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Harris Syngenetic inclusions in diamond from the Birim Ā®eld (Ghana) Ā± a deep peridotitic proĀ®le with...inclusions from placer deposits (Akwatia mine) along the Birim River, Ghana were studied, thus providing...contents indicate an almost exclusively peridotitic diamond suite, with the vast majority being part of the...harzburgitic paragenesis. Chemically the Akwatian diamond inclusions diĀer from those in our 1100 sample...(66.4 mol%) so far observed in an inclusion in diamond. The same garnet also contained a minor enstatite |
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West African economy during the interwar period Ghana, independence and gold: a case study Conclusion...assessment of relations between ASM and large-scale mine parties in West Africa Possible ways forward Artisanal...in Sanmatenga: a case study Oral history of the mine sites at Liliga-Goren Conclusion 136 140 144 147...artisanal diamond mining in Kono District, Sierra Leone Estelle Levin An overview of diamond mining in...A political economy of contemporary artisanal diamond production Illegal mining Monitoring and disciplining |
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Comparison with inclusions in diamonds from Akwatia (Ghana) shows that there are no significant differences...lherzolitic garnets from Roberts Victor (nodules) and Akwatia (diamonds) were crystallised from precursor rocks...depletion by partial melting in the spinel stability field which resulted in high Cr=Al in the residue. Harzburgitic...(partial melting) originating