Paleo-Asian Oceanic slab to mantle depths beneath the NCC. Extensive mantle recycling of sedimentary carbonate could have contributed to the modification of the lithospheric mantle along the northern margin of the North China Craton.
DS201905-1030
2019
Foley, S.F.Forster, M.W., Prelevic, D., Buhre, S., Mertz-Kraus, R., Foley, S.F.An experimental study of the role of partial melts of sediments versus mantle melts in the sources of potassic magmatism.Journal of Asian Earth Sciences, Vol. 177, pp. 76-88.Mantlelamproite

Abstract: Potassium-rich lavas with K/Na of >2 are common in orogenic and anorogenic intraplate magmatic provinces. However, in the primitive mantle, the concentration of Na exceeds that of K by 10 times. The source of K-rich lavas thus needs to be either K-enriched or Na-depleted to account for high K/Na ratios. The geochemical and isotopic compositions of high 87Sr/86Sr post-collisional lavas show that their mantle source contains a recycled crustal component. These highly K-enriched lavas with crustal like trace element patterns are termed “orogenic lamproites” and are compositionally distinct from K-rich “anorogenic lamproites” that show lower 87Sr/86Sr and a trace element pattern that resembles that of primary mantle melts. For both groups the processes of K-enrichment within their source are uncertain and are thought to be linked to melts of sedimentary rocks for “orogenic lamproites” and low-degree melts of ultramafic mantle rocks for “anorogenic lamproites”. In both cases, metasomatism of the mantle lithosphere is the precursor to K-rich magmatism. In this study we experimentally determine the effects of mantle metasomatism by sediment- and hydrous mantle melts. The experiments simulate the interaction of refractory lithospheric mantle and metasomatizing melt in a 2-layer reaction experiment. The sediment/dunite reaction experiments lead to formation of a strongly K-enriched phlogopite-pyroxenite layer sandwiched between the two starting materials. The low temperature of the sediment/dunite reaction runs at <1000?°C simulates a fore-arc subduction environment, in which the melts of sediment are consumed during interaction with dunite as the temperature is below the solidus of the produced phlogopite-pyroxenites. The hydrous mantle melt/dunite reaction run is simulated by reacting a hydrated basanite with dunite. Since the temperature of the reaction is higher than the solidus of the resulting phlogopite-pyroxenites (1200?°C), the hydrous melt is not consumed but flows further, increasing in K2O and K/Na as it reacts with the refractory peridotite. In both cases, melts are enriched in K and K/Na increases by crystallizing a low K and low K/Na eclogitic residue. Compositions of glass and phlogopite from both types of reactions are comparable to glasses and phlogopites found within post-collisional lavas. Since the enrichment of K within the reaction zone is strongly controlled by the formation of low K/Na and low-K residues, metasomatic enrichment of the mantle lithosphere in K does not need a highly K-enriched metasomatic agent.
DS201907-1545
2019
Foley, S.F.Forster, M.W., Foley, S.F., Marschall, H.R., Alard, O., Buhre, S.Melting of sediments in the deep mantle produces saline fluid inclusions in diamonds.Science Advances, Vol. 5, 5, eaau 2620 7p.Mantlediamond inclusions

Abstract: Diamonds growing in the Earth’s mantle often trap inclusions of fluids that are highly saline in composition. These fluids are thought to emerge from deep in subduction zones and may also be involved in the generation of some of the kimberlite magmas. However, the source of these fluids and the mechanism of their transport into the mantle lithosphere are unresolved. Here, we present experimental results showing that alkali chlorides are stable solid phases in the mantle lithosphere below 110 km. These alkali chlorides are formed by the reaction of subducted marine sediments with peridotite and show identical K/Na ratios to fluid inclusions in diamond. At temperatures >1100°C and low pressures, the chlorides are unstable; here, potassium is accommodated in mica and melt. The reaction of subducted sediments with peridotite explains the occurrence of Mg carbonates and the highly saline fluids found in diamonds and in chlorine-enriched kimberlite magmas.
DS201909-2039
2019
Foley, S.F.Forster, M.W., Foley, S.F., Alard, O., Buhre, S.Partitioning of nitrogen during melting and recycling in subduction zones and the evolution of atmospheric nitrogen.Chemical Geology, in press available 31p. PdfMantlesubduction, metasomatism

Abstract: The subduction of sediment connects the surface nitrogen cycle to that of the deep Earth. To understand the evolution of nitrogen in the atmosphere, the behavior of nitrogen during the subduction and melting of subducted sediments has to be estimated. This study presents high-pressure experimental measurements of the partitioning of nitrogen during the melting of sediments at sub-arc depths. For quantitative analysis of nitrogen in minerals and glasses, we calibrated the electron probe micro-analyzer on synthetic ammonium feldspar to measure nitrogen concentrations as low as 500?µg?g-1. Nitrogen abundances in melt and mica are used together with mass balance calculations to determine DN(Mica/Melt), DN(Fluid/Mica), and DN(Fluid/Melt). Calculated partition coefficients correspond to expected values for NH4+, which behaves similarly to Rb+ due to its nearly identical size. Nitrogen partitioning between fluid and melt (DN(Fluid/Melt)) and fluid and bulk residue (melt+mica) (DN(Fluid/Bulk)) increase linearly with temperature normalized to pressure. This linear relationship can be used to calculate DN(Fluid/Melt) and DN(Fluid/Bulk) for slab melts from 800 to 1200?°C following: and [nasty equation that did not copy]. We used these partition coefficients to quantify the amount of N recycled into the mantle as 50?±?6% of today's atmospheric N. Depending on the rate of mantle N degassing we calculated 4 different scenarios for atmospheric pN2 evolution. All 4 scenarios estimate pN2 to be 8-12% higher at the beginning of the Phanerozoic. These estimates diverge towards the past due to uncertainties in the mechanism and magnitude of N degassing from the mantle. Assuming degassing of N in the past was close to modern degassing rates from MORB, pN2 was up to 40% higher at the onset of plate tectonics at 3-4?Ga. However, degassing rates were probably higher than this: assuming 10× and 20× times higher rates at the onset of plate tectonics leads to pN2 within 20% of modern values. If N degassing from the mantle is increased to 40× the modern MORB rate, pN2 in the Archean would have been 50% lower than today's, which is in accordance with observations from paleoatmospheric studies.
DS201912-2780
2019
Foley, S.F.Foley, S.F., Yaxley, G.M., Kjarsgaard, B.A.Kimberlites: from source to surface, insights from experiments.Elements, Vol. 15, 6, pp.Mantlepetrology
DS201912-2781
2019
Foley, S.F.Forster. M.W., Prelevic, D., Buhre, S., Mertz-Kraus, R., Foley, S.F.An experimental study of the role of partial melts of sediments versus mantle melts in the sources of potassic magmatism.Journal of Asian Earth Sciences, Vol. 177, pp. 76-88.Mantlemetasomatism

Abstract: Potassium-rich lavas with K/Na of >2 are common in orogenic and anorogenic intraplate magmatic provinces. However, in the primitive mantle, the concentration of Na exceeds that of K by 10 times. The source of K-rich lavas thus needs to be either K-enriched or Na-depleted to account for high K/Na ratios. The geochemical and isotopic compositions of high 87Sr/86Sr post-collisional lavas show that their mantle source contains a recycled crustal component. These highly K-enriched lavas with crustal like trace element patterns are termed “orogenic lamproites” and are compositionally distinct from K-rich “anorogenic lamproites” that show lower 87Sr/86Sr and a trace element pattern that resembles that of primary mantle melts. For both groups the processes of K-enrichment within their source are uncertain and are thought to be linked to melts of sedimentary rocks for “orogenic lamproites” and low-degree melts of ultramafic mantle rocks for “anorogenic lamproites”. In both cases, metasomatism of the mantle lithosphere is the precursor to K-rich magmatism. In this study we experimentally determine the effects of mantle metasomatism by sediment- and hydrous mantle melts. The experiments simulate the interaction of refractory lithospheric mantle and metasomatizing melt in a 2-layer reaction experiment. The sediment/dunite reaction experiments lead to formation of a strongly K-enriched phlogopite-pyroxenite layer sandwiched between the two starting materials. The low temperature of the sediment/dunite reaction runs at <1000?°C simulates a fore-arc subduction environment, in which the melts of sediment are consumed during interaction with dunite as the temperature is below the solidus of the produced phlogopite-pyroxenites. The hydrous mantle melt/dunite reaction run is simulated by reacting a hydrated basanite with dunite. Since the temperature of the reaction is higher than the solidus of the resulting phlogopite-pyroxenites (1200?°C), the hydrous melt is not consumed but flows further, increasing in K2O and K/Na as it reacts with the refractory peridotite. In both cases, melts are enriched in K and K/Na increases by crystallizing a low K and low K/Na eclogitic residue. Compositions of glass and phlogopite from both types of reactions are comparable to glasses and phlogopites found within post-collisional lavas. Since the enrichment of K within the reaction zone is strongly controlled by the formation of low K/Na and low-K residues, metasomatic enrichment of the mantle lithosphere in K does not need a highly K-enriched metasomatic agent.
DS202002-0185
2020
Foley, S.F.Forster, M.W., Buhre, S., Xu, B., Prelevic, D., Mertz-Kraus, R., Foley, S.F.Two stage origin of K-enrichment in ultrapotassic magmatism simulated by melting of experimentally metasomatized mantle.MDPI Minerals, Vol. 10, 41;doe.10.3390/min10010041 21p. PdfMantlemetasomatism

Abstract: The generation of strongly potassic melts in the mantle requires the presence of phlogopite in the melting assemblage, while isotopic and trace element analyses of ultrapotassic rocks frequently indicate the involvement of subducted crustal lithologies in the source. However, phlogopite-free experiments that focus on melting of sedimentary rocks and subsequent hybridization with mantle rocks at pressures of 1-3 GPa have not successfully produced melts with K2O >5 wt%-6 wt%, while ultrapotassic igneous rocks reach up to 12 wt% K2O. Accordingly, a two-stage process that enriches K2O and increases K/Na in intermediary assemblages in the source prior to ultrapotassic magmatism seems likely. Here, we simulate this two-stage formation of ultrapotassic magmas using an experimental approach that involves re-melting of parts of an experimental product in a second experiment. In the first stage, reaction experiments containing layered sediment and dunite produced a modally metasomatized reaction zone at the border of a depleted peridotite. For the second-stage experiment, the metasomatized dunite was separated from the residue of the sedimentary rock and transferred to a smaller capsule, and melts were produced with 8 wt%-8.5 wt% K2O and K/Na of 6-7. This is the first time that extremely K-enriched ultrapotassic melts have been generated experimentally from sediments at low pressure applicable to a post-collisional setting.
DS202002-0220
2019
Foley, S.F.Xu, R., Liu, Y., Wang, X-C, Foley, S.F., Zhang, Y., Yuan, H.Generation of continental intraplate alkali basalts and deep carbon cycle.Earth Science Reviews, in press available, 38p. Doi.org/1010.1016 /jearsciev.2019.103073Globalcarbon

Abstract: Although the deep recycling of carbon has been proposed to play a key role in producing intraplate magmatism, the question of how it controls or triggers mantle melting remains poorly understood. In addition, generation of incipient carbonated melts in the mantle and their subsequent reaction with the mantle are critical processes that can influence the geochemistry of intraplate basalts, but the details of such processes are also unclear. Here we present geochemical evidence for the existence of pervasive carbonate melt in the mantle source of Cenozoic continental intraplate highly alkali basalts (SiO2 < 45 wt%), which are volumetrically minor but widespread in eastern China. The primary magma compositions of these basalts cannot be explained by either partial melting of a single mantle source lithology or mixing of magmas derived from distinct mantle sources, but can be adequately explained by carbonate-fluxed melting of eclogite and subsequent reaction between silica-rich melts and peridotite that ultimately transformed the initial carbonated silica-rich melts into silica-undersaturated alkalic magmas. The source of the carbonate is in subducted eclogites associated with the Pacific plate, which stagnated in the mantle transition zone (MTZ). The spatial distribution of the alkali basalts is in accord with large-scale seismic low-velocity anomalies in the upper mantle above the MTZ. Similar scenarios in central-western Europe and eastern Australia lead us to propose that reaction between carbonated silica-rich melt and peridotite may be a pivotal mechanism for the generation of continental intraplate alkali basalts elsewhere in the world.
DS202007-1132
2020
Foley, S.F.Choi, F.M., Fiorentini, M.L., Giuliani, A., Foley, S.F., Maas, R., Taylor, W.R.Subduction related tetrogenesis of late Archean calc-alkaline lamprophyres in the Yilgarn craton ( Western Australia).Precambrian Research, Vol. 338, 105550Australialamprophyres

Abstract: We present a comprehensive petrographic, mineralogical and geochemical study of calc-alkaline lamprophyres (CAL) from the Archean Yilgarn Craton, Western Australia. Previous studies have shown that the emplacement age of CAL from the Eastern Goldfields Superterrane of the Yilgarn Craton is ~2684 to ~2640 Ma. A new Rb/Sr mica age for a CAL sample in the Western Yilgarn is ~2070 Ma. Both Archean and Proterozoic CAL analysed in this study display porphyritic textures and contain phenocrysts of amphibole, minor clinopyroxene and biotite in a fine-grained groundmass dominated by feldspar. High MgO, Ni and Cr abundances (up to 11.9 wt%, 373 and 993 ppm. respectively) are consistent with derivation of primitive magmas from a mantle source. Enrichment in H2O, reflected in the abundance of magmatic amphibole and mica, combined with high whole-rock LILE, Th/Yb ratios and negative Nb-Ta anomalies in trace element patterns are consistent with a source that was metasomatised by hydrous fluids analogous to those generated by Phanerozoic subduction-related processes. Chondritic ?Nd and ?Hf signatures and Archean mantle-like Sr isotope signatures of the Late Archean CAL indicate that the fluid metasomatism required to explain their volatile and trace-element enriched composition shortly preceded partial melting (i.e. there was insufficient time to develop enriched radiogenic isotopic signatures). The concurrence of apparently juvenile radiogenic isotopes and fluid-related trace element compositions requires a geodynamic scenario whereby dehydration of a subducted slab triggered metasomatism of the overlying mantle wedge. Our findings therefore support a subduction setting at ~2.6-2.7 Ga along the eastern margin of the Yilgarn Craton. The CAL from the Western Yilgarn have similar compositions but enriched Sr-Nd-Hf isotopes compared to those in the Eastern Goldfields Superterrane. This signature is consistent with melting of lithospheric mantle domains previously enriched by subduction-related metasomatism. Hence, our study suggests the presence of a subduction setting in the Western Yilgarn during the Archean, which is consistent with previous geodynamic reconstructions. However, the geodynamic trigger for the early Proterozoic event that generated CAL magmatism in the Western Yilgarn is currently unclear.
DS202007-1142
2020
Foley, S.F.Giuliani, A., Pearson, D.G., Soltys, A., Dalton, H., Phillips, D., Foley, S.F., Lim, E.Kimberlite genesis from a common primary melt modified by lithospheric mantle assimilation.Science Advances, Vol. 6, eeaz0424Mantlemelting

Abstract: Quantifying the compositional evolution of mantle-derived melts from source to surface is fundamental for constraining the nature of primary melts and deep Earth composition. Despite abundant evidence for interaction between carbonate-rich melts, including diamondiferous kimberlites, and mantle wall rocks en route to surface, the effects of this interaction on melt compositions are poorly constrained. Here, we demonstrate a robust linear correlation between the Mg/Si ratios of kimberlites and their entrained mantle components and between Mg/Fe ratios of mantle-derived olivine cores and magmatic olivine rims in kimberlites worldwide. Combined with numerical modeling, these findings indicate that kimberlite melts with highly variable composition were broadly similar before lithosphere assimilation. This implies that kimberlites worldwide originated by partial melting of compositionally similar convective mantle sources under comparable physical conditions. We conclude that mantle assimilation markedly alters the major element composition of carbonate-rich melts and is a major process in the evolution of mantle-derived magmas.
DS202008-1380
2020
Foley, S.F.Choi, E., Fiorentini, M.L., Giuliani, A., Foley, S.F., Maas, R., Taylor, W.R.Subduction related petrogenesis of late Archean calc-alkaline lamprophyres in the Yilgarn craton, western Australia.Precambrian Research, Vol. 338, 105550, 18p. PdfAustralialamprophyres

Abstract: We present a comprehensive petrographic, mineralogical and geochemical study of calc-alkaline lamprophyres (CAL) from the Archean Yilgarn Craton, Western Australia. Previous studies have shown that the emplacement age of CAL from the Eastern Goldfields Superterrane of the Yilgarn Craton is ~2684 to ~2640 Ma. A new Rb/Sr mica age for a CAL sample in the Western Yilgarn is ~2070 Ma. Both Archean and Proterozoic CAL analysed in this study display porphyritic textures and contain phenocrysts of amphibole, minor clinopyroxene and biotite in a fine-grained groundmass dominated by feldspar. High MgO, Ni and Cr abundances (up to 11.9 wt%, 373 and 993 ppm. respectively) are consistent with derivation of primitive magmas from a mantle source. Enrichment in H2O, reflected in the abundance of magmatic amphibole and mica, combined with high whole-rock LILE, Th/Yb ratios and negative Nb-Ta anomalies in trace element patterns are consistent with a source that was metasomatised by hydrous fluids analogous to those generated by Phanerozoic subduction-related processes. Chondritic ?Nd and ?Hf signatures and Archean mantle-like Sr isotope signatures of the Late Archean CAL indicate that the fluid metasomatism required to explain their volatile and trace-element enriched composition shortly preceded partial melting (i.e. there was insufficient time to develop enriched radiogenic isotopic signatures). The concurrence of apparently juvenile radiogenic isotopes and fluid-related trace element compositions requires a geodynamic scenario whereby dehydration of a subducted slab triggered metasomatism of the overlying mantle wedge. Our findings therefore support a subduction setting at ~2.6-2.7 Ga along the eastern margin of the Yilgarn Craton. The CAL from the Western Yilgarn have similar compositions but enriched Sr-Nd-Hf isotopes compared to those in the Eastern Goldfields Superterrane. This signature is consistent with melting of lithospheric mantle domains previously enriched by subduction-related metasomatism. Hence, our study suggests the presence of a subduction setting in the Western Yilgarn during the Archean, which is consistent with previous geodynamic reconstructions. However, the geodynamic trigger for the early Proterozoic event that generated CAL magmatism in the Western Yilgarn is currently unclear.
DS202102-0212
2021
Foley, S.F.Otter, L.M., Forster, M.W., Belousova, E., O'Reilly, P., Nowak, D., Parlk, S., Clar, S., Foley, S.F., Jacob, D.E.GGR cutting-edge review nanoscale chemical imaging by photo-induced force microscopy: technical aspects and application to the geosciences. ( not specific to diamonds)Geostandards and Geoanalytical Research, doi:10.111/ GGR.12373. 51p. PdfGlobalspectroscopy, mineralogy

Abstract: Photo-induced force microscopy (PiFM) is a new-frontier technique that combines the advantages of atomic force microscopy with infrared spectroscopy and allows for the simultaneous acquisition of 3D topographic data with molecular chemical information at high spatial (~ 5 nm) and spectral (~ 1 cm-1) resolution at the nanoscale. This non-destructive technique is time efficient as it requires only conventional mirror-polishing and has fast mapping rates on the order of a few minutes that allow the study of dynamic processes via time series. Here, we review the method’s historical development, working principle, data acquisition, evaluation, and provide a comparison with traditional geochemical methods. We review PiFM studies in the areas of materials science, chemistry, and biology. In addition, we provide the first applications for geochemical samples including the visualisation of faint growth zonation in zircons, the identification of fluid speciation in high-pressure experimental samples, and of nanoscale organic phases in biominerals. We demonstrate that PiFM analysis is a time- and cost-efficient technique combining high-resolution surface imaging with molecular chemical information at the nanoscale and, thus, complements and expands traditional geochemical methods.
DS202106-0929
2021
Foley, S.F.Choi, E., Fiorentini, M.L., Giuliani, A., Foley, S.F., Maas, R., Graham, S.Petrogenesis of Proterozoic alkaline ultramafic rocks in the Yilgarn Craton, western Australia.Gondwana Research, Vol. 93, pp. 197-217. pdfAustraliacarbonatites

Abstract: The Yilgarn Craton and its northern margin contain a variety of petrogenetically poorly defined small-volume alkaline ultramafic rocks of Proterozoic age. This study documents the petrography, mineral and bulk-rock geochemistry and Nd-Hf-Sr-Pb isotope compositions of a selected suite of these rocks. They comprise ~2.03-2.06 Ga ultramafic lamprophyres (UML) and carbonatites from the Eastern Goldfields Superterrane (EGS), ~0.86 Ga UML from Norseman, and orangeites from the Earaheedy Basin, including samples from Jewill (~1.3 Ga), Bulljah (~1.4 Ga) and Nabberu (~1.8-1.9 Ga). The Proterozoic UML and carbonatites from the EGS and Norseman display very consistent chondritic to superchondritic Nd-Hf isotope compositions and trace-element ratios similar to modern OIBs, which are indicative of a common mantle source across this wide alkaline province. These Nd-Hf isotope compositions overlap with the evolution trends of global kimberlites through time, thus suggesting that this mantle source could be deep and ancient as that proposed for kimberlites. Conversely, the orangeites located in the Earaheedy Basin along the northern margin of the Yilgarn Craton display trace element signatures similar to subduction-related calc-alkaline magmas. Taken together with their highly enriched Sr-Nd-Hf isotope compositions, these characteristics indicate an ancient lithospheric mantle source, which was probably metasomatised by subduction-related fluids. As the ages of the Bulljah and Jewill orangeites overlap with the breakup of the Columbia supercontinent, it is proposed that orangeite magmatism was triggered by changes in plate stress conditions associated with this event. This study provides a comprehensive picture of the genesis of Proterozoic alkaline magmatism in the Yilgarn Craton, highlighting the complex tectono-magmatic evolution of this lithospheric block after its assembly in the Archean.
DS1990-0482
1990
Folger, D.W.Folger, D.W., Irwin, B.J., McCullough, J.R., Rowland, R.W., PolloniMap showing free-air gravity anomalies off the southern coast of west-central Africa; Liberia to GhanaUnited States Geological Survey (USGS) Map, MF 2098-E, 1: 500, 000 $ 1.50GlobalGeophysics -gravity, Coast
DS1990-0483
1990
Folger, D.W.Folger, D.W., Irwin, B.J., McCullough, J.R., Rowland, R.W., PolloniMap showing free air gravity anomalies off the southern coast of west central Africa: Liberia to GhanaUnited States Geological Survey (USGS) Map, No. MF-2098-E 1: 500, 000 $ 1.50West AfricaGravity, Map, Geophysics
DS1983-0189
1983
Folkes, J.A.Crawford, E.S., Folkes, J.A., Williams, J.O., Barnicoat, A.C.Electron Microscope Studies of Minerals: Phase Boundaries In an Extremely Slowly Cooled Clinopyroxene (augite).Royal Society of London Proceedings, Vol. 387, No. 1792, PP. 21-30.ScotlandMicroscopy, Mineral Chemistry
DS2001-0337
2001
Folling, P.G.Frimmel, H.E., Folling, P.G., Diamond, R.Metamorphism of the Permo Triassic Cape Fold Belt and its basement, South AfricaMineralogy and Petrology, Vol. 73, No. 4, pp. 325-45.South AfricaMetamorphism
DS1992-0321
1992
Follmer, L.R.Curry, B.B., Follmer, L.R.The last Interglacial-glacial transition in IllinoisGeological Society of America, Special Paper No. 270, pp. 71-89GlobalGeomorphology, Glacial deposits
DS201112-0113
2011
Foltz, J.Bromley, D., Foltz, J.Sustainability under siege: transport costs and corruption on West Africa's trade corridors.Natural Resources Forum, Vol. 35, 1, Feb. pp. 32-48.Africa, West AfricaCSR
DS2001-0007
2001
FominAgashev, A.M., Watanabe, Bydaev, Pokhilenko, FominGeochemistry of kimberlites from the Nakyn field, Siberia: evidence for unique source composition.Geology, Vol. 29, No. 3, Mar. pp. 267-70.Russia, SiberiaGeochronology, geochemistry
DS1992-1327
1992
Fomin, A.S.Sarychev, I.K., Fomin, A.S.A typical geological genetic model of kimberlite pipe from the Daldyn-Alakit region.Russian Geology and Geophysics formerly Soviet Geology and Geophysics, Vol. 33, No. 1, pp. 107-113.Russia, Commonwealth of Independent States (CIS), YakutiaKimberlite genesis, Model
DS1995-0548
1995
Fomin, A.S.Fomin, A.S., Serenko, V.P., Zankovich, N.S.Two phase pipes of the Yakutian Diamondiferous provinceProceedings of the Sixth International Kimberlite Conference Almazy Rossii Sakha abstract, p. 6.Russia, YakutiaAutoliths, Deposit -Daldyn Alakit, Malo Botuobiya, Malokuonamka
DS1995-0549
1995
Fomin, A.S.Fomin, A.S., Serenko, V.P., Zinchuk, N.N.Three series of kimberlite bodies from Dadlyn-Alakit region of westernSiberia.Proceedings of the Sixth International Kimberlite Conference Extended Abstracts, p. 167-8.Russia, Siberia, Daldyn AlakitTectonics, Deposit -Aikal, Komsomolskaya
DS1995-1329
1995
Fomin, A.S.Nasurdinov, T.G., Sarychev, I.K., Fomin, A.S.The features of the geological structure of the Upper Horizons of the Yubileinaya pipe.Proceedings of the Sixth International Kimberlite Conference Almazy Rossii Sakha abstract, p. 25.Russia, YakutiaStructure, Deposit -Jubilee
DS1998-0010
1998
Fomin, A.S.Agashev, A.M., Fomin, A.S., Watanabe, T., Pokhilenko, N.Preliminary age determination of recently discovered kimberlites of the Siberian kimberlite province.7th International Kimberlite Conference Abstract, pp. 9-10.Russia, SiberiaGeochronology, Deposit - Sredne-Marxz, Botuobinskaya, Nurbinskaya
DS1998-0179
1998
Fomin, A.S.Budaev, D.A., Dolgunin, A.V., Fomin, A.S.An algorithm of kimberlite Diamondiferous estimations7th International Kimberlite Conference Abstract, pp. 111-12.Russia, YakutiaDiamond petrochemistry - Ti contnent, Deposit - Botuobinskaya
DS1998-0244
1998
Fomin, A.S.Cherny, S.D., Fomin, A.S., Yanygin, Ju.T., Banzeruk, V.Geology and composition of the Nakyn field kimberlite pipes and diamond properties (Yakutia).7th International Kimberlite Conference Abstract, pp. 147-148.Russia, YakutiaPetrology, Deposit - Botuobinskaya, Nurbinskaya
DS1998-1473
1998
Fomin, A.S.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
DS200612-0404
2006
Fomin, T.Fomin, T., Goleby, B.R.Lessons from a joint interpretation of vibroseis wide angle and near vertical reflection dat a in the northeastern Yilgarn, Western Australia.Tectonophysics, in pressAustraliaCraton, Geophysics - seismics, wide-angle reflection
DS1991-0499
1991
Fomin, Y.M.Fomin, Y.M.Ore controlling structures for diamonds and role of cosmic photos in theirrevealing.(Russian)Izvest. Akad. Nauk SSS, Geol., (Russian), No. 11, November pp. 145-149RussiaStructure, Diamond bearing
DS1992-0473
1992
Fomin, Y.M.Fomin, Y.M.Structural position of diamond bearing areas of the East of Siberian Platform (technical note).(Russian)Izvest, Akad, Nauk SSSR, (Russian), No. 12, December pp. 152-155Russia, SiberiaTectonics, Structure
DS1993-0557
1993
Fomin, Yu.A.Goncharenko, A.I., Fomin, Yu.A.Oxygen isotope distribution in plastically deformed and recrystallized olivine from Alpine type ultramaficsDoklady Academy of Sciences USSR, Earth Science Section, Vol. 317, pp. 207-210RussiaGeochronology, Ultramafics
DS202008-1436
2020
Fomina, E.Prokopyev, I.R., Kozlov, E., Fomina,E., Doroshkevich, A.Mineralogy and fluid regime of formation of the REE-Late-Stage hydrothermal mineralization of Petyayan-Vara carbonatites ( Vuoriyarvi, Kola region, NW Russia.Minerals, 19p. PdfRussia, Kola Peninsulacarbonatite

Abstract: The Vuoriyarvi Devonian alkaline-ultramafic complex (northwest Russia) contains magnesiocarbonatites with rare earth mineralization localized in the Petyayan-Vara area. High concentrations of rare earth elements are found in two types of these rocks: (a) ancylite-dominant magnesiocarbonatites with ancylite-baryte-strontianite-calcite-quartz (±late Ca-Fe-Mg carbonates) ore assemblage, i.e., “ancylite ores”; (b) breccias of magnesiocarbonatites with a quartz-bastnäsite matrix (±late Ca-Fe-Mg carbonates), i.e., “bastnäsite ores.” We studied fluid inclusions in quartz and late-stage Ca-Fe-Mg carbonates from these ore assemblages. Fluid inclusion data show that ore-related mineralization was formed in several stages. We propose the following TX evolution scheme for ore-related processes: (1) the formation of ancylite ores began under the influence of highly concentrated (>50 wt.%) sulphate fluids (with thenardite and anhydrite predominant in the daughter phases of inclusions) at a temperature above300-350 °C; (2) the completion of the formation of ancylite ores and their auto-metasomatic alteration occurred under the influence of concentrated (40-45 wt.%) carbonate fluids (shortite and synchysite-Ce in fluid inclusions) at a temperature above 250-275 °C; (3) bastnäsite ores deposited from low-concentrated (20-30 wt.%) hydrocarbonate-chloride fluids (halite, nahcolite, and/or gaylussite in fluid inclusions) at a temperature of 190-250 °C or higher. Later hydrothermal mineralization was related to the low-concentration hydrocarbonate-chloride fluids (<15 wt.% NaCl-equ.) at 150-200 °C. The presented data show the specific features of the mineral and fluid evolution of ore-related late-stage hydrothermal rare earth element (REE) mineralization of the Vuoriyarvi alkaline-ultramafic complex.
DS202103-0388
2018
Fomina, E.Kozlov, E., Fomina, E., Sidorov, M., Shilovskikh, V.Ti-Nb mineralization of late carbonatites and role of fluid in its formation: Petyayan-Vara rare-earth carbonatites ( Vuoriyarvi Massif, Russia). ***dateMDPI Applied Sciences, 19p. PdfRussiacarbonatite

Abstract: This article is devoted to the geology of titanium-rich varieties of the Petyayan-Vara rare-earth dolomitic carbonatites in Vuoriyarvi, Northwest Russia. Analogues of these varieties are present in many carbonatite complexes. The aim of this study was to investigate the behavior of high field strength elements during the late stages of carbonatite formation. We conducted a multilateral study of titanium- and niobium-bearing minerals, including a petrographic study, Raman spectroscopy, microprobe determination of chemical composition, and electron backscatter diffraction. Three TiO2-polymorphs (anatase, brookite and rutile) and three pyrochlore group members (hydroxycalcio-, fluorcalcio-, and kenoplumbopyrochlore) were found to coexist in the studied rocks. The formation of these minerals occurred in several stages. First, Nb-poor Ti-oxides were formed in the fluid-permeable zones. The overprinting of this assemblage by residual fluids led to the generation of Nb-rich brookite (the main niobium concentrator in the Petyayan-Vara) and minerals of the pyrochlore group. This process also caused niobium enrichment with of early generations of Ti oxides. Our results indicate abrupt changes in the physicochemical parameters at the late hydro (carbo) thermal stage of the carbonatite formation and high migration capacity of Ti and Nb under these conditions. The metasomatism was accompanied by the separation of these elements.
DS202108-1283
2021
Fomina, E.N.Fomina, E.N., Kozlov, E.N.Stable ( C, O) radiogenic ( Sr, Nd) isotopic evidence for REE- carbonatite formation processes in Petyayan-Vara ( Vuoriyarvi Massif, NW Russia).Lithos, Vol. 398-399, 17p. PdfRussiaREE

Abstract: A study of radiogenic (Sr, Nd) and stable (C, O) isotopic data for rare earth carbonatites from the Petyayan-Vara field of the Devonian Vuoriyarvi alkaline-ultrabasic massif is presented. The cumulative evidence indicates that the primary igneous rocks of the Petyayan-Vara area are burbankite-bearing magnesiocarbonatites having isotopic signatures of the depleted mantle (eNd365Ma = 5.0, 87Sr/86Sr(i) = 0.7031, d13C ca. -4‰, and d18O ca. 11‰). Interaction of the primary carbonatite melt with the host silicate rocks produced high-Ti carbonatites with a mantle d13C (ca. -4‰) and isotopically heavy d18O (ca. 20‰). These rocks trapped K, Na, Mg, CO2, and rare earth elements (REEs) (mainly heavy REEs) from the melt and Si, Al, Fe, Ti, and P from the host rocks. Early post-magmatic exposure of burbankite-bearing carbonatites to a mixture of fluids of crustal and orthomagmatic carbonatite origin caused redistribution of REEs, Ba, and Sr and formation of REE-rich carbonatites with abundant ancylite mineralization. This effect did not disturb the Smsingle bondNd system but induced radiogenic Sr accumulation and a change in C and O isotopic composition towards heavier values. Later, but most likely before denudation, the Petyayan-Vara rocks underwent another metasomatic event involving crustal fluids infiltrating through fracture systems. This event triggered formation of bastnäsite-rich carbonatites with fewer REEs at the expense of ancylite-rich carbonatites, and changed all the isotopic systems in the affected rocks. This model successfully accounts for the evolution of all the carbonatite varieties discovered to date in the Petyayan-Vara field.
DS200812-0905
2008
Fomina, L.N.Pokhilenko, L.N., Pokhilenko, N.P., Fedorov, L.I., Tomilenko, A.A., Usova, L.V., Fomina, L.N., Sobolev, V.S.Fluid regime pecularities of the lithosphere mantle of the Siberian Platform.Deep Seated Magmatism, its sources and plumes, Ed. Vladykin, N.V., 2008 pp. 122-136.Russia, SiberiaMantle chemistry
DS1982-0348
1982
Fominykh, V.I.Krivenko, A.P., Fominykh, V.I.Picrites and the Genesis of Gabbro Monzodiorite Plutonites. RusTrudy Institute Geol. Geofiz., (Russian), No. 455, pp. 34-39RussiaPicrite
DS201412-0704
2013
Fomradas, G.Porrit, L-A., Russell, J.K., McLean, H., Fomradas, G., Eichenberg, D.A phreatomagmatic kimberlite: the 418A kimberlite pipe, Northwest Territories, Canada.Proceedings of the 10th. International Kimberlite Conference, Vol. 2, pp. 97-108.Canada, Northwest TerritoriesDeposit - 418A
DS201602-0231
2016
Fomradas, G.Petts, D.C., Stachel, T., Stern, R.A., Hunt, L., Fomradas, G.Multiple carbon and nitrogen sources associated with the parental mantle fluids of fibrous diamonds from Diavik, Canada revealed by SIMS microanalysis.Contributions to Mineralogy and Petrology, Vol. 171, 15p.Canada, Northwest TerritoriesDeposit - Diavik

Abstract: Fibrous diamonds are often interpreted as direct precipitates of primary carbonate-bearing fluids in the lithospheric mantle, sourced directly from common reservoirs of “mantle” carbon and nitrogen. Here we have examined fibrous growth layers in five diamonds (as three rims or “coats” and two whole-crystal cuboids) from the Diavik Diamond Mine, Canada, using in situ C- and N-isotope and N-abundance measurements to investigate the origin and evolution of their parental fluids, and in particular, to test for isotopic variability within a suite of fibrous diamonds. High-resolution growth structure information was gleaned from cathodoluminescence (CL) imaging and, in combination with the isotopic data, was used to assess the nature of the transition from gem to fibrous growth in the coated diamonds. The two cuboids are characterized by fine concentric bands of fibrous and/or milky opaque diamond, with one sample (S1719) having intermittent gem-like growth layers that are transparent and colourless. The three coated diamonds comprise octahedral gem cores mantled by massive or weakly zoned fibrous rims, with sharp and well-defined gem-fibrous boundaries. For the two cuboid samples, d 13C and d 15N values were -7.7 to -3.2 ‰ (mean -6.3 ± 1.3 ‰; 1 SD; n = 84) and -5.6 to -2.1 ‰ (mean -4.0 ± 0.8 ‰; 1 SD; n = 48), respectively. The three fibrous rims have combined d 13C values of -8.3 to -4.8 ‰ (mean -6.9 ± 0.7 ‰; 1 SD; n = 113) and d 15N values of -3.8 to -1.9 ‰ (mean -2.7 ± 0.4 ‰; 1 SD; n = 43). N-abundances of the combined cuboid-fibrous rim dataset range from 339 to 1714 at. ppm. The gem cores have d 13C and d 15N values of -5.4 to -3.5 ‰ and -17.7 to +4.5 ‰, respectively, and N-abundances of 480 to 1699 at. ppm. Broadly uniform C- and N-isotope compositions were observed in each of the gem cores (variations of ~<1 ‰ for carbon and ~<3 ‰ for nitrogen). This limited C- and N- isotope variability implies that the gem cores formed from separate pulses of fluid that remained isotopically uniform throughout the duration of growth. Significant isotopic and abundance differences were observed between the gem and fibrous growth zones, including in one detailed isotopic profile d 13C and d 15N offsets of ~-2.4 and ~-3.7 ‰, respectively, and a ~230 at. ppm increase in N-abundance. Combined with the well-defined gem-fibrous boundaries in plane light and CL, these sharp isotopic differences indicate separate parental fluid histories. Notably, in the combined fibrous diamond dataset prominent C- and N-isotope differences between the whole-crystal cuboid and fibrous rim data were observed, including a consistent ~1.3 ‰ offset in d 15N values between the two growth types. This bimodal N-isotope distribution is interpreted as formation from separate parental fluids, associated with distinct nitrogen sources. The bimodal N-isotope distribution could also be explained by differences in N-speciation between the respective parental fluids, which would largely be controlled by the oxidation state of the fibrous rim and cuboid growth environments (i.e., N2 vs. NH4 + or NH3). We also note that this C- and N-isotope variability could indicate temporal changes to the source(s) of the respective parental fluids, such that each stage of fibrous diamond growth reflects the emplacement of separate pulses of proto-kimberlitic fluid—from distinct carbon and nitrogen sources, and/or with varying N-species—into the lithospheric mantle.
DS201812-2852
2018
Fomradas, G.Moss, S., Porritt, L., Pollock, K., Fomradas, G., Stubley, M., Eichenberg, D., Cutts, J.Diavik deposit: Geology, mineral chemistry, and structure of the kimberlites at Diavik diamond mine: indicators of cluster-scale cross-fertilization, mantle provenance, and pipe morphology.Society of Economic Geology Geoscience and Exploration of the Argyle, Bunder, Diavik, and Murowa Diamond Deposits, Special Publication no. 20, pp. 287-318.Canada, Northwest Territoriesdeposit - Diavik
DS200712-0754
2007
Fomrades, G.Moss, S., Russel, J.K., Fomrades, G., Young, R., McLean, H.Crater in-fill at Diavik: facies architecture, textures, volcanic processes and implications.Geological Association of Canada, Gac-Mac Yellowknife 2007, 1 pg. abstract p.57-58.Canada, Northwest TerritoriesDiavik petrology
DS201212-0569
2012
Fomrades, G.Porritt, L.A., Russell, J.K., McLean, H., Fomrades, G., Eicheberg,D.Geology and volcanology of the A418 kimberlite pipe, NWT, Canada10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractCanada, Northwest TerritoriesDeposit - A418
DS201312-0011
2013
Fonanella, S.Ahlqvist, O., Harvey, F., Ban, H., Chen, W., Fonanella, S., Guo, M.,Singh, N.Making journal articles 'live': turning academic writing into scientific dialog.Geojournal, Vol. 78, 1, pp. 61-68.TechnologyKnowledge dissemination
DS1991-0500
1991
Fonarev, V.I.Fonarev, V.I., Graphchikov, A.A., Konilov, A.N.A consistent system of geothermometers for metamorphic complexesInternational Geology Review, Vol. 33, No. 8, August pp. 743-783RussiaGeothermometry, Metamorphic complexes
DS1995-0550
1995
Fonarev, V.I.Fonarev, V.I., Gavrilkova, S.N., Sultanov, D.M.Metamorphic events in the Precambrian on the southern Aldan Shield, EastSiberia, Russia.Petrology, Vol. 3, No. 2, March-April pp. 152-162.RussiaAldan Shield, metamorphism
DS1998-0439
1998
Fonarev, V.I.Fonarev, V.I., Touret, J.L.R., Kotelnikova, Z.A.Fluid inclusions in rocks from the Central Kola granulite area- BalticShield.Eur. Journal of Mineralogy, Vol. 10, No. 6, Nov. 1, pp. 1181-2000.Russia, Kola PeninsulaBaltic area - general not specific to diamonds
DS1860-0345
1880
Fonentay, E.Schlesinger, M., Fonentay, E.Compagnie Francaise des Mines des Diamants du CapParis:, 8P.Africa, South AfricaDiamond Mining
DS1990-0484
1990
Fong, D.G.Fong, D.G.Chin a and specialty metalsWorld Mineral Notes, Vol. 6, No. 5, November 1990, pp. 1-5ChinaRare earths, Carbonatite
DS200612-0975
2006
Fonini, W.R.Nichols, K.K., Bierman, P.R., Fonini, W.R., Gillespie, A., Caffee, M., Finkel, R.Dates and rates of arid region geomorphic process.GSA Today, August pp. 4- 11.United States, California, ArizonaGeomorphology, desert landscapes
DS200512-1137
2004
Fonsec, M.A.Ventura Santos, R., Souza de Alvarenga, C.J., Babinski, M., Ramos, M.L.S., Cukrov, N., Fonsec, M.A., Da NorbregaCarbon isotopes of Mesoproterozoic Neoproterozoic sequences from southern Sao Francisco craton and Aracuai Belt, Brazil: paleogeorgraphic implications.Journal of South American Earth Sciences, Vol. 18, 1, Dec. 30, pp. 27-39.South America, BrazilGeomorphology, glaciation, geochronology,carbonatites
DS201312-0944
2013
Fonsec, R.O.C.Wainwright, A.N., Luguet, A., Fonsec, R.O.C.Sulfide Re-Os dating in modally metasomatised peridotites, insights from Lethlhakane ( Botswana).Goldschmidt 2013, 1p. AbstractAfrica, BotswanaDeposit - Lethlhakane
DS201509-0435
2015
Fonsec, R.O.C.Wainwright, A.N., Luguet, A., Fonsec, R.O.C., Pearson, D.G.Investigating metasomatic effects on the 187Os isotopic signature: a case study on the micrometric base metal sulphides in metasomatised peridotite from the Letlhakane kimberlite, (Botswana). Lithos, Vol. 232, pp. 35-48.Africa, BotswanaDeposit - Letlhakane

Abstract: The peridotite xenoliths of the Letlhakane kimberlite (Botswana), which intrude the Proterozoic Magondi Belt on the western margin of the Zimbabwe craton, represent highly depleted melting residues. These residues suffered subsequent variable metasomatic overprinting, evidenced by cryptic trace element enrichments in the spinel peridotites to modal addition of phlogopite, clinopyroxene and spinel within the garnet peridotites. In order to assess the robustness of the Re–Os chronometer in such highly metasomatised peridotites, detailed investigations of base metal sulphide (BMS) petrography and single-BMS grain 187Os/188Os analyses have been undertaken in three representative peridotites.
DS201312-0272
2013
Fonseca, A.Fonseca, A., Fitzpatrick, P., McAllister, M.L.Government and voluntary policy making for sustainability in mining towns: a longitudinal analysis.Natural Resources Forum, Vol. 37, 4, Nov. 1, pp. 211-220.GlobalLegislation
DS1995-0234
1995
Fonseca, A.L.Bundtzen, T.K., Fonseca, A.L., Mann, R.Geology and mineral deposits of the Russian Far EastGlacier House Publications, 160p. $ 40.00RussiaBook -table of contents, Mneral deposits of Far East
DS1991-0314
1991
Fonseca, L.R.Costa, M.L., Fonseca, L.R., Angelica, R.S., Lemos, V.P., LemosGeochemical exploration of the Maicuru alkaline-ultramafic-carbonatitecomplex, northern BrasilJournal of Geochemical Exploration, Special Publications Geochemical Exploration, Vol. 40, No. 1-3, pp. 193-204GlobalCarbonatite, Maicuru
DS2001-0013
2001
Fonseca, M.A.Alkmim, F.F., Marshal\k, S., Fonseca, M.A.Assembling West Gondwana in the Neoproterozoic: clues from the Sao Francisco craton region, Brasil.Geology, Vol. 29, No. 4, Apr. pp.319-22.BrazilGondwana, tectonics, Brasiliano orogeny, Craton
DS201112-0053
2011
Fonseca, R.Ballhaus, C., Laurenz, V., Fonseca, R., Munker, C., Albarede, Rohrbach, Schmidt, Jochum, Stoll, Weis, HelmyLate volatile addition to Earth.Goldschmidt Conference 2011, abstract p.475.MantleW and Cr elements
DS201112-0330
2011
Fonseca, R.O.Fonseca, R.O., Luguet, A., Ballhaus, C., Pohl, F.Experimental constraints on the development of Os isotopic heterogeneity in the Earth's mantle.Goldschmidt Conference 2011, abstract p.858.MantleMelting - tracer
DS201312-0053
2013
Fonseca, R.O.C.Ballhaus, C., Laurenz, V., Munker, C., Fonseca, R.O.C., Albarede, F., Rohrbach, A., Lagos, M., Schmidt, M.W., Jochum, K-P., Stoll, B., Weis, U., Helmy, H.M.The U /Pb ratio of the Earth's mantle - a signature of late volatile addition.Earth and Planetary Interiors, Vol. 362, pp. 237-245.MantleMelting
DS201312-0093
2013
Fonseca, R.O.C.Bragagni, A., Luguet, A., Pearson, D.G., Fonseca, R.O.C., Kjarsgaard, B.A.Insight on formation and evolution of cratonic mantle: Re-Os dating of single sulfides from Somerset mantle xenoliths ( Rae Craton) Canada.Goldschmidt 2013, AbstractCanada, NunavutGeochronolgy
DS201607-1319
2016
Fonseca, R.O.C.Wainwright, A.N., Luguet, A., Schreiber, A., Fonseca, R.O.C., Nowell, G.M.Nanoscale variations in 187Os isotopic composition and HSE systematics in a Bultfontein peridotite.Earth and Planetary Science Letters, Vol. 447, pp. 60-71.Africa, South AfricaDeposit - Bultfontein

Abstract: Understanding the mineralogical controls on radiogenic chronometers is a fundamental aspect of all geochronological tools. As with other common dating tools, it has become increasingly clear that the Re -Os system can be impacted by multiple mineral formation events. The accessory and micrometric nature of the Re -Os-bearing minerals has made assessing this influence complex. This is especially evident in cratonic peridotites, where long residence times and multiple metasomatic events have created a complex melting and re-enrichment history. Here we investigate a harzburgitic peridotite from the Bultfontein kimberlite (South Africa) which contains sub-micron Pt -Fe-alloy inclusions within base metal sulphides (BMS). Through the combination of the focused ion beam lift-out technique and low blank mass spectrometry we were able to remove and analyse the Pt -Fe-alloy inclusions for their Re -Os composition and highly siderophile element (HSE) systematics. Six repeats of the whole-rock yield 187Os/188Os compositions of 0.10893 -0.10965, which correspond to Re depletion model ages (TRD) of 2.69 -2.79 Ga. The Os, Ir and Pt concentrations are slightly variable across the different digestions, whilst Pd and Re remain constant. The resulting HSE pattern is typical of cratonic peridotites displaying depleted Pt and Pd. The Pt -Fe-alloys have PUM-like 187Os/188Os compositions of 0.1294±24 (2-s.d.) and 0.1342±38, and exhibit a saw-tooth HSE pattern with enriched Re and Pt. In contrast, their BMS hosts have unradiogenic 187Os/188Os of 0.1084±6 and 0.1066±3, with TRD ages of 2.86 and 3.09 Ga, similar to the whole-rock systematics. The metasomatic origin of the BMS is supported by (i) the highly depleted nature of the mantle peridotite and (ii) their Ni-rich sulphide assemblage. Occurrence of Pt -Fe-alloys as inclusions within BMS grains demonstrates the genetic link between the BMS and Pt -Fe-alloys and argues for formation during a single but continuous event of silicate melt percolation. While the high solubility of HSE within sulphide mattes rules out early formation of the alloys from a S-undersaturated silicate melt and subsequent scavenging in a sulphide matte, the alignment of the Pt -Fe-alloy inclusions attests that they are exsolutions formed during the sub-solidus re-equilibration of the high temperature sulphide phases. The significant difference in 187Os/188Os composition between the included Pt -Fe-alloys and their BMS host can only be accounted for by different Re/Os. This suggests that the formation of Pt -Fe-alloy inclusions within a BMS can result in the fractionation of Re from Os. A survey experiment examining the partitioning of Re and Os confirmed this observation, with the Re/Os of the Pt -Fe-alloy inclusion up to ten times higher than the co-existing BMS. This fractionation implies that, when Re is present in the sulphide melt, the TRD ages of BMS containing alloy inclusions do not date the loss of Re due to partial melting, but rather its fractionation into the Pt -Fe-alloys. As such, BMS ages should be used with caution when dating ancient partial melting events.
DS201703-0436
2017
Fonseca, R.O.C.Van Acken, D., Luguet, A., Pearson, D.G., Nowell, G.M., Fonseca, R.O.C., Nagel, T.J., Schulz, T.Mesoarchean melting and Neoarchean ro Paleoproterozoic metasomatism during the formation of the cratonic mantle keel beneath West Greenland.Geochimica et Cosmochimica Acta, Vol. 203, pp. 37-53.Europe, GreenlandCraton
DS201710-2217
2017
Fonseca, R.O.C.Bragagni, A., Luguet, A., Fonseca, R.O.C., Pearson, D.G.,Lorand, J-P., Nowell, G.M., Kjarsgaard, B.A.The geological record of base metal sulfides in the cratonic mantle: a microscale 187Os/188Os study of peridotite xenoliths from Somerset Island, Rae Craton ( Canada).Geochimica et Cosmochimia Acta, Vol. 216, pp. 264-285.Canada, Nunavut, Somerset IslandGeochronology

Abstract: We report detailed petrographic investigations along with 187Os/188Os data in Base Metal Sulfide (BMS) on four cratonic mantle xenoliths from Somerset Island (Rae Craton, Canada). The results shed light on the processes affecting the Re-Os systematics and provide time constraints on the formation and evolution of the cratonic lithospheric mantle beneath the Rae craton. When devoid of alteration, BMS grains mainly consist of pentlandite + pyrrhotite ± chalcopyrite. The relatively high BMS modal abundance of the four investigated xenoliths cannot be reconciled with the residual nature of these peridotites, but requires addition of metasomatic BMS. This is especially evident in the two peridotites with the highest bulk Pd/Ir and Pd/Pt. Metasomatic BMS likely formed during melt/fluid percolation in the Sub Continental Lithospheric Mantle (SCLM) as well as during infiltration of the host kimberlite magma, when djerfisherite crystallized around older Fe-Ni-sulfides. On the whole-rock scale, kimberlite metasomatism is visible in a subset of bulk xenoliths, which defines a Re-Os errorchron that dates the host magma emplacement. The 187Os/188Os measured in the twenty analysed BMS grains vary from 0.1084 to >0.17 and it shows no systematic variation depending on the sulfide mineralogical assemblage. The largest range in 187Os/188Os is observed in BMS grains from the two xenoliths with the highest Pd/Ir, Pd/Pt, and sulfide modal abundance. The whole-rock TRD ages of these two samples underestimate the melting age obtained from BMS, demonstrating that bulk Re-Os model ages from peridotites with clear evidence of metasomatism should be treated with caution. The TRD ages determined in BMS grains are clustered around 2.8-2.7, ~2.2 and ~1.9 Ga. The 2.8-2.7 Ga TRD ages document the main SCLM building event in the Rae craton, which is likely related to the formation of the local greenstone belts in a continental rift setting. The Paleoproterozoic TRD ages can be explained by addition of metasomatic BMS during (i) major lithospheric rifting at ~2.2 Ga and (ii) the Taltson-Thelon orogeny at ~1.9 Ga. The data suggest that even metasomatic BMS can inherit 187Os/188Os from their original mantle source. The lack of isotopic equilibration, even at the micro-scale, allowed the preservation of different populations of BMS grains with distinct 187Os/188Os, providing age information on multiple magmatic events that affected the SCLM.
DS201706-1064
2017
Fonsecca, R.O.C.Bragagni, A., Luguet, A., Fonsecca, R.O.C., Pearson, D.G., Lorand, D.G., Nowell, G.M., Kjarsgaard, B.A.The geological record of base metal sulfides in the cratonic mantle: a microscale 187Os/188/Os study of peridotite xenoliths from Somerset Island, Rae craton,( Canada).Geochimica et Cosmochimica Acta, in press available 49p.Canada, Nunavut, Somerset Islandperidotite

Abstract: We report detailed petrographic investigations along with 187Os/188Os data in Base Metal Sulfide (BMS) on four cratonic mantle xenoliths from Somerset Island (Rae Craton, Canada). The results shed light on the processes affecting the Re-Os systematics and provide time constraints on the formation and evolution of the cratonic lithospheric mantle beneath the Rae craton. When devoid of alteration, BMS grains mainly consist of pentlandite + pyrrhotite ± chalcopyrite. The relatively high BMS modal abundance of the four investigated xenoliths cannot be reconciled with the residual nature of these peridotites, but requires addition of metasomatic BMS. This is especially evident in the two peridotites with the highest bulk Pd/Ir and Pd/Pt. Metasomatic BMS likely formed during melt/fluid percolation in the Sub Continental Lithospheric Mantle (SCLM) as well as during infiltration of the host kimberlite magma, when djerfisherite crystallized around older Fe-Ni-sulfides. On the whole-rock scale, kimberlite metasomatism is visible in a subset of bulk xenoliths, which defines a Re-Os errorchron that dates the host magma emplacement. The 187Os/188Os measured in the twenty analysed BMS grains vary from 0.1084 to >0.17 and it shows no systematic variation depending on the sulfide mineralogical assemblage. The largest range in 187Os/188Os is observed in BMS grains from the two xenoliths with the highest Pd/Ir, Pd/Pt, and sulfide modal abundance. The whole-rock TRD ages of these two samples underestimate the melting age obtained from BMS, demonstrating that bulk Re-Os model ages from peridotites with clear evidence of metasomatism should be treated with caution. The TRD ages determined in BMS grains are clustered around 2.8-2.7, ~2.2 and ~1.9 Ga. The 2.8-2.7 Ga TRD ages document the main SCLM building event in the Rae craton, which is likely related to the formation of the local greenstone belts in a continental rift setting. The Paleoproterozoic TRD ages can be explained by addition of metasomatic BMS during (i) major lithospheric rifting at ~2.2 Ga and (ii) the Taltson-Thelon orogeny at ~1.9 Ga. The data suggest that even metasomatic BMS can inherit 187Os/188Os from their original mantle source. The lack of isotopic equilibration, even at the micro-scale, allowed the preservation of different populations of BMS grains with distinct 187Os/188Os, providing age information on multiple magmatic events that affected the SCLM.
DS1984-0280
1984
Font altaba, M.Font altaba, M.Some Aspects of Diamonds. *catMemoiras de la real Academia de Ciencias y artes de Barcelone, *CAT., Vol. 45, No. 23, 31pGlobalDiamond Morphology
DS1989-0364
1989
Fontan, F.Domergue, C., Fontan, F., Herail, G.Les techniques artisanales d'exploitation des gites alluviaux: analogies dans le temps et dans l'espaceChron. Rech. Min., (in French), No. 497, pp. 131-138GlobalPlacers, Mining technology -alluvials
DS1990-0411
1990
Fontan, F.Domergue, C., Fontan, F., Herail, G.Les techiques artisanales d'exploitation des gitesalluviaux: analogies dans le temps et dans l'espace. (in French)Chron. Rech. Min., (in French), No. 497, pp. 131-138GlobalAlluvials, Placer mining
DS1993-0885
1993
Fontan, F.Laval, M., Kosakevitch, A., Fontan, F.Behaviour of rare earth elements (REE) in lateritic profile, example of Mabounie GabonRare earth Minerals: chemistry, origin and ore deposits, International Geological Correlation Programme (IGCP) Project, p. 66. abstractGlobalCarbonatite, Weathering
DS200412-0427
2004
Fontan, F.De Toledo, M.C.M., Lenharo, S.L.R., Ferrari, V.C., Fontan, F., Parseval, P.De, Leroy, G.The compositional evolution of apatite in the weathering profile of the Catalao 1 alkaline carbonatitic complex, Goias, Brazil.Canadian Mineralogist, Vol. 42, 4, August, pp. 1139-1158.South America, Brazil, GoiasCarbonatite, geomorphology
DS200612-1342
2006
FontanaSparks, R.S.J., Baker, Brooker, Brown, Field, Fontana, Gernon, Kavanagh, Shumacher, Stripp, Walter, Walters, White, WindsorDynamical constraints on kimberlite volcanism,Emplacement Workshop held September, 5p. abstractGlobalMagmatism, water, stages
DS200912-0247
2009
Fontana, G.Gernon, T.M., Fontana, G., Field, M., Sparks, R.S.J., Brown, R.J., Niocaill, C.M.Pyroclastic flow deposits from a kimberlite eruption: the Orapa south crater, Botswana.Lithos, In press available 13p.Africa, BotswanaDeposit - Orapa
DS201112-0331
2011
Fontana, G.Fontana, G., Niocaill, C.M., Brown, R.J., Sparks, R.S.J., Field, M.Emplacement temperatures of pyroclastic and volcaniclastic deposits in kimberlite pipes in southern Africa.Bulletin Volcanology, In press available, 21p.Africa, South Africa, BotswanaPaleomagnetism
DS201212-0091
2012
Fontana, G.Brown, R.J., Buisman, M.I., Fontana, G., Field, M., Mac Niocaill, C., Sparks, R.S.J., Stuart, F.M.Eruption of kimberlite magmas: physical volcanology, geomorphology and age of the youngest kimberlitic volcanoes known on Earth ( the Upper Pleistocene/Holocene Igwisi Hills volcanoes, Tanzania).Bulletin Volcanology, in press availableAfrica, TanzaniaDeposit - Igwisi
DS201212-0092
2012
Fontana, G.Brown, R.J., Manya, S., Buisman, I., Fontana, G., Field, M., MacNiocaill, C., Sparks, R.S.J., Stuart, F.M.Eruption of kimberlite magmas: physical volcanology, geomrphology and age of the youngest kimberlitic volcanoes known on Earth ( the Upper Pleistocene-Holocene Igwisi Hills, volcanoes, Tanzania.Bulletin of Volcanology, Vol. 74, 7, pp. 1621-1643.Africa, TanzaniaIgwisi Hills
DS201212-0093
2012
Fontana, G.Brown, R.J., Manya, S., Buisman, I., Sparks, R.S.J., Field, M., Stuart, F.M., Fontana, G.Physical volcanology, geomorphology, and cosmogenic 3HE dating of the youngest kimberlite volcanoes on Earth ( The Holocene Igwisi Hills, Volcanoes, Tanzania.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractAfrica, TanzaniaIgwisi Hills - geochronology
DS200912-0224
2009
Fontana, G.P.Fontana, G.P.,MacNiocaill, C., Brown, R.J., Sparks, S.R., Field, M., Gernon, T.M.Emplacement temperatures of pyroclastic and colcaniclastic deposits in kimberlite pipes in southern Africa: new constraints from paleomagnetic measurementsGAC/MAC/AGU Meeting held May 23-27 Toronto, Abstract onlyAfrica, Botswana, South AfricaDeposit - AK1, Orapa, K1, K2 Venetia
DS201112-0211
2010
Fontanella, G.Costa, V.S., Figueirdo, B.R., Weska, R.K., Fontanella, G.Determinacao do conteudo de elementos tracos em solo do kimberlito Batovi 6, provincia de Paranatinga, MT.5th Brasilian Symposium on Diamond Geology, Nov. 6-12, abstract p. 76-78.South America, Brazil, Mato GrossoOverview of area
DS201112-0332
2011
FontannaFontannaEmplacement temperatures of pyroclastic and volcaniclastic deposits in kimberlite pipes in BotswanaIUGG Held July 6, AbstractAfrica, BotswanaAK 1, BK9, DK2
DS2002-0390
2002
Fontbote, L.Dold, B., Fontbote, L.Element cycling and secondary mineralogy in porphyry copper tailings as a function of climate, mineralogyJournal of Geochemical Exploration, Vol.74,1-3,pp.3-55.ChileCopper - mining, primary mineralogy, mineral processing, Deposit - la Andina, El Teniente, El Salvador
DS201712-2674
2017
Fontbote, L.Arndt, N.T., Fontbote, L., Hedenquist, J.W., Kesler, S.E., Thompson, J. F.H., Wood, D.G.Future Global and Mineral Resources.geochemicalperspectives.org, Vol. 6, 1, April, 187p. Pdf 28 MBGlobalgeochemistry

Abstract: Some scientists and journalists, and many members of the general public, have been led to believe that the world is rapidly running out of the metals on which our modern society is based. Advocates of the peak metal concept have predicted for many decades that increasing consumption will soon lead to exhaustion of mineral resources. Yet, despite ever-increasing production and consumption, supplies of minerals have continued to meet the needs of industry and society, and lifetimes of reserves remain similar to what they were 30-40 years ago. In this volume, we discuss the reasons for this apparent paradox using our broad experience and expertise on both academic and industrial sides of the minerals sector. Many misconceptions arise from flawed estimates of the size of global mineral resources which stem from a lack of understanding of the critical difference between reserves and resources. Some authors use quoted reserves – the amount of metal proven to exist and to be economic for mining at present – when predicting imminent shortages. Resources – the amount that may be accessible in the upper few kilometres of the crust – are far larger.Over the last 150 years, improved technologies, economies of scale and increased efficiency have combined to reduce costs hence allowing lower-grade ore to be mined economically. The net result is that the long-term inflation-adjusted price of most metals has decreased more or less in parallel with increasing production, a second apparent paradox that frequently is not well understood. Using copper as the principal example and other metals as appropriate, we summarise the latest research on ore deposits and the activities of the minerals industry. Following a description of the numerous geological processes that form ore deposits, we outline the scientific methods used by the minerals industry to explore for new deposits. We also discuss how resources are mined and how minerals are processed, as well as recent efforts to reduce related environmental impacts. Economic and societal factors influence supply, and these are as important as the actual presence of a resource. Finally, we discuss the critical roles that geoscientists will play in assuring continued supplies of minerals. These include the development of new concepts and techniques that will assist the discovery, mining, processing, remediation, and management of mineral resources. It is essential that researchers help to educate the general public about the need for continued exploration to find new resources to meet growth in world living standards. We demonstrate that global resources of copper, and probably of most other metals, are much larger than most currently available estimates, especially if increasing efficiencies and higher prices allow lower-grade ores to be mined. These observations indicate that supplies of important mineral commodities will remain adequate for the foreseeable future.
DS2001-0891
2001
FonteillesPascal, M.L., Fonteilles, Verkaeren, Piret, MarinceaThe melilite bearing high temperature skarns of the Apuseni Mountains, Carpathians, Romania.Canadian Mineralogist, Vol. 39, No. 5, Oct. pp. 1405-34.RomaniaMelilite
DS1860-0367
1881
Fontenay, E.Jannettaz, E., Fontenay, E., Vanderheym, E., Coutance, A.Diamant et Pierres Precieuses. Cristall. Descript. Emplois, evaluation.Paris:, 580P. SECOND EDITION.GlobalGemology
DS200612-0147
2006
Fontes, S.Bologna, M., Padilha, A.L., Vitorello, Fontes, S.Tectonic insight into a pericratonic subcrustal lithosphere affected by anorogenic Cretaceous magmatism in Brazil inferred from long period magnetotellurices.Earth and Planetary Science Letters, Vol. 241, 3-4, pp. 603-616.South America, BrazilTectonics
DS1997-0367
1997
Foord, E.E.Gaines, R.V., Skinner, H.C., Foord, E.E., Mason, B.Dana's new mineralogy. Eigth editionJ. Wiley, approx. $ 300.00 United StatesGlobalBook - ad, Mineralogy
DS1860-0010
1862
Foord, G.Foord, G.On the Occurrence of the Diamond and Chlorobromide of Silver Amongst the Ovens gold Ores of Australia.Chem. News, Vol. 6, P. 14.Australia, VictoriaDiamond Occurrence
DS1993-0449
1993
Foose, M.P.Foose, M.P.Digital metallogenic dat a set for North an South AmericaUnited States Geological Survey (USGS) Open File, No. 93-0328, $ 10.00GlobalMetallogeny, Maps -digital data
DS1993-0450
1993
Foose, M.P.Foose, M.P., Bryant, K.Annotated bibliography of metallogenic maps ( 1960-1987)United States Geological Survey (USGS) Open File, No. 93-0208 A, B, paper copy $ 14.00 disc $ 10.00United StatesMap -bibliography, Metallogenic maps
DS1860-0550
1887
Foote, A.E.Foote, A.E.Gems and Ornamental Stones of the USANature., Vol. 37, Nov. 17TH. PP. 68-69.United StatesDiamond Occurrence
DS1860-0698
1891
Foote, A.E.Foote, A.E.A New Locality for Meteoritic Iron with a Preliminary Notice of the Discovery of Diamonds in the Iron.American Journal of Science SER. 3, Vol. 42, PP. 413-417.United States, Arizona, Colorado PlateauDiamond Occurrence
DS1860-0433
1884
Foote, G.B.Foote, G.B.The Mason DiamondLetter To G.f. Kunz, APRIL 18TH.United States, Montana, Canada, AlbertaDiamonds notable
DS1860-0263
1876
Foote, R.B.Foote, R.B.The Geological Features of the South Mahratta Country and Adjacent Districts.India Geological Survey Memoir., Vol. 12, PT. 1, PP. 143-144.India, Andhra PradeshRegional Geology
DS1860-0464
1885
Foote, R.B.Foote, R.B.Singareni Coal Field to the Khistna. Part Iii, the River Alluvia.India Geological Survey Records, Vol. 18, PT. 1, PP. 23-25India, Andhra PradeshProspecting, Alluvial Placers
DS1860-0505
1886
Foote, R.B.Foote, R.B.The Tuff Agglomerate at WajrakarurIndia Geological Survey Records, Vol. 19, PT. 2, PP. 109-110.India, Andhra PradeshPetrography
DS1860-0506
1886
Foote, R.B.Foote, R.B.Notes on the Geology of Parts of Bellary and Anantapur Districts.India Geological Survey Records, Vol. 19, PT. 2, PP. 97-109.India, Andhra PradeshRegional Geology
DS1860-0629
1889
Foote, R.B.Foote, R.B.Notes on the Wajrakarur Diamonds and on M. Chaper's Alleged discovery of Diamonds in Pegmatite Near that Place.India Geological Survey Records, Vol. 22, PP. 39-49.India, Andhra Pradesh Diamond Occurrences
DS200612-0132
2005
Foran, G.J.Berry, A.J., Hermann, J., O'Neill, H.S.C., Foran, G.J.Fingerprinting the water site in mantle olivine.Geology, Vol. 33, 11, Nov., pp. 869-872.MantleSpectroscopy, anhydrous minerals
DS201012-0050
2010
Foran, G.J.Berry, A.J., Yaxley, G.M., Woodland, A.B., Foran, G.J.A XANES calibration for determining the oxidation state of iron in mantle garnet.Chemical Geology, Vol. 278, 1-2, Nov. pp. 31-37.TechnologyGarnet mineralogy
DS200912-0225
2009
ForbesForbesDe Beers plan to stay shiny.Forbes.com, April 9, 1/4p.GlobalNews item - De Beers
DS200912-0226
2009
ForbesForbesRussia stockpiles diamonds.Forbes.com, July 8, 1p.RussiaNews item - economics
DS202011-2041
2013
Forbes, C.Henderson, B., Collins, A.S., Payne, J., Forbes, C., Saha, D.Geological and geochemistry constraining India in Columbia: the age, isotopic provenance and geochemistry of the protoliths of the Ongole Domain, southern eastern Ghats, India. *** NOTE DATEGondwana Research, in press available. 19p. PdfIndiaNuna

Abstract: The Ongole Domain in the southern Eastern Ghats Belt of India formed during the final stages of Columbia amalgamation at ca. 1600 Ma. Yet very little is known about the protolith ages, tectonic evolution or geographic affinity of the region. We present new detrital and igneous U-Pb-Hf zircon data and in-situ monazite data to further understand the tectonic evolution of this Columbia-forming orogen. Detrital zircon patterns from the metasedimentary rocks are dominated by major populations of Palaeoproterozoic grains (ca. 2460, 2320, 2260, 2200-2100, 2080-2010, 1980-1920, 1850 and 1750 Ma), and minor Archaean grains (ca. 2850, 2740, 2600 and 2550 Ma). Combined U-Pb ages and Lu-Hf zircon isotopic data suggest that the sedimentary protoliths were not sourced from the adjacent Dharwar Craton. Instead they were likely derived from East Antarctica, possibly the same source as parts of Proterozoic Australia. Magmatism occurred episodically between 1.64 and 1.57 Ga in the Ongole Domain, forming felsic orthopyroxene-bearing granitoids. Isotopically, the granitoids are evolved, producing eHf values between - 2 and - 12. The magmatism is interpreted to have been derived from the reworking of Archaean crust with only a minor juvenile input. Metamorphism between 1.68 and 1.60 Ga resulted in the partial to complete resetting of detrital zircon grains, as well as the growth of new metamorphic zircon at 1.67 and 1.63 Ga. In-situ monazite geochronology indicates metamorphism occurred between 1.68 and 1.59 Ga. The Ongole Domain is interpreted to represent part of an exotic terrane, which was transferred to proto-India in the late Palaeoproterozoic as part of a linear accretionary orogenic belt that may also have included south-west Baltica and south-eastern Laurentia. Given the isotopic, geological and geochemical similarities, the proposed exotic terrane is interpreted to be an extension of the Napier Complex, Antarctica, and may also have been connected to Proterozoic Australia (North Australian Craton and Gawler Craton).
DS1975-1023
1979
Forbes, M.D.Forbes, M.D. , Houston Oil and Minerals Australia Inc.A to P 2057m to 2060m, Final ReportQueensland Open File., No. GSQ CR 7391, 12P. UNPUBL.Australia, QueenslandDetrital Minerals, Stream Sediment Sampling, Geochemistry
DS1981-0160
1981
Forbes, M.D.Forbes, M.D. , Houston Oil and Minerals Australia Inc.A to P 2556m- Cawana Lake, Relinquishment ReportQueensland Open File., No. GSQ CR 9017, 13P. UNPUBL.Australia, QueenslandPlacer Deposits, Prospecting
DS201808-1763
2018
Forbes, N.Li, Z., Fedortchouk, Y., Fulop, A., Chinn, I.L., Forbes, N.Positively oriented trigons - a unique resorption feature of diamonds from Snap Lake kimberlite dyke, Canada.minsocam.org/ MSA/AMMin/ special-collections, doi.org/10.2138/am-2018-6496. 48p. Canada, Northwest Territoriesdeposit - Snap Lake
DS201811-2590
2018
Forbes, N.Li, Z., Fedortchouk, Y., Fulop, A., Chinn, I.L., Forbes, N.Positively oriented trigons on diamonds from the Snap Lake kimberlite dike, Canada: implications for fluids and kimberlite cooling rates.American Mineralogist, Vol. 103, pp. 1634-1648.Canada, Northwest Territoriesdeposit - Snap Lake

Abstract: The role of fluid(s) in the formation of different lithological facies of kimberlites is still poorly understood. The uncertainty in the composition of kimberlite melts hampers understanding the composition of volatiles, the depth of exsolution, and the effect on magma ascent and fragmentation. Recent estimates of H2O and CO2 solubility in kimberlite-like magmas suggest very shallow exsolution of fluid, while many features of kimberlites indicate the presence of significant fluid fraction at depth. Deep magmatic fluid produces negative trigonal etch pits on natural diamonds, the characteristics of which depend on the temperature and composition of the fluid. Positively oriented trigonal etch pits are very rare on natural diamonds and are likely a feature of resorption events unique to only some kimberlite magmas. Here we present the first systematic study of positively oriented trigonal etch pits on natural diamonds from Snap Lake kimberlite dike, Northwest Territories, Canada. The study used 91 micro-diamonds selected from a population of 251 diamonds representative of all six kimberlite litho-facies identified in the Snap Lake dike. We established that unlike the majority of diamonds from kimberlite pipes in the Northwest Territories, every studied Snap Lake diamond shows positively oriented trigons. These trigons cover the whole diamond surface starting from the {111} faces and continuing over the resorbed edges. They overprint negatively oriented trigons and modify them into hexagons. Atomic force microscopy obtained detailed geometry of 154 positive trigons on 14 diamonds. Three distinct trigon morphologies dependent on the type of the crystal lattice defect were recognized. The point-bottomed shape and positive correlation between the depth and diameter of the individual pits suggest a high CO2 content in the fluid. Comparison with the existing experimental data on positive trigons implies resorption at low-pressure conditions in the 800-1000 °C temperature range by trapped magmatic fluid after the dike emplacement. The intensity of this late resorption event (and the size of the positive trigons) increases from the dike contact with the country rock into the interior of the dike. Such a late resorption event is absent in the majority of kimberlites, which form pipes, and might be a specific feature of hypabyssal kimberlite bodies (dikes). The absence of positive trigons on diamonds from the majority of kimberlites suggests very quick magma cooling below ~800 °C after the pipe emplacement, precluding the development of any late resorption features. Our study shows that for kimberlitic magmas, for which mineral chemistry is unable to provide a robust record of magmatic fluid, morphological details of dissolution features on the surface of diamond and other mantle-derived minerals can serve as a fluid proxy. Better constraints of the pressure, temperature, and oxygen fugacity of the reversal in the trigon orientation on diamond may help to reconstruct the emplacement path of geologically diverse kimberlite bodies.
DS1985-0195
1985
Forbes, R.B.Forbes, R.B.Prospecting for Diamonds in AlaskaAlaska Mins And Geology, Vol. 34, No. 2, P. 7.United States, AlaskaDiamond Occurrence
DS1986-0250
1986
Forbes, R.B.Forbes, R.B., Kline, J.T., Clough, A.H.A preliminary evaluation of alluvial diamond discoveries in the placer gravels of Crooked Creek, Circle district, AlaskaAlaska Open File, preprint, 27pAlaskaEconomics, Placers
DS1987-0219
1987
Forbes, R.B.Forbes, R.B., Kline, J.T., clough, A.H.A preliminary evaluation of alluvial diamond discoveries in placer gravelsof Crooked Creek, Circle district, AlaskaAlaska Div. Geol. and Geophys, . Reports of Investigation, No. RI 87-1, 26pAlluvials, Placers
DS200812-0364
2008
Forbes.comForbes.comDiamond mining resurges in Latin America.Forbes.com, Sept. 24, 1p.South America, Brazil, ParaguayNews item - LAT
DS1975-0509
1977
Force, E.R.Force, E.R., Berge, J.B.Geological Map of the Sanokole Quadrangle, LiberiaUnited States Geological Survey (USGS) MAP, I-774-D.GlobalBlank
DS1981-0161
1981
Force, E.R.Force, E.R.Geology of Nimba County, Liberia #1Proj. Rep. Liberia Inv. (ir) Li-86, 40P. ( United States Geological Survey (USGS))GlobalBlank
DS1983-0231
1983
Force, E.R.Force, E.R.Geology of Nimba County, Liberia #2United States Geological Survey (USGS) Bulletin., No. 1540, 27P.GlobalGeology, Economics, Diamond, Production, Alluvial, Genesis
DS1991-0501
1991
Force, E.R.Force, E.R.Fluvial gold placers and basin-margin rotationUnited States Geological Survey (USGS) Open File, No. 91-0306, 14p. $ 2.25GlobalPlacers, Basin model
DS1993-0188
1993
Force, E.R.Bultman, M.W., Force, E.R., Gettings, M.E., Fisher, F.S.Comments on the three step method for quantification of undiscovered mineral resourcesUnited States Geological Survey (USGS) Open File, No. 93-0023, 59p. approx. $ 9.75GlobalEconomics, Resources
DS1975-0279
1976
Forcella, F.Forcella, F., Rossi, P.M.Sferoidi Lherzolitici in Serpentini Gruppo Di Voltri)Bol. Soc. Geol. It., Vol. 95, pp. 133-46.ItalyLherzolite
DS201112-0333
2010
Ford, A.Ford, A., McCuaig, T.C.The effect of map scale on geological complexity for computer-aided exploration targeting.Ore Geology Reviews, Vol. 38, pp. 156-167.TechnologyMethodology - computing
DS1986-0194
1986
Ford, A.B.Drinkwater, J.L., Ford, A.B., Czamanske, G.K.Apatites of the Dufek intrusion; a preliminary studyAntarctic Journal of the United States, Vol. 21, No. 5, pp. 66-69AntarcticaAlkaline rocks, Dufek
DS1986-0251
1986
Ford, A.B.Ford, A.B., Kistler, R.W., White, L.D.Strontium and oxygen isotope study of the Dufek intrusionAntarctic Journal of the United States, Vol. 21, No. 5, pp. 63-65AntarcticaGeochronology, Dufek
DS1986-0327
1986
Ford, A.B.Haensel, J.M.Jr., Himmelberg, G.R., Ford, A.B.Plagioclase compositional variations in anorthosites of the lower part Of the Dufek intrusionAntarctic Journal of the United States, Vol. 21, No. 5, pp. 61-63AntarcticaDufek
DS200712-0303
2007
Ford, C.E.Fallon, T.J., Danyushevsky, L.V., Ariskin, A., Green, D.H., Ford, C.E.The application of olivine geothermometry to infer crystallization temperatures of parental liquids; implications for the temperature of MORB magmas.Chemical Geology, Vol. 241, 3-4, pp. 207-233.MantleGeothermometry
DS201812-2869
2018
Ford, D.Rayner, M.J., Jaques, A.L., Boxer, G.L., Smith, C.B., Lorenz, V., Moss, S.W., Webb, K., Ford, D.Argyle deposit: The geology of the Argyle ( AK1) diamond deposit, western Australia.Society of Economic Geology Geoscience and Exploration of the Argyle, Bunder, Diavik, and Murowa Diamond Deposits, Special Publication no. 20, pp. 89-118.Australia, western Australiadeposit - Argyle
DS1994-0533
1994
Ford, G.Ford, G., et al.Who pays for past sins? Policy issues surrounding contaminated sitere mediation in CanadaAlternatives, Regulatory Issues environment, Vol. 20, No. 4, Sept-Oct. pp. 26-47CanadaEnvironment, Legal, laws
DS201503-0173
2015
Ford, H.Selway, K., Ford, H., Kelemen, P.The seismic mid-lithosphere discontinuity.Earth and Planetary Science Letters, Vol. 414, March 15, pp. 45-57.MantleGeophysics - seismic
DS201012-0200
2010
Ford, H.A.Fischer, K.M., Ford, H.A., Abt, D.L., Rychert, C.A.The lithosphere asthenosphere boundary.Annual Review of Earth and Planetary Sciences, Vol. 38, pp. 551-575.MantleBoundary
DS201112-0334
2010
Ford, H.A.Ford, H.A., Fischer, K.M., Abt, D.L., Rychert, C.A., Elkins-Tanton, L.T.The lithosphere asthenosphere boundary and cratonic lithospheric layering beneath Australia from Sp wave imaging.Earth and Planetary Science Letters, Vol. 300, 3-4, pp. 299-310.AustraliaGeophysics - seismics
DS201412-0369
2014
Ford, H.A.Hopper, E., Ford, H.A., Fischer, K.M., Lekic, V., Fouch, M.J.The lithosphere-asthenosphere boundary and the tectonic and magmatic history of the northwestern United States.Earth and Planetary Science Letters, Vol. 402, pp. 69-81.United StatesGeophysics - seismics
DS201701-0010
2016
Ford, H.A.Ford, H.A., Long, M.D., Wirth, E.A.Mid-lithospheric discontinuities and complex anistropic layering in the mantle lithosphere beneath the Wyoming and Superior provinces.Journal of Geophysical Research, Vol. 121, 9, pp. 6675-6697.United States, CanadaGeophysics

Abstract: The observation of widespread seismic discontinuities within Archean and Proterozoic lithosphere is intriguing, as their presence may shed light on the formation and early evolution of cratons. A clear explanation for the discontinuities, which generally manifest as a sharp decrease in seismic velocity with depth, remains elusive. Recent work has suggested that midlithospheric discontinuities (MLDs) may correspond to a sharp gradient in seismic anisotropy, produced via deformation associated with craton formation. Here we test this hypothesis beneath the Archean Superior and Wyoming Provinces using anisotropic Ps receiver function (RF) analysis to characterize the relationship between MLDs and seismic anisotropy. We computed radial and transverse component RFs for 13 long-running seismic stations. Of these, six stations with particularly clear signals were analyzed using a harmonic regression technique. In agreement with previous studies, we find evidence for multiple MLDs within the cratonic lithosphere of the Wyoming and Superior Provinces. Our harmonic regression results reveal that (1) MLDs can be primarily explained by an isotropic negative velocity gradient, (2) multiple anisotropic boundaries exist within the lithospheric mantle, (3) the isotropic MLD and the anisotropic boundaries do not necessarily occur at the same depths, and (4) the depth and geometry of the anisotropic boundaries vary among stations. We infer that the MLD does not directly correspond to a change in anisotropy within the mantle lithosphere. Furthermore, our results reveal a surprising level of complexity within the cratonic lithospheric mantle, suggesting that the processes responsible for shaping surface geology produce similar structural complexity at depth.
DS1985-0196
1985
Ford, K.L.Ford, K.L., Dilabio, R.N.W., Rencz, A.N.Preliminary Results of Multidisciplinary Studies Around The recently Discovered Allan Lake Carbonatite, Algonquin Park, ontario.11th. International Geochem. Symposium Held Toronto, April 28-may, ABSTRACT VOLUME P. 70. (abstract.).Canada, OntarioCarbonatite
DS1988-0220
1988
Ford, K.L.Ford, K.L., Dilabio, R.N.W., Rencz, A.N.Geological, geophysical and geochemical studies around the Allan Lakecarbonatite, Algonquin Park,OntarioJournal of Geochemical Exploration, Vol. 30, No. 2, July pp. 99-122OntarioCarbonatite, Allan Lake
DS2001-0323
2001
Ford, K.L.Ford, K.L.Reconnaissance gamma ray spectrometry studies of the Paleoproterozoic Piling Group and adjacent Archean baseCan. Geological Survey Current Research, No. 200-E4, 21p.Northwest Territories, Nunavut, Baffin IslandSpectrometry, Archean basement
DS2001-0547
2001
Ford, K.L.Jones, A.G., Snyder, D., Ford, K.L., Spratt, J., EvansGeophysical experiments in central Baffin Island29th. Yellowknife Geoscience Forum, Nov. 21-23, abstract p. 38-9.Northwest Territories, Baffin IslandGeophysics, Trans Hudson Orogen
DS201012-0785
2010
Ford, K.L.Thomas, M.D., Ford, K.L., Keating, P.Exploration geophysics for intrusion hosted rare earth metals.International Workshop Geology of Rare Metals, held Nov9-10, Victoria BC, Open file 2010-10, extended abstract pp.59-61.Canada, Ontario, QuebecGeophysics - Alkaline and carbonatite
DS201604-0635
2016
Ford, K.L.Thomas, M.D., Ford, K.L., Keating, P.Review paper: exploration geophysics for intrusion hosted rare metals. Geophysical Prospecting, in press availableAustralia, United States, NebraskaCarbonatite, Alkaline rocks

Abstract: Igneous intrusions, notably carbonatitic-alkalic intrusions, peralkaline intrusions, and pegmatites, represent significant sources of rare-earth metals. Geophysical exploration for and of such intrusions has met with considerable success. Examples of the application of the gravity, magnetic, and radiometric methods in the search for rare metals are presented and described. Ground gravity surveys defining small positive gravity anomalies helped outline the shape and depth of the Nechalacho (formerly Lake) deposit within the Blatchford Lake alkaline complex, Northwest Territories, and of spodumene-rich mineralization associated with the Tanco deposit, Manitoba, within the hosting Tanco pegmatite. Based on density considerations, the bastnaesite-bearing main ore body within the Mountain Pass carbonatite, California, should produce a gravity high similar in amplitude to those associated with the Nechalacho and Tanco deposits. Gravity also has utility in modelling hosting carbonatite intrusions, such as the Mount Weld intrusion, Western Australia, and Elk Creek intrusion, Nebraska. The magnetic method is probably the most successful geophysical technique for locating carbonatitic-alkalic host intrusions, which are typically characterized by intense positive, circular to sub-circular, crescentic, or annular anomalies. Intrusions found by this technique include the Mount Weld carbonatite and the Misery Lake alkali complex, Quebec. Two potential carbonatitic-alkalic intrusions are proposed in the Grenville Province of Eastern Quebec, where application of an automatic technique to locate circular magnetic anomalies identified several examples. Two in particular displayed strong similarities in magnetic pattern to anomalies accompanying known carbonatitic or alkalic intrusions hosting rare-metal mineralization and are proposed to have a similar origin. Discovery of carbonatitic-alkalic hosts of rare metals has also been achieved by the radiometric method. The Thor Lake group of rare-earth metal deposits, which includes the Nechalacho deposit, were found by follow-up investigations of strong equivalent thorium and uranium peaks defined by an airborne survey. Prominent linear radiometric anomalies associated with glacial till in the Canadian Shield have provided vectors based on ice flow directions to source intrusions. The Allan Lake carbonatite in the Grenville Province of Ontario is one such intrusion found by this method. Although not discovered by its radiometric characteristics, the Strange Lake alkali intrusion on the Quebec-Labrador border is associated with prominent linear thorium and uranium anomalies extending at least 50 km down ice from the intrusion. Radiometric exploration of rare metals hosted by pegmatites is evaluated through examination of radiometric signatures of peraluminous pegmatitic granites in the area of the Tanco pegmatite.
DS201608-1443
2016
Ford, K.L.Thomas, M.D., Ford, K.L., Keating, P.Review paper: Exploration geophysics for intrusion hosted rare metals.Geophysical Prospecting, Vol. 64, 5, pp. 1275-1304.Geophysics

Abstract: Igneous intrusions, notably carbonatitic-alkalic intrusions, peralkaline intrusions, and pegmatites, represent significant sources of rare-earth metals. Geophysical exploration for and of such intrusions has met with considerable success. Examples of the application of the gravity, magnetic, and radiometric methods in the search for rare metals are presented and described. Ground gravity surveys defining small positive gravity anomalies helped outline the shape and depth of the Nechalacho (formerly Lake) deposit within the Blatchford Lake alkaline complex, Northwest Territories, and of spodumene-rich mineralization associated with the Tanco deposit, Manitoba, within the hosting Tanco pegmatite. Based on density considerations, the bastnaesite-bearing main ore body within the Mountain Pass carbonatite, California, should produce a gravity high similar in amplitude to those associated with the Nechalacho and Tanco deposits. Gravity also has utility in modelling hosting carbonatite intrusions, such as the Mount Weld intrusion, Western Australia, and Elk Creek intrusion, Nebraska. The magnetic method is probably the most successful geophysical technique for locating carbonatitic-alkalic host intrusions, which are typically characterized by intense positive, circular to sub-circular, crescentic, or annular anomalies. Intrusions found by this technique include the Mount Weld carbonatite and the Misery Lake alkali complex, Quebec. Two potential carbonatitic-alkalic intrusions are proposed in the Grenville Province of Eastern Quebec, where application of an automatic technique to locate circular magnetic anomalies identified several examples. Two in particular displayed strong similarities in magnetic pattern to anomalies accompanying known carbonatitic or alkalic intrusions hosting rare-metal mineralization and are proposed to have a similar origin. Discovery of carbonatitic-alkalic hosts of rare metals has also been achieved by the radiometric method. The Thor Lake group of rare-earth metal deposits, which includes the Nechalacho deposit, were found by follow-up investigations of strong equivalent thorium and uranium peaks defined by an airborne survey. Prominent linear radiometric anomalies associated with glacial till in the Canadian Shield have provided vectors based on ice flow directions to source intrusions. The Allan Lake carbonatite in the Grenville Province of Ontario is one such intrusion found by this method. Although not discovered by its radiometric characteristics, the Strange Lake alkali intrusion on the Quebec-Labrador border is associated with prominent linear thorium and uranium anomalies extending at least 50 km down ice from the intrusion. Radiometric exploration of rare metals hosted by pegmatites is evaluated through examination of radiometric signatures of peraluminous pegmatitic granites in the area of the Tanco pegmatite.
DS1990-1558
1990
Ford, M.Williams, E.A., Ford, M., Edwards, H.E.Discussion of a model for the development of the Irish VariscadesJournal of the Geological Society of London, Vol. 147, pt. 3, May pp. 566-571IrelandTectonics
DS1996-0195
1996
Ford, M.Burg, J.P., Ford, M.Orogeny through time #1Geological Society of London, No. 121, 272p. approx. $ 99.00 United StatesGlobalOrogeny through time, Book -ad
DS1997-0144
1997
Ford, M.Burg, J.P., Ford, M.Orogeny through time #2Geological Society of London, Publ, No. 121, 250pAustraliaBook - table of contents, Orogeny, Rheology, lithosphere
DS1986-0252
1986
Ford, M.J.Ford, M.J.Industrial minerals of the Cargill township and Martison Lake carbonatitecomplexesOntario geological survey, M.P.No. 132, pp. 325-330OntarioCarbonatite
DS201412-0997
2014
Forder, S.D.Yambissa, M.T., Bingham, P.A., Forder, S.D.Mantle conditions and geochemical environment as controls of diamond survival and grade variation in kimberlitic diamond deposits: Lunda Province NE Angola.30th. International Conference on Ore Potential of alkaline, kimberlite and carbonatite magmatism. Sept. 29-, http://alkaline2014.comAfrica, AngolaDiamond grade
DS1960-0450
1964
Foreign Service DispatchForeign Service DispatchIndia Mineral Development ProgramForeign Service Despatch, No. A 517, Dec. 1. 1P.IndiaAeromagnetic Survey
DS200512-0293
2005
Foreman, R.Foreman, R., Andersen, T.B., Wheeler, J.Eclogite facies polyphase deformation of the Drosdal eclogite, Western Gneiss Complex, Norway, and implications for exhumation.Tectonophysics, Vol. 398, 1-2, March 30, pp. 1-32.Europe, NorwayTectonics, eclogites, not specific to diamonds
DS200512-0673
2005
Forest, S.Madi, K., Forest, S., Cordier, P., Boussuge, M.Numerical study of creep in two phase aggregates with a large rheology contrast: implications for the lower mantle.Earth and Planetary Science Letters, Vol. 237, 1-2, Aug, 30, pp. 223-238.MantleSeismic anistropy
DS200712-0320
2007
Forest Gate Resources Inc.Forest Gate Resources Inc.Forest Gate and Majescor recover 83 diamonds from new kimberlite float at Portage, Quebec.Forest Gate Resources Inc., Jan. 18, 2p.Canada, QuebecNews item - press release, Majescor
DS201212-0626
2012
Forien, M.Schmidt, M.W., Forien, M., Solferino, G., Bagdassarov, N.Setting and compaction of olivine in basaltic magmas: an experimental study on the time scales of cumulate formation.Contributions to Mineralogy and Petrology, Vol. 164, 6, pp. 959-976.MantleMagmatism
DS1970-0213
1970
Forman, D.J.Wells, A.T., Forman, D.J., et al.Geology of the Amadeus Basin, Central AustraliaB.m.r. Min. Res. Bulletin., No. 100, 222P.Australia, South AustraliaKimberlite, Regional Geology, Tectonics, Kimberley
DS202009-1610
2020
Forman, S.L.Bassoo, R., Befus, K.S., Liang, P., Forman, S.L., Sharman, G.Deciphering the enigmatic origin of Guyana's diamonds.The American Mineralogist, in press available 59p. PdfSouth America, Guyanadiamond crystallography

Abstract: Diamonds have long been mined from alluvial terrace deposits within the rainforest of Guyana, South America. No primary kimberlite deposits have been discovered in Guyana, nor has there been previous studies on the mineralogy and origin of the diamonds. Paleoproterozoic terranes in Guyana are prospective to diamond occurrences because the most productive deposits are associated spatially with the eastern escarpment of the Paleoproterozoic Roraima Supergroup. Geographic proximity suggests that the diamonds are detrital grains eroding from the <1.98 Ga conglomerates, metamorphosed to zeolite and greenschist facies. The provenance and paragenesis of the alluvial diamonds are described using a suite of placer diamonds from different locations across the Guiana Shield. Guyanese diamonds are typically small, and those in our collection range from 0.3 to 2.7 mm in diameter; octahedral and dodecahedral, with lesser cubic and minor macle forms. The diamonds are further subdivided into those with abraded and non-abraded surfaces. Abraded diamonds show various colors in cathodoluminescence whereas most non-abraded diamonds appear blue. In all populations, diamonds are predominantly colorless, with lesser brown to yellow and very rare white. Diamonds are predominantly Type IaAB and preserve moderate nitrogen aggregation and total nitrogen concentrations ranging from trace to ~1971 ppm. The kinetics of nitrogen aggregation indicate mantle-derived residence temperatures of 1124 ± 100 ºC, assuming residence times of 1.3 Ga and 2.6 Ga for abraded and non-abraded diamonds respectively. The diamonds are largely sourced from the peridotitic to eclogitic lithospheric upper mantle based on both d13C values of -5.82 ± 2.45‰ (VPDB-LSVEC) and inclusion suites predominantly comprised of forsterite, enstatite, Cr-pyrope, chromite, rutile, clinopyroxene, coesite, and almandine garnet. Detrital, accessory minerals are non-kimberlitic. Detrital zircon geochronology indicates diamondiferous deposits are predominantly sourced from Paleoproterozoic rocks of 2079 ± 88 Ma.
DS1986-0006
1986
Formin, A.M.Akulshina, E.P., Betekhtina, O.A., Ivashutin, V.I., Formin, A.M.Geology of upper Paleozoic diamond bearing formations of theTunguskasynclise, methods of study.(Russian)Transactions of the Institute of Institute Geologiya i Geofizika Akademii Nauk, Vol. 646, pp. 5-19, 160-166RussiaBlank
DS1989-1351
1989
Formoso, M.L.L.Schiebe, L.F., Formoso, M.L.L., Nardi, L.V.S., Hartmann, L.A.Geochemistry of rare earth elements of alkalic rocks,carbonatites and kimberlite rocks; study of Brazilianoccurrence.(in Portugese).In: Geochemistry of rare earth elements in Brasil, Co. Pesqui Rec. Miner., pp. 37-46BrazilAlkaline rocks, Kimberlites -geochemistry
DS201112-0150
2010
Fornaciari, G.Carolino, J., Newman, J.A., Teixeira Carvalho de Newman, D., Fornaciari, G., Mendes, J.C.Minerais industriais: o casa dos diamantes sinteticos.5th Brasilian Symposium on Diamond Geology, Nov. 6-12, abstract p. 53.South America, BrazilIndustrial - synthetics
DS1988-0619
1988
FornariSebrier, M., Lavenu, A., Fornari, SoulasTectonics and uplift in Central Andes from Eocene to presentGeodynamique, Eng., Vol. 3, No. 1-2, pp. 85-106.Peru, Bolivia, ChileTectonics
DS200512-0137
2005
Fornari, M.Carlier, G., Lorand, J.P., Liegeois, J.P., Fornari, M., Soler, P., Carlotto, V., Cardenas, J.Potassic ultrapotassic mafic rocks delineate two lithospheric mantle blocks beneath southern Peruvian Altiplano.Geology, Vol. 33, 7, July, pp. 601-604.South America, PeruLamproite
DS1994-0030
1994
Forrest, A.H.Aitcheson, S.J., Forrest, A.H.Quantification of crustal contamination in open magmatic systemsJournal of Petrology, Vol. 35, No. 2, April pp. 461-488GlobalMagmatism, Crustal contamination
DS200512-0294
2004
Forrest, M.Forrest, M.Diamonds in Canada.Materials World, Vol. 12, no. 10, October pp. 36-38.CanadaOverview - brief
DS200612-0405
2006
Forrest, M.Forrest, M.Diamonds from the desert: Namibia is a major diamond producer, but until now no primary diamonds have been found. Mount Burgess discoveries.Materials World, Vol. 14, 3, March pp. 27-29.Africa, NamibiaHistory - Mount Burgess Mining
DS200612-0406
2006
Forrest, M.Forrest, M.Diamond life - exploration projects in Canada are revealing promising results for diamond mining. Ekati and Diavik and Ashton.Materials World, Vol. 14, 8, pp. 25-27.CanadaMining - brief
DS201512-1964
2015
Forrester, K.Saxon, M., Leijd, M., Forrester, K., Berg, J.Geology, mineralogy, and metallurgical processing of the Norra Karr heavy REE deposit, Sweden.Symposium on critical and strategic materials, British Columbia Geological Survey Paper 2015-3, held Nov. 13-14, pp. 97-108.Europe, SwedenRare earths

Abstract: The Norra Kärr peralkaline complex is about 300 km southwest of Stockholm in southern Sweden (Fig. 1). As the only heavy REE deposit in the European Union, Norra Kärr is signifi cant for the security of future REE, zirconium (Zr) and hafnium (Hf) supply (European Commission’s European Rare Earths Competency Network; ERECON, 2015). The project is well serviced by power and other infrastructure that will allow year-round mining and processing. A four-lane highway links Scandinavia to mainland Europe and passes with 1km of Norra Kärr. The skill-rich cities of Linköping and Jönköping, lie within daily commuting distances from Norra Kärr. A rail line that passes within 30 km of the site may be used to transport feed stocks and products. If Norra Kärr is developed, European REE users will no longer require substantial material stockpiles to deal with market uncertainties.
DS1960-0546
1965
Forristal, C.J.Forristal, C.J.The Sewa Dredge ExperimentFreetown: Diamond Exploration Co. Ltd., UNPUB.Sierra Leone, West AfricaMining, Sampling
DS200512-0434
2005
ForsbergHinze, W.J., Aiken, C., Brozena, J., Coakley, Dater, Flanagan, Forsberg, Hildenbrand, Keller, KelloggNew standards for reducing gravity data: the North American gravity database.Geophysics, Vol. 70, 4, pp. J25-J32.Canada, United StatesGeophysics - gravity
DS1993-0451
1993
Forster, A.Forster, A., Merriam, D.F., Brower, J.C.Relationship of geological and geothermal field properties: midcontinentarea, USA, an exampleMathematical Geology, Vol. 25, No. 7, pp. 937-947Midcontinent, KansasGeothermal
DS1994-0534
1994
Forster, A.Forster, A., Merriam, D.F.Geothermal field interpretation in south central Kansas for parts of the Nemaha anticline and flanking cherokee and Sedgwick basins.Basin Reesearch, Vol. 5, pp. 213-234.KansasStructure -Midcontinent, Geothermal -Precambrian
DS1997-0355
1997
Forster, A.Forster, A., Merriam, D.F.Geologic modeling and mappingPlenum Press, 348p. approx. $ 100.00GlobalBook - ad, Geologic modeling, mapping
DS1998-1394
1998
Forster, A.Springer, M., Forster, A.Heat flow density across the Central Andean subduction zoneTectonophysics, Vol. 291, No. 1-4, June 15, pp. 123-140.Andes, South AmericaSubduction
DS201804-0688
2017
Forster, B.Forster, B., Aulbach, S., Symes, C., Gerdes, A., Hofer, H.E., Chacko, T.A reconnaissance study of Ti minerals in cratonic granulite xenoliths and their potential as recorders of lower crust formation and evolution.Journal of Petrology, Vol. 58, 10, pp. 2007-2034.Canada, Northwest Territoriesdeposit - Diavik

Abstract: A comprehensive petrographic and in situ major and trace element study of rutile, ilmenite and Ti-magnetite was undertaken in six lower crustal xenoliths of metabasaltic (?underplate) and metasedimentary (subduction) origin from the Diavik kimberlites (central Slave Craton, Canada). The aims of the study were to improve our understanding of trace element incorporation into these Ti-minerals, and to use these systematics to obtain insights into lower continental crust formation and evolution. Abundant (oxy)exsolution of titanomagnetite lamellae, blocky rutile, as well as minor pleonaste and zircon in ilmenite from metabasaltic granulites are proposed to reflect cooling from magmatic or metamorphic temperatures and subsequent secular mantle cooling. This explains the large spread in Zr-in-rutile temperatures (>200°C) and may partly be responsible for the substantial heterogeneity of other trace element concentrations in rutile and ilmenite. Even after accounting for trace element heterogeneity and modal uncertainties, mass-balance calculations indicate that both Ti and Nb in lower crustal granulites are largely controlled by rutile and ilmenite. Rutile U-Pb data define discordia arrays that yield upper intercept ages broadly coincident with the 1•27 Ga giant Mackenzie dike swarm event, suggesting reheating of the lower crust above the rutile U-Pb closure temperature, whereas lower intercept ages roughly correspond to the age of Cretaceous to Eocene kimberlite magmatism. Subsequent cooling led to partial resetting and data spread along the concordia. Closer inspection reveals that inter-grain concentrations of elements that are compatible in rutile (Nb, Ta, W, U), but highly incompatible in the abundant silicate minerals (in equilibrium with melt), are heterogeneous and contrast with the more homogeneous concentrations of the transition metals (NiO, V). This may indicate that local reaction partners for diffusive homogenization of these element concentrations were absent. Nb/Ta is also highly variable at the sample scale. This may be explained by prograde growth from high-Nb/Ta mineral precursors (e.g. biotite) in the metasedimentary granulites and crystallization of the protoliths to the metabasaltic granulites from a mafic magma that had experienced fractionation of ilmenite with low Nb/Ta in a crustal magma chamber. Thus, (Fe)-Ti minerals represent high field strength element ‘islands’ in the granulite silicate matrix. The lack of homogenization and persistence of high-energy grain boundaries, such as exsolution lamellae, further indicate that the lower continental crust remained essentially dry and did not recrystallize, possibly since Neoarchaean metamorphism.
DS1995-0551
1995
Forster, D.Forster, D., Gravelle, J.Structuring foreign investments in the mining industryMining Tax Strategies, Held Feb. 1995, 25pCanadaTaxation, Economics -foreign investments
DS1989-1361
1989
Forster, I.F.Scogings, A.J., Forster, I.F.Gneissose carbonatites in the Bulletin's Run Complex, NatalSouth African Journal of Geology, Vol. 92, No. 1, March pp. 1-10South AfricaCarbonatite, Bulletin's Run
DS1860-0434
1884
Forster, J.A.Forster, J.A.Diamonds and their HistoryJournal of Microscopy Natural Science, Vol. 3, PP. 92-101.; PP. 170-175.Africa, South AfricaDiamond Genesis
DS2002-0471
2002
Forster, J.J.Forster, J.J., Bill, J.H.Comparison of the impact of the fiscal regime on gold projects in Tanzania and Burkin a Faso.Tranactions of the Institution of Mining and Metallurgy, Section B. Applied Earth, Vol. 111, pp. B195-199.Tanzania, Burkina FasoMineral law and policy
DS200412-0566
2002
Forster, J.J.Forster, J.J., Bill, J.H.Comparison of the impact of the fiscal regime on gold projects in Tanzania and Burkin a Faso.Transactions of the Institution of Mining and Metallurgy, Section B. Applied Earth Science ( incorporating Aus, Vol. 111, pp. B195-199.Africa, Tanzania, Burkina FasoMineral law and policy
DS201610-1860
2016
Forster, M.W.Forster, M.W., Prelevic, D., Schmuck, H.R., Jacob, D.E.Melting and dynamic metasomatism of mixed harzburgite + glimmerite mantle source: implications for the genesis of orogenic potassic magmas.Chemical Geology, in press available 10p.MantleUltrapotassic magmas

Abstract: Tectonically young, orogenic settings are commonly the sites of post-collisional silica-rich ultrapotassic magmas with extreme K2O-contents of up to 9 wt% and K2O/Na2O > 2. Many experimental studies investigating the generation of these melts have concentrated on melting of homogenous phlogopite bearing peridotites, whereas geochemical signatures indicate the involvement of at least two types of source rocks: ultra-depleted and K and trace elements-enriched ones. We report the results of melting experiments at 1-2 GPa of mixed glimmerite and harzburgite, in which these rock types make up two halves each capsule. Melting begins in the glimmerite, and its metasomatic effects on the harzburgite are apparent at 1100 °C even before melt pools are visible. The first melts are Na-rich, seen in zoning of olivines and as growth of clinopyroxene in the harzburgite, but change at higher degrees of melting to produce a typical lamproite-like melt with K2O > 10 wt%. A major advantage of this study is the preservation of distinct melts in different parts of the capsule, which reflect a process of dynamic metasomatism: within the harzburgite matrix, the infiltrating melt derived from melting of the glimmerite changes consistently with the distance of travel through the harzburgite, enabling quantification of the metasomatic effects as an increase in SiO2 and K2O. This results principally from assimilation of orthopyroxene, which increases the Ol/Opx ratio of the residual harzburgite. The effects of quench olivine growth are recognizable and can be quantified due to a step-change in composition at the glimmerite/harzburgite border: the large total surface area of olivine and small melt fraction mean that the amount of quench olivine is high within the harzburgite, but negligible in the almost completely molten glimmerite. Melts of the glimmerite contain up to 8-10 wt% K2O and 53 wt% SiO2, which increase to 55-56 wt% after interaction with the harzburgite. Mediterranean lamproites resemble melts of glimmerite, whereas melts that have interacted with harzburgite are more similar to less potassic, but more SiO2-rich shoshonites of the Mediterranean region.
DS201707-1323
2017
Forster, M.W.Forster, M.W., Orelevic, D., Schmuck, H.R., Buhre, S., Veter, M., Mertz-Kraus, R., Foley, S.F., Jacob, D.E.Melting and dynamic metasomatism of mixed harzburgite + glimmerite mantle source: implications for the genesis of orogenic potassic magmas.Chemical Geology, Vol. 455, pp. 182-191.Mantlemetasomatism

Abstract: Tectonically young, orogenic settings are commonly the sites of post-collisional silica-rich ultrapotassic magmas with extreme K2O-contents of up to 9 wt% and K2O/Na2O > 2. Many experimental studies investigating the generation of these melts have concentrated on melting of homogenous phlogopite bearing peridotites, whereas geochemical signatures indicate the involvement of at least two types of source rocks: ultra-depleted and K and trace elements-enriched ones. We report the results of melting experiments at 1–2 GPa of mixed glimmerite and harzburgite, in which these rock types make up two halves each capsule. Melting begins in the glimmerite, and its metasomatic effects on the harzburgite are apparent at 1100 °C even before melt pools are visible. The first melts are Na-rich, seen in zoning of olivines and as growth of clinopyroxene in the harzburgite, but change at higher degrees of melting to produce a typical lamproite-like melt with K2O > 10 wt%. A major advantage of this study is the preservation of distinct melts in different parts of the capsule, which reflect a process of dynamic metasomatism: within the harzburgite matrix, the infiltrating melt derived from melting of the glimmerite changes consistently with the distance of travel through the harzburgite, enabling quantification of the metasomatic effects as an increase in SiO2 and K2O. This results principally from assimilation of orthopyroxene, which increases the Ol/Opx ratio of the residual harzburgite. The effects of quench olivine growth are recognizable and can be quantified due to a step-change in composition at the glimmerite/harzburgite border: the large total surface area of olivine and small melt fraction mean that the amount of quench olivine is high within the harzburgite, but negligible in the almost completely molten glimmerite. Melts of the glimmerite contain up to 8–10 wt% K2O and 53 wt% SiO2, which increase to 55–56 wt% after interaction with the harzburgite. Mediterranean lamproites resemble melts of glimmerite, whereas melts that have interacted with harzburgite are more similar to less potassic, but more SiO2-rich shoshonites of the Mediterranean region.
DS201804-0689
2018
Forster, M.W.Forster, M.W., Prelevic, D., Schmuck, H.R., Buhre, S., Marschall, H.R., Mertz-Kraus, R., Jacob, D.E.Melting phologopite rich MARID: lamproites and the role of alkalis in olivine liquid Ni partioning.Chemical Geology, Vol. 476, 1, pp. 429-440.Technologylamproites

Abstract: In this study, we show how veined lithospheric mantle is involved in the genesis of ultrapotassic magmatism in cratonic settings. We conducted high pressure experiments to simulate vein + wall rock melting within the Earth's lithospheric mantle by reacting assemblages of harzburgite and phlogopite-rich hydrous mantle xenoliths. These comprised a mica-, amphibole-, rutile-, ilmenite-, diopside (MARID) assemblage at 3-5 GPa and 1325-1450 °C. Melting of the MARID assemblages results in infiltration of melt through the harzburgite, leading to its chemical alteration. At 3 and 4 GPa, melts are high in K2O (> 9 wt%) with K2O/Na2O > > 2 comparable to anorogenic lamproites. Higher pressures and temperatures (5 GPa/1450 °C) lead to increasing MgO contents of the melt and to some extent lower K2O contents (5-7 wt%) at equally high K2O/Na2O ratios. Our experiments provide insights into the role of alkalis in nickel-partitioning (DNi) between olivine and ultrapotassic melt. We observe that the high contents of Na, K, and Al are indicative of high DNi values, implying that the melt polymerization is the dominant factor influencing the olivine/melt nickel partitioning. The change of DNi as a function of melt composition results in a pressure independent, empirical geothermometer: Element oxides represent the composition of the glass (in wt%), and DNi is the liquid/olivine Ni-partitioning coefficient. We propose that this geothermometer is applicable to all natural silicate melts that crystallized olivine in a temperature interval between 1000 and 1600 °C. Application to glass-olivine pairs from calc-alkaline settings (Mexico), MORB (East Pacific Rise), and OIB (Hawaii) yielded reasonable values of 996-1199 °C, 1265 °C, and 1330 °C, respectively.
DS201905-1029
2019
Forster, M.W.Forster, M.W.Subduction zone metasomatism and its consequences for potassium rich magmatism and deep nitrogen cycling. ( mentions salty kimberlites Udachnaya)Ph.d Thesis Macquarie University, researchgate.com 250p. Pdf availableMantlelamproites

Abstract: In total, subduction zones span 40,000 km across Earth’s surface and recycle an average thickness of 500 m of sediment. During burial and heating these sediments eventually start melting at T >675 °C, following which Si-rich hydrous melts infiltrate the peridotites of the mantle wedge above the subducting slab. In this thesis, a high-pressure experimental approach is used to examine the reaction of sediments and peridotites at 2-6 GPa in subduction zones and its consequences on the generation of K-rich magmatism and on deep nitrogen cycling. All experiments are conducted in a layered arrangement, where the depleted peridotite is placed above the sediments in a 1:1 ratio. At 2-3 GPa, the reaction of melts of sediment with depleted peridotite, simulating the fore-arc of a subduction zone, leads to the formation of layered phlogopite pyroxenites and selective incorporation of major and trace elements in these metasomatic layers. Partial melting of these phlogopite pyroxenites produces melts rich in K2O (>9 wt%) with K/Na >>2 and a trace element pattern comparable to “orogenic lamproites”. At similar pressures, the reaction of hydrous mantle melts with depleted peridotites produces metasomatic layers that show K/Na ~1 and a trace element pattern that closely resembles “anorogenic lamproites”. In both cases, K-enrichment is facilitated by the crystallization of an eclogitic residue rich in Na, poor in K, and consequently with low K/Na. At 4-6 GPa, the reaction of melts of sediment with depleted peridotite is does not produce mica, instead resulting in alkali chlorides with K/Na ratios similar to saline fluid inclusions in diamonds. Besides the chlorides, magnesite also crystallises in the peridotite. Both phases are important ingredients for the generation of salty kimberlites such as Udachnaya East. The change in metasomatic style from mica- to chloride formation between 3 to 4 GPa corresponds to the depth of the mid-lithospheric discontinuity, a zone of low seismic velocities that is found intermittently beneath all continents at a depth of 80-100 km. The subduction of sediment is the main mechanism that recycles nitrogen back to Earth’s mantle. The partitioning of nitrogen between fluid and melt (DN(Fluid/Melt)) and fluid and bulk residue (melt+mica) (DN(Fluid/Bulk)) was found to increase linearly with temperature normalized to pressure. Using the new partition coefficients, the amount of N recycled to Earth’s mantle since the onset of subduction is calculated as 50 ±6 %.
DS201905-1030
2019
Forster, M.W.Forster, M.W., Prelevic, D., Buhre, S., Mertz-Kraus, R., Foley, S.F.An experimental study of the role of partial melts of sediments versus mantle melts in the sources of potassic magmatism.Journal of Asian Earth Sciences, Vol. 177, pp. 76-88.Mantlelamproite

Abstract: Potassium-rich lavas with K/Na of >2 are common in orogenic and anorogenic intraplate magmatic provinces. However, in the primitive mantle, the concentration of Na exceeds that of K by 10 times. The source of K-rich lavas thus needs to be either K-enriched or Na-depleted to account for high K/Na ratios. The geochemical and isotopic compositions of high 87Sr/86Sr post-collisional lavas show that their mantle source contains a recycled crustal component. These highly K-enriched lavas with crustal like trace element patterns are termed “orogenic lamproites” and are compositionally distinct from K-rich “anorogenic lamproites” that show lower 87Sr/86Sr and a trace element pattern that resembles that of primary mantle melts. For both groups the processes of K-enrichment within their source are uncertain and are thought to be linked to melts of sedimentary rocks for “orogenic lamproites” and low-degree melts of ultramafic mantle rocks for “anorogenic lamproites”. In both cases, metasomatism of the mantle lithosphere is the precursor to K-rich magmatism. In this study we experimentally determine the effects of mantle metasomatism by sediment- and hydrous mantle melts. The experiments simulate the interaction of refractory lithospheric mantle and metasomatizing melt in a 2-layer reaction experiment. The sediment/dunite reaction experiments lead to formation of a strongly K-enriched phlogopite-pyroxenite layer sandwiched between the two starting materials. The low temperature of the sediment/dunite reaction runs at <1000?°C simulates a fore-arc subduction environment, in which the melts of sediment are consumed during interaction with dunite as the temperature is below the solidus of the produced phlogopite-pyroxenites. The hydrous mantle melt/dunite reaction run is simulated by reacting a hydrated basanite with dunite. Since the temperature of the reaction is higher than the solidus of the resulting phlogopite-pyroxenites (1200?°C), the hydrous melt is not consumed but flows further, increasing in K2O and K/Na as it reacts with the refractory peridotite. In both cases, melts are enriched in K and K/Na increases by crystallizing a low K and low K/Na eclogitic residue. Compositions of glass and phlogopite from both types of reactions are comparable to glasses and phlogopites found within post-collisional lavas. Since the enrichment of K within the reaction zone is strongly controlled by the formation of low K/Na and low-K residues, metasomatic enrichment of the mantle lithosphere in K does not need a highly K-enriched metasomatic agent.
DS201907-1545
2019
Forster, M.W.Forster, M.W., Foley, S.F., Marschall, H.R., Alard, O., Buhre, S.Melting of sediments in the deep mantle produces saline fluid inclusions in diamonds.Science Advances, Vol. 5, 5, eaau 2620 7p.Mantlediamond inclusions

Abstract: Diamonds growing in the Earth’s mantle often trap inclusions of fluids that are highly saline in composition. These fluids are thought to emerge from deep in subduction zones and may also be involved in the generation of some of the kimberlite magmas. However, the source of these fluids and the mechanism of their transport into the mantle lithosphere are unresolved. Here, we present experimental results showing that alkali chlorides are stable solid phases in the mantle lithosphere below 110 km. These alkali chlorides are formed by the reaction of subducted marine sediments with peridotite and show identical K/Na ratios to fluid inclusions in diamond. At temperatures >1100°C and low pressures, the chlorides are unstable; here, potassium is accommodated in mica and melt. The reaction of subducted sediments with peridotite explains the occurrence of Mg carbonates and the highly saline fluids found in diamonds and in chlorine-enriched kimberlite magmas.
DS201909-2039
2019
Forster, M.W.Forster, M.W., Foley, S.F., Alard, O., Buhre, S.Partitioning of nitrogen during melting and recycling in subduction zones and the evolution of atmospheric nitrogen.Chemical Geology, in press available 31p. PdfMantlesubduction, metasomatism

Abstract: The subduction of sediment connects the surface nitrogen cycle to that of the deep Earth. To understand the evolution of nitrogen in the atmosphere, the behavior of nitrogen during the subduction and melting of subducted sediments has to be estimated. This study presents high-pressure experimental measurements of the partitioning of nitrogen during the melting of sediments at sub-arc depths. For quantitative analysis of nitrogen in minerals and glasses, we calibrated the electron probe micro-analyzer on synthetic ammonium feldspar to measure nitrogen concentrations as low as 500?µg?g-1. Nitrogen abundances in melt and mica are used together with mass balance calculations to determine DN(Mica/Melt), DN(Fluid/Mica), and DN(Fluid/Melt). Calculated partition coefficients correspond to expected values for NH4+, which behaves similarly to Rb+ due to its nearly identical size. Nitrogen partitioning between fluid and melt (DN(Fluid/Melt)) and fluid and bulk residue (melt+mica) (DN(Fluid/Bulk)) increase linearly with temperature normalized to pressure. This linear relationship can be used to calculate DN(Fluid/Melt) and DN(Fluid/Bulk) for slab melts from 800 to 1200?°C following: and [nasty equation that did not copy]. We used these partition coefficients to quantify the amount of N recycled into the mantle as 50?±?6% of today's atmospheric N. Depending on the rate of mantle N degassing we calculated 4 different scenarios for atmospheric pN2 evolution. All 4 scenarios estimate pN2 to be 8-12% higher at the beginning of the Phanerozoic. These estimates diverge towards the past due to uncertainties in the mechanism and magnitude of N degassing from the mantle. Assuming degassing of N in the past was close to modern degassing rates from MORB, pN2 was up to 40% higher at the onset of plate tectonics at 3-4?Ga. However, degassing rates were probably higher than this: assuming 10× and 20× times higher rates at the onset of plate tectonics leads to pN2 within 20% of modern values. If N degassing from the mantle is increased to 40× the modern MORB rate, pN2 in the Archean would have been 50% lower than today's, which is in accordance with observations from paleoatmospheric studies.
DS202002-0184
2019
Forster, M.W.Forster, M.W.Subduction zone metasomatism and its consequences for potassium rich magmatism and deep nitrogen recycling.Thesis Phd .Macquarie University, 250p. PdfMantlemetasomatism

Abstract: In total, subduction zones span 40,000 km across Earth’s surface and recycle an average thickness of 500 m of sediment. During burial and heating these sediments eventually start melting at T >675 °C, following which Si-rich hydrous melts infiltrate the peridotites of the mantle wedge above the subducting slab. In this thesis, a high-pressure experimental approach is used to examine the reaction of sediments and peridotites at 2-6 GPa in subduction zones and its consequences on the generation of K-rich magmatism and on deep nitrogen cycling. All experiments are conducted in a layered arrangement, where the depleted peridotite is placed above the sediments in a 1:1 ratio. At 2-3 GPa, the reaction of melts of sediment with depleted peridotite, simulating the fore-arc of a subduction zone, leads to the formation of layered phlogopite pyroxenites and selective incorporation of major and trace elements in these metasomatic layers. Partial melting of these phlogopite pyroxenites produces melts rich in K2O (>9 wt%) with K/Na >>2 and a trace element pattern comparable to “orogenic lamproites”. At similar pressures, the reaction of hydrous mantle melts with depleted peridotites produces metasomatic layers that show K/Na ~1 and a trace element pattern that closely resembles “anorogenic lamproites”. In both cases, K-enrichment is facilitated by the crystallization of an eclogitic residue rich in Na, poor in K, and consequently with low K/Na. At 4-6 GPa, the reaction of melts of sediment with depleted peridotite is does not produce mica, instead resulting in alkali chlorides with K/Na ratios similar to saline fluid inclusions in diamonds. Besides the chlorides, magnesite also crystallises in the peridotite. Both phases are important ingredients for the generation of salty kimberlites such as Udachnaya East. The change in metasomatic style from mica- to chloride formation between 3 to 4 GPa corresponds to the depth of the mid-lithospheric discontinuity, a zone of low seismic velocities that is found intermittently beneath all continents at a depth of 80-100 km. The subduction of sediment is the main mechanism that recycles nitrogen back to Earth’s mantle. The partitioning of nitrogen between fluid and melt (DN(Fluid/Melt)) and fluid and bulk residue (melt+mica) (DN(Fluid/Bulk)) was found to increase linearly with temperature normalized to pressure. Using the new partition coefficients, the amount of N recycled to Earth’s mantle since the onset of subduction is calculated as 50 ±6 %.
DS202002-0185
2020
Forster, M.W.Forster, M.W., Buhre, S., Xu, B., Prelevic, D., Mertz-Kraus, R., Foley, S.F.Two stage origin of K-enrichment in ultrapotassic magmatism simulated by melting of experimentally metasomatized mantle.MDPI Minerals, Vol. 10, 41;doe.10.3390/min10010041 21p. PdfMantlemetasomatism

Abstract: The generation of strongly potassic melts in the mantle requires the presence of phlogopite in the melting assemblage, while isotopic and trace element analyses of ultrapotassic rocks frequently indicate the involvement of subducted crustal lithologies in the source. However, phlogopite-free experiments that focus on melting of sedimentary rocks and subsequent hybridization with mantle rocks at pressures of 1-3 GPa have not successfully produced melts with K2O >5 wt%-6 wt%, while ultrapotassic igneous rocks reach up to 12 wt% K2O. Accordingly, a two-stage process that enriches K2O and increases K/Na in intermediary assemblages in the source prior to ultrapotassic magmatism seems likely. Here, we simulate this two-stage formation of ultrapotassic magmas using an experimental approach that involves re-melting of parts of an experimental product in a second experiment. In the first stage, reaction experiments containing layered sediment and dunite produced a modally metasomatized reaction zone at the border of a depleted peridotite. For the second-stage experiment, the metasomatized dunite was separated from the residue of the sedimentary rock and transferred to a smaller capsule, and melts were produced with 8 wt%-8.5 wt% K2O and K/Na of 6-7. This is the first time that extremely K-enriched ultrapotassic melts have been generated experimentally from sediments at low pressure applicable to a post-collisional setting.
DS202102-0212
2021
Forster, M.W.Otter, L.M., Forster, M.W., Belousova, E., O'Reilly, P., Nowak, D., Parlk, S., Clar, S., Foley, S.F., Jacob, D.E.GGR cutting-edge review nanoscale chemical imaging by photo-induced force microscopy: technical aspects and application to the geosciences. ( not specific to diamonds)Geostandards and Geoanalytical Research, doi:10.111/ GGR.12373. 51p. PdfGlobalspectroscopy, mineralogy

Abstract: Photo-induced force microscopy (PiFM) is a new-frontier technique that combines the advantages of atomic force microscopy with infrared spectroscopy and allows for the simultaneous acquisition of 3D topographic data with molecular chemical information at high spatial (~ 5 nm) and spectral (~ 1 cm-1) resolution at the nanoscale. This non-destructive technique is time efficient as it requires only conventional mirror-polishing and has fast mapping rates on the order of a few minutes that allow the study of dynamic processes via time series. Here, we review the method’s historical development, working principle, data acquisition, evaluation, and provide a comparison with traditional geochemical methods. We review PiFM studies in the areas of materials science, chemistry, and biology. In addition, we provide the first applications for geochemical samples including the visualisation of faint growth zonation in zircons, the identification of fluid speciation in high-pressure experimental samples, and of nanoscale organic phases in biominerals. We demonstrate that PiFM analysis is a time- and cost-efficient technique combining high-resolution surface imaging with molecular chemical information at the nanoscale and, thus, complements and expands traditional geochemical methods.
DS201912-2781
2019
Forster. M.W.Forster. M.W., Prelevic, D., Buhre, S., Mertz-Kraus, R., Foley, S.F.An experimental study of the role of partial melts of sediments versus mantle melts in the sources of potassic magmatism.Journal of Asian Earth Sciences, Vol. 177, pp. 76-88.Mantlemetasomatism

Abstract: Potassium-rich lavas with K/Na of >2 are common in orogenic and anorogenic intraplate magmatic provinces. However, in the primitive mantle, the concentration of Na exceeds that of K by 10 times. The source of K-rich lavas thus needs to be either K-enriched or Na-depleted to account for high K/Na ratios. The geochemical and isotopic compositions of high 87Sr/86Sr post-collisional lavas show that their mantle source contains a recycled crustal component. These highly K-enriched lavas with crustal like trace element patterns are termed “orogenic lamproites” and are compositionally distinct from K-rich “anorogenic lamproites” that show lower 87Sr/86Sr and a trace element pattern that resembles that of primary mantle melts. For both groups the processes of K-enrichment within their source are uncertain and are thought to be linked to melts of sedimentary rocks for “orogenic lamproites” and low-degree melts of ultramafic mantle rocks for “anorogenic lamproites”. In both cases, metasomatism of the mantle lithosphere is the precursor to K-rich magmatism. In this study we experimentally determine the effects of mantle metasomatism by sediment- and hydrous mantle melts. The experiments simulate the interaction of refractory lithospheric mantle and metasomatizing melt in a 2-layer reaction experiment. The sediment/dunite reaction experiments lead to formation of a strongly K-enriched phlogopite-pyroxenite layer sandwiched between the two starting materials. The low temperature of the sediment/dunite reaction runs at <1000?°C simulates a fore-arc subduction environment, in which the melts of sediment are consumed during interaction with dunite as the temperature is below the solidus of the produced phlogopite-pyroxenites. The hydrous mantle melt/dunite reaction run is simulated by reacting a hydrated basanite with dunite. Since the temperature of the reaction is higher than the solidus of the resulting phlogopite-pyroxenites (1200?°C), the hydrous melt is not consumed but flows further, increasing in K2O and K/Na as it reacts with the refractory peridotite. In both cases, melts are enriched in K and K/Na increases by crystallizing a low K and low K/Na eclogitic residue. Compositions of glass and phlogopite from both types of reactions are comparable to glasses and phlogopites found within post-collisional lavas. Since the enrichment of K within the reaction zone is strongly controlled by the formation of low K/Na and low-K residues, metasomatic enrichment of the mantle lithosphere in K does not need a highly K-enriched metasomatic agent.
DS1995-1648
1995
Forstner, U.Salomons, W., Forstner, U., Mader, P.Heavy metals... problems and solutionsSpringer, 270p. approx. $ 110.00GlobalBook -ad, Environment -heavy metals
DS1983-0232
1983
Forsyth, D.Forsyth, D., Morel, P., Hasegawa, H., Wetmiller, R., Adams, J.Comparative Study of the Geophysical and Geological InformatAtomic Energy of Canada Research Limited., No. TR-238, 52P.Canada, OntarioTectonics
DS1988-0221
1988
Forsyth, D.A.Forsyth, D.A., Thomas, M.D., Broome, J., Abbinett, D., Halpenny, J.Regional geophysics of the central metasedimentary beltGeological Society of America (GSA) Abstract Volume, Vol. 20, No. 5, March p. 344. abstractGlobalBlank
DS1990-0485
1990
Forsyth, D.A.Forsyth, D.A., Pilkington, M., Grieve, R.A.F., Abbinett, D.Major circular structure beneath southern Lake Huron defined from potential field dataGeology, Vol. 18, No. 8, August pp. 773-777Ontario, Great LakesGeophysics -aeromagnetics, Tectonics
DS1992-1063
1992
Forsyth, D.A.Milkereit, B., Forsyth, D.A., Green, A.G., Davidson, A., Hanmer, S.Seismic images of a Grenvillian terrane boundaryGeology, Vol. 20, No. 11, November pp. 1027-1030OntarioGeophysics -seismics, Terrane
DS1994-0535
1994
Forsyth, D.A.Forsyth, D.A., Milkereit, B., et al.Seismic images of a tectonic subdivision of the Grenville Orogen beneath lakes Ontario and Erie.Canadian Journal of Earth Sciences, Vol. 31, No. 2, Feb. pp. 229-242.OntarioLithoprobe -Grenville, Geophysics -seismics
DS1994-0536
1994
Forsyth, D.A.Forsyth, D.A., Milkereit, B., et al.Deep structure beneath Lake Ontario: crustal scale Grenville subdivisionsCanadian Journal of Earth Sciences, Vol. 31, No. 2, Feb. pp. 255-270.OntarioLithoprobe -Grenville, Geophysics -seismics
DS1994-1980
1994
Forsyth, D.A.Zelt, C.A., Forsyth, D.A.Modeling wide angle seismic dat a for crustal structure: southeastern Grenville ProvinceJournal of Geophy. Res, Vol. 99, B6, June 10, pp. 11, 687-704OntarioGeophysics - seismics, Grenville
DS1994-1981
1994
Forsyth, D.A.Zelt, C.A., Forsyth, D.A., et al.Seismic structure of the Central Metasedimentary Belt, southern GrenvilleProvince.Canadian Journal of Earth Sciences, Vol. 31, No. 2, Feb. pp. 243-254.OntarioLithoprobe -Grenville, Geophysics -seismics
DS1997-0467
1997
Forsyth, D.A.Hajnal, Z., Nemeth, B., Forsyth, D.A.Mantle involvement in lithospheric collision: seismic evidence from the Trans-Hudson Orogen, Western Canada.Geophy. Res. Letters, Vol. 24, No. 16, Au. 15, pp. 2079-82.Saskatchewan, AlbertaMantle tectonics, Lithosphere
DS1990-0181
1990
Forsyth, D.W.Bechtel, T.D., Forsyth, D.W., Sharpton, V.L., Grieve, R.A.F.Variations in effective elastic thickness of the NorthAmericanlithosphereNature, Vol. 343, No. 6259, February 15, pp. 636-638MidcontinentGeophysics, Bouguer gravity
DS1993-0127
1993
Forsyth, D.W.Blackman, D.K., Orcutt, J.A., Forsyth, D.W., Kendall, J-M.Seismic anisotropy in the mantle beneath an oceanic spreading centreNature, Vol. 366, December 16, pp. 675-677MantleGeophysics -seismics, Mid ocean ridge
DS2003-0806
2003
Forsyth, D.W.Li, A., Forsyth, D.W., Fischer, K.M.Shear velocity structure and azimuthal anisotropy beneath eastern North America fromJournal of Geophysical Research, Vol. 108, B8, 2362 Aug. 2, 10.1029/2002jb002259United StatesGeophysics - seismics
DS2003-1464
2003
Forsyth, D.W.Weeraratne, D.S., Forsyth, D.W., Fischer, K.M., Nyblade, A.A.Evidence for an upper mantle plume beneath the Tanzanian craton from Rayleigh waveJournal of Geophysical Research, Vol. 108, B9, Sept. 16, 10.1029/2002JB002273TanzaniaGeophysics - seismic, tomography, craton
DS200412-1124
2003
Forsyth, D.W.Li, A., Forsyth, D.W., Fischer, K.M.Shear velocity structure and azimuthal anisotropy beneath eastern North America from Rayleigh inversion.Journal of Geophysical Research, Vol. 108, B8, 2362 Aug. 2, 10.1029/2002 jb002259United StatesGeophysics - seismics
DS200412-2095
2003
Forsyth, D.W.Weeraratne, D.S., Forsyth, D.W., Fischer, K.M., Nyblade, A.A.Evidence for an upper mantle plume beneath the Tanzanian craton from Rayleigh wave tomography.Journal of Geophysical Research, Vol. 108, B9, Sept. 16, 10.1029/2002 JB002273Africa, TanzaniaGeophysics - seismic, tomography, craton
DS200812-1294
2008
Forsyth, D.W.Yang, Y., Forsyth, D.W.Attenuation in the upper mantle beneath southern California: physical state of the lithosphere and asenthosphere.Journal of Geophysical Research, Vol. 113, B03308.United States, CaliforniaTectonics
DS1998-1401
1998
ForsytheStalder, R., Foley, S.F., Brey, G.P., Forsythe, HornFirst results from a new experimental technique to determine fluid/solidtrace element partition coeffic.Neues Jahrbuch fnr Mineralogie Abh., Vol. 172, No. 1, pp. 117-132.GlobalPetrology - experimental, Diamond aggregates
DS1991-0502
1991
Forsythe, D.A.Forsythe, D.A., Milkereit, B., Davidson, A.Seismic images of Grenville crustal structures beneath Lakes Ontario andErieGeological Society of America Annual Meeting Abstract Volume, Vol. 23, No. 5, San Diego, p. A 315OntarioStructure, Tectonics
DS1994-0537
1994
Forsythe, R.Forsythe, R., Chisholm, L.Paleomagnetic and structural constraints on rotations in the north Chilean coast rangesJournal of South American Earth Sciences, Vol. 7, No. 3-4. pp. 279-294ChileStructure, paleomagnetics, Tectonics
DS1994-1272
1994
Forsythe, R.Nelson, E., Forsythe, R., Arit, I.Ridge collision tectonics in terrane developmentJournal of South American Earth Sciences, Vol. 7, No. 3-4. pp. 271-278ChileTectonics
DS1930-0107
1932
Fort, G.S.Fort, G.S.Alfred Beit- a Study of the Man and His WorkLondon: Ivor Nicholson And Watson., 221P.South AfricaBiography, Kimberley
DS201712-2685
2017
Fortaleche, D.Fortaleche, D., Lucas, A., Muyal, J., Hsu, T., Padua, P.The Colombian emerald industry: winds of change. Gems & Gemology, Vol. 53, 3, pp. 332-358.South America, Colombiaemerald

Abstract: Colombia is synonymous with fine emerald, and production is believed to date back well over a thousand years. Over the centuries the beautiful verdant gemstone, which emerges from areas that are also a lush green, has been linked to violence and human exploitation. Nevertheless, the desire of the Colombian people to mine for this treasure and strike it rich has endured, with enough dreams coming true to drive their passion. In recent years, industry changes have accelerated, perhaps more profoundly than ever before. While government ownership and regulation, criminal activity, and violence have affected production over the years, the industry’s greatest opportunities may still be ahead. Multinational companies are investing heavily in Colombian emerald mining, which has led to modernization. The government’s position on emerald mining has also improved dramatically in this period. Calls for transparency and traceability have led to branding and a revamping of the industry’s image. The loose system of independent miners (figure 1) is seeing efforts at formalization. These landmark changes are occurring at a time when most of the country’s emerald reserves have yet to be mined. In October 2015, a joint GIA and Colombian team met at the First International Emerald Symposium in Bogotá to interview industry leaders and government officials. Many topics involving industry change were discussed at the symposium. Afterward, the team traveled to Colombia’s major mines and visited dealers and cutters in Bogotá to document the current state of the mine-to-market industry. We were also able to collect rough emerald samples for the GIA laboratory’s country-of-origin reference collection.
DS201811-2596
2015
Fortaleche, D.Ochoa, C.J.C., Herreno Daza, M.J., Fortaleche, D., Jimenez, J.F.Progress on the study of parameters related to the origin of Colombian diamonds.InColor, December pp. 88-97.South America, Colombiaemeralds
DS201012-0575
2010
Forte, A.Perry, H.K.C., Forte, A.Upper mantle thermochemical structure from seismic geodynamic flow models: constraints from the Lithoprobe initiative.Canadian Journal of Earth Sciences, Vol. 47, 4, pp. 463-484.MantleGeophysics - seismic
DS1991-0503
1991
Forte, A.M.Forte, A.M., Peltier, W.R., Dziewonski, A.M.Inferences of mantle viscosity from tectonic plate velocitiesGeophysical Research Letters, Vol. 18, No. 9, September pp. 1747-1750GlobalMantle, Geophysics -plate tectonics
DS1995-0552
1995
Forte, A.M.Forte, A.M., Dziewonski, A.M., O'Connell, R.J.Continent ocean chemical heterogeneity in the mantle based on seismictomography.Science, Vol. 268, April 21, pp. 386-388.MantleGeodynamic, Geophysics -seismics
DS1995-0553
1995
Forte, A.M.Forte, A.M.Continent-ocean chemical heterogeneity in the mantle based on seismictomographyScience, Vol. 268, No. 5209, April 21, pp. 386-388MantleGeophysics -seismics, Tomography
DS1997-0356
1997
Forte, A.M.Forte, A.M., Woodward, R.L.Seismic geodynamic constraints on three dimensional structure, vertical flow and heat transfer in mantle.Journal of Geophysical Research, Vol. 102, No. 8, Aug. 10, pp. 17981-94.MantleGeophysics - seismics, Geodynamics, tectonics
DS2000-0296
2000
Forte, A.M.Forte, A.M.Multidisciplinary analyses of deep Earth structure and dynamicsGeological Association of Canada (GAC)/Mineralogical Association of Canada (MAC) 2000 Conference, 2p. abstract.MantleGeophysics - seismics tomography, Geochemistry
DS2000-0297
2000
Forte, A.M.Forte, A.M.Inferences of global three dimensional structure in Earth's mantle from seismic and geodynamic data.Geological Association of Canada (GAC)/Mineralogical Association of Canada (MAC) 2000 Conference, 2p. abstract.MantleGeophysics - seismics tomography, Mantle heterogeneity
DS2000-0298
2000
Forte, A.M.Forte, A.M., Mitrovica, J.X.A high viscosity layer in Earth's lower mantle: implications for deep mantle flow and mixing.Geological Association of Canada (GAC)/Mineralogical Association of Canada (MAC) 2000 Conference, 2p. abstract.MantleGeophysics - seismics tomography, Core mantle boundary
DS2000-0299
2000
Forte, A.M.Forte, A.M., Perry, H.K.C.Geodynamics evidence for a chemically depleted continental tectosphereScience, Vol. 290, no, 5498, Dec. 8, pp. 1940-6.MantleGeodynamics - tectonics, Lithosphere
DS2001-0324
2001
Forte, A.M.Forte, A.M., Mitrovica, J.X.Deep mantle high viscosity flow and thermochemical structure inferred from seismic and geodynamic data.Nature, Vol. 410, Apr. 26, pp. 1049-56.MantleGeodynamics, Convective flow
DS2002-0472
2002
Forte, A.M.Forte, A.M., Mitrovica, J.X., Espesset, A.Geodynamic and seismic constraints on the thermochemical structure and dynamics of convection in the deep mantle.Philosophical Transactions, Royal Society of London Series A Mathematical, Vol.1800, pp. 2521-44.MantleGeophysics - seismic, geothermometry
DS2002-0809
2002
Forte, A.M.Karato, S., Forte, A.M.,Liebermann, R.C., Masters, G., Stixrude, L.Earth's deep interior: mineral physics and tomography from the atomic to the global scale.American Geophysical Union, Geophysical Monograph Series, 117,289p., 289p.MantleBook - geodynamics, seismic tomography, core, boundary, Discontinuities, mantle minerals, mantle structure
DS2002-1065
2002
Forte, A.M.Mitrovica, J.X., Forte, A.M.On the radial profile of mantle viscosityAmerican Geophysical Union, Geodynamics Series, Vol. 29, pp. 187-200.MantleGeophysics - seismics
DS2003-0433
2003
Forte, A.M.Gaboret, C., Forte, A.M., Montagner, J.P.The unique dynamics of the Pacific hemisphere mantle and its signature on seismicEarth and Planetary Science Letters, Vol. 208, 3-4, pp. 219-233.MantleGeophysics - seismics
DS2003-1068
2003
Forte, A.M.Perry, H.K.C., Forte, A.M., Eaton, F.W.S.Upper mantle thermochemical structure below North America from seismicGeophysical Journal International, Vol. 154, 2, pp. 279-99.MantleGeophysics - seismics, Discontinuity
DS200412-0596
2003
Forte, A.M.Gaboret, C., Forte, A.M., Montagner, J.P.The unique dynamics of the Pacific hemisphere mantle and its signature on seismic anisotropy.Earth and Planetary Science Letters, Vol. 208, 3-4, pp. 219-233.MantleGeophysics - seismics
DS200412-1339
2002
Forte, A.M.Mitrovica, J.X., Forte, A.M.On the radial profile of mantle viscosity.American Geophysical Union, Geodynamics Series, Vol. 29, pp. 187-200.MantleGeophysics - seismics
DS200412-1531
2004
Forte, A.M.Perry, H.K.C., Forte, A.M., Eaton, D.W.S.Upper mantle thermochemical structure below North America from seismic geodynamic flow models.Geophysical Journal International, Vol. 154, 2, pp. 279-299.Canada, Northwest TerritoriesGeothermometry, geophysics - seismics, discontinuity
DS200612-1118
2006
Forte, A.M.Quere, S., Forte, A.M.Influence of past and present day plate motions on spherical models of mantle convection: implications for mantle plumes and hotspots.Geophysical Journal International, Vol. 165, 3, pp. 1041-1057.MantleTectonics
DS200612-1307
2006
Forte, A.M.Simmons, N.A., Forte, A.M., Grand, S.P.Constraining mantle flow with seismic and geodynamic data: a joint approach.Earth and Planetary Science Letters, Vol. 246, 1-2, June 15, pp. 109-124.MantleGeophysics - seismics
DS200712-0755
2007
Forte, A.M.Moucha, R., Forte, A.M., Mitrovica, J.X., Daradich, A.Lateral variations in mantle rheology: implications for convection related surface observables and inferred viscosity models.Geophysical Journal International, Vol. 169, 1, pp. 113-135.MantleGeophysics - seismics
DS200712-0756
2007
Forte, A.M.Moucha, R., Forte, A.M., Mitrovica, J.X., Daradich, A.Lateral variations in mantle rheology: implications for convection related surface observables and inferred viscosity models.Geophysical Journal International, Vol. 169, 1, pp. 113-135.MantleGeophysics - seismics
DS200812-0770
2008
Forte, A.M.Moucha, R., Forte, A.M., Mitrovica, J.X., Rowley, D.B., Quere, S., Simmons, Grand, S.P.Dynamic topography and long term sea level variations: there is no such thing as a stable continental platform.Earth and Planetary Science Letters, Vol. 271, 1-4, pp. 101-108.MantleGeomorphology
DS200812-0771
2008
Forte, A.M.Moucha, R., Forte, A.M., Mitrovica, J.X., Rowley, D.B., Quere, S., Simmons, N.A., Grand, S.P.Dynamic topography and long term sea level variations: there is no such thing as a stable continental platform.Earth and Planetary Science Letters, Vol. 271, 1-4, pp. 101-108.MantleCraton
DS200812-0772
2008
Forte, A.M.Moucha, R., Forte, A.M., Rowley, D.B., Mitrovica, J.X., Simmons, N.A., Grand, S.P.Mantle convection and the recent evolution of the Colorado Plateau and the Rio Grande Rift valley.Geology, Vol. 36, 6, pp. 439-442.United States, Colorado PlateauConvection
DS201012-0206
2010
Forte, A.M.Forte, A.M., Moucha, R., Simmons, N.A., Grand, S.P., Mitrovica, J.X.Deep mantle contributions to the surface dynamics of the North American continent.Tectonophysics, Vol.481, 1-4, pp. 3-15.Canada, United StatesTectonics
DS201012-0207
2010
Forte, A.M.Forte, A.M., Quere, S., Moucha, R., Simmons, N.A., Grand, S.P., Mitrovica, J.X., Rowley, D.B.Joint seismic geodynamic mineral physical modeling of African geodynamics: a reconciliation of deep mantle convection with surface geophysical constraints.Earth and Planetary Science Letters, Vol. 295, 3-4, pp. 329-341.AfricaGeophysics - seismics
DS201212-0248
2012
Forte, A.M.Glisovic, P., Forte, A.M., Moucha, R.Time dependent convection models of mantle thermal structure constrained by seismic tomography and geodynamics: implications for mantle plume dynamics and CMB heat flow.Geophysical Journal International, Vol. 190, 2, pp. 785-815.MantleGeothermometry
DS201212-0491
2012
Forte, A.M.Morrow, E., Mitrovica, J.X., Forte, A.M., Gilisovic, P., Huybers, P.An enigma in estimates of the Earth's dynamic ellipticity.Geophysical Journal International, in press availableMantleGeodynamics
DS201212-0688
2012
Forte, A.M.Soldati, G., Boschi, L., Forte, A.M.Tomography of core mantle boundary and lowermost mantle coupled by geodynamics.Geophysical Journal International, Vol. 189, 2, pp. 730-746.MantleGeodynamics
DS1992-0474
1992
Fortescue, J.A.C.Fortescue, J.A.C.Lands cape geochemistry: retrospect and prospect -1990Applied Geochemistry, Vol. 7, No. 1, January pp. 1-54GlobalGeomorphology, geochemistry, Environmental geochemistry -review
DS1975-0510
1977
Forth, H.Forth, H.Diamonds in Canada, 1977Collection of Articles And Comments By A Gem Merchant In Tor, APPROX. 30P.Canada, Ontario, QuebecKimberlite, Diamond Distribution, Carbonatite
DS1995-0554
1995
Fortier, S.M.Fortier, S.M., et al.Determination of the magnetite water equilibrium oxygen isotope fractionation factor at 350: ion microprobe..Geochimica et Cosmochimica Acta, Vol. 59, No. 18, pp. 3871-3875GlobalHematite, Microscopy
DS1995-0780
1995
Fortier, S.M.Hegner, E., Ruddick, J.C., Fortier, S.M., Hulbert, L.neodymium, Strontium, Phosphorus, Argon, and Oxygen isotopic systematics of Sturgeon Lake kimberlite-emplacement age, alteration, source..Contributions to Mineralogy and Petrology, Vol. 120, No. 2, Jun. pp. 212-222.SaskatchewanGeochronology, Deposit -Sturgeon Lake
DS200612-0407
2005
Fortin, B.Fortin, B.Ekati Diamond Mine - Panda, Koala and Fox, can these animals be caged? Geotechnical considerations and ground support at the Ekati Diamond Mine.32ndYellowknife Geoscience Forum, p. 21 abstractCanada, Northwest TerritoriesGeotectonics
DS1989-0440
1989
Fortin, P.Fortin, P., Trescases, J.J., Melfi, A.J., Schmitt, J.M., Thiryrare earth elements (REE) accumulations in the Curtibia basin, BrasilXiii International Geochemical Exploration Symposium, Rio 89 Brazilian Geochemical, pp. 66-68. AbstractBrazilCarbonatite, Curtiba
DS2003-0838
2003
Fortov, V.E.Lomonosov, I.V., Fortov, V.E., Frolova, A.A., Khishchenko, K.V.The simulation of transformation of graphite to diamond under conditions of dynamicHigh Temperature, (Kluwer Publication), Vol. 41, 4, pp. 447-458.GlobalDiamond synthesis
DS200412-1171
2003
Fortov, V.E.Lomonosov, I.V., Fortov, V.E., Frolova, A.A., Khishchenko, K.V., Charakhchyan, A.A., Shurshalov, L.V.The simulation of transformation of graphite to diamond under conditions of dynamic compression in a conic target.High Temperature, Vol. 41, 4, pp. 447-458.TechnologyDiamond synthesis
DS1995-0555
1995
Forty First Annual MeetingForty First Annual Meeting, Institute Lake Superior GeologyProceedings VolumeInstitute on Lake Superior Geology, AbstractsOntario, Wisconsin, MinnesotaGreenstone belts, Book -Table of contents
DS200912-0867
2009
ForuieZimmermann, U., Foruie, Naidoo, Van Staden, Chemalle, Nakamura, Koyayashi, Kosler, Beukes, Tait.Unroofing the Kalahari craton: provenance dat a from neoproterozoic to Paleozoic successions.Goldschmidt Conference 2009, p. A1536 Abstract.Africa, South AfricaTectonics
DS1920-0459
1929
Foshag, W.F.Merrill, G.P., Foshag, W.F.Minerals from the Earth and Sky. Part I, the Story of Meteorites. Part Ii, Gems and Gem Minerals.New York: Smithsonian Sci. Series, 331P.GlobalKimberlite
DS1940-0207
1949
Foshag, W.F.Foshag, W.F., Switzer, G.Gem Stones; United States Bureau of Mines, 1949United States Bureau of Mines MINERALS YEARBOOK, United StatesBlank
DS1950-0024
1950
Foshag, W.F.Foshag, W.F., Jones, G.The Diamond Industry in 1949Gems And Gemology, Vol. 6, No. 11, NOVEMBER PP. 341-343.United States, Canada, GlobalEconomics, Imports, Production
DS1992-0475
1992
Fossen, H.Fossen, H., Rykkelid, E.Post collisional extension of the Caledonide orogen in Scandinavia:structural expressions and tectonic significanceGeology, Vol. 20, No. 8, August pp. 737-740ScandinaviaOrogeny, Structure
DS2002-0656
2002
Fossen, H.Harris, L.B., Koyi, H.A., Fossen, H.Mechanisms for folding of high grade rocks in extensional tectonic settingsEarth Science Reviews, Vol. 59, 1-4, Nov. pp. 163-210.GlobalUHP, Tectonics
DS201810-2376
2018
Fossen, H.Salazar-Mora, C.A., Huismans, R.S., Fossen, H., Egydio-Silva, M.The Wilson cycle and effects of tectonic structural inheritance on rifted passive margin formations.Tectonics, doi.org/10.1029/ 2018TC004962Oceanstectonics

Abstract: The parallelism between older collisional belts and younger rift systems is widely known and particularly well portrayed along the Atlantic Ocean. How tectonic inherited and new-formed shear zones control rift nucleation and the final architecture of rifted conjugate passive margins is still poorly understood. Here we present lithospheric-scale thermo-mechanical numerical models that self-consistently create extensional and contractional tectonic inheritance, where prior extension and contraction are systematically varied. Our results show that (1) initial reactivation occurs along the former lithospheric suture zones; (2) upper crustal thick-skinned basement thrusts are partially or fully reactivated depending on the amount of prior contraction and size of the orogen; (3) with a small amount of contraction, thick-skinned thrusts are efficiently reactivated in extension and provide the template for rifted margin formation; (4) with larger amounts of contraction, thick-skinned thrusts distal to the lithospheric suture zone do not reactivate in extension; and (5) reactivation of prior contractional shear zones dominates during the early stages of rifting, while during the final stage of margin formation new-formed extensional shear zones dominate. Force balance analysis predicts an inverse relation between midcrustal viscosity and the maximum offset for reactivation of weak upper crustal structures. Force balance also predicts that the degree of weakening or healing of the weak suture and the thermal thinning of the necking area control at which stage suture reactivation is deactivated and extension proceeds by mantle lithosphere thermal necking. Two rifted conjugate margins with orogenic inheritance in the North and South Atlantic are used for comparison.
DS1860-0182
1872
FossorFossorTwelve Months at the South African Diamond FieldsLondon: E. Stanford., 68P.Africa, South Africa, Cape ProvinceHistory
DS1996-0559
1996
FosterGraham, S., Lambert, D.D., Shee, S.R., Hamilton, R., FosterAlkaline ultramafic rocks as probes of lithospheric mantle enrichment events in the eastern Yilgarn craton.Australia Nat. University of Diamond Workshop July 29, 30. abstract, 1p.AustraliaCraton, Alkaline rocks, geochronology
DS1997-0307
1997
FosterEbinger, C., Djomani, Y.P., Mbede, E., Foster, DawsonRifting Archean lithosphere: the Eyasi Manyara Natron Rifts, East AfricaJournal of the Geological Society of London, Vol. 154, pp. 947-960.Tanzania, East AfricaTectonics, Geophysics - gravity anomalies
DS1997-0357
1997
Foster, A.Foster, A., Ebinger, C., Rex, D.Tectonic development of the northern Tanzanian sector of the East African rift systemJournal of Geological Society, Vol. 154, No. 4, July pp. 689-699.TanzaniaTectonics, Rifting
DS202006-0920
2020
Foster, A.Foster, A., Darbyshire, F., Schaeffer, A.Anisotropic structure of the central North American craton surrounding the Mid-continent rift: evidence form Rayleigh waves.Precambrian Research, Vol. 342, 18p. PdfUnited States, Canadageophysics - seismics
DS1970-0079
1970
Foster, B.P.Foster, B.P.Study of the Kimberlite-alnoite Dikes in Central New YorkMsc. Thesis, University Buffalo, 59P.United States, Appalachia, New YorkPetrography, Dike Descriptions, Mineralogy, Geochemistry
DS1970-0182
1970
Foster, B.P.Reitan, P.H., Szekely, J., Foster, B.P.Material Emplacement Models for Dikes Extending to the MantlEos, Vol. 51, P. 447. (abstract.).United States, Appalachia, New YorkBlank
DS1970-0511
1972
Foster, B.P.Foster, B.P., Reitan, P.H.Kimberlite Dike Emplacement in the Central Finger Lakes Region.Geological Society of America (GSA), Vol. 4, P. 17. (abstract.).United States, Kansas, Central States, WilsonBlank
DS1983-0348
1983
Foster, B.P.Kay, S.M., Snedden, W.T., Foster, B.P., Kay, R.W.Upper Mantle Crustal Fragments in the Ithaca KimberlitesJournal of GEOLOGY, Vol. 91, No. 3, PP. 277-290.United States, Appalachia, New YorkNodules, Xenoliths, Petrography
DS1986-0426
1986
Foster, B.P.Kay, S.M., Foster, B.P.Kimberlites of the Finger Lakes regionNew York State Geol. Association Field Trip Guidebook, 58th. Annual Meeting, pp. 219-238GlobalDike, Age
DS1992-0163
1992
Foster, C.T.Briggs, W., Foster, C.T.Pressure-temperature conditions of Early Proterozoic metamorphism During the Trans-Hudson Orogen as determined rocks straddling the Flin Flon-KisseynewboundaryCanadian Journal of Earth Sciences, Vol. 29, No. 11, November, pp. 2497-2507ManitobaMetamorphic terrain, Proterozoic
DS200512-0752
2004
Foster, D.Mueller, P., Foster, D., Mogk, D., Wooden, J.New insights into the Proterozoic evolution of the western margin of Laurentia and their tectonic implications.Geological Society of America Annual Meeting ABSTRACTS, Nov. 7-10, Paper 173-6, Vol. 36, 5, p. 404.United States, WyomingGeothermometry
DS200512-1150
2004
Foster, D.Vogl, J.J., Foster, D., Mueller, P., Wooden, J.L.Paleoproterozoic suturing of the Wyoming craton and Medicine Hat Block and it's influence on Phanerozoic crustal evolution.Geological Society of America Annual Meeting ABSTRACTS, Nov. 7-10, Paper 217-2, Vol. 36, 5, p. 507.United States, WyomingAccretion, magmatism
DS201502-0057
2014
Foster, D.AGifford, J.N., Mueller, P.A., Foster, D.A, Mogk, D.W.Precambrian crustal evolution in the Great Falls Tectonic Zone: insights from xenoliths from the Montana Alkali province.Journal of Geology, Vol. 122, Sept. pp. 531-548.United States, MontanaAlkalic
DS1991-0409
1991
Foster, D.A.Dumitru, T.A., Gans, P.B., Foster, D.A., Miller, E.L.Refrigeration of the western Cordilleran lithosphere during Laramide shallow angle subductionGeology, Vol. 19, No. 11, November pp. 1145-1148CordilleraSubduction, Tectonics
DS1993-0452
1993
Foster, D.A.Foster, D.A., Gleadow, A.J.W.Episodic denudation in East Africa: a legacy of intracontinentaltectonism.Geophysical Research Letters, Vol. 20, No. 21, November 5, pp. 2395-2398.East Africa, Kenya, TanzaniaTectonics, Isostacy, Thermochronology
DS1996-0461
1996
Foster, D.A.Foster, D.A., Gleadow, J.W.Structural framework and denudation history of the flanks of the Kenya and Anza Rifts, East Africa.Tectonics, Vol. 15, No. 2, Apr. pp. 258-71.Kenya, East AfricaTectonics, Rifting
DS1997-0438
1997
Foster, D.A.Gray, D.R., Foster, D.A.Orogenic concepts - application and definition: Lachlan Fold Belt, EasternAustraliaAmerican Journal of Science, Vol. 297, No. 9, Nov. 1, pp. 859-891AustraliaTectonics, Lachlan fold belt
DS1997-0439
1997
Foster, D.A.Gray, D.R., Foster, D.A., Bucher, M.Recognition and definition of orogenic events in the Lachlan Fold BeltAustralian Journal ofEarth Science, Vol. 44, No. 4, Aug. pp. 489-502AustraliaTectonics, orogeny, Lachlan Fold Belt, model
DS1997-1077
1997
Foster, D.A.Soesoo, A., Bons, P.D., Gray, D.R., Foster, D.A.Divergent double subduction: tectonics and petrologic consequencesGeology, Vol. 25, No. 8, August pp. 755-758.MantleTectonics, Subduction
DS1998-0440
1998
Foster, D.A.Foster, D.A., Ehlers, K.40Ar 39Ar thermochronology of the southern Gawler Craton - implications for East Gondwana and Rondinia.Journal of Geophysical Research, Vol. 103, No. 5, May 10, pp. 10177-94.AustraliaMesoproterozoic, Neoproterozoic, Geochronology, Gondwana
DS2000-0300
2000
Foster, D.A.Foster, D.A., Gray, D.R.Timing of orogenic events in the Lachlan Orogen (2000)Australian Journal of Earth Sciences, Vol. 47, No. 4, Aug. 1, pp. 813-22.AustraliaTectonics - orogeny
DS2002-0473
2002
Foster, D.A.Foster, D.A., Mueller, P.A., Heatherington, A., Vogl, J., Meert, J., Lewis, R.Configuration of the 2.0 - 1.6 GA accretionary margin NW of the Wyoming Province:Geological Society of America Annual Meeting Oct. 27-30, Abstract p. 559.WyomingTectonics, Gondwana
DS200512-1028
2004
Foster, D.A.Spaggiardi, C.V., Gray, D.R., Foster, D.A.Lachlan Orogen subduction accretion systematics revisited.Australia Journal of Earth Sciences, Vol. 51, 4, pp. 549-553.AustraliaSubduction - not specific to diamonds
DS200712-0321
2006
Foster, D.A.Foster, D.A., Mueller, P.A.,Mogk, D.W., Wooden, J.L., Vogl, J.J.Proterozoic evolution of the western margin of the Wyoming Craton: implications for the tectonic and magmatic evolution of the northern Rocky Mountains.Canadian Journal of Earth Sciences, Vol. 43, 10, pp. 1601-1619,United States, Wyoming, Colorado PlateauMagmatism
DS201412-0248
2015
Foster, D.A.Foster, D.A., Goscombe, B.D., Newstead, B., Mapani, B., Mueller, P.A., Gregory, L.C., Muvangua, E.U-Pb age and Lu-Hf isotopic dat a of detrital zircons from the Neoproterozoic Damara sequence: implications for Congo and Kalahari before Gondwana.Gondwana Research, Vol. 28, 1, pp. 179-190.AfricaGeochronology
DS201412-0291
2014
Foster, D.A.Gifford, J.N., Mueller, P.A., Foster, D.A., Mogk, D.W.Precambrian crustal evolution in the Great Falls Tectonic Zone: insights from xenoliths from the Montana alkali province.Journal of Geology, Vol. 122, 5, pp. 531-548.United States, MontanaAlkalic
DS201412-0601
2013
Foster, D.A.Mueller, P.A., Mogk, D.W., Henry, D.J., Wooden, J.L., Foster, D.A.The plume to plate transition: Hadean and Archean crustal evolution in the northern Wyoming province, USA.Dilek & Furnes eds. Evolution of Archean crust and early life. Springer Publication, pp. 23-54.United StatesMantle plume
DS201509-0399
2015
Foster, D.A.Hongsresawat, S., Panning, M.P., Russo, R.M., Foster, D.A., Monteiller, V., Chevrot, S.USArray shear wave splitting shows seismic anisotropy from both lithosphere and asthenosphere.Geology, Vol. 43, 8, pp. 667-670.United StatesSeismic -anisotropy

Abstract: North America provides an important test for assessing the coupling of large continents with heterogeneous Archean- to Cenozoic-aged lithospheric provinces to the mantle flow. We use the unprecedented spatial coverage of the USArray seismic network to obtain an extensive and consistent data set of shear wave splitting intensity measurements at 1436 stations. Overall, the measurements are consistent with simple shear deformation in the asthenosphere due to viscous coupling to the overriding lithosphere. The fast directions agree with the absolute plate motion direction with a mean difference of 2° with 27° standard deviation. There are, however, deviations from this simple pattern, including a band along the Rocky Mountain front, indicative of flow complication due to gradients in lithospheric thickness, and variations in amplitude through the central United States, which can be explained through varying contributions of lithospheric anisotropy. Thus, seismic anisotropy may be sourced in both the asthenosphere and lithosphere, and variations in splitting intensity are due to lithospheric anisotropy developed during deformation over long time scales.
DS201809-2027
2018
Foster, D.A.Gifford, J.N., Mueller, P.A., Foster, D.A., Mogk, D.W.Extending the realm of Archean crust in the Great Falls tectonic zone: evidence from the Little Rocky Mountains, Montana.Precambrian Research, Vol. 315, pp. 264-281.United States, Montanacraton

Abstract: Two prominent features separate the Archean Wyoming and Hearne cratons: the Paleoproterozoic Great Falls tectonic zone (GFTZ) and the Medicine Hat block (MHB), neither of which is well defined spatially because of Phanerozoic sedimentary cover. Based on limited data, the MHB is thought to be a structurally complex mix of Archean (2.6-3.1?Ga) and Proterozoic (1.75?Ga) crust, but is recognized primarily by its geophysical signature, and its influence on the geochemistry of younger igneous rocks. Similarly, the GFTZ was recognized on the basis of broad differences in geophysical patterns, isopachs of Paleozoic sedimentary sections, and lineaments; however, juvenile arc rocks in the Little Belt Mountains (LBM) and strongly overprinted Archean rocks in southwestern Montana show it to be a dominantly Paleoproterozoic feature. The Little Rocky Mountains (LRM) of Montana provide access to exposures of the northeastern-most Precambrian crust in the MHB-GFTZ region. U/Pb ages of zircons from Precambrian rocks of the LRM range from 2.4 to 3.3?Ga, with most ages between 2.6 and 2.8?Ga. Whole-rock analyses yield Sm-Nd TDM from 3.1 to 4.0?Ga and initial eNd(T) values calculated at U-Pb zircon crystallization ages range from -0.9 to -10.5, indicating significant contributions from older Archean crust. The high proportion of 2.6-2.8?Ga U/Pb ages differentiates LRM crust from arc-related Paleoproterozoic magmatic rocks exposed in the LBM to the southwest. The age and isotopic composition of the LRM gneisses are similar to crust in the northern Wyoming Province (2.8-2.9?Ga), but Paleoproterozoic K-Ar cooling ages suggest crust in the LRM experienced the Paleoproterozoic metamorphism and deformation that characterizes the GFTZ. Consequently, its history differs markedly from the adjacent Beartooth-Bighorn magmatic zone of the northern Wyoming Province, which does not record Paleoproterozoic tectonism, but has a strong correlation with the Montana metasedimentary terrane that was strongly overprinted during the Paleoproterozoic Great Falls orogeny that defines the GFTZ. The LRM, therefore, likely provides a unique, and perhaps the only, opportunity to characterize Archean crust of the MHB.
DS1989-0283
1989
Foster, D.S.Coman, S.M., Foster, D.S., Oldale, R.N.Evidence from seismic-reflection profiles of late Wisconsinian icereadvances in the Lake Michigan basinGeological Society of America (GSA) Abstract Volume, Vol. 21, No. 4, p. 7. (abstract.)MichiganGeomorphology
DS1994-0538
1994
Foster, F.J.Foster, F.J.Australian mineral sands -problems but confidenceEngineering and Mining Journal, Vol. 195, No. 1, January pp. WW 56-58, 60, 62.AustraliaAlluvials -dredging problems, Minerals sands -not specific to diamonds but useful
DS1994-0539
1994
Foster, F.J.Foster, F.J.The art of negotiation... communication, observation, concentration and persuasion are keyEngineering and Mining Journal, Vol. 195, No. 9, Sept. p. ww 33-37GlobalAgreements, Mining equipment
DS1989-1323
1989
Foster, G.A.Saari, D.S., Foster, G.A.Head to head evaluation of the Pro-cite and Sci-mate bibliographic database management systemsDatabase, Vol. 12, No. 1, February pp. 22-38. Database # 17984GlobalComputer, Program - Pro-cite/Sci-mate
DS200612-0684
2006
Foster, G.L.Kemp, A.J.S., Hawkesworth, C.J., Paterson, B.A., Foster, G.L., Woodhead, J.D., Hergt, J.M., Wormald, R.J.The case of crust mantle interaction during silicic magma genesis: the zircon testimony.Geochimica et Cosmochimica Acta, Vol. 70, 18, 1, p. 12, abstract only.MantleMagmatism
DS1995-0556
1995
Foster, J.A.Foster, J.A.Environmental management systemMining and the Environment: regulation and liability, 12pCanadaLegal, Environment
DS1991-0504
1991
Foster, J.G.Foster, J.G., Hamilton, R., Rock, N.M.S.The mineralogy, petrology and geochemistry of ultramafic lamprophyres Of the Yilgarn craton, western AustraliaProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 112-115AustraliaGeochronology, Mineralogy -cognate
DS1996-0462
1996
Foster, J.G.Foster, J.G.Coupled Rhenium- Osmium (Re-Os) isotopic and fluid dynamic constraints on the genesis of Archean komatiite Association iron nickel copper (platinum group elements (PGE)Geological Society of Australia 13th. held Feb, No. 41, abstracts p. 147AustraliaNickel, copper, geochronology, Deposit -Mount Keith, Kambalda, Perseverance
DS1996-0463
1996
Foster, J.G.Foster, J.G., Lambert, D.D., Maas, R.Rhenium- Osmium (Re-Os) isotopic evidence for genesis of Archean nickel ores from uncontaminated komatiitesNature, Vol. 382, No. 6593, Aug. 22, pp. 703-705AustraliaNickel, komatiites, Geochronology
DS201412-0249
2014
Foster, K.Foster, K., Dueker, K., Schmandt, B., Yuan, H.A sharp cratonic lithosphere-asthenosphere boundary beneath the American Midwest and its relation to mantle flow.Earth and Planetary Science Letters, Vol. 402, pp. 82-89.United States, Colorado PlateauGeophysics - seismics
DS201609-1718
2016
Foster, R.Foster, R.Mineral deposits of Africa: a compilation ( 1907-2016) 300 papers sourced from Economic Geology, SP, Monographs, Newsletter.Society of Economic Geologists, Disc Compilation, Vol. 12, Member price $ 68. USAfricaCompilation of deposits ( not specific to diamonds)
DS1989-1447
1989
Foster, R.P.Starling, A., Gilligan, J.M., Carter, A.H.C., Foster, R.P.Experimental evidence for very low solubility of rareearth elements inCO2 rich fluids at mantle conditions #2Nature, Vol.340, No. 6231, July 27, pp. 298-300GlobalRare earth, Mantle
DS1993-0453
1993
Foster, R.P.Foster, R.P., Piper, D.P.Archean lode gold deposits in Africa: crustal setting, metallogenesis andcratonizationOre Geology Reviews, Vol. 8, pp. 303-347South Africa, Tanzania, Zaire, ZimbabweGold, Deposits
DS1970-0154
1970
Foster, R.W.Murray, L.G., Joynt, R.H., O'shea, D.O.C., Foster, R.W., Kleinja.The Geological Environment of Some Diamond Deposits Off The coast of Southwest Africa.Institute of Geological Sciences Report, No. 70/13, PP. 119-142.Southwest Africa, NamibiaGeology, Geomorphology, Diamond Mining Recovery, Littoral Placers
DS1995-0557
1995
Foster, R.W.Foster, R.W.A historical review of de Beers marine (PTY) role in the development of marine diamond mining off southwest Africa.Exploration and Mining Geology, Vol. 4, No. 1, p. 85-86.NamibiaAlluvial, placers, Mining
DS1997-0854
1997
Fosterm D.A.Noble, W.P., Fosterm D.A., Gleadow, A.J.W.The Post Pan African thermal and extensional history of crystalline basement rocks in eastern TanzaniaTectonophysics, Vol. 275, No. 4, July 20, pp. 313-330TanzaniaTectonics, Geothermometry
DS1990-0885
1990
Fostiropoulos, K.Kratschmer, W., Lamb, L.D., Fostiropoulos, K., Huffman, D.R.Solid C 60: a new form of carbonNature, Vol. 347, No. 6291, September 27, pp. 354-358GlobalExperimental petrology, Carbon- Solid C 60
DS202004-0511
2020
Fosu, B.R.Fosu, B.R., Ghosh, P., Viladkar, S.G.Clumped isotope geochemistry of carbonatites in the north-western Deccan igneous province: aspects of evolution, post-depositional alteration and mineralization.Geochimica et Cosmochimica Acta, Vol. 274, pp. 118-135.Indiacarbonatite

Abstract: Carbonatites crystallise along a wide range of solidus temperatures and are commonly affected by post-magmatic textural re-equilibration and diagenesis. Further insights into the formation and modification of carbonatites are provided using carbon, oxygen and clumped isotope (?47) data of rocks from spatially associated Amba Dongar and Siriwasan alkaline complexes in the north-western Deccan igneous province, India. We derive apparent equilibrium blocking temperatures to help constrain the thermal evolution of the different rock types found within the alkaline complexes in a petrographic context. The apparent temperatures for the carbonatites are significantly low but are consistent with reports on other global carbonatites and model predictions. Rapidly cooled Oldoinyo Lengai natrocarbonatite yielded similar low temperatures, even in the absence of bulk isotopic alteration. The isotopic proxies and petrographic observations favour both isotopic exchange reactions and diagenesis in altering ?47 values in calciocarbonatites. Diagenetic reactions are however strongly favoured, as secondary calcites in nephelinites and ferrocarbonatites record much lower temperatures than in the calciocarbonatites, highlighting the effect of fluids and diagenetic reactions in 13C18O bond ordering in carbonatites. Variations in the CO isotope data reveal the coupling of fractional crystallisation and post-magmatic fluid-rock interactions on bulk rock composition. After emplacement, the resetting of clumped isotope signatures in carbonatites is facilitated by post-magmatic processes in both open and closed systems.
DS202105-0763
2021
Fosu, B.R.Fosu, B.R., Ghosh, P., Weisenberger, T.B., Spurgin, S., Viladar, S.G.A triple oxygen isotope perspective on the origin, evolution, and diagenetic alteration of carbonatites.Geochimica et Cosmochimica Acta, Vol. 299, pp. 52-68. pdfMantlecarbonatites

Abstract: Carbonatites are unique magmatic rocks that are essentially composed of carbonates, and they usually host a diverse suite of minor and accessory minerals. To provide additional insights on their petrogenesis, triple oxygen isotope analyses were carried out on carbonatites from sixteen localities worldwide in order to assess the behaviour of oxygen isotopes (mass-dependent fractionation) during their formation. The study evaluates the mineralogical differences, i.e., calcite, dolomite, ankerite, and Na-carbonates, and the mode of emplacement (intrusive or extrusive) in the mantle-derived carbonatites to further constrain the triple oxygen isotopic composition (?'17O) of the upper mantle. ?'17O values in the intrusive calcite carbonatites vary between -0.003 to -0.088‰ (n?=?20) and -0.024 to -0.085‰ (n?=?5) in the dolomite varieties. We surmise that the magnitude of isotopic fractionation in the different carbonate phases during their formation is similar and thus, the observed variations are independent of mineralogy and may be related to alteration in the rocks. Taking the samples that classify as primary igneous carbonatites altogether, the average ?'17O value of the mantle is estimated as -0.047?±?0.027‰ (1SD, n?=?18) which overlaps those of other mantle rocks, minerals and xenoliths, indicating that the mantle has a relatively homogenous oxygen isotope composition. Two ankerite carbonatites have identical ?'17O values as calcite but a few samples, together with pyroclastic tuffs have significantly lower ?'17O values (-0.108 to -0.161‰). This deviation from mantle ?'17O signature suggests diagenetic alteration (dissolution and recrystallisation) and mixing of carbonate sources (juvenile and secondary carbonates) which is consistent with the high d18O and clumped isotope (?47) values recorded in the pyroclastic and ankeritic rocks. In summary, diagenetic alteration driven by fluid-rock interaction at low temperatures, sub-solidus re-equilibration with magmatic waters, and the incorporation of secondary carbonates altogether facilitate the alteration of original isotopic compositions of carbonatites, obliterating their primary mantle signatures.
DS2001-1182
2001
FouchVan der Lee, S., Van De Car, Fouch, JamesCombined sensitivity to the Kaapvaal tectosphere of regional and teleseismic surface and S Waves.Slave-Kaapvaal Workshop, Sept. Ottawa, 3p. abstractSouth AfricaGeophysics - seismics, Lithosphere
DS2001-0528
2001
Fouch, D.J.James, D.E., Fouch, D.J., Van De Car, M.J., VanderleeTectosphere structure beneath southern AfricaGeophysical Research Letters, Vol. 28, No. 13, July 1, pp. 2485-88.South AfricaTectonics
DS2000-0440
2000
Fouch, M.James, D., Fouch, M., Vandecar, J.Seismic studies of lithsopheric structure beneath southern Africa: implications for formation cratons...Geological Society of America (GSA) Abstracts, Vol. 32, No. 7, p.A-163.South AfricaCraton - evolution Kaapvaal, Geophysics - seismics
DS2003-1267
2003
Fouch, M.Shirey, S.B., Harris, J.W., Richardson, S.H.,Fouch, M., James, D.E., CartignyRegional patterns in the paragenesis and age of inclusions in diamond, diamondLithos, Vol. 71, 2-4, pp. 243-258.South AfricaDiamond inclusions
DS200412-1806
2003
Fouch, M.Shirey, S.B., Harris, J.W., Richardson, S.H.,Fouch, M., James, D.E., Cartigny, P.,Deines, P., Vijoen, F.Regional patterns in the paragenesis and age of inclusions in diamond, diamond composition and the lithospheric seismic structurLithos, Vol. 71, 2-4, pp. 243-258.Africa, South AfricaDiamond inclusions
DS2001-0325
2001
Fouch, M.J.Fouch, M.J., James, Silver, VanDecar, Van der LeeImaging broad ranges in structural variations beneath the Kaapvaal and Zimbabwe Cratons, southern Africa.Slave-Kaapvaal Workshop, Sept. Ottawa, 5p. abstractSouth Africa, ZimbabweGeophysics - seismics, Tomography - Kimberley array
DS2002-0761
2002
Fouch, M.J.James, D.E., Fouch, M.J.Formation and evolution of Archean cratons: insights from southern AfricaGeological Society of London Special Publication, No. 199, pp. 1-26.South AfricaTectonics
DS200412-0567
2004
Fouch, M.J.Fouch, M.J., James, D.E., Van De Car, J.C., Van Der Lee, S.Mantle seismic structure beneath the Kaapvaal and Zimbabwe Cratons.South African Journal of Geology, Vol. 107, 1/2, pp. 33-44.Africa, South Africa, ZimbabweGeophysics - seismics, tectonics, magmatism
DS200412-0568
2004
Fouch, M.J.Fouch, M.J., Silver, P.G., Lee, J.N.Small scale variations in seismic anisotropy near Kimberley, South Africa.Geophysical Journal International, Vol. 157, 2, pp. 764-774.Africa, South AfricaGeophysics - seismics
DS200412-1824
2004
Fouch, M.J.Silver, P.G., Fouch, M.J., Gao, S.S., Schmitz, M.Seismic anisotropy, mantle fabric, and the magmatic evolution of Precambrian southern Africa.South African Journal of Geology, Vol. 107, 1/2, pp. 45-58.Africa, South AfricaGeophysics - seismics, tectonics, magmatism
DS200612-0408
2006
Fouch, M.J.Fouch, M.J., Rondenay, S.Seismic anisotropy beneath stable continental interiors.Physics of the Earth and Planetary Interiors, In press - availableMantleGeophysics - seismics, plate tectonics
DS200612-0767
2006
Fouch, M.J.Lassak, T.M., Fouch, M.J., Hall, C.E., Kaminski, E.Seismic characterization of mantle flow in subduction systems: can we resolve a hydrated mantle wedge?Earth and Planetary Science Letters, Vol. 243, 3-4, March 30, pp. 632-649.MantleSubduction, water
DS200612-1572
2006
Fouch, M.J.Yoburn, J.B., Fouch, M.J., Arrowsmith, J.R., Keller, G.R.A new GIS driven geophysical database for the southwestern United States.In: Sinha, A.K. Geoinformatics: data to knowledge, GSA Special Paper, 397, 397,pp.249-268.United StatesGeophysics - data
DS201112-0603
2011
Fouch, M.J.Lin, F-C., Ritzwoller, M.H., Yang, Y., Moschetti, M.P., Fouch, M.J.Complex and variable crustal and uppermost mantle seismic anisotropy in the western United States.Nature Geoscience, Vol. 4, pp. 55-71.MantleTomography
DS201412-0369
2014
Fouch, M.J.Hopper, E., Ford, H.A., Fischer, K.M., Lekic, V., Fouch, M.J.The lithosphere-asthenosphere boundary and the tectonic and magmatic history of the northwestern United States.Earth and Planetary Science Letters, Vol. 402, pp. 69-81.United StatesGeophysics - seismics
DS201605-0836
2016
Fouchee, A.Fouchee, A., Stabbert, W.Technological advances of Longi-Multotec high intensity rare earth magnetic seperators improving DMS media circuits.Diamonds Still Sparkling SAIMM 2016 Conference, Mar. 14-17, pp. 153-158.TechnologyDMS - applied
DS201804-0731
2018
Fougerouse, D.Reddy, S., Saxey, D., Rickard, W., Fougerouse, D.Atom probe microscopy and potential applications to diamond research.4th International Diamond School: Diamonds, Geology, Gemology and Exploration Bressanone Italy Jan. 29-Feb. 2nd., pp. 36-37. abstractTechnologydiamond inclusions
DS2002-0290
2002
Foulger, G.R.Christiansen, R.L., Foulger, G.R., Evans, J.R.Upper mantle origin of the Yellowstone hotspotGeological Society of America Bulletin, Vol. 114,10,Oct. pp. 1245-56.IdahoPlumes
DS2003-0417
2003
Foulger, G.R.Foulger, G.R., Anderson, D.L.Iceland is cool: an origin for the Iceland volcanic province in the remelting of subductedJournal of Geothermal Research, IcelandBlank
DS2003-0418
2003
Foulger, G.R.Foulger, G.R., Du, Z., Julian, B.R.Iclandic type crustGeophysical Journal International, IcelandBlank
DS2003-0419
2003
Foulger, G.R.Foulger, G.R., Narland, J.H.Is hotspot volcanism a consequence of plate tectonics?Science, No. 5621, May 9, pp. 921-5.MantleTectonics
DS2003-0420
2003
Foulger, G.R.Foulger, G.R., Natland, J.H., Anderson, D.L.Iceland is fertile: the geochemistry of Icelandic lavas indicates extensive melting ofJournal of Geothermal Research, IcelandBlank
DS200412-0487
2004
Foulger, G.R.Du, Z., Foulger, G.R.Surface wave waveform inversion for variation in upper mantle structure beneath Iceland.Geophysical Journal International, Vol. 157, 1, pp. 305-314.Europe, IcelandGeophysics - seismics
DS200412-0569
2003
Foulger, G.R.Foulger, G.R., Anderson, D.L.Iceland is cool: an origin for the Iceland volcanic province in the remelting of subducted Iapetus slabs at normal mantle temperJournal of Geothermal Research, Vol. June 30p.Europe, IcelandGeophysics - seismics, mantle, plume
DS200412-0570
2003
Foulger, G.R.Foulger, G.R., Du, Z., Julian, B.R.Iclandic type crust.Geophysical Journal International, Vol. 155, pp. 567-590.Europe, IcelandGeophysics - seismics, mantle, plume
DS200412-0571
2003
Foulger, G.R.Foulger, G.R., Narland, J.H.Is hotspot volcanism a consequence of plate tectonics?Science, No. 5621, May 9, pp. 921-5.MantleTectonics
DS200412-0572
2003
Foulger, G.R.Foulger, G.R., Natland, J.H., Anderson, D.L.Iceland is fertile: the geochemistry of Icelandic lavas indicates extensive melting of subducted Iapetus crust in the CaledonianJournal of Geothermal Research, Vol. June 27p.Europe, IcelandEclogite, volcanism, subduction
DS200512-0295
2005
Foulger, G.R.Foulger, G.R.The generation of melting anomalies by plate tectonic processes.Chapman Conference held in Scotland August 28-Sept. 1 2005, 1p. abstractMantleMantle plume, geodynamics
DS200512-0296
2005
Foulger, G.R.Foulger, G.R.Plume skepticism: motivation and approaches.Chapman Conference held in Scotland August 28-Sept. 1 2005, 1p. abstractMantleMantle plume, geothermometry
DS200512-0297
2005
Foulger, G.R.Foulger, G.R.How hot is Iceland?Chapman Conference held in Scotland August 28-Sept. 1 2005, 1p. abstractMantle, IcelandMantle plume, geothermometry
DS200512-0298
2005
Foulger, G.R.Foulger, G.R., Anderson, D.L.A cool model for the Iceland hotspot.Journal of Volcanology and Geothermal Research, Vol. 141, 1-2, March 1, pp. 1-22.Europe, IcelandMagmatism, subduction, tectonics
DS200512-0299
2005
Foulger, G.R.Foulger, G.R., Natland, J.H., Anderson, D.L.A source for Icelandic magmas in remelted Iapetus crust.Journal of Volcanology and Geothermal Research, Vol. 141, 1-2, March 1, pp.23-44.Europe, IcelandRecycled, subduction, tectonics, plates, gechemistry
DS200512-0300
2005
Foulger, G.R.Foulger, G.R., Natland, J.H., Anderson, D.L.Genesis of Iceland melt anomaly by plate tectonic processes.Plates, Plumes, and Paradigms, pp. 595-626. ( total book 861p. $ 144.00)Europe, IcelandTectonics - melting
DS200512-0964
2005
Foulger, G.R.Sharma, K.K., Foulger, G.R.Neoproterozoic anorogenic magmatism associated with Rodinia breakup: not a result of mantle superplume.Chapman Conference held in Scotland August 28-Sept. 1 2005, 1p. abstractMantle, GondwanaMantle plume, rifting
DS200512-1145
2005
Foulger, G.R.Vinnick, L.P., Foulger, G.R., Du,Z.Seismic boundaries in the mantle beneath Iceland: a new constraint on temperature.Geophysical Journal International, Vol. 160, 2, pp. 533-538.Europe, IcelandGeophysics - seismics
DS200612-0356
2005
Foulger, G.R.Du, Z., Vinnik, L.P., Foulger, G.R.Evidence from P to S mantle converted waves for a flat '660 km' discontinuity beneath Iceland.Earth and Planetary Science Letters, Vol. 241, 1-2, pp. 271-280.Europe, IcelandPlume, boundary, hot spot
DS200612-0409
2006
Foulger, G.R.Foulger, G.R.Older crust underlies Iceland.Geophysical Journal International, Vol. 165, 2, pp. 672-676.Europe, IcelandGeophysics - seismics
DS200712-0322
2007
Foulger, G.R.Foulger, G.R.The plate model for the genesis of melting anomalies.Plates, plumes and Planetary Processes, pp. 1-28.MantleMelting
DS200712-0323
2007
Foulger, G.R.Foulger, G.R., Jurdy, D.M.Plates, plumes and planetary processes.GSA Bookstore, 950p. approx. $ 180.00MantleBook - individual papers of interest cited separately
DS200712-0324
2007
Foulger, G.R.Foulger, G.R., Meyer, R.The European Cenozoic volcanic province: the type example of an implausible mantle plume (IMP)?AGU Fall meeting, December 10-14, 1p. abstract on mantleplumes.orgEurope, GermanyMantle plume
DS201012-0208
2010
Foulger, G.R.Foulger, G.R.Plates vs plumes: a geological controversy.Wiley Blackwell, 364p. Oct. 2010 $ 130.00MantlePlume theories - book
DS201212-0206
2012
Foulger, G.R.Foulger, G.R.Are 'hot spots' hot spots?Journal of Geodynamics, Vol. 58, pp. 1-28.MantlePlume
DS201312-0273
2013
Foulger, G.R.Foulger, G.R., Panza, G.F., Artemieva, I.M., Bastow, I.D., Cammarano, F., Evans, J.R., Hamilton, W.B., Julian, B.R., Lustrino, M., Thybo, H., Yanovskaya, T.B.Caveat on tomographic images.Terra Nova, Vol. 25, 4, pp. 259-281.MantleSeismic tomography, geodynamics
DS201511-1847
2015
Foulger, G.R.Julian, B.R., Foulger, G.R., Hatfield, O., Jackson, S.E., Simpson, E., Einbeck, J., Moore, A.Hotspots in hindsight. Mentions kimberlitesGeological Society of America Special Paper, No. 514, pp. SPE514-08.MantleHotspots

Abstract: Thorne et al. (2004), Torsvik et al. (2010; 2006) and Burke et al. (2008) have suggested that the locations of melting anomalies ("hot spots") and the original locations of large igneous provinces ("LIPs") and kimberlite pipes, lie preferentially above the margins of two "large lower-mantle shear velocity provinces", or LLSVPs, near the bottom of the mantle, and that the geographical correlations have high confidence levels (> 99.9999%) (Burke et al., 2008, Fig. 5). They conclude that the LLSVP margins are "Plume-Generation Zones", and that deep-mantle plumes cause hot spots, LIPs, and kimberlites. This conclusion raises questions about what physical processes could be responsible, because, for example, the LLSVPs are apparently dense and not abnormally hot (Trampert et al., 2004). The supposed LIP-hot spot-LLSVP correlations probably are examples of the "Hindsight Heresy" (Acton, 1959), of performing a statistical test using the same data sample that led to the initial formulation of a hypothesis. In this process, an analyst will consider and reject many competing hypotheses, but will not adjust statistical assessments correspondingly. Furthermore, an analyst will test extreme deviations of the data, , but not take this fact into account. "Hindsight heresy" errors are particularly problematical in Earth science, where it often is impossible to conduct controlled experiments. For random locations on the globe, the number of points within a specified distance of a given curve follows a cumulative binomial distribution. We use this fact to test the statistical significance of the observed hot spot-LLSVP correlation using several hot-spot catalogs and mantle models. The results indicate that the actual confidence levels of the correlations are two or three orders of magnitude smaller than claimed. The tests also show that hot spots correlate well with presumably shallowly rooted features such as spreading plate boundaries. Nevertheless, the correlations are significant at confidence levels in excess of 99%. But this is confidence that the null hypothesis of random coincidence is wrong. It is not confidence about what hypothesis is correct. The correlations probably are symptoms of as-yet-unidentified processes.
DS201604-0604
2016
Foulger, G.R.Foulger, G.R.Fundamentals of the plates vs plume plates.Japan Geoscience Union Meeting, 1p. AbstractMantleDebate - magmatism
DS201711-2512
2017
Foulger, G.R.Foulger, G.R.Origin of the South Atlantic igneous province. ( Lucapa zone)Journal of Volcanology and Geothermal Research, in press available, 19p.Africa, Angola, Democratic Republic of Congocarbonatites

Abstract: The South Atlantic Igneous Province comprises the Paraná Basalts, Rio Grande Rise, Tristan archipelago and surrounding guyot province,Walvis Ridge, Etendeka basalts and, in somemodels, the alkaline igneous lineament in the Lucapa corridor, Angola. Although these volcanics are often considered to have a single generic origin, complexities that suggest otherwise are observed. The Paraná Basalts erupted ~5 Ma before sea-floor spreading started in the neighborhood, and far more voluminous volcanic margins were emplaced later. A continental microcontinent likely forms much of the Rio Grande Rise, and variable styles of volcanism built the Walvis Ridge and the Tristan da Cunha archipelago and guyot province. Such complexities, coupled with the northward-propagating mid-ocean ridge crossing amajor transverse transtensional intracontinental structure, suggest that fragmentation of Pangaea was complex at this latitude and that the volcanism may have occurred in response to distributed extension. The alternative model, a deep mantle plume, is less able to account for many observations and no model variant can account for all the primary features that include eruption of the Paraná Basalts in a subsiding basin, continental breakup by rift propagation that originated far to the south, the absence of a time-progressive volcanic chain between the Paraná Basalts and the Rio Grande Rise, derivation of the lavas from different sources, and the lack of evidence for a plume conduit in seismic-tomography- and magnetotelluric images. The region shares many common features with the North Atlantic Igneous Province which also features persistent, widespread volcanismwhere a propagating mid-ocean ridge crossed a transverse structural discontinuity in the disintegrating supercontinent.
DS1996-0294
1996
Foulkes, J.Cookenboo, H., Foulkes, J.Discovery and preliminary evaluation of the 5034 kimberlite at KennedyLake, northwest Territories.northwest Territories Exploration overview 1995, March pp. 3-7. abstractNorthwest TerritoriesHistory, Mineralogy, Deposit -5034
DS1996-0396
1996
Foulkes, J.Dupuis, J., Cookenboo, H., Foulkes, J.Integrated kimberlite exploration program in northwest Territories: Ranch Lake, Jericho and5034 Diamondiferous kimberlites.northwest Territories Exploration overview 1995, March pp. 3-10. abstractNorthwest TerritoriesHistory, GIS, Deposit -Ranch Lake, Jericho, 5034
DS200412-0573
2004
Foulkes, J.Foulkes, J.Canadian diamond exploration techniques. an introduction.Resource World Magazine, Vol. 2, 5, July/August pp. 15,16,18.Canada, Northwest Territories, Saskatchewan, Quebec, OntarioNews item - layman's overview
DS200512-0310
2004
Founch, M.J.Ganero, E.J., Maupin, V., Lay, T., Founch, M.J.Variable azimuthal anisotropy in Earth's lowermost mantle.Science, No. 5694, Oct. 8, p. 259-260.MantleGeophysics
DS200712-1081
2007
Fountain, D.Thomson, S., Fountain, D., Watts, T.Airborne geophysics - evolution and revolution.Proceedings of Exploration 07 edited by B. Milkereit, pp. 19-37.TechnologyGeophysics - airborne - review
DS1986-0258
1986
Fountain, D.M.Furlong, K.P., Fountain, D.M.Continental crustal underplating-thermal considerations and seismicpetrologic consequencesJournal of Geophysical Research, Vol. 91, no, 8, July 10, pp. 8285-8294GlobalCrustal genesis, Geophysics
DS1987-0220
1987
Fountain, D.M.Fountain, D.M.Geological and geophysical nature of the lower continental crust based on laboratory seismologyUnited States Geological Survey (USGS) Circular No. 956 Geophysics and petrology of the deep crust and, pp. 25-26GlobalCrust, Geophysics
DS1989-0441
1989
Fountain, D.M.Fountain, D.M.Seismic properties of the lower continental crust - a reviewGeological Association of Canada (GAC) Annual Meeting Program Abstracts, Vol. 14, p. A101. (abstract.)OntarioTectonics, Kapuskasing Lithoprobe
DS1989-0442
1989
Fountain, D.M.Fountain, D.M.Nature of Superior Province lower continental crust based on rock velocity measurements from the Kapuskasing uplift, OntarioGeological Society of America (GSA) Annual Meeting Abstracts, Vol. 21, No. 6, p. A99. AbstractOntarioTectonics, Kapuskasing rift
DS1989-1011
1989
Fountain, D.M.Mereu, R.F., Mueller, S., Fountain, D.M.Properties and processes of earth's lower crustAmerican Geophysical Union (AGU) Geophysical Monograph Series, No. GM 51/IUGG 6, 352p. ISBN 0-87590-456-4 @ 32.00GlobalMantle
DS1990-0486
1990
Fountain, D.M.Fountain, D.M., Percival, J., Salisbury, M.H.Exposed cross sections of the continental crust- synopsisExposed cross sections of the Continental Crust, ed. M.H. Salisbury and, pp. 653-662GlobalCrust, Geophysics
DS1990-0487
1990
Fountain, D.M.Fountain, D.M., Salisbury, M.H., Percival, J.Seismic structure of the continental crust based on rock velocity measurements from the Kapuskasing UpliftJournal of Geophysical Research, Vol. 95, No. B2, February 10, pp. 1167-1186OntarioGeophysics -seismics, Kapuskasing Zone
DS1992-0476
1992
Fountain, D.M.Fountain, D.M., Arculus, R., Kay, R.M.Continental Lower Crust #3Elsevier, 700p. $ approx. $ 120.00MantleMantle -lower continental crust, Xenoliths
DS1992-0477
1992
Fountain, D.M.Fountain, D.M., Arculus, R., Kay, R.M.Continental lower crust #1Elsevier, approx. $ 120.00GlobalBook -ad, Continental lower crust
DS1992-0478
1992
Fountain, D.M.Fountain, D.M., Arculus, R., Kay, R.W.Continental lower crust #2Elsevier, 485pGlobalCrust, lithosphere, magma, fluids, granulite terranes, Geophysics, seismics, MOHO, xenoliths
DS1993-0446
1993
Fountain, D.M.Florio, G., Fedi, M., Rapolla, A., Fountain, D.M., Shive, P.N.Anisotropic magnetic susceptibility in the continental lower crust and its implications for the shape of magnetic anomalies.Geophysical Research Letters, Vol. 20, No. 23, December 14, pp. 2623-2626.MantleGeophysics Magnetics
DS1994-0540
1994
Fountain, D.M.Fountain, D.M., Boundy, T.M., et al.Eclogite facies shear zones - deep crustal reflectors?Tectonophysics, Vol. 232, pp. 411-424.NorwayTectonics -shear zones, Eclogites
DS1994-1517
1994
Fountain, D.M.Salisbury, M.H., Fountain, D.M.The seismic velocity and Poisson's ratio structure of the Kapuskasing uplift from laboratory measurements.Canadian Journal of Earth Sciences, Vol. 31, No. 7, July pp. 1052-1063.OntarioGeophysics -seismics, Tectonics -Kapuskasing uplift
DS1995-1623
1995
Fountain, D.M.Rudnick, R.L., Fountain, D.M.Nature and composition of the continental crust: a lwoer crustalperspective.Reviews of Geophysics, Vol. 33, No. 3, August pp. 267-310.MantleGeophysics -seismics, geochemistry, Crust -continental, glossary, heat flow
DS1860-0312
1879
Fouque, F.Fouque, F., Michel-Levy, A.Note sur Les Roches Accompagnant et Contenant le Diamant Dans l'afrique Australe.Soc. Min. France (paris) Bulletin., Vol. 2, PP. 216-228.Africa, South AfricaDiamond, Mineralogy
DS1860-0313
1879
Fouque, F.Fouque, F., Michel-Levy, A.Sur la Presence du Diamant dans une Roche Ophitique de l'afrique Australe. Dolerite dyke Academy of Science (PARIS) C.R., Vol. 89, PP. 1125-1127.Africa, South AfricaMineralogy
DS1988-0054
1988
Fourcade, S.Bernard-Griffiths, J., Peucat, J.J., Fourcade, S., Kienast, J.R.Origin and evolution of 2 Ga old carbonatite complex(lhouhaouene, Ahaggar, Algeria:) neodymium and Sr isotopicevidenceContributions to Mineralogy and Petrology, Vol. 100, No. 3, pp. 339-348AlgeriaGeochronology, Carbonatite
DS1988-0530
1988
Fourcade, S.Ouzegane, K., Fourcade, S., Kienast, J.R., Javoy, M.New carbonatite complexes in the Archean In ouzzal nucleus(Ahaggar, Algeria)- mineralogical and geochemical dataContributions to Mineralogy and Petrology, Vol. 52, pp. 247-275AlgeriaCarbonatite
DS1991-0102
1991
Fourcade, S.Bernardgriffiths, J., Fourcade, S., Dupuy, C.Isotopic study (Strontium, neodymium, Oxygen and Carbon) of lamprophyresEarth Planetary Science Letters, Vol. 103, No. 1-4, April pp. 190-199MoroccoGeochronology, Crust, lamprophyres
DS1991-1742
1991
Fourcade, S.Tourpin, S., Gruau, G., Blais, S., Fourcade, S.Resetting of rare earth elements (REE) and neodymium and Strontium isotopes during carbonization of a komatiite flow from FinlandChemical Geology, Vol. 90, No. 1-2 March 25, pp. 15-30FinlandKomatiite, Alteration
DS1991-1743
1991
Fourcade, S.Tourpin, S., Gruau, G., Blais, S., Fourcade, S.Resetting of rare earth elements (REE) and neodymium and StrontiumChemical Geology, Vol. 90, No. 1-2 March 25, pp. 15-30FinlandKomatiite, Alteration
DS1993-0899
1993
Fourcade, S.Lecuyer, C., Gruau, G., Anhaeusser, C.R., Fourcade, S.The origin of fluids and the effects of metamorphism on the primary chemical compositions of Barberton komatiites: new evidence from geochemistry, isotopesEconomic Geology Research Unit, University of the Witwatersrand, Inf. Circular No. 272, 32pSouth AfricaGeochemistry, Komatiites
DS1993-1667
1993
Fourcade, S.Viladkar, S.G., Kienast, J.R., Fourcade, S.Mineralogy of the Newania carbonatites Rajasthan, IndiaTerra Abstracts, IAGOD International Symposium on mineralization related to mafic, Vol. 5, No. 3, abstract supplement p. 55.IndiaCarbonatite, Mineralogy
DS1994-1011
1994
Fourcade, S.Lecuyer, C., Gruau, G., Anhaeusser, C.R., Fourcade, S.The origin of fluids and effects of metamorphism on the primary chemical compositions of Barberton komatiites: new evidenceGeochimica et Cosmochimica Acta, Vol. 58, No. 2, January pp. 1043South AfricaGeochemistry, Geochronology
DS1996-0464
1996
Fourcade, S.Fourcade, S., Kienast, J.R., Ouzegane, K.Metasomatic effects related to channelled fluid streaming through deepcrust: fenites and carbonatitesJournal of Metamorphic Geology, Vol. 14, pp. 763-781.AlgeriaHoggar, Proterozoic granuiltes, Carbonatite
DS2002-0331
2002
Fourcade, S.Coulon, C., Megartsi, M., Fourcade, S., Maury, R.C., Bellon, H., Louni Hacini, A.Post collisional transition from calc-alkaline to alkaline volcanism during the Neogene inLithos, Vol.62,3-4,pp. 87-110.AlgeriaSubduction - slab
DS200912-0211
2009
Fourcault, J-M.Farges, F., Sucher, S., Horovitz, H., Fourcault, J-M.The French Blue and the Hope' new dat a from the discovery of a historical lead cast.Gems & Gemology, Vol. 45, 1, Spring pp. 4-19.TechnologyDiamonds notable
DS201506-0268
2015
Fourdan, B.Frizon de Lamotte, D., Fourdan, B., Leleu, S., Leparmentier, F., de Clarens, P.Style of rifting and the stages of Pangea break up.Tectonics, Vol. 34, 5, pp. 1009-1029.Global, RussiaPangea
DS201512-1909
2015
Fourdan, D.De Lamotte, F., Fourdan, D., Leleu, B., Leparmentier, S., Clarens, F.Style of rifting and the stages of Pangea.Tectonics, Vol. 34, 5, pp. 1009-1029.MantlePangea

Abstract: Pangea results from the progressive amalgamation of continental blocks achieved at 320?Ma. Assuming that the ancient concept of “active” versus “passive” rifting remains pertinent as end-members of more complex processes, we show that the progressive Pangea breakup occurred through a succession of rifting episodes characterized by different tectonic evolutions. A first episode of passive continental rifting during the Upper Carboniferous and Permian led to the formation of the Neo-Tethys Ocean. Then at the beginning of Triassic times, two short episodes of active rifting associated to the Siberian and Emeishan large igneous provinces (LIPs) failed. The true disintegration of Pangea resulted from (1) a Triassic passive rifting leading to the emplacement of the central Atlantic magmatic province (200?Ma) LIP and the subsequent opening of the central Atlantic Ocean during the lowermost Jurassic and from (2) a Lower Jurassic active rifting triggered by the Karoo-Ferrar LIP (183?Ma), which led to the opening of the West Indian Ocean. The same sequence of passive then active rifting is observed during the Lower Cretaceous with, in between, the Parana-Etendeka LIP at 135?Ma. We show that the relationships between the style of rifts and their breakdown or with the type of resulting margins (as magma poor or magma dominated) are not straightforward. Finally, we discuss the respective role of mantle global warming promoted by continental agglomeration and mantle plumes in the weakening of the continental lithosphere and their roles as rifting triggers.
DS201904-0757
2019
Fourdrin, S.Malavergegne, V., Bureau, H., Raepsaet, C., Gaillard, C., Poncet, F., Surble, M., Sifre, S., Shcheka, D., Fourdrin, S., Deldicque, C., Khodja, D., HichamExperimental constraints on the fate of H and C during planetary core-mantle differentiation. Implications for the Earth.Icarus - New York, Vol. 321, 1, pp. 473-485.Mantlecarbon

Abstract: Hydrogen (H) and carbon (C) have probably been delivered to the Earth mainly during accretion processes at High Temperature (HT) and High Pressure (HP) and at variable redox conditions. We performed HP (1-15?GPa) and HT (1600-2300°C) experiments, combined with state-of-the-art analytical techniques to better understand the behavior of H and C during planetary differentiation processes. We show that increasing pressure makes H slightly siderophile and slightly decreases the highly siderophile nature of C. This implies that the capacity of a growing core to retain significant amounts of H or C is mainly controlled by the size of the planet: small planetary bodies may retain C in their cores while H may have rather been lost in space; larger bodies may store both H and C in their cores. During the Earth's differentiation, both C and H might be sequestrated in the core. However, the H content of the core would remain one or two orders of magnitude lower than that of C since the (H/C)core ratio might range between 0.04 and 0.27.
DS201707-1332
2016
Fourestier, J.Guowu, L., Guangming, Y., Fude, L., Ming, X., Xiangkun, G., Baoming, P., Fourestier, J.Fluorcalciopyrochlore, a new mineral species from Bayan Obo, inner Mongolia, P.R. China.The Canadian Mineralogist, Vol. 54, pp. 1285-1291.China, Mongoliacarbonatite - Bayan Obo

Abstract: Fluorcalciopyrochlore, ideally (Ca,Na)2Nb2O6F, cubic, is a new mineral species (IMA2013-055) occurring in the Bayan Obo Fe-Nb-REE deposit, Inner Mongolia, People's Republic of China. The mineral is found in a dolomite-type niobium rare-earth ore deposit. Associated minerals are dolomite, aegirine, riebeckite, diopside, fluorite, baryte, phlogopite, britholite-(Ce), bastnäsite-(Ce), zircon, magnetite, pyrite, fersmite, columbite-(Fe), monazite-(Ce), rutile, and others. Crystals mostly form as octahedra {111}, dodecahedra {110}, and cubes {100}, or combinations thereof, and generally range in size from 0.01 to 0.3 mm. It is brownish-yellow to reddish-orange in color with a light yellow streak. Crystals of fluorcalciopyrochlore are translucent to transparent with an adamantine to greasy luster on fractured surfaces. It has a conchoidal fracture. No parting or cleavage was observed. The Mohs hardness is 5, and the calculated density is 4.34(1) g/cm3. The empirical formula is (Ca1.14Na0.74Ce0.06Sr0.03Th0.01Fe0.01Y0.01La0.01Nd0.01)S2.02(Nb1.68Ti0.29Zr0.02Sn0.01)S2.00O6.00(F0.92O0.08)S1.00 on the basis of 7(O,F) anions pfu. The simplified formula is (Ca,Na)2Nb2O6F. The strongest four reflections in the X-ray powder-diffraction pattern [d in Å (I) hkl] are: 6.040 (9) 1 1 1, 3.017 (100) 2 2 2, 2.613 (17) 0 0 4, 1.843 (29) 0 4 4, and 1.571 (15) 2 2 6. The unit-cell parameters are a 10.4164(9) Å, V 1130.2(2) Å3, Z = 8. The structure was solved and refined in space group FdEmbedded Image m with R = 0.05. The type material is deposited in the Geological Museum of China, Beijing, People's Republic of China, catalogue number M12182.
DS1998-1158
1998
FouriePhillips, D., Harris, J.W., Kiviets, Burgess, Fourie40 Ar39 Laser probe analyses of clinopyroxene diamond inclusions from the Orapa and Mbuyi Miya Mines.7th. Kimberlite Conference abstract, pp. 687-9.GlobalGeochronology, diamond inclusions, Deposit - Orapa, Mbuyi Miya
DS1998-1159
1998
FouriePhillips, D., Kiviets, Barton, Smith, Viljoen, Fourie40 Ar39 dating of kimberlites and related rocks: problems and solutions7th. Kimberlite Conference abstract, pp. 690-2.South Africa, Botswana, ZimbabweGeochronology, Deposit - Venetia, Oaks, Colorssus, Lace, Rex, Pniel
DS200912-0522
2009
FourieMuller, M.R., Jones, Evans, Grutter, Hatton, Garcia, Hamilton, Miensopust, Cole, Ngwisanyi, Hutchins, Fourie, Jelsma,Aravanis.Pettit, Webb, WasborgLithospheric structure, evolution and diamond prospectivity of the Rehoboth Terrane and western Kaapvaal Craton, southern Africa: constraints from broadbandLithos, In press - available 57p..Africa, South Africa, BotswanaGeophysics - broadband magnetotellurics
DS201112-0312
2011
FourieEvans, R.L., Jones, A.G., Garcia, X., Muller, M., Hamilton, Evans, Fourie, Spratt, Webb, Jelsma, HutchinsElectrical lithosphere beneath the Kaapvaal craton, southern Africa.Journal of Geophysical Research, Vol. 116, B4, B04105.Africa, South AfricaGeophysics - seismics
DS201810-2381
2018
Fourie, A.Stamm, N., Schmidt. M.W., Szymanowski, D., von Quadt, A., Mohapi, T., Fourie, A.Primary petrology, mineralogy and age of the Letseng-la-Terae kimberlite ( Lesotho), southern Africa) and parental magmas of Group 1 kimberlites.Contributions to Mineralogy and Petrology, Vol. 173, pp. 76- doi.org/10.1007/ s00410-018-1502-1Africa, Lesothodeposit - Letseng

Abstract: The Letšeng-la-Terae kimberlite (Lesotho), famous for its large high-value diamonds, has five distinct phases that are mined in a Main and a Satellite pipe. These diatreme phases are heavily altered but parts of a directly adjacent kimberlite blow are exceptionally fresh. The blow groundmass consists of preserved primary olivine with Fo86-88, chromite, magnesio-ulvöspinel and magnetite, perovskite, monticellite, occasional Sr-rich carbonate, phlogopite, apatite, calcite and serpentine. The bulk composition of the groundmass, extracted by micro-drilling, yields 24-26 wt% SiO2, 20-21 wt% MgO, 16-19 wt% CaO and 1.9-2.1 wt% K2O, the latter being retained in phlogopite. Without a proper mineral host, groundmass Na2O is only 0.09-0.16 wt%. However, Na-rich K-richterite observed in orthopyroxene coronae allows to reconstruct a parent melt Na2O content of 3.5-5 wt%, an amount similar to that of highly undersaturated primitive ocean island basanites. The groundmass contains 10-12 wt% CO2, H2O is estimated to 4-5 wt%, but volatiles and alkalis were considerably reduced by degassing. Mg# of 77.9 and 530 ppm Ni are in equilibrium with olivine phenocrysts, characterize the parent melt and are not due to olivine fractionation. 87Sr/86Sr(i)?=?0.703602-0.703656, 143Nd/144Nd(i)?=?0.512660 and 176Hf/177Hf(i)?=?0.282677-0.282679 indicate that the Letšeng kimberlite originates from the convective upper mantle. U-Pb dating of groundmass perovskite reveals an emplacement age of 85.5?±?0.3 (2s) Ma, which is significantly younger than previously proposed for the Letšeng kimberlite.
DS200612-0524
2006
Fourie, C.J.S.Hamilton, M.P., Jones, A.G., Evans, R.L., Evans, S., Fourie, C.J.S., Garcia, X., Mountford, A., Spratt, J.E., SAMTEX MTElectrical anisotropy of South African lithosphere compared with seismic anisotropy from shear wave splitting analyses.Physics of the Earth and Planetary Interiors, In press, availableAfrica, South AfricaGeophysics - magnetotellurics
DS200712-0404
2006
Fourie, C.J.S.Hamilton, M.P., Jones, A.G., Evans, R.L., Evans, S., Fourie, C.J.S., Mountford, SprattElectrical anisotropy of South African lithosphere compared with seismic from shear wave splitting analyses.Physics of the Earth and Planetary Interiors, Vol. 158, 2-4, Oct. 16, pp. 226-239.Africa, South AfricaGeophysics - seismics
DS1950-0386
1958
Fourie, G.P.Fourie, G.P.Die Diamant voorkomste in die Omgewing Van Swartruggens Transvaal.Geological Survey of South Africa Bulletin., No. 26, PP. 1-16.South Africa, TransvaalGeology, Diamond Occurrences
DS200912-0285
2009
Fourie, L.Harvey, S., Kjarsgaard, McClintock, M., Shimell, M., Fourie, L., Du Plessis, P., Read, G.Geology and evaluation strategy of the Star and Orion South kimberlites, Fort a la Corne, Canada.Lithos, In press availableCanada, SaskatchewanDeposit - Star, Orion
DS201212-0288
2012
Fourie, L.Harvey, S., Read, G., DesGagnes, B., Shimell, M., Danoczi, J., Van Breugel, B., Fourie, L., Stilling, A.Utilization of olivine macrocryst grain size and abundance dat a as a proxy for diamond size and grade in pyroclastic deposits of the Orion South kimberlite Fort a la Corne, Sasakatchewan, Canada.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractCanada, SaskatchewanDeposit - Orion South
DS201412-0344
2013
Fourie, L.Harvey, S., Read, G., DesGagnes, B., Shimell, M., van Breugel, B., Fourie, L.Utilization of olivine macrocryst grain size and abundance dat a as a proxy for diamond size and grade in pyroclastic deposits of the Orion South kimberlite, Fort a la Corne, Saskatchewan, Canada.Proceedings of the 10th. International Kimberlite Conference, Vol. 2, pp. 79-96.Canada, SaskatchewanDeposit - Orion South
DS2000-0421
2000
Fourie, L.F.Hoosen, Z., Kurzlaukis, S., Kiviets, G.B., Fourie, L.F.New high Pressure precision ages from the Gideon and Maltahohe kimberlite fields, southern Namibia.Journal of African Earth Sciences, p. 31. abstract.NamibiaGeochronology - age determination, Deposit - Gibeon, Maltahohe
DS201412-0967
2014
Fourie, P.Ward, J.D., Bowen, D.C., Fourie, P., Ntsalong, L.The Kao kimberlite, Lesotho: main pipe - main mine?GSSA Kimberley Diamond Symposium and Trade Show provisional programme, Sept. 12, title onlyAfrica, LesothoDeposit - Kao
DS201112-0335
2011
Fourie, P.H.Fourie, P.H., Zimmermana, U., Beukes, N.J., Naidoo, T., Kobayasji, K., Kosler, J., Nakamura, Tait, TheronProvenance and reconnaissance study of detrital zircons of the Paleozoic Cape Supergroup: revealing the interaction of Kalahari and Rio de la Plat a cratons.International Journal of Earth Sciences, Vol. 100, 2, pp. 527-541.Africa, South Africa, South America, BrazilGeochronology
DS1985-0175
1985
Fourie, P.J.Eriksson, S.C., Fourie, P.J., Dejager, D.H.A Cumulate Origin for the Minerals in Clinopyroxenites of ThephalaborwacomplexTransactions Geological Society of South Africa, Vol. 88, pt. 2, May-August pp. 207-214South AfricaCarbonatite
DS200712-0795
2007
FournellePage, F.Z., Fu, B., Kita, N.T., Fournelle, Spicuzza, Schulze, Viljoen, Basei, ValleyZircons from kimberlite: new insights into oxygen isotopes, trace elements, and Ti in zircon thermometry.Geochimica et Cosmochimica Acta, Vol. 71, 15, pp. 3887-3903.TechnologyZircon thermometry
DS200812-0372
2008
Fournelle, J.Fu, B., Page, F.Z., Cavosie, A.J., Fournelle, J., Kita, N.T., Lackey, J.S., Wilde, S.A., Valley, J.W.Ti in zircon thermometry: applications and limitations.Contributions to Mineralogy and Petrology, 37p. in press availableTechnologyGeothermometry - kimberlites
DS201901-0039
2018
Fournelle, J.Gu, T., Valley, J., Kitajima, K., Spicuzza, M., Fournelle, J., Stern, R., Ohfuji, H., Wang, W.Evidence of subducted altered oceanic crust into deep mantle from inclusions of type IaB diamonds,Gems & Gemology, Sixth International Gemological Symposium Vol. 54, 3, 1p. Abstract p. 306-7.Mantlediamond inclusions

Abstract: Nitrogen is one of the most common impurities in diamond, and its aggregation styles have been used as criteria for diamond classification. Pure type IaB diamonds (with 100% nitrogen in B aggregation) are rather rare among natural diamonds. The occurrence of the B center is generally associated with high temperature and a long residence time of the host diamond, which would potentially provide information on the earth’s deep interior. Seawater circulation is the unique process that shapes the surface of our planet and potentially has a profound effect on its interior due to slab subduction. In about 50 type IaB diamonds with detectable micro-inclusions submitted to GIA for screening, we found that more than 70% of them contained a typical mineral assemblage from the sublithosphere. Jeffbenite (TAPP), majorite garnet, enstatite, and ferropericlase have been observed, which could be retrograde products of former bridgmanite. CaSiO3-walstromite with larnite and titanite is the dominant phase present in approximately 40% of all diamond samples. Direct evidence from oxygen isotope ratios measured by secondary ion mass spectrometry, or SIMS, (d18OVSMOWin the range +10.7 to +12.5‰) of CaSiO3-walstromite with coexisting larnite and titanite that retrograde from CaSiO3-perovskite suggest that hydrothermally altered oceanic basalt can subduct to depths of >410 km in the transition zone. Incorporation of materials from subducted altered oceanic crust into the deep mantle produced diamond inclusions that have both lower mantle and subduction signatures. Ca(Si,Al)O3-perovskite was observed with a high concentration of rare earth elements (>5 wt.%) that could be enriched under P-Tconditions in the lower mantle. Evidence from ringwoodite with a hydroxide bond, coexisting tuite and apatite, precipitates of an NH3phase, and cohenite with trace amounts of Cl imply that the subducted brines can potentially introduce hydrous fluid to the bottom of the transition zone. In the diamonds with subducted materials, the increasing carbon isotope ratio from the core to the rim region detected by SIMS (d13C from -5.5‰ to -4‰) suggests that an oxidized carbonate-dominated fluid was associated with recycling of the subducted hydrous material. The deep subduction played an important role in balancing redox exchange with the reduced lower mantle indicated by precipitated iron nanoparticles and coexisting hydrocarbons and carbonate phases.
DS201911-2562
2019
Fournelle, J.Siegrist, M., Yogodzinski, G., Bizimis, M., Fournelle, J., Churikova, T., Dektor, C., Mobley, R.Fragments of metasomatized forearc: origin and implications of mafic and ultramafic xenoliths from Kharchinsky volcano, Kamchatka.Geochemistry, Geophysics, Geosystems, Vol. 20, 9, pp. 4426-4456.Russiaxenoliths

Abstract: This paper presents the results of a study of rare rock fragments (xenoliths) that were transported from the Earth's deep interior to the surface during an eruption of Kharchinsky volcano, Kamchatka. The chemical compositions, mineralogy, and textures of the samples were studied with the goal of understanding the processes that affected rocks, which may play a role in the formation of magmas in the Kamchatka subduction zone. The key process that affected the xenoliths involved the addition of fluids and dissolved elements to the samples at temperatures of 500-700 °C. These fluids are derived from seawater that was transported to 30- to 50-km depths by subduction of the Pacific Plate beneath Kamchatka. Subsequent to the addition of fluid, there was a shift in the position of the Kamchatka-Pacific Plate boundary that led to an increase in temperature and the formation of small quantities of melt that crystallized to a distinctive group of secondary minerals that are present in the samples and that postdate (overprint) the initial effects of fluid addition. The final step in the evolution of the samples was infiltration by an Fe- and Mg-rich magma that crystallized principally amphibole-group minerals.
DS1995-1224
1995
Fournelle, J.H.Medaris, L.G.Jr., Fournelle, J.H., Jelinek, E.Thermobarometry and reconstructed chemical composition pyroxene spinelsymplectites: Czech Neogene lavas.Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 371-373.GlobalGeobarometry, Symplectites
DS1999-0555
1999
FourniePhillips, D., Kiviets, Barton, Smith, Viljoen, Fournie40 Ar-39 Ar dating of kimberlites and related rocks, problems and solutions.7th International Kimberlite Conference Nixon, Vol. 2, pp. 677-88.South Africa, Zimbabwe, Barkly WestGeochronology, argon, Venetia, Colossus, Postmas, Pniel, Marnitz, Rex, Lace
DS1993-0454
1993
Fournier, A.Fournier, A.Magmatic and hydrothermal controls of the light rare earth element (LREE) mineralization of the Sainte Honore carbonatite, QuebecMcGill University, Msc. thesisQuebecCarbonatite, Thesis
DS1993-0455
1993
Fournier, A.Fournier, A., Williams-Jones, A.E., Wood, S.A.Magmatic and hydrothermal controls of light rare earth element (LREE) mineralization of the St. Honorecarbonatite, QuebecTerra Abstracts, IAGOD International Symposium on mineralization related to mafic, Vol. 5, No. 3, abstract supplement p. 15QuebecCarbonatite, St. Honore
DS201412-0522
2014
Fournier, A.Livermore, P.W., Fournier, A., Gallet, Y.Core-flow constraints on extreme archeomagnetic intensity changes.Earth and Planetary Science Letters, Vol. 387, pp. 145-156.MantleGeophysics - magnetics
DS201805-0936
2018
Fournier, A.Bocher, M., Fournier, A., Coltice, N.Ensemble Kalman filter for the reconstruction of the Earth's mantle circulation.Nonlinear Processes Geophysics, Vol. 25, pp. 99-123. pdfMantleconvection

Abstract: Recent advances in mantle convection modeling led to the release of a new generation of convection codes, able to self-consistently generate plate-like tectonics at their surface. Those models physically link mantle dynamics to surface tectonics. Combined with plate tectonic reconstructions, they have the potential to produce a new generation of mantle circulation models that use data assimilation methods and where uncertainties in plate tectonic reconstructions are taken into account. We provided a proof of this concept by applying a suboptimal Kalman filter to the reconstruction of mantle circulation (Bocher et al., 2016). Here, we propose to go one step further and apply the ensemble Kalman filter (EnKF) to this problem. The EnKF is a sequential Monte Carlo method particularly adapted to solve high-dimensional data assimilation problems with nonlinear dynamics. We tested the EnKF using synthetic observations consisting of surface velocity and heat flow measurements on a 2-D-spherical annulus model and compared it with the method developed previously. The EnKF performs on average better and is more stable than the former method. Less than 300 ensemble members are sufficient to reconstruct an evolution. We use covariance adaptive inflation and localization to correct for sampling errors. We show that the EnKF results are robust over a wide range of covariance localization parameters. The reconstruction is associated with an estimation of the error, and provides valuable information on where the reconstruction is to be trusted or not.
DS201412-0184
2014
Fournier, D.Devriese, S.G.R., Corcoran, N., Cowan, D., Davis, K., Bild-Enkin, D., Fournier, D., Heagy, L., Kang, S., Marchant, D., McMillan, M.S., Mitchell, M., Rosenkjar, G., Yang, D., Oldenburg, D.W.Magnetic inversion of three airborne dat a sets over the Tli Kwi Cho kimberlite complex.SEG Annual Meeting Denver, pp. 1790-1794 extended abstractCanada, Northwest TerritoriesGeophysics - Tli Kwi Cho
DS201412-0250
2014
Fournier, D.Fournier, D., Heagy, L., Corcoran, N., Devriese, S.G.R., Bild-Enkin, D., Davis, K., Kang, S., Marchant, D., McMillan, M.S., Mitchell, M., Rosenkjar, G., Yang, D., Oldenburg, D.W.Multi-EM systems inversion - towards a common conductivity model for Tli Kwi Cho complex.SEG Annual Meeting Denver, pp. 1795-1798. Extended abstractCanada, Northwest TerritoriesGeophysics - Tli Kwi Cho complex
DS201501-0006
2014
Fournier, D.Devriese, S.G.R., Corcoran, N., Cowan, D., Davis, K., Bild-Enkin, D., Fournier, D., Heagy, L., Kang, S., Marchant, D., McMillan, M.S., Mitchell, M., Rosenkjar, G., Yang, D., Oldenburg, D.W.Magnetic inversion of three airborne dat a sets over the Tli Kwi Cho kimberlite complex.SEG Annual Meeting Denver, 5p. Extended abstractCanada, Northwest TerritoriesDeposit - Tli Kwi Cho, geophysics

Abstract: The magnetic and electromagnetic responses from airborne systems at Tli Kwi Cho, a kimberlite complex in the Northwest Territories, Canada, have received considerable attention over the last two decades but a complete understanding of the causative physical properties is not yet at hand. Our analysis is distributed among three papers. In the first, we find a 3D magnetic susceptibility model for the area; in the second, we find a 3D conductivity model; and in the third paper, we find a 3D chargeability model. Our goal is to explain all the geophysical results within a geologic framework. In this first paper, we invert three independent airborne magnetic data sets flown over the Tli Kwi Cho kimberlite complex located in the Lac de Gras kimberlite field in Northwest Territories, Canada. The complex consists of two kimberlites known as DO-27 and DO-18. An initial airborne DIGHEM survey was flown in 1992 and AeroTEM and VTEM data subsequently acquired in 2003 and 2004, respectively. In this paper, we invert each magnetic data set in three dimensions. Both kimberlites are recovered in each model, with DO-27 as a more susceptible body than DO-18. Our goal is to simultaneously invert the three data sets to generate a single susceptibility model for Tli Kwi Cho. This project is part of a larger, on-going investigation by UBC-GIF on inverting magnetic, electromagnetic, and induced polarization data from the Tli Kwi Cho area.
DS201501-0009
2014
Fournier, D.Fournier, D., Heagy, L., Corcoran, N., Cowan, D., Devriese, S.G.R., Bild-Enkin, D., Davis, K., Kang, S., Marchant, D., McMillan, M.S., Mitchell, M., Rosenkjar, G., Yang, D., Oldenburg, D.W.Multi-EM systems inversion - towards a common conductivity model for Tli Kwi Cho complex.SEG Annual Meeting Denver, 5p. Extended abstractCanada, Northwest TerritoriesDeposit - Tli Kwi Cho, geophysics

Abstract: The magnetic and electromagnetic responses from airborne systems at Tli Kwi Cho, a kimberlite complex in the Northwest Territories, Canada, have received considerable attention over the last two decades but a complete understanding of the causative physical properties is not yet at hand. Our analysis is distributed among three posters. In the first we find a 3D magnetic susceptibility model for the area; in the second we find a 3D conductivity model; and in the third we find a 3D chargeability model that can explain the negative transient responses measured over the kimberlite pipes. In this second paper we focus upon the task of finding a conductivity model that is compatible with three airborne data sets flown between 1992 and 2004: one frequency-domain data set (DIGHEM) and two time-domain systems (AeroTEM and VTEM). The goal is to obtain a 3D model from which geologic questions can be answered, but even more importantly, to provide a background conductivity needed to complete the 3D IP inversion of airborne EM data. We begin by modifying our pre-existing 1D frequency and time domain inversion codes to produce models that have more lateral continuity. The results are useful in their own right but we have also found that 1D analysis is often very effective in bringing to light erroneous data, assisting in estimating noise floors, and providing some starting information for developing a background model for the 3D EM inversion. Here we show some results from our Laterally Constrained Inversion (LCI) framework. The recovered conductivity models seem to agree on the general location of the kimberlite pipes but disagree on the geometry and conductivity values at depth. The complete 3D inversions in time and frequency, needed to resolved these issues, are currently in progress.
DS201611-2103
2014
Fournier, D.Devriese, S.G.R., Corcoran, N., Cowan, D., Davis, K., Bild-Enkin, D., Fournier, D., Heagy, L., Kang, S., Marchant, D., McMillan, M.S., Mitchell, M., Rosenkjar, G., Yang, D., Oldenburg, D.W.Magnetic inversion of three airborne dat a sets over the Tli Kwi Cho kimberlite complex.SEG Annual Meeting Denver, pp. 1790-1794. pdfCanada, Northwest TerritoriesDeposit - Tli Kwi Cho

Abstract: The magnetic and electromagnetic responses from airborne systems at Tli Kwi Cho, a kimberlite complex in the Northwest Territories, Canada, have received considerable attention over the last two decades but a complete understanding of the causative physical properties is not yet at hand. Our analysis is distributed among three papers. In the first, we find a 3D magnetic susceptibility model for the area; in the second, we find a 3D conductivity model; and in the third paper, we find a 3D chargeability model. Our goal is to explain all the geophysical results within a geologic framework. In this first paper, we invert three independent airborne magnetic data sets flown over the Tli Kwi Cho kimberlite complex located in the Lac de Gras kimberlite field in Northwest Territories, Canada. The complex consists of two kimberlites known as DO-27 and DO- 18. An initial airborne DIGHEM survey was flown in 1992 and AeroTEM and VTEM data subsequently acquired in 2003 and 2004, respectively. In this paper, we invert each magnetic data set in three dimensions. Both kimberlites are recovered in each model, with DO-27 as a more susceptible body than DO-18. Our goal is to simultaneously invert the three data sets to generate a single susceptibility model for Tli Kwi Cho. This project is part of a larger, on-going investigation by UBC-GIF on inverting magnetic, electromagnetic, and induced polarization data from the Tli Kwi Cho area.
DS201611-2106
2016
Fournier, D.Fournier, D., Heagy, L.Where are the diamonds? - using Earth's potentialsSimPEG Team, 1p. Poster pdfTechnologyGeophysics - Magnetics, gravity
DS201611-2107
2014
Fournier, D.Fournier, D., Heagy, L., Corcoran, N., Cowan, D., Devriese, S.G.R., Bild-Enkin, D., Davis, K., Marchant, M., McMillan, M.S., Mitchell, M., Rosenkjar, G., Yang, D., Oldenburg, D.W.Multi-EM systems inversion - towards a common conductivity model for Tli Kwi Cho complex.SEG Annual Meeting Denver, pp. 1795-1799. pdfCanada, Northwest TerritoriesDeposit - Tli Kwi Cho

Abstract: The magnetic and electromagnetic responses from airborne systems at Tli Kwi Cho, a kimberlite complex in the Northwest Territories, Canada, have received considerable attention over the last two decades but a complete understanding of the causative physical properties is not yet at hand. Our analysis is distributed among three posters. In the first we find a 3D magnetic susceptibility model for the area; in the second we find a 3D conductivity model; and in the third we find a 3D chargeability model that can explain the negative transient responses measured over the kimberlite pipes. In this second paper we focus upon the task of finding a conductivity model that is compatible with three airborne data sets flown between 1992 and 2004: one frequency-domain data set (DIGHEM) and two time-domain systems (AeroTEM and VTEM). The goal is to obtain a 3D model from which geologic questions can be answered, but even more importantly, to provide a background conductivity needed to complete the 3D IP inversion of airborne EM data. We begin by modifying our pre-existing 1D frequency and time domain inversion codes to produce models that have more lateral continuity. The results are useful in their own right but we have also found that 1D analysis is often very effective in bringing to light erroneous data, assisting in estimating noise floors, and providing some starting information for developing a background model for the 3D EM inversion. Here we show some results from our Laterally Constrained Inversion (LCI) framework. The recovered conductivity models seem to agree on the general location of the kimberlite pipes but disagree on the geometry and conductivity values at depth. The complete 3D inversions in time and frequency, needed to resolved these issues, are currently in progress.
DS201611-2108
2016
Fournier, D.Fournier, D., Kang, S., McMillan, M.S., Oldenburg, D.W.Inversion of airborne geophysics over the Tli Kwi Cho kimberlite complex, Part II: electromagnetics.Tli Kwi Cho Workshop UBC, Sept. 8, 43p. Contact sdevriese @eos.ubc.caCanada, Northwest TerritoriesDeposit - Tli Kwi Cho
DS201611-2119
2015
Fournier, D.Kang, S., Fournier, D., Oldenburg, D.W.Inversion of airborne geophysics over the Tli Kwi Cho kimberlite complex.Tli Kwi Cho Workshop UBC, 24p. Contact Canada, Northwest TerritoriesDeposit - Tli Kwi Cho
DS201705-0868
2016
fournier, D.Oldenburg, D., Kang, S., fournier, D.Airborne IP at Tli Kwi Cho.SEG Annual Meeting Dallas, 19 ppt.Canada, Northwest TerritoriesDeposit - Tli Kwi Cho
DS201804-0690
2017
Fournier, D.Fournier, D., Kang, S., Mmillan, M.S., Oldenburg, D.W.Inversion of airborne geophysics over the DO-27/DO18 kimberlites. Part 2. Electromagnetics.Society of Exploration Geophysicists, Interpretation, August T 313, 13p.Canada, Northwest Territoriesdeposit - Tli Kwi Cho

Abstract: We focus on the task of finding a 3D conductivity structure for the DO-18 and DO-27 kimberlites, historically known as the Tli Kwi Cho (TKC) kimberlite complex in the Northwest Territories, Canada. Two airborne electromagnetic (EM) surveys are analyzed: a frequency-domain DIGHEM and a time-domain VTEM survey. Airborne time-domain data at TKC are particularly challenging because of the negative values that exist even at the earliest time channels. Heretofore, such data have not been inverted in three dimensions. In our analysis, we start by inverting frequency-domain data and positive VTEM data with a laterally constrained 1D inversion. This is important for assessing the noise levels associated with the data and for estimating the general conductivity structure. The analysis is then extended to a 3D inversion with our most recent optimized and parallelized inversion codes. We first address the issue about whether the conductivity anomaly is due to a shallow flat-lying conductor (associated with the lake bottom) or a vertical conductive pipe; we conclude that it is the latter. Both data sets are then cooperatively inverted to obtain a consistent 3D conductivity model for TKC that can be used for geologic interpretation. The conductivity model is then jointly interpreted with the density and magnetic susceptibility models from a previous paper. The addition of conductivity enriches the interpretation made with the potential fields in characterizing several distinct petrophysical kimberlite units. The final conductivity model also helps better define the lateral extent and upper boundary of the kimberlite pipes. This conductivity model is a crucial component of the follow-up paper in which our colleagues invert the airborne EM data to recover the time-dependent chargeability that further advances our geologic interpretation.
DS201804-0705
2017
Fournier, D.Kang, S., Fournier, D., Oldenburg, D.W.Inversion of airborne geophysics over D0-27/D0-18 kimberlites. Part 3: Induced polarization.Society of Exploration Geophysicists, Interpretation, August T 327, 14p.Canada, Northwest Territoriesdeposit -Tli Kwi Cho

Abstract: The geologically distinct DO-27 and DO-18 kimberlites, often called the Tli Kwi Cho (TKC) kimberlites, have been used as a testbed for airborne geophysical methods applied to kimberlite exploration. This paper, which is the last of a three-part series, focuses on extracting chargeability information from time-domain electromagnetic (TEM) data. Three different TEM surveys, having similar coincident-loop geometry, have been carried out over TKC. Each records negative transients over the main kimberlite units and this is a signature of induced polarization (IP) effects. By applying a TEM-IP inversion workflow to a VTEM data set we decouple the EM and IP responses in the observations and then recover 3D pseudo-chargeability models at multiple times. A subsequent analysis is used to recover Cole-Cole parameters. Our models demonstrate that both DO-18 and DO-27 pipes are chargeable, but they have different Cole-Cole time constants: 110 and 1160 µs, respectively. At DO-27, we also distinguish between two adjacent kimberlite units based on their respective Cole-Cole time constants. Our chargeability models are combined with the den-sity, magnetic susceptibility and conductivity models from Papers I and II and allow us to build a 3D petrophysical model of TKC using only information obtained from airborne geophysics. Comparison of this final petrophysical model to a 3D geological model derived from the extensive drilling program demonstrates that we can characterize the three main kimberlite units at TKC: HK, VK, and PK in 3D by using airborne geophysics.
DS200412-0574
2004
Fournier, M.Fournier, M., Jolivet, L., Davy, P., Thomas, J-C.Backarc extension and collision: an experimental approach to the tectonics of Asia.Geophysical Journal International, Vol. 157, 2, pp. 871-889.AsiaTectonics
DS1920-0153
1923
Fournier d'albe, E.E.Fournier d'albe, E.E.The Life of Sir William CrookesLondon: Unwin., 412P.South AfricaBiography, Kimberley Genesis, Sythesis
DS201909-2023
2019
Fouskas, F.Bosco-Santos, A., Gilholy, W.P., Fouskas, F., Baldim, M., Oliveira, E.P.Ferruginous - euxinc - oxic: a three step redox change in the Neoarchean record.Goldschmidt2019, 1p. AbstractSouth America, Brazilcraton

Abstract: Much of the secular record of sulfur mass independet fractionation (S-MIF) is based on pyrites extracted from a limited number of formations from Western Australia and Southern Africa. Here we present multiproxy evidence for an episodic loss of S-MIF in sulfides from a 2.7 Ga sedimentary record in the São Francisco craton, Brazil. Based on combined proxies, we assigned three phases, in a continous drill core, that track evolving water column redox conditions and changes in ecology. In Phase-I, the stratigraphically older rocks, reactive iron ratios suggest ferruginous conditions. The pyrites have modest S-MIF values (D33S from -0.7 to 2.6‰) and the carbon isotope composition of the iron formations is indicative of carbon fixation by anoxygenic photosynthetic bacteria that oxidized Fe2+ (d13Corg from -27.7 to -17.5‰). Within Phase-II, an intermediate phase characterized by graphite schist, the iron ratios, expansion of the S-MIF (D33S from 2.15 to 3.4‰) and an excess of Mo relative to Corg suggest deposition in an anoxic environment with periodic development of euxinic conditions. Phase-III culminates in fully oxic conditions with a loss of S-MIF and emergence of sulfur mass dependent fractionation (S-MDF) with homogeneous d34S pyrite values (average = 3.3 ± 0.5‰). The loss of S-MIF in the Archean sulfides of Phase-III was interpreted as a response to increased oxygen levels that lead to an intensification of oxidative weathering. Based on the continous deposition within this drillcore, the development of more oxidizing conditions may have been relatively rapid, reinforcing the model that the transition from S-MIF to S-MDF can happen on rapid geological time scales and was recorded about 400 million years prior to the GOE in the Brazilian craton.
DS202004-0534
2020
Foustoukos, D.J.Stagno, V., Stopponi, V., Kono, Y., D'Arco, A., Lupi, S., Romano, C., Poe, B.T., Foustoukos, D.J., Scarlato, P., Manning, C.E.The viscosity and atomic structure of volatile bearing melililititic melts at high pressure and temperature and the transport of deep carbon.Minerals MDPI, Vol. 10, 267 doi: 10.23390/min10030267 14p. PdfMantleMelililite, carbon

Abstract: Understanding the viscosity of mantle-derived magmas is needed to model their migration mechanisms and ascent rate from the source rock to the surface. High pressure-temperature experimental data are now available on the viscosity of synthetic melts, pure carbonatitic to carbonate-silicate compositions, anhydrous basalts, dacites and rhyolites. However, the viscosity of volatile-bearing melilititic melts, among the most plausible carriers of deep carbon, has not been investigated. In this study, we experimentally determined the viscosity of synthetic liquids with ~31 and ~39 wt% SiO2, 1.60 and 1.42 wt% CO2 and 5.7 and 1 wt% H2O, respectively, at pressures from 1 to 4.7 GPa and temperatures between 1265 and 1755 °C, using the falling-sphere technique combined with in situ X-ray radiography. Our results show viscosities between 0.1044 and 2.1221 Pa•s, with a clear dependence on temperature and SiO2 content. The atomic structure of both melt compositions was also determined at high pressure and temperature, using in situ multi-angle energy-dispersive X-ray diffraction supported by ex situ microFTIR and microRaman spectroscopic measurements. Our results yield evidence that the T-T and T-O (T = Si,Al) interatomic distances of ultrabasic melts are higher than those for basaltic melts known from similar recent studies. Based on our experimental data, melilititic melts are expected to migrate at a rate ~from 2 to 57 km•yr-1 in the present-day or the Archaean mantle, respectively.
DS2000-0694
2000
FowlerMurphy, J.B., Strachan, R.A., Nance, Parker, FowlerProto-Avalonia: a 1.2 - 1.0 Ga tectonothermal event and constraints for the evolution of Rodinia.Geology, Vol. 28, No. 12, Dec. pp. 1071-4.GlobalGeodynamics, Geochronology
DS1993-0456
1993
Fowler, A.C.Fowler, A.C.Boundary layer theory and subductionJournal of Geophysical Research, Vol. 98, No. B 12, December 10, pp. 21, 997- 22, 005.MantleMantle convection, Plate tectonics
DS1993-0457
1993
Fowler, A.D.Fowler, A.D., Roach, D.E.Dimensionality analysis of time-series data: nonlinear methodsComputers and Geosciences, Vol. 19, No. 1, pp. 41-52GlobalComputer applications, Fractals
DS200912-0298
2009
Fowler, A.F.Hewitt, L.J., Fowler, A.F.Melt characterization in ascending mantle.Journal of Geophysical Research, Vol. 114, B06210.MantleMagma flow, melting
DS200512-0686
2005
Fowler, C.M.Mareschal, J.C., Jaupart, C., Rolandone, F., Gariepy, C., Fowler, C.M., Bienfait, G., Carbonne, C., Lapointe, R.Heat flow, thermal regime, and elastic thickness of the lithosphere in the Trans-Hudson Orogen.Canadian Journal of Earth Sciences, Vol. 42, 4, April pp. 517-532.Canada, Northwest TerritoriesGeothermometry
DS1985-0197
1985
Fowler, C.M.R.Fowler, C.M.R., Nisbet, E.G.The Subsidence of the Wiliston BasinCanadian Journal of Earth Sciences, Vol. 22, pp. 408-15.SaskatchewanCrust - Eustatic Control
DS1992-0479
1992
Fowler, C.M.R.Fowler, C.M.R., Stead, D., Pandit, B.I., Nisbet, E.G.Physical properties of rocks from the Trans-Hudson OrogenEos Transactions, Vol. 73, No. 14, April 7, supplement abstracts p. 322SaskatchewanLithoprobe, Geophysics -magnetics
DS2002-0474
2002
Fowler, C.M.R.Fowler, C.M.R., Ebinger, C., Hawkesworth, C.J.The Early Earth: physical, chemical and biological developmentGeological Society of London (U.K.), 352p.$ 142.00 http://bookshop.geolsoc.org.ukMantleBook - tectonics, deformation, lithosphere, Geophysics, models, plumes
DS2002-0475
2002
Fowler, C.M.R.Fowler, C.M.R., Ebinger, C.J., Hawkesworth, C.J.The early Earth: physical, chemical and biological developmentsGeological Society of London Special Publication, No. 199, 352p. $ 142. http://bookshop.geolsoc.org.ukBookArchean lithosphere, petrology, geophysics, structure, craton - evolution, models, environment
DS2002-0476
2002
Fowler, J.A.Fowler, J.A., Grutter, H.S., Kong, J.M., Wood, B.D.Diamond exploration in Northern Ontario with reference to the Victor kimberlite, near Attawapiskat.Exploration and Mining Geology, Vol. 10, 1-2, pp. 67-75.OntarioExploration - time lines for mining sequence, Evaluation, program
DS201212-0207
2012
Fowler, J.A.Fowler, J.A., Biscaye, E., Metatawabin, S.H.A.Diamond mining and sustainability at De Beers Canadian mines.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractCanada, Ontario, Northwest TerritoriesDebeers - CSR
DS201312-0274
2013
Fowler, J.A.Fowler, J.A., Biscaye, E.S.Diamond mining and sustainability at De Beers' Canadian mines.Proceedings of the 10th. International Kimberlite Conference, Vol. 2, Special Issue of the Journal of the Geological Society of India,, Vol. 2, pp. 289-294.Canada, Ontario, Northwest TerritoriesDeposit - Victor, Snap Lake, CRS
DS201412-0251
2013
Fowler, J.A.Fowler, J.A., Biscaye, E.S., Metatawabin, S.H.A.Diamond mining and sustainability at De Beers' Canadian mines.Proceedings of the 10th. International Kimberlite Conference, Vol. 2, pp. 289-293.Canada, Ontario, Northwest TerritoriesEconomics - social responsibility
DS2001-0326
2001
Fowler, M.Fowler, M.Hope: adventures of a diamondAmazon.com $ approx. 20.00, $ approx. 20.00GlobalBook - history of the Hope Diamond
DS2001-0327
2001
Fowler, M.Fowler, M.Hope: adventures of a diamondAmazon.com $ approx. 20.00, $ approx. 20.00GlobalBook - history of the Hope Diamond
DS1987-0737
1987
Fowler, M.B.Thompson, R.N., Fowler, M.B.Subduction related shoshonitic and ultrapotassic magmatism, a study of Siluro Ordovician syenites from the Scottish CaledonidesContributions to Mineralogy and Petrology, Vol. 94, No. 6, June pp. 507-522ScotlandCaledonide, Shoshonite
DS1990-0661
1990
Fowler, M.B.Harmon, R.S., Fowler, M.B.Oxygen isotope composition of the lower crustV.m. Goldschmidt Conference Held May 2-4, 1990, Program And Abstract, p. 51. Abstract onlyGlobalMantle, Geochronology
DS1996-0465
1996
Fowler, M.B.Fowler, M.B., Henney, P.J.Mixed Caledonian appinite magmas: implications for lamprophyre fractionation and high BaSr granite genesisContributions to Mineralogy and Petrology, Vol. 126, pp. 199-215.ScotlandLamprophyres
DS1993-1196
1993
Fowler, T.K.Jr.Paterson, S.R., Fowler, T.K.Jr.Extensional pluton emplacement models: do they work for large plutoniccomplexes?Geology, Vol. 21, No. 9, September pp. 781-784GlobalMagma emplacement model, Mantle, Tectonics
DS1992-0710
1992
Fox, A.J.Hinze, W.J., Allen, D.J., Fox, A.J., Sunwood, D., Woelk, T., GreenGeophysical investigations and crustal of the North American Midcontinent rift systemTectonophysics, Vol. 213, No. 1-2, special issue, pp. 17-32MidcontinentTectonics, Geophysics
DS1860-0264
1876
Fox, C.Fox, C.A Diamond Field. West Griqualand, South AfricaRoy. Geological Society (cornwall) Report, Vol. 19, No. 2, PP. 165-166.Africa, South Africa, Cape Province, Vaal RiverGeology
DS1920-0105
1922
Fox, C.S.Fox, C.S.Diamond Industry of IndiaDiamond Worker., Nov. P. 4.IndiaMining Methods
DS1988-0042
1988
Fox, J.S.Barrett, T.J., Wares, R.P., Fox, J.S.Two stage hydrothermal formation of a lower Proterozoic sediment hosted massive sulfide deposit, northern Labrador Trough, QuebecCanadian Mineralogist, Vol. 26, pp. 871-888. Database # 17329LabradorSulphides, Deposit- Soucy # 1
DS201812-2883
2018
Fox, K.Sims, K., Fox, K., Harris, M., Chimuka, L., Reichhardt, F., Muchemwa, E., Gowera, R., Hinks, D., Smith, C.B.Murowa deposit: Discovery of the Murowa kimberlites, Zimbabwe.Society of Economic Geology Geoscience and Exploration of the Argyle, Bunder, Diavik, and Murowa Diamond Deposits, Special Publication no. 20, pp. 359-378.Africa, Zimbabwedeposit - Murowa
DS1989-1192
1989
Fox, M.Pell, J., Fox, M.The Kechika yttrium and rare earth prospectBritish Columbia Ministry of Energy, Mines, and Petroleum Resources, Geological Fieldwork Report 1989-1, pp. 417-421British ColumbiaAlkaline igneous, rare earth elements (REE).
DS200512-0301
2005
Fox, O.C.Fox, O.C., Sheehan, A.F.Upper mantle anisotropy beneath Precambrian Province boundaries, Southern Rocky Mountains.American Geophysical Union, Geophysical Monograph, No. 154, pp. 347-360.United States,Wyoming, Colorado PlateauGeophysics - seismics, tectonics
DS201709-2035
2017
Fox, P.Morrison, S.M., Liu, C., Prabhu, E.A., Li, C., Downs, R.J., Golden, J.J., Fox, P., Hummer, D.R., Meyer, M.B., Hazen, R.M.Network analysis of mineralogical systems.American Mineralogist, in press availableTechnologydata sets

Abstract: A fundamental goal of mineralogy and petrology is the deep understanding of mineral phase relationships and the consequent spatial and temporal patterns of mineral coexistence in rocks, ore bodies, sediments, meteorites, and other natural polycrystalline materials. The multi-dimensional chemical complexity of such mineral assemblages has traditionally led to experimental and theoretical consideration of 2-, 3-, or n-component systems that represent simplified approximations of natural systems. Network analysis provides a dynamic, quantitative, and predictive visualization framework for employing “big data” to explore complex and otherwise hidden higher-dimensional patterns of diversity and distribution in such mineral systems. We introduce and explore applications of mineral network analysis, in which mineral species are represented by nodes, while coexistence of minerals is indicated by lines between nodes. This approach provides a dynamic visualization platform for higher-dimensional analysis of phase relationships, because topologies of equilibrium phase assemblages and pathways of mineral reaction series are embedded within the networks. Mineral networks also facilitate quantitative comparison of lithologies from different planets and moons, the analysis of coexistence patterns simultaneously among hundreds of mineral species and their localities, the exploration of varied paragenetic modes of mineral groups, and investigation of changing patterns of mineral occurrence through deep time. Mineral network analysis, furthermore, represents an effective visual approach to teaching and learning in mineralogy and petrology.
DS1990-0966
1990
Fox, P.J.Macdonald, K.C., Fox, P.J.The mid-ocean ridgeOcean Resources NL., Trans Hex International Ltd., Vol. 262, No. 6, June pp. 72-95Ocean RidgeTectonics, Plate tectonics
DS1993-0944
1993
Fox, P.J.Macdonald, K.C., Fox, P.J.It's only topography: part 2Gsa Today, Vol. 3, No. 2, February pp. 29, 30, 31, 34, 35GlobalOverview, Topography -computers
DS1950-0470
1959
Fozzard, P.M.H.Fozzard, P.M.H.Further Notes on the Volcanic Hills of IgwisiGeological Survey TANGANIKA RECORDS, Vol. 6, PP. 69-75.Tanzania, East AfricaGeology, Related Rocks
DS1990-0488
1990
Fozzard, P.M.H.Fozzard, P.M.H.Mining development in sub-Saharan Africa. Investment and its relationship to the enabling environmentNatural Resources forum, May pp. 97-105GlobalEconomics, Diamond production
DS1900-0553
1907
Fraas, E.Fraas, E.Pleistocene Fauna aus den Diamant seifen von SuedafrikaZeitschr. Deut. Geol. Ges., Vol. 59, BD. 1, PP. 232-243.Africa, South AfricaPalaeontology, Diamonds
DS1900-0554
1907
Fraas, E.Fraas, E.Fauna aus den Diamant seifen von Sud AfrikaZeitschr. Deut. Geol. Ges., Vol. 59, HEFT 2, PP. 232-243. ALSO: Neues Jahrbuch fnr MineralogieAfrica, South AfricaStratigraphy, Paleontology, Alluvial Diamond Placers
DS1996-0101
1996
Fracacci, K.N.Beard, B.L., Fracacci, K.N., Sobolev, N.V.Petrography and geochemistry of eclogites from the Mir kimberlite, Russia.Contributions to Mineralogy and Petrology, Vol. 125, No. 4, pp. 293-310.Russia, YakutiaGeochemistry, Deposit - Mir
DS1992-0480
1992
Fracolli, D.Fracolli, D.International initiatives in geoscience information: a global perspectiveGeoscience Information Society, proceedings, October 1991, Vol. 22, 220p. approx. $ 40.00BookGeoscience information, Table of contents
DS201412-0615
2014
Fradkov, A.S.Nauheimer, G., Fradkov, A.S., Neugebaurer, H.J.Mantle convection behaviour with segregation in the core-mantle boundary.Geophysical Research Letters, Vol. 23, 16, pp. 2061-2064.MantleConvection
DS2000-0198
2000
FragaDallagnol, R., Lafon, Fraga, Scandolara, BarrosThe Precambrian evolution of the Amazonian Craton: one of the last unknown Precambrian terranes in the world.Igc 30th. Brasil, Aug. abstract only 1p.Brazil, Guyana ShieldCraton - Amazon, Tectonics
DS201707-1360
2017
Fraga, L.M.Reis, N.J., Nadeau, S., Fraga, L.M., Menezes Betiollo, L., Telma Lins Faraco, M., Reece, J., Lachhman, D., Ault, R.Stratigraphy of the Roraima Supergroup along the Brazil Guyana border in the Guiana shield, northern Amazonian craton - results of the Brazil Guyana geology and geodiversity mapping project.Brazil Journal of Geology, Vol. 47, 1, pp. 43-57.South America, Brazil, Guyanacraton

Abstract: The Geological and Geodiversity Mapping binational program along the Brazil-Guyana border zone allowed reviewing and in- tegrating the stratigraphy and nomenclature of the Roraima Supergroup along the Pakaraima Sedimentary Block present in northeastern Brazil and western Guyana. The area mapped corresponds to a buffer zone of approximately 25 km in width on both sides of the border, of a region extending along the Maú-Ireng River between Mount Roraima (the tri- ple-border region) and Mutum Village in Brazil and Monkey Mountain in Guyana. The south border of the Roraima basin is overlain exclusively by effusive and volcaniclastic rocks of the Surumu Group of Brazil and its correlated equivalent the Burro-Burro Group of Guyana.
DS201803-0447
2017
Fraga, L.M.Fraga, L.M., Cordani, U., Reis, N., Nadeau, S., Camara Maurer, V.U Pb shrimp and La ICPMS new dat a for different A type granites of the Orocaima igneous belt, central Guyana shield, northern Amazonian craton. ( Project Geology of the Guiana Shield)Anais Do 15 Simposio Geologia da Amazonia, Belem , Dec. 5p. Abstract pdfSouth America, Guianacraton

Abstract: The Orocaima Igneous Belt (OIB) is a huge plutono-volcanic belt at the central part of Guiana Shield, consisting mainly of 1.99-1.96 Ga volcano-plutonic rocks with high-K calc-alkaline, A-type and shosho-nitic geochemical signatures. Three A-type granitic bodies from the central part of the OIB have been dated using U-Pb SHRIMP and LA-ICPMS methods. A 1985±11 Ma age was calculated for the Macucal Mountain Granite of the Saracura Suite (Brazil) and ages of 1977±3.9 Ma and 1975±5 were calculated for the alkaline riebeckite granites respectively of the Lontra (Brazil) and Makarapan (Guyana) bodies. These ages are in the same range of those reported for the Aricamã A-type granitoids and the results indicate that different A-type magmatism took place in the 1.993-1.975 Ma interval along the OIB, coeval to high-K calc-alkaline and shoshonitic magmatism. This scenario fits well to a post-collisional setting.
DS201810-2371
2018
Fraga, L.M.Reis, N.J., Nadeau, S., Fraga, L.M., Betiollo, L.M., Faraco, M.T.L., Reece, J., Lachhman, D., Ault, R.Stratigraphy of the Roraima Supergroup along the Brazil-Guyana border in the Guiana shield, northern Amazonian craton- results of the Brazil-Guyana geology and geodiversity mapping project.Brazilian Journal of Geology, Vol. 47, 1, pp. 43-57.South America, Brazil, Guyanacraton

Abstract: The Geological and Geodiversity Mapping binational program along the Brazil-Guyana border zone allowed reviewing and in- tegrating the stratigraphy and nomenclature of the Roraima Supergroup along the Pakaraima Sedimentary Block present in northeastern Brazil and western Guyana. The area mapped corresponds to a buffer zone of approximately 25 km in width on both sides of the border, of a region extending along the Maú-Ireng River between Mount Roraima (the tri- ple-border region) and Mutum Village in Brazil and Monkey Mountain in Guyana. The south border of the Roraima basin is overlain exclusively by effusive and volcaniclastic rocks of the Surumu Group of Brazil and its correlated equivalent the Burro-Burro Group of Guyana.
DS201812-2833
2016
Fraga, L.M.Kroonenberg, S.B., de Roever, E.W.F., Fraga, L.M., Faraco, T., Lafon, J-M., Cordani, U., Wong, T.E.Paleoproterzoic evolution of the Guiana Shield in Suriname: a revised model.Netherlands Journal of Geolsciences, Vol. 95, 4, pp. 491-522.South America, SurinameGuiana shield

Abstract: The Proterozoic basement of Suriname consists of a greenstone-tonalite-trondhjemite-granodiorite belt in the northeast of the country, two high-grade belts in the northwest and southwest, respectively, and a large granitoid-felsic volcanic terrain in the central part of the country, punctuated by numerous gabbroic intrusions. The basement is overlain by the subhorizontal Proterozoic Roraima sandstone formation and transected by two Proterozoic and one Jurassic dolerite dyke swarms. Late Proterozoic mylonitisation affected large parts of the basement. Almost 50 new U-Pb and Pb-Pb zircon ages and geochemical data have been obtained in Suriname, and much new data are also available from the neighbouring countries. This has led to a considerable revision of the geological evolution of the basement. The main orogenic event is the Trans-Amazonian Orogeny, resulting from southwards subduction and later collision between the Guiana Shield and the West African Craton. The first phase, between 2.18 and 2.09 Ga, shows ocean floor magmatism, volcanic arc development, sedimentation, metamorphism, anatexis and plutonism in the Marowijne Greenstone Belt and the adjacent older granites and gneisses. The second phase encompasses the evolution of the Bakhuis Granulite Belt and Coeroeni Gneiss Belt through rift-type basin formation, volcanism, sedimentation and, between 2.07 and 2.05 Ga, high-grade metamorphism. The third phase, between 1.99 and 1.95 Ga, is characterised by renewed high-grade metamorphism in the Bakhuis and Coeroeni belts along an anticlockwise cooling path, and ignimbritic volcanism and extensive and varied intrusive magmatism in the western half of the country. An alternative scenario is also discussed, implying an origin of the Coeroeni Gneiss Belt as an active continental margin, recording northwards subduction and finally collision between a magmatic arc in the south and an older northern continent. The Grenvillian collision between Laurentia and Amazonia around 1.2-1.0 Ga caused widespread mylonitisation and mica age resetting in the basement.
DS201904-0772
2017
Fraga, L.M.Reis, N.J., Nadeau, S., Fraga, L.M., Menezes Betiollo, L., Telma Lins, Faraco, M., Reece, J., Lachhman, D., Ault, R.Stratigraphy of the Roraima Supergroup along the Brazil-Guyana border in the Guiana shield, northern Amazonian craton - results of the Brazil Guyana geology and geodiversity mapping project.Brazilian Journal of Geology, Vol. 41, 1, pp. 43-57.South America, Brazil, GuyanaGuiana shield

Abstract: The Geological and Geodiversity Mapping binational program along the Brazil-Guyana border zone allowed reviewing and integrating the stratigraphy and nomenclature of the Roraima Supergroup along the Pakaraima Sedimentary Block present in northeastern Brazil and western Guyana. The area mapped corresponds to a buffer zone of approximately 25 km in width on both sides of the border, of a region extending along the Maú-Ireng River between Mount Roraima (the triple-border region) and Mutum Village in Brazil and Monkey Mountain in Guyana. The south border of the Roraima basin is overlain exclusively by effusive and volcaniclastic rocks of the Surumu Group of Brazil and its correlated equivalent the Burro-Burro Group of Guyana.
DS201904-0718
1991
Fragoso-Cesar, A.R.Bossi, J., Campal, N., Civetta, L., Demarchi, G., Girardi, V.V., Mazzucchelli, M., Piccirillo, E.M., Rivalenti, G., Sinigol, S., Teixeira, W., Fragoso-Cesar, A.R.Petrological and geochronological aspects of the Precambrian mafic dyke swarm of Uruguay. IN: Eng. Note Date****BOL.IG-USP, Publ.Esp., Vol. 10, pp. 35-42.South America, Uruguaydykes

Abstract: The subparallel maflc dykes of the Aorida-Durazno-S.José region (SW Uruguay) trend N60-80W and vary in thickness from 0.6 to 50 m. They are part of the mafic dyke swarms intrudlng granitic-gnelssic basement that were mappecl by BOSSI et ai. (1989), In an ares approximately 200 km In length and 100 km in bresdth. Plagioclass, augite, subcalclc augite (plgeonite) and opaques are the maln components of the dykes. Orthopyroxene and oIlvine are very rare. Blotite and homblende are secondary minerais. Quartz-feldspar Intergrowths occur In the coarser gralnecl dykes. The characterlstlc textures are subophitic and intersertal.
DS1991-0505
1991
Fralick, P.Fralick, P., Barrett, T.J.Precambrian depositional systems along the southwestern edge of the Superior cratonGeological Association of Canada (GAC) Annual Meeting held Toronto May 1991, Guidebook, No. A3, 55pOntarioArchean sediments, Precambrian depositional systems
DS200512-0127
2004
Fralick, P.Burton, J.P., Fralick, P.Depositional placer accumulations in coarse grained alluvial braided river systems.Economic Geology, Vol. 98, August no. 5, pp. 995-1001.Canada, Alberta, OntarioGeomorphology, placers, indicator minerals
DS1994-0494
1994
Fralick, P.W.Eriksson, K.A., Krapez, B., Fralick, P.W.Sedimentology of Archean greenstone belts: signatures of tectonicevolutionEarth Science Reviews, Vol. 37, pp. 1-88South Africa, Canada, Ontario, Zimbabwe, AustraliaCraton -greenstone belts, Kaapvaal, Superior, Zimbabwe, Pilbara
DS1993-0458
1993
Fram, M.S.Fram, M.S., Lesher, C.E.Geochemical constraints on mantle melting during creation of the North Atlantic basinNature, Vol. 363, No. 6431, June 24, pp. 712-715MantleCraton, Geochemistry
DS1993-0459
1993
Fram, M.S.Fram, M.S., Lesher, C.E.Geochemical constraints on mantle melting during creation of the North-Atlantic BasinNature, Vol. 363, No. 6431, June 24, pp. 712-714MantleGeochemistry, Basin
DS1900-0405
1906
Frames, M.Frames, M.Note on Peridotite Breccia Dykes and Diamond PipesSouth Africa Mines Commerce and Industry, Vol. 4, SEPT. 15TH. PP. 36-37.Africa, South AfricaGeology, Detailed
DS1910-0527
1917
Frames, M.Frames, M.Alluvial Diamond Diggings: Wasted Energy. I. and IiSouth African Mining Journal, Vol. 27, PT. 1, No. 1366, Dec. 1ST. P. 292-293. ALSO: Dec. 8South AfricaMining Economics, Mining Engineering, Conditions
DS1860-1029
1898
Frames, M.E.Draper, D., Frames, M.E.The Diamond (1898)Johannesburg: Mathews And Walker., 40P.Africa, South AfricaProspecting
DS1860-1081
1899
Frames, M.E.Draper, D., Frames, M.E.On the Diamond Pipes of the South African RepublicGeological Society of South Africa Transactions, Vol. 4, PT. 1, P. 5. P. 34.Africa, South AfricaGeology
DS1993-0424
1993
Franca, A.B.Eyles, C.H., Eyles, N., Franca, A.B.Glaciation and tectonics in an active intracratonic basin: the late Palaeozoic Itar are Group, Parana Basin, BrasilSedimentology, Vol. 40, No. 1, February pp. 1-26BrazilGeomorphology, Tectonics
DS201907-1567
2017
Franca, O.S.Pereira, R.G., Fuck, R.A., Franca, O.S., Leite, A.A.Evidence of young, proximal and primary ( YPP) diamond source occurring in alluviums in the Sant Antonio do Bonito, Santo Inacio and Dourahinho rivers in the Coromandel region, Minas Gerais.Brazil Journal of Geology, Vol. 47, 3, pp. 383-401. pdfSouth America, Brazilkimberlites, kamafugites, Tres Ranchos, Coromandel

Abstract: Magmatism associated with the Alto Paranaíba structural high comprises kimberlites, kamafugites, and alkaline complexes, forming an approximately 400 x 150 km NW-SE belt in the southern São Francisco Craton. Dating of some intrusions reveals ages between 120 and 75 Ma. Chemical analyses of garnet recovered in alluvium from traditional diamond digging areas indicate peridotitic garnet windows in Três Ranchos and Coromandel. Six hundred and eighty (680) diamonds acquired or recovered during mineral exploration in the digging areas of Romaria, Estrela do Sul, Três Ranchos and Coromandel show unique characteristics, certain populations indicating young, proximal and primary sources (YPP). Analyses of 201 stones from Santo Antônio do Bonito, Santo Inácio and Douradinho rivers alluvium, Coromandel, present no evidence of transport, characterizing a proximal source. Within these river basins, exposures of the Late Cretaceous Capacete Formation basal conglomerate contain mainly small rounded and/or angular quartzite pebbles and of basic and ultrabasic rocks, as well as kimberlite minerals (garnet, ilmenite, spinel, sometimes diamond). A magnetotelluric profile between the Paraná and Sanfranciscana basins shows that the thick underlying lithosphere in the Coromandel region coincides with the peridotitic garnet window and with a diamond population displaying proximal source characteristics. Diamond-bearing kimberlite intrusions occur in different areas of Alto Paranaíba.
DS1997-0210
1997
Francala, L.Conticelli, S., Francala, L., Manetti, P. Cioni, R.Petrology and geochemistry of the ultrapotassic rocks from the SabatiniJournal of Volcanology, Vol. 75, No. 1-2 Jan. pp. 107-136.ItalyUltrapotassic, Magma
DS1987-0221
1987
Francalanci, L.Francalanci, L., Peccerillo, A., Poli, G.Partition coefficients for minerals in potassium alkaline rocks: dat a from Roman province (Central Italy)Geochemical Journal, Vol. 21, No. 1, pp. 1-10ItalyAlkaline rocks, Analyses
DS1975-0743
1978
France, J.France, J.The Areal Geology and Economic Geology of BotswanaGeol. Pruzkum., Vol. 20, No. 3, PP. 81-84.BotswanaBlank
DS200912-0227
2008
France, L.France, L., Ouillon, N., Chazot, G., Kornprobst, J., Boivin, P.CMAS 3D a new program to visualize and project major element composites in the CMAS system.Computers & Geosciences, in press availableTechnologyMineral chemistry - not specific to diamonds
DS201509-0396
2015
France, L.France, L., Chazot, G., Kornprobst, J., Dallai, L., Vannucci, R., Gregoire, M., Bertrand, H., Boivin, P.Mantle refertilization and magmatism in old orogenic regions: the role of late-orogenic pyroxenites.Lithos, Vol. 232, pp. 49-75.Africa, Morocco, Cameroon, Jordan, Europe, FranceXenoliths

Abstract: Pyroxenites and garnet pyroxenites are mantle heterogeneities characterized by a lower solidus temperature than the enclosing peridotites; it follows that they are preferentially involved during magma genesis. Constraining their origin, composition, and the interactions they underwent during their subsequent evolution is therefore essential to discuss the sources of magmatism in a given area. Pyroxenites could represent either recycling of crustal rocks in mantle domains or mantle originated rocks (formed either by olivine consuming melt-rock reactions or by crystal fractionation). Petrological and geochemical (major and trace elements, Sr-Nd and O isotopes) features of xenoliths from various occurrences (French Massif-Central, Jordan, Morocco and Cameroon) show that these samples represent cumulates crystallized during melt percolation at mantle conditions. They formed in mantle domains at pressures of 1-2 GPa during post-collisional magmatism (possibly Hercynian for the French Massif-Central, and Panafrican for Morocco, Jordan and Cameroon). The thermal re-equilibration of lithospheric domains, typical of the late orogenic exhumation stages, is also recorded by the samples. Most of the samples display a metasomatic overprint that may be either inherited or likely linked to the recent volcanic activity that occurred in the investigated regions. The crystallization of pyroxenites during late orogenic events has implications for the subsequent evolution of the mantle domains. The presence of large amounts of mantle pyroxenites in old orogenic regions indeed imparts peculiar physical and chemical characteristics to these domains. Among others, the global solidus temperature of the whole lithospheric domain will be lowered; in turn, this implies that old orogenic regions are refertilized zones where magmatic activity would be enhanced.
DS201709-1985
2017
France, L.France, L., Boulanger, M., Mollex, G., Devidal, J-L. .Oldoinyo Lengai natrocarbonatite derives from calciocarbonatite.Goldschmidt Conference, abstract 1p.Africa, Tanzaniadeposit, Oldoinyo

Abstract: Carbonatites are rare magmas containing almost no silica; the corresponding crystallized rocks represent the main rare earth elements (REE) deposits in production. Oldoinyo Lengai (Tanzania) is the only active carbonatite volcano on Earth, and may be used as a natural laboratory to identify the parameters responsible for the genesis of the >500 reported fossil occurrences of carbonatite magmas. Nevertheless the carbonatites emitted at Oldoinyo Lengai are unique as alkalirich (natrocarbonatites), and their origin may not be representative of the fossil carbonatites (calcio-, ferro-, magnesio-carbonatites). Here we use three-phases melt inclusions trapped in clinopyroxenes and nephelines from cognate cumulates – that sample the active magma chamber of Oldoinyo Lengai – emitted during the 2007-08 sub-plinian explosive eruption to track the carbonatite presence within the plumbing system, and to eventually quantify its composition at depth. We show that although natrocarbonatites are emitted at Oldoinyo Lengai summit, more classical calciocarbonatites are present at magma chamber depth, consistent with rare natrocarbonatites being derived from more classical calciocarbonatites by further magma differentiation. Those unique cognate samples allows us to provide the first direct measurements of partition coefficients for major and trace elements of natural coexisting in equilibrium carbonatite and silicate melts. Partition coefficients suggests that natrocarbonatites derive from calciocarbonatites by fractionating Ca-rich, and Na-poor phases. The Oldoinyo Lengai can therefore be used as a perfect analogue of fossil igneous systems that are now exhumed, commonly lacking any relation with the initial geodynamic setting, and form REE mineral deposits.
DS201709-2034
2017
France, L.Mollex, G., France, L., Furi, E., Bonnet, R., Botcharnikov, R.E., Zimmermann, L., Wilke, S., Deloule, E., Chazot, G., Kazimoto. E.O., Marty, B., Burnard, P.The Oldoinyo Lengai volcano plumbing system architecture, and composition from source to surface.Goldschmidt Conference, abstract 1p.Africa, Tanzaniadeposit, Oldoinyo

Abstract: Cognate xenoliths that have been emitted during the last sub-plinian eruption in 2007-08 at Oldoinyo Lengai (OL) represent a unique opportunity to document the igneous processes occuring within the active magma chamber. Detailed petrographic descriptions coupled to a thermobarometric approach, and to the determination of volatile solubility models, allow us to identify the melt evolution at magma chamber conditions, and the storage parameters (P, T). Results indicate that a fresh phonolite melt (~1060°C) was injected into a crustal magma chamber at 11.5 ±3.5 km depth, in agreement with geophysical surveys performed during the eruption. The phonolite contains high volatile contents: 3.2 wt.% H2O and 1.4 wt.% CO2. The liquid line of descent highlights an evolution to nephelinite compositions by cooling down to 880°C. Our results support previous results related to this eruption, and are similar to the historical products emitted during the whole volcano history, allowing us to suggest that no major modification in the plumbing system has occured during the OL evolution. New noble gas results show that: i. fumaroles display constant He isotopic signature since 1988; ii. Cognate xenoliths documenting the active magma chamber and fumaroles display similar He isotopic values (6.58±0.46RA, and 7.31±0.40RA, respectively); iii. OL He isotopic composition is similar to that of other silicate volcanoes of the Arusha region, and comparable to the typical subcontinental lithospheric mantle (SCLM) range (5.2 to 7.0 RA); iv. Ne isotopic ratio of OL is following the MORB signature. Those results are interpreted as showing that 1/ no major modification in the hydrothermal system architecture has occured since 1988 despite major modification of the summit crater morphology, 2/ no contamination by either the atmospheric gases, or crustal material assimilation has occured between the magma chamber and the surface, and 3/ the source of OL and of the other silicate volcanoes in the Arusha region is a SCLM metasomatized by asthenospheric fluids.
DS201802-0240
2018
France, L.Gu, X., Ingrin, J., Deloule, E., France, L., Xia, Q.Metasomatism in the sub-continental lithospheric mantle beneath the south French Massif Central: constraints from trace elements, Li and H in peridotite minerals.Chemical Geology, Vol. 478, pp. 2-17.Europe, Franceperidotite

Abstract: Mantle metasomatism by percolating melts/fluids can significantly modify the geochemical and mineralogical compositions of the sub-continental lithospheric mantle (SCLM). We present a detailed study of water contents and Li concentrations and isotopic compositions in mantle minerals from a suite of peridotite xenoliths entrained by a Cenozoic Strombolian volcano in the southern French Massif Central (FMC). Wide ranging clinopyroxene trace element distributions (e.g., (La/Yb)N from 0.25 to 22.21; Ti/Eu ratios from 453 to 4892) suggest that the SCLM has undergone metasomatism by carbonatitic melts/fluids or melts/fluids related to subducted materials. Two amphibole-bearing samples exhibit depletion of light rare earth elements (LREE; (La/Yb)N = 0.26 and 0.30, respectively) in amphiboles, similar to that in co-existing clinopyroxenes; these samples indicate that amphiboles grew during a separate modally metasomatic event predating the cryptic metasomatism accounting for LREE enrichment and negative HFSE anomalies in other samples. Mineral Li concentrations are similar to those in the normal mantle, with inter-mineral Li partitioning nearly equilibrated and intragranular Li distributions nearly homogeneous. However, negative d7Li values of pyroxenes in some samples (as low as - 8.8‰ in clinopyroxene of sample MC38) can be attributed to diffusive exchange with a small-volume melt of moderate Li concentration and light Li isotopic composition, originally associated with a recycled component. Preservation of the currently observed large inter-mineral Li isotopic variations indicates that melt percolation occurred shortly before entrainment of the peridotite xenoliths by the host magma. Mineral water contents vary from 41 to 428 ppm in clinopyroxenes and from 28 to 152 ppm in orthopyroxenes, and their roughly negative co-variation with coexisting olivine Fo contents imply that partial melting was the main control over mineral water content variations in most samples. Varied water contents in LREE-enriched metasomatized samples indicate the involvement of metasomatic agents of different origins. The aqueous agent responsible for generation of amphiboles in two samples did not produce a notable increase in the water contents of coexisting nominally anhydrous minerals.
DS201909-2020
2019
France, L.Baudouin, C., France, L., Boulanger, M., Dalou, C., Devidal, J-L.New constraints on trace element partitioning between minerals and alkaline melts.Goldschmidt2019, 1p. AbstractGlobalalkaline rocks
DS201909-2063
2019
France, L.Mollex, G., France, L., Boulanger, M., Devidal, J-L.Oldoinyo Lengai natrocarbonatites derive from classical calciocarbonatites: a melt inclusion approach.Goldschmidt2019, 1p. AbstractAfrica, Tanzaniadeposit - Oldoinyo Lengai

Abstract: Carbonatites are rare magmas containing almost no silica; their igneous counterparts represent the main rare earth element deposits inoperation. No consensus exists on their origin, genesis and evolution. Oldoinyo Lengai (Tanzania) is the only active carbonatite volcano, but the alkali-rich natrocarbonatites it erupts are unique among the >500 reported fossil carbonatite occurrences. Here, we use threephase melt inclusions hosted in minerals from cognate cumulates (clinopyroxene, nepheline, Ti-garnet, interstitial melt)— which sampled the active Oldoinyo Lengai magma chamber during the 2007-08 sub-Plinian explosive eruption—to track the carbonatite presence within the plumbing system, and to eventually quantify its composition at depth. We show that although natrocarbonatites are emitted at the Oldoinyo Lengai summit, more classical calciocarbonatites are present at magma chamber depth (~3.5 kbar, 1050 to 900°C), which is consistent with the model of rare natrocarbonatites deriving from calciocarbonatites by further magma differentiation. We also show that those calciocarbonatites are not isolated but rather conjugated with alkali-rich silica melt suggesting a joint evolution. We eventually present the first direct measurements of major and trace element partition coefficients between natural coexisting carbonate and silicate melts. Partitioning behaviour and recent experiments support our conclusion that natrocarbonatites derive from calciocarbonatites by fractionating Ca-rich, Na-poor phases. As natrocarbonatites are highly unstable at surface conditions, they were likely erupted but not preserved in association with fossil calciocarbonatites worldwide. Oldoinyo Lengai can then be considered as representative of other carbonatite systems, and provide us with the unique opportunity to observe the plumbing system architecture, and to constrain the protracted differentiation path of a carbonatite system.
DS202006-0911
2020
France, L.Baudouin, C., France, L., Boulanger, M., Dalou, C., Devidal, J-L.Trace element partitioning between clinopyroxene and alkaline magmas: parametrization and role of M1 site on HREE enrichment in clinopyroxenes.Contributions to Mineralogy and Petrology, Vol. 175, 15p. PdfAfrica, Tanzaniadeposit - Oldoinyo Lengai

Abstract: Trace element partitioning between minerals and liquids provides crucial constraints on igneous processes. We quantified trace element concentrations in clinopyroxene (Cpx) phenocrysts and their phonolite melt inclusions from the 2007-08 eruption of Oldoinyo Lengai (Tanzania), and report Cpx-melt partition coefficients (D) and corresponding partitioning equations for rare earth elements (REE) and high field strength elements (HFSE) in alkaline magmas. Heavy REE (HREE: Er, Tm, Yb, Lu) are enriched relative to middle REE in alkaline Cpx and display a specific partitioning behavior that is characteristic of alkaline systems. HFSE (Ti, Zr, Hf) and HREE have similar D values (DHf?=?0.25; DLu?=?0.4) that are significantly higher than MREE (DSm?=?0.06). High DHREE/DMREE are strongly correlated with the high values of DZr and DHf relative to the low DMREE values. In this study, REE partitioning between phonolite melt and Cpx is not consistent with standard models assuming incorporation of all REE in the Cpx M2 site, but rather highlights HREE substitution in both the M1 and M2 sites. Here we highlight the preferential incorporation of HREE in the VI-coordinated M1 site, whereas light REE and MREE remain mostly distributed in the VIII-coordinated M2 site. REE partitioning is strongly dependent on Cpx chemistry: the ideal ionic radius and HREE incorporation in the M1 site increase with increasing Fe3+ content and decrease with increasing Mg2+ and AlVI content. In our study, we focus on alkaline evolved magmas, and update existing models to obtain adequate DHREE for alkaline evolved melts. We provide equations to quantify REE and HFSE partitioning, and HREE enrichment in Cpx that are based on Cpx major element composition and temperature. We propose a new model based on the lattice strain approach that predicts HREE partitioning between Cpx and alkaline magmas. The knowledge of the melt composition or of the trace element contents is not required to obtain DREE from the new model. An improved parameterization of HFSE partitioning between Cpx and phonolite and trachy-phonolite melts is also provided herein. We discuss the potential implications of the new data on our understanding of REE deposits that are commonly associated with igneous alkaline complexes.
DS202011-2033
2020
France, L.Casola, V., France, L., Galy, A., Bouden, N., Villeneuve, J.No evidence for carbon enrichment in the mantle source of carbonatites in eastern Africa.Geology, Vol. 48, 10, pp. 971976. pdfAfrica, Tanzaniadeposit - Oldoinyo Lengai

Abstract: Carbonatites are unusual, carbon-rich magmas thought to form either by the melting of a carbon-rich mantle source or by low-degree partial melting of a carbon-poor (<80 ppm C) mantle followed by protracted differentiation and/or immiscibility. Carbonate-bearing mantle xenoliths from Oldoinyo Lengai (East African Rift), the only active volcano erupting carbonatites, have provided key support for a C-rich mantle source. Here, we report unique microscale O and C isotopic analyses of those carbonates, which are present as interstitial grains in the silicate host lava, veins in the xenoliths, and pseudo-inclusions in olivine xenoliths. The d18O values vary little, from 19‰ to 29‰, whereas d13C values are more variable, ranging from -23‰ to +0.5‰. We show that such carbonate d18O values result from the low-temperature precipitation of carbonate in equilibrium with meteoric water, rather than under mantle conditions. In this framework, the observed d13C values can be reproduced by Rayleigh distillation driven by carbonate precipitation and associated degassing. Together with petrological evidence of a physical connection between the three types of carbonates, our isotopic data support the pedogenic formation of carbonates in the studied xenoliths by soil-water percolation and protracted crystallization along xenolith cracks. Our results refute a mechanism of C enrichment in the form of mantle carbonates in the mantle beneath the Natron Lake magmatic province and instead support carbonatite formation by low-degree partial melting of a C-poor mantle and subsequent protracted differentiation of alkaline magmas.
DS202012-2210
2020
France, L.Casola, V., France, L., Galy, A., Bouden, N., Villeneuve, J.No evidence for carbon enrichment in the mantle source of carbonatites in eastern Africa.Geology, Vol. 48, 10, 5p. PdfAfrica, Tanzaniacarbonatites

Abstract: Carbonatites are unusual, carbon-rich magmas thought to form either by the melting of a carbon-rich mantle source or by low-degree partial melting of a carbon-poor (<80 ppm C) mantle followed by protracted differentiation and/or immiscibility. Carbonate-bearing mantle xenoliths from Oldoinyo Lengai (East African Rift), the only active volcano erupting carbonatites, have provided key support for a C-rich mantle source. Here, we report unique microscale O and C isotopic analyses of those carbonates, which are present as interstitial grains in the silicate host lava, veins in the xenoliths, and pseudo-inclusions in olivine xenoliths. The d18O values vary little, from 19‰ to 29, whereas d13C values are more variable, ranging from -23‰ to +0.5‰. We show that such carbonate d18O values result from the low-temperature precipitation of carbonate in equilibrium with meteoric water, rather than under mantle conditions. In this framework, the observed d13C values can be reproduced by Rayleigh distillation driven by carbonate precipitation and associated degassing. Together with petrological evidence of a physical connection between the three types of carbonates, our isotopic data support the pedogenic formation of carbonates in the studied xenoliths by soil-water percolation and protracted crystallization along xenolith cracks. Our results refute a mechanism of C enrichment in the form of mantle carbonates in the mantle beneath the Natron Lake magmatic province and instead support carbonatite formation by low-degree partial melting of a C-poor mantle and subsequent protracted differentiation of alkaline magmas.
DS1992-0072
1992
Franceschi, G.Bakker, P.J., Franceschi, G., Kieley, J.W.The use of electromagnetic and magnetic methods in the exploration for kimberlitic rock: a case history from Western KenyaJournal of African Earth Sciences, Vol. 14, No. 4, May pp. 511-518KenyaGeophysics -magnetics, Kimberlites
DS1997-0171
1997
Franceschi, G.Castelli, D., Connolly, J., Franceschi, G.VERTEXVIEW: an interactive program to analyze and plot petrological phasediagramsComputers and geosciences, Vol. 23, No. 8, pp. 883-888GlobalComputer - VERTEXVIEW., Petrology
DS1982-0529
1982
Francesson, E.V.Rozova, E.V., Francesson, E.V., et al.Ferrigenous Chromespinelides in Kimberlites of YakutiaAcademy of Science USSR GEOL. SERIES, No. 11, PP. 78-86.RussiaKimberlite
DS2001-0563
2001
Francheschi, D.Kahn, J.R., Francheschi, D., Curi, A., Vale, E.Economic and financial aspects of mine closureNatural Res. Forum, Vol. 25, No. 4, pp. 265-74.GlobalLegal - economics, Mine closure
DS1992-0570
1992
Franchi, I.A.Gilmour, I., Russell, S.S., Arden, J.W., Lee, M.R., Franchi, I.A.Terrestrial carbon and nitrogen isotopic ratios from Cretaceous-Tertiary boundary nanodiamondsScience, Vol. 258, December 4, pp. 1624-1626GlobalGeochronology, Nanodiamonds
DS201412-0577
2014
Franchi, I.A.Mikhail, S., Guillermier, C., Franchi, I.A., Beard, A.D., Crispin, K., Verchovsky, A.B., Jones, A.P., Milledge, H.J.Empirical evidence for the fractionation of carbon isotopes between diamond and iron carbide from the Earth's mantle.Geochemistry, Geophysics, Geosystems: G3, Vol. 15, 4, pp. 855-866.MantleGeochronology
DS2003-0935
2003
Franciosi, L.Melluso, L., Morra, V., Brotzu, P., Franciosi, L., Lieberknecht, A.M.P., BennioGeochemical provinciality in the Cretaceous basaltic magmatism of northernJournal of the Geological Society of London, Vol. 160, 3, pp. 477-488.MadagascarBlank
DS2003-0936
2003
Franciosi, L.Melluso, L., Morra, V., Brotzu, P., Franciosi, L., Petteruti Lieberknecht, A.M.Geochemical provinciality in the Cretaceous basaltic magmatism of northernJournal of the Geological Society of London, Vol. 160, 3, May pp. 477-88.MadagascarMagmatism - not specific to diamonds
DS200412-1295
2003
Franciosi, L.Melluso, L., Morra, V., Brotzu, P., Franciosi, L., Lieberknecht, A.M.P., Bennio, L.Geochemical provinciality in the Cretaceous basaltic magmatism of northern Madagascar: mantle source immplications.Journal of the Geological Society, Vol. 160, 3, pp. 477-488.Africa, MadagascarGeochemistry - not specific to diamonds
DS200412-1296
2003
Franciosi, L.Melluso, L., Morra, V., Brotzu, P., Franciosi, L., Petteruti Lieberknecht, A.M., Benno, L.Geochemical provinciality in the Cretaceous basaltic magmatism of northern Madagascar: mantle source implications.Journal of the Geological Society, Vol. 160, 3, May pp. 477-88.Africa, MadagascarMagmatism - not specific to diamonds
DS200512-0716
2005
Franciosi, L.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
DS1984-0146
1984
FrancisBedard, J.H., Francis, HYNES, Nadeau.Fractionation in the Feeder System at a Proterozoic Rifted MarginCanadian Journal of Earth Sciences, Vol. 21, pp. 489-99.GlobalBasalts, Tectonics
DS1992-0512
1992
FrancisGaonach, H., Ludden, Picard, FrancisHighly alkaline lavas in a Proterozoic rift zone: implications for Precambrian mantle metasomatic processGeology, Vol. 20, Mar. pp. 247-50.Labrador, Ungava, QuebecTectonics, Cape Smith thrust belt, Mantle metasomatism, Alkaline lavas, Nephelinites, basanites
DS1998-0734
1998
FrancisKent, A.J.R., Stolper, Woodhead, Hutcheon, FrancisUsing glass inclusions to investigate a heterogeneous mantle: an example from N and EMORB like lavas BaffinMineralogical Magazine, Goldschmidt abstract, Vol. 62A, p. 765-6.Northwest Territories, Baffin IslandBasalts - phenocrysts, olivine
DS1989-0939
1989
Francis, C.A.Mariano, A.N., Francis, C.A.Dalyite from fenites in carbonatite complexes of the Minas Gerais-Goiasbelt, BrasilGeological Society of America (GSA) Annual Meeting Abstracts, Vol. 21, No. 6, p. A46. AbstractBrazilCarbonatite, Mineralogy -Dalyite
DS201412-0252
2014
Francis, C.A.Francis, C.A., Betts, J.H.Coming to terms with diamonds: a matter of facts.Rocks and Minerals, Jan.-Feb. pp. 30-34.Diamond terms
DS1985-0198
1985
Francis, D.Francis, D.The Baffin Bay lavas and the value of picrites as analogues ofprimarymagmasContributions to Mineralogy and Petrology, Vol. 89, No. 2-3, pp. 144-154Northwest Territories, Padloping IslandPicrite
DS1986-0253
1986
Francis, D.Francis, D.The pyroxene paradox in Mid Ocean Ridge Basalt (MORB) glasses- a signature of picriticparentalmagmasNature, Vol. 319, No. 6054, Feb. 13, pp. 586-588GlobalPicrite
DS1987-0222
1987
Francis, D.Francis, D.Mantle melt interaction recorded in spinel lherzolite xenoliths from the Alligator Lake volcanic complex, Yukon CanadaJournal of Petrology, Vol. 28, pt. 3, pp. 569-597YukonMagma genesis, Xenolith
DS1989-0443
1989
Francis, D.Francis, D.Mantle xenoliths and the sources of alkaline magmasGeological Association of Canada (GAC) Annual Meeting Program Abstracts, Vol. 14, p. A50. (abstract.)GlobalExperimental Petrology, Xenoliths
DS1989-0444
1989
Francis, D.Francis, D., Ludden, J.The mantle sources for Quaternary alkaline volcanism in the Northern Canadian CorrdilleraNew Mexico Bureau of Mines Bulletin., Continental Magmatism Abstract Volume, Held, Bulletin. No. 131, p. 97 Abstract held June 25-July 1British Columbia, YukonVolcanology, Mantle
DS1990-0489
1990
Francis, D.Francis, D., Ludden, J.The mantle source for olivine nephelinite, basanite and alkaline olivine basalt at Fort Selkirk, Yukon,CanadaJournal of Petrology, Vol. 31, No. 2, pp. 371-400YukonBasanite, Alkaline rocks
DS1990-1082
1990
Francis, D.Nadeau, S., Pineau, F., Javoy, M., Francis, D.Carbon concentrations and isotopic ratios in fluid-inclusion bearing upper mantle xenoliths along the northwestern margin of North AmericaChemical Geology, Vol. 81, No. 4, February 20, pp. 271-298United StatesGeochemistry, Xenolith inclusions
DS1991-0506
1991
Francis, D.Francis, D.Some implications of xenolith glasses for the mantle sources of alkaline mafic magmasContributions to Mineralogy and Petrology, Vol. 108, No. 1-2, pp. 175-180GlobalXenoliths, Mantle
DS1992-0481
1992
Francis, D.Francis, D., Chartrand, A., Ludden, J.Implications of HFS/LIL trace element variations for the mantle sources of recent alkaline volcanism in northern British Columbia and the Yukon, CanadaEos Transactions, Vol. 73, No. 14, April 7, supplement abstracts p.325British Columbia, YukonAlkaline volcanism., Geochemistry
DS1992-1283
1992
Francis, D.Robillard, I., Francis, D., Ludden, J.N.The relationship between E and N type magmas in the Baffin Bay lavasContribution to Mineralogy and Petrology, Vol. 112, pp. 230-241.GlobalPicrite, Crustal contamination
DS1993-1607
1993
Francis, D.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
DS1994-0541
1994
Francis, D.Francis, D.Chemical interaction between picrite magmas and upper crust along the margins of the Muskox intrusionGeological Survey of Canada Paper, No. 92-12, 94pNorthwest TerritoriesMagma, Muskox intrusion
DS1994-0542
1994
Francis, D.Francis, D., Ludden, J., Shi, L.Tertiary olivine nephelinite intrusions of the Mount Llangorse alkaline volcanic field of northern British Columbia.Geological Association of Canada (GAC) Abstract Volume, Vol. 19, p.British ColumbiaAlkaline rocks, Llangorse
DS1994-0802
1994
Francis, D.Hynes, A., Francis, D., Legault, F.Basalt petrochemistry as a probe of crustal thickness in the Hudson BayArc, Quebec.Earth and Planetary Science Letters, Vol. 127, No. 1-4, October pp. 11-24.QuebecGeochemistry, Crustal thickness
DS1994-1023
1994
Francis, D.Legault, F., Francis, D., Hynes, A., Budkewitsch, P.Proterozoic continental volcanism in the Belcher Islands: implications For the evolution Circum UngavaCanadian Journal of Earth Sciences, Vol. 31, pp. 1536-49.Quebec, Ungava, Labrador, Belcher Islandsvolcanism., Fold Belt
DS1995-0462
1995
Francis, D.Dunphy, J.M., Ludden, J.N., Francis, D.Geochemistry of mafic magmas from the Ungava orogen : implications for mantle reservoir compositions at 2.OGaChemical Geology, Vol. 120, pp. 361-380Quebec, Labrador, UngavaGeochemistry, Proterozoic mobile belts
DS1995-0558
1995
Francis, D.Francis, D.The implications of picritic lavas for the mantle sources of terrestrialvolcanism.Lithos, Vol. 34, No. 1-3, Jan. pp. 89-106MantleMagmatism, Picrites
DS1995-0559
1995
Francis, D.Francis, D., Ludden, J.The signature of amphibole in mafic alkaline lavas, a study in the Northern Canadian Cordillera.Journal of Petrology, Vol. 36, No. 5, Oct. 1, pp. 1171-1192.British Columbia, YukonAlkaline rocks
DS1996-0229
1996
Francis, D.Carignan, J., Ludden, J., Francis, D.On the recent enrichment of subcontinental lithosphere: a detailed uranium-lead (U-Pb)study of spinel lherzolite xenoliths...Geochimica et Cosmochimica Acta, Vol. 60, No. 21, pp. 4241-52.YukonXenoliths
DS1997-0015
1997
Francis, D.Akinin, V.V., Roden, M., Francis, D., Apt, J., Moll-StalcupCompositional and thermal state of the upper mantle beneath the Bering Seabasalt Province: evidence....Canadian Journal of Earth Sciences, Vol. 34, No. 6, June pp. 789-800.RussiaChukchi Peninsula, Basalts
DS1997-0358
1997
Francis, D.Francis, D., et al.Mantle xenolith and alkaline basalt mapping of the lithospheric mantle beneath northwestern Canada.Lithoprobe Slave/SNORCLE., p. 128.MantleXenolith
DS1998-1294
1998
Francis, D.Schmidberger, S.S., Francis, D.The deep cratonic mantle roots beneath the Canadian craton: mantle xenolith evidence from Somerset Island.Mineralogical Magazine, Goldschmidt abstract, Vol. 62A, p. 1340.Northwest Territories, Somerset IslandOrthopyroxene, Deposit - Nikos
DS1998-1295
1998
Francis, D.Schmidberger, S.S., Francis, D.lead, neodymium, Strontium, Hafnium isotope dat a for Somerset Island mantle xenoliths - evidence for Archean deep mantle roots...Geological Association of Canada (GAC)/Mineralogical Association of, p. A167. abstract.Northwest Territories, Somerset IslandXenolith - petrology, Nikos kimberlites
DS1998-1334
1998
Francis, D.Shi, L., Francis, D., Bostock, M.Xenolith evidence for lithospheric melting above anomalously hot mantle under the northern Cordillera.Contributions to Mineralogy and Petrology, Vol. 131, No. 1, pp. 39-53.Canada, Northwest TerritoriesXenoltihs
DS1999-0222
1999
Francis, D.Francis, D., Ludden, J., Davis, W.Picrite evidence for more iron in Archean mantle reservoirsEarth and Planetary Science Letters, Vol. 167, No. 3-4, Apr. 15, pp. 197-214.MantlePicrite, Magma
DS1999-0633
1999
Francis, D.Schmidberger, S.S., Francis, D.Nature of the mantle roots beneath the North American Craton: mantle xenolith evidence from Somerset Island.Lithos, Vol. 48, No. 1-4, Sept. pp. 195-216.Northwest Territories, Somerset IslandXenoliths, Craton
DS2000-0674
2000
Francis, D.Modeland, S., Francis, D., Hynes, A.Geochemistry of mafic lavas from the Cape Smith foldbelt: as an eg. Paleoproterozoic Hawaiian hotspot?Geological Association of Canada (GAC)/Mineralogical Association of Canada (MAC) 2000 Conference, 1p. abstract.Quebec, Labrador, UngavaMagmatism, Mobile Belt
DS2000-0760
2000
Francis, D.Peslier, A.H., Reisberg, L., Francis, D.Rhenium- Osmium (Re-Os) constraints on harzburgite and lherzolite formation in the lithospheric mantle: a study xenolithsGeochimica et Cosmochimica Acta, Vol. 64, No. 17, Sept. 1, pp. 3061-Northwest Territories, Western Canada, AlbertaXenoliths, Geochronology
DS2001-0003
2001
Francis, D.Abraham, A.C., Francis, D., Polve, M.Recent alkaline basalts as probes of the lithospheric mantle roots of the Northern Canadian Cordillera.Chemical Geology, Vol. 175, pp. 361-86.Yukon, British Columbia, CordilleraTectonics, Geochronology
DS2001-0328
2001
Francis, D.Francis, D.Cratonic mantle roots: the remnants of a chondritic Archean mantleKegs Diamond Short Course, Prospectors And Developers Association Of Canada (pdac)., MantleCraton - chondrites
DS2001-0329
2001
Francis, D.Francis, D.The composition, age and origin of the Canadian continental lithospheric mantle #1Slave-Kaapvaal Workshop, Sept. Ottawa, 2p. abstractNorthwest Territories, MantleGeochemistry, geochronology, Jericho, Somerset, Cordillera
DS2001-0330
2001
Francis, D.Francis, D., Schmidberger, S.The composition, age and origin of the Canadian continental lithospheric mantle #2Prospectors and Developers Association of Canada (PDAC) Short Course, 23p.Northwest Territories, Manitoba, Saskatchewan, OntarioXenolith - suites, Geochronology
DS2001-1031
2001
Francis, D.Schmidberger, S.S., Francis, D.Constraints on the trace element composition of the Archean mantle root beneath Somerset Island, Arctic .Journal of Petrology, Vol. 42, No. 6, pp. 1095-1118.Northwest Territories, Nunavut, Somerset IslandGeochemistry
DS2001-1032
2001
Francis, D.Schmidberger, S.S., Simonetti, A., Francis, D.Strontium, neodymium, lead isotopes systematics of mantle xenoliths from Somerset island kimberlites. ( age 100 Ma).Geochimica et Cosmochimica Acta, Vol. 65, No. 22, pp. 4243-55.Northwest Territories, Somerset IslandGeochronology - peridottites, pyroxenite xenoliths, Deposit - Nikos
DS2002-1069
2002
Francis, D.Modeland, S., Francis, D.Paleoproterozoic magmatism of central Baffin Island NunuvutGac/mac Annual Meeting, Saskatoon, Abstract Volume, P.76., p.76.Northwest Territories, Nunavut, Baffin IslandPicrites
DS2002-1070
2002
Francis, D.Modeland, S., Francis, D.Paleoproterozoic magmatism of central Baffin Island NunuvutGac/mac Annual Meeting, Saskatoon, Abstract Volume, P.76., p.76.Northwest Territories, Nunavut, Baffin IslandPicrites
DS2002-1420
2002
Francis, D.Schmidberger, S., Simonetti, A., Francis, D., GariepyProbing Archean lithosphere using the Lu Hf isotope systematics of peridotite xenoliths Somerset Island.Earth and Planetary Science Letters, Vol.197,3-4,pp.245-59.Northwest Territories, Somerset IslandCraton, geochronology, Deposit - Nikos
DS2003-0421
2003
Francis, D.Francis, D.Implication of major element composition for the mantle sources of kimberlite, aillikite8 Ikc Www.venuewest.com/8ikc/program.htm, Session 7, AbstractMantleKimberlite petrogenesis, Review
DS2003-0422
2003
Francis, D.Francis, D.Cratonic mantle roots, remnants of a more chrondritic Archean mantle?Lithos, Vol. 71, 2-4, pp. 135-152.MantlePetrology - chrondite
DS2003-0423
2003
Francis, D.Francis, D., Abraham, A.C.Interrogating the Cordillera lithosphere with mafic volcanics and mantle xenolithsGeological Association of Canada Annual Meeting, Abstract onlyNorthwest TerritoriesXenoliths
DS2003-0962
2003
Francis, D.Modeland, S., Francis, D., Hynes, A.Enriched mantle components in Proterozoic continental flood basalts of the Cape SmithLithos, Vol. 71, 1, Nov. pp. 1-17.QuebecAlkaline rocks, Magmatism
DS2003-1226
2003
Francis, D.Schmidberger, S.S., Simonetti, A., Francis, D.Small scale Sr isotope investigation of clinopyroxenes from peridotite xenoliths by laserChemical Geology, Vol. Sept. 15, pp. 317-329.Somerset IslandGeochronology, Deposit - Nikos
DS2003-1227
2003
Francis, D.Schmidberger, S.S., Simonetti,. A., Francis, D.Small scale Sr isotope investigation of clinopyroxenes from peridotite xenoliths by laserChemical Geology, Vol. 199, No. 3-4, pp.317-29.MantleBlank
DS200412-0575
2003
Francis, D.Francis, D.Implication of major element composition for the mantle sources of kimberlite, aillikite, olivine lamproite and meimechite.8 IKC Program, Session 7, AbstractMantleKimberlite petrogenesis Review
DS200412-0576
2003
Francis, D.Francis, D.Cratonic mantle roots, remnants of a more chrondritic Archean mantle?Lithos, Vol. 71, 2-4, pp. 135-152.MantlePetrology - chrondite
DS200412-0577
2003
Francis, D.Francis, D., Abraham, A.C.Interrogating the Cordillera lithosphere with mafic volcanics and mantle xenoliths.Geological Association of Canada Annual Meeting, Abstract onlyCanada, Northwest TerritoriesXenoliths
DS200412-1342
2003
Francis, D.Modeland, S., Francis, D., Hynes, A.Enriched mantle components in Proterozoic continental flood basalts of the Cape Smith foldbelt, northern Quebec.Lithos, Vol. 71, 1, Nov. pp. 1-17.Canada, QuebecAlkaline rocks, Magmatism
DS200412-1756
2003
Francis, D.Schmidberger, S.S., Simonetti, A., Francis, D.Small scale Sr isotope investigation of clinopyroxenes from peridotite xenoliths by laser ablation MC-ICP-MS implications for maChemical Geology, Vol. 199, no. 3-4, pp.317-29.MantleGeochronology - Nikos
DS200512-0511
2004
Francis, D.Kent, A.J.R., Stolper, E.M., Francis, D., Woodhead, J., Frei, R., Eiler, J.Mantle heterogeneity during the formation of the North Atlantic igneous province: constraints from trace element and Sr Nd Os O isotope - Baffin Island picritesGeochemistry, Geophysics, Geosystems: G3, Vol. 5, pp. Q11004 10.1029/2004GC000743Canada, Nunavut, Baffin IslandGeochemistry
DS200512-0748
2004
Francis, D.Morissette, C.J., Francis, D.Fragments of the Archean mantle in ultramafic dykes from Wawa ( Ontario).EOS Transaction of AGU, Vol. 85, no. 17, Joint Assembly Suppl. Abstract V23A-06. 1p.Canada, Ontario, WawaLamprophyre
DS200512-1045
2004
Francis, D.Stefan, I.A., Francis, D.Proterozoic mantle xenoliths in ultramafic dykes near Wawa, Ontario: implications for the lithospheic mantle underneath the central North American craton.Geological Society of America Annual Meeting ABSTRACTS, Nov. 7-10, Paper 17-7, Vol. 36, 5, p. 47.Canada, Ontario, WawaPicrite, ailikites
DS200512-1218
2004
Francis, D.Yaxley, G.M., Kamenetsky, V.S., Kamenetsky, M., Norman, M.D., Francis, D.Origins of compositional heterogeneity in olivine hosted melt inclusions from the Baffin Island picrites.Contributions to Mineralogy and Petrology, Vol. 148, 4, pp. 426-442.Canada, Nunavut, Baffin IslandPicrite
DS200612-0729
2006
Francis, D.Kopylova, M., Francis, D., Barron, L.The Earth's Mantle: new insights from diamonds and mantle xenoliths.Mineralogical Association of Canada, www.gacmac2006.caCanada, QuebecTechnical meeting - alluvials, UHP, craton
DS200712-0325
2007
Francis, D.Francis, D.Kimberlites as probes of the sub-continental lithospheric mantle.Geological Association of Canada, Gac-Mac Yellowknife 2007, May 23-25, Volume 32, 1 pg. abstract p.28.MantleMagma genesis
DS200812-0365
2008
Francis, D.Francis, D., Maurice, C.Ferropicrites and Archean crustal reworking in the northeastern Superior Provionce of Quebec.Goldschmidt Conference 2008, Abstract p.A281.Canada, QuebecPicrite
DS200812-0422
2008
Francis, D.Goldstein, S.B., Francis, D.The petrogenesis and mantle source of Archean ferropicrite from the Western Superior Province, Ontario, Canada.Journal of Petrology, Vol. 49, 10, pp. 1729-1753.Canada, Ontario, ManitobaPicrite
DS200812-0819
2008
Francis, D.O'Neil, J., Carlson, R.W., Francis, D., Stevenson, R.Neodynium 142 evidence for Hadean mafic crust. (Northern Quebec)Science, Vol. 321, 5807 Sept. 28, pp. 1828-1831.Canada, QuebecGeochronology
DS200812-0861
2008
Francis, D.Patterson, M., Francis, D., McCandless, T.Autoliths as samples of kimberlite magma.Goldschmidt Conference 2008, Abstract p.A727.Canada, AlbertaDeposit - Buffalo Head Hills
DS200812-0862
2008
Francis, D.Patterson, M., Francis, D., McCandless, T.Kimberlite: magmas or mixtures? Hypabyssal dykes from Foxtrot.9IKC.com, 3p. extended abstractCanada, QuebecDeposit - Foxtrot
DS200912-0228
2009
Francis, D.Francis, D., Patterson, M.Kimberlites and aillikites as probes of the continental lithospheric mantle.Lithos, Vol. 109, 1-2, pp. 72-80.Canadadiamond, carbonatite
DS200912-0484
2009
Francis, D.Maurice, C., Francis, D.Enriched crustal and mantle components and the role of the lithosphere in generating Paleoproterozoic dyke swarms of the Ungava Peninsula, Canada.Lithos, in press availableCanada, LabradorDykes
DS200912-0575
2009
Francis, D.Patterson, M., Francis, D., McCandless, T.Kimberlites: magmas or mixtures?Lithos, In press available, 20p.Canada, QuebecGeochemistry - whole rock, Foxtrot
DS201012-0209
2010
Francis, D.Francis, D., Minarik, W., Proenza, Y., Shi, L.An overview of the Canadian Cordilleran lithospheric mantle.Canadian Journal of Earth Sciences, Vol. 47, 4, pp. 353-368.Canada, British ColumbiaGeophysics - seismic
DS201012-0478
2010
Francis, D.Maurice, C., Francis, D.Enriched crustal and mantle components and the role of the lithosphere in generating Paleoproterozoic dyke swarms of the Ungava Peninsula, Canada.Lithos, Vol. 114, pp. 95-108.Canada, Quebec, UngavaDykes
DS201012-0566
2010
Francis, D.Patterson, M.V., Francis, D.High -Al kimberlite produced by monticellite fractionation. Renard Stornoway38th. Geoscience Forum Northwest Territories, Abstract p. 74.Canada, QuebecFoxtrot, Lynx, Hibou dykes
DS201112-0759
2011
Francis, D.O'Neill, J., Francis, D., Carlson, R.W.Implications of the Nuvvuagittuq greenstone belt for the formation of Earth's early crust.Journal of Petrology, Vol. 52, 5, pp.985-1009.Canada, Ontario, Superior ProvinceGeochronology, magmatism
DS201212-0542
2012
Francis, D.Patterson, M.V., Francis, D.The carbonatitic character of kimberlite magma.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractGlobalCarbonatite
DS201312-0687
2013
Francis, D.Patterson, M.V., Francis, D.Kimberlite eruptions as triggers for early Cenozoic hyperthermals.Geochemistry, Geophysics, Geosystems: G3, Vol. 14, pp. 448-456.MantleKimberlite genesis
DS201412-0463
2014
Francis, D.Kitayama, Y.C., Francis, D.Iron rich alkaline magmatism in the Archean Wawa greenstone belts ( Ontario, Canada).Precambrian Research, Vol. 252, pp. 53-70.Canada, OntarioNot specific to diamonds
DS201501-0020
2014
Francis, D.Mildragovic, D., Francis, D., Weis, D., Constantin, M.Neoarchean ( c.2.7Ga) plutons of the Ungava craton, Quebec, Canada: parental magma compositions and implications for Fe-rich mantle source regions.Journal of Petrology, Vol. 55, 12, pp. 2481-2512.Canada, QuebecMelting
DS201511-1864
2015
Francis, D.Milidragovic, D., Francis, D.Ca. 2.7 Ga ferropicrite magmatism: a record of Fe-rich heterogeneities during Neoarchean global mantle melting.Geochimica et Cosmochimica Acta, in press available 20p.Canada, Ontario, QuebecUngava craton

Abstract: Although terrestrial picritic magmas with FeOTOT ?13 wt.% are rare in the geological record, they were relatively common ca. 2.7 Ga during the Neoarchean episode of enhanced global growth of continental crust. Recent evidence that ferropicritic underplating played an important role in the ca. 2.74–2.70 Ga reworking of the Ungava craton provides the impetus for a comparison of ca. 2.7 Ga ferropicrite occurrences in the global Neoarchean magmatic record. In addition to the Fe-rich plutons of the Ungava craton, volumetrically minor ferropicritic flows, pyroclastic deposits, and intrusive rocks form parts of the Neoarchean greenstone belt stratigraphy of the Abitibi, Wawa, Wabigoon and Vermillion domains of the southern and western Superior Province. Neoarchean ferropicritic rocks also occur on five other Archean cratons: West Churchill, Slave, Yilgarn, Kaapvaal, and Karelia; suggesting that ca. 2.7 Ga Fe-rich magmatism was globally widespread. Neoarchean ferropicrites form two distinct groups in terms of their trace element geochemistry. Alkaline ferropicrites have fractionated REE profiles and show no systematic HFSE anomalies, broadly resembling the trace element character of modern-day ocean island basalt (OIB) magmas. Magmas parental to ca. 2.7 Ga alkaline ferropicrites also had high Nb/YPM (>2), low Al2O3/TiO2 (<8) and Sc/Fe (-3 × 10-4) ratios, and were enriched in Ni relative to primary pyrolite mantle-derived melts. The high Ni contents of the alkaline ferropicrites coupled with the low Sc/Fe ratios are consistent with derivation from olivine-free garnet-pyroxenite sources. The second ferropicrite group is characterized by decisively non-alkaline primary trace element profiles that range from flat to LREE-depleted, resembling Archean tholeiitic basalts and komatiites. In contrast to the alkaline ferropicrites, the magmas parental to the subalkaline ferropicrites had flat HREE, lower Nb/YPM (<2), higher Al2O3/TiO2 (8-25) and Sc/Fe (-4 × 10-4) ratios, and were depleted in Ni relative to melts of pyrolitic peridotite; suggesting they were derived from garnet-free peridotite sources. Neodymium isotopic evidence indicates that the source of alkaline ferropicrites was metasomatically enriched shortly before magma generation (-3.0 Ga), but the subalkaline ferropicrites do not show evidence of precursor metasomatism. The metasomatic enrichment of the alkaline ferropicrite sources may have been accompanied by conversion of Fe-rich peridotite to secondary garnet-pyroxenite. Melting experiments on "pyrolitic" compositions and consideration of the dependence of the density of silicate liquids on pressure and temperature, suggest that ferropicrites cannot originate by melting of normal terrestrial mantle (Mg-number = 0.88-0.92) at high pressures and temperatures. The geochemical similarity between the subalkaline ferropicrites and the shergottite-nakhlite-chassigny (SNC) and howardite-eucrite-diogenite (HED) differentiated meteorites suggests, however, that the Fe-rich mantle may originate from the infall of Fe-rich chondritic meteorites. The occurrence of ca. 2.7 Ga Fe-rich rocks on at least six cratons that are commonly coeval with the more ubiquitous komatiites and Mg-tholeiites is consistent with the existence of heterogeneous Fe-rich "plums" throughout the Neoarchean mantle. The paucity of ferropicrites in the post-2.7 Ga geological record suggests that majority of these Fe-rich plums have been melted out during the global Neoarchean melting of the mantle.
DS201601-0029
2015
Francis, D.Milidragovic, D., Francis, D.Ca 2.7 Ga ferropicrite magmatism: a record of Fe-rich heterogeneities during Neoarchean global mantle melting.Geochimica et Cosmochimica Acta, in press available, 14p.Canada, Africa, RussiaMelting

Abstract: Although terrestrial picritic magmas with FeOTOT ?13 wt.% are rare in the geological record, they were relatively common ca. 2.7 Ga during the Neoarchean episode of enhanced global growth of continental crust. Recent evidence that ferropicritic underplating played an important role in the ca. 2.74-2.70 Ga reworking of the Ungava craton provides the impetus for a comparison of ca. 2.7 Ga ferropicrite occurrences in the global Neoarchean magmatic record. In addition to the Fe-rich plutons of the Ungava craton, volumetrically minor ferropicritic flows, pyroclastic deposits, and intrusive rocks form parts of the Neoarchean greenstone belt stratigraphy of the Abitibi, Wawa, Wabigoon and Vermillion domains of the southern and western Superior Province. Neoarchean ferropicritic rocks also occur on five other Archean cratons: West Churchill, Slave, Yilgarn, Kaapvaal, and Karelia; suggesting that ca. 2.7 Ga Fe-rich magmatism was globally widespread.
DS201606-1110
2016
Francis, D.Rizo, H., Walker, R.J., Carlson, R.W., Horan, M.F., Mukhopadhyay, S., Manthos, V., Francis, D., Jackson, M.G.Preservation of Earth forming events in the tungsten isotopic composition of modern flood basalts…… ancient rocksScience, Vol. 352, no. 6287, May 13, pp. 809-812.Canada, Nunavut, Baffin IslandGeochronology

Abstract: How much of Earth's compositional variation dates to processes that occurred during planet formation remains an unanswered question. High-precision tungsten isotopic data from rocks from two large igneous provinces, the North Atlantic Igneous Province and the Ontong Java Plateau, reveal preservation to the Phanerozoic of tungsten isotopic heterogeneities in the mantle. These heterogeneities, caused by the decay of hafnium-182 in mantle domains with high hafnium/tungsten ratios, were created during the first ~50 million years of solar system history, indicating that portions of the mantle that formed during Earth’s primary accretionary period have survived to the present
DS1970-0909
1974
Francis, D.M.Francis, D.M., Mcgetchin, T.R.Compositional and Textural Relations in Lherzolite Nodules, nunivak Island Alaska.Eos, Vol. 55, No. 4, PP. 484-485. (abstract.).United States, AlaskaBlank
DS1975-0744
1978
Francis, D.M.Francis, D.M.The Implications of the Compositional Dependence of Texture in Spinel Lherzlite Xenoliths.Journal of GEOLOGY, Vol. 86, No. 4, PP. 473-485.United States, AlaskaBlank
DS1987-0040
1987
Francis, D.M.Bedard, J.H.J., Ludden, J.N., Francis, D.M.The Megantic intrusive complex, Quebec, a study of the derivation of silicaOver saturated anorogenic magmas of alkaline affinityJournal of Petrology, Vol. 28, No. 2, April pp. 355-388QuebecAlkaline rocks
DS1987-0041
1987
Francis, D.M.Bedard, J.H.J., Ludden, J.N., Francis, D.M.The Megantic intrusive complex, Quebec-a study of the derivation of silicaOver saturated anorogenic magmas of alkaline affinityJournal of Petrology, Vol. 28, No. 2, April pp. 355-388QuebecBlank
DS1988-0046
1988
Francis, D.M.Bedard, J.H.J., Francis, D.M., Ludden, J.Petrology and pyroxene chemistry of Montregian dykes-the origin of concentric zoning and green cores in clinopyroxenes from alkali basalts andlamprophyresCanadian Journal of Earth Sciences, Vol. 25, No. 12, December pp. 2041-2058QuebecPetrology, Montregian dykes
DS1989-0245
1989
Francis, D.M.Charland, A., Francis, D.M., Ludden, J.Petrological evolution of the Itcha Mt. Shield volcano central BritishColumbia; implications for alkaline volcanism in the Anahim beltNew Mexico Bureau of Mines Bulletin., Continental Magmatism Abstract Volume, Held, Bulletin. No. 131, p. 49. AbstractBritish ColumbiaAlkaline rocks, Mt. Shield
DS1989-0468
1989
Francis, D.M.Gaonach, H., Picard, C., Ludden, J.N., Francis, D.M.Alkaline rocks from a Proterozoic volcanic island in the Cape Smith thrustbelt, New Quebec.Geoscience Canada, Vol. 16, No. 3, September pp. 137-139QuebecBasanite, Nephelinite, phonolites, Proterozoic
DS1989-0469
1989
Francis, D.M.Gaonac'h, H., Picard, C., Ludden, J.N., Francis, D.M.Alkaline rocks from a Proterozoic volcanic island In the Cape Smith thrust belt, New QuebecGeoscience Canada, Vol. 16, No. 3, pp. 137-9.Quebec, Ungava, LabradorAlkaline rocks
DS1995-1617
1995
Francis, D.M.Rowins, S.M., Francis, D.M.The late Tertiary to recent Beaver River alkaline complex, southeasternYukon, Canada.Geological Society of America (GSA) Abstracts, Vol. 27, No. 6, abstract p. A 46.YukonAlkaline rocks, Deposit -Beaver River
DS1859-0130
1859
Francis, J.G.Francis, J.G.Beach Rambles in Search of Seaside Pebbles and Crystals. With Some Observations on the Origin of the Diamond and Other Precious Stones.London: Routledge, Warne And Routledge., 186P. ( CHAPTER 8- DIAMONDS).GlobalGemology, Kimberley
DS1991-0356
1991
Francis, P.W.De Silva, S.L., Francis, P.W.Volcanoes of the central Andes.Section of the book -large silicic systemsxeroxed. Not well in black and white as the photographs are in colour in thebookSpringer-Verlag, pp. 158-178Andes, ChileVolcanoes, Silicia systems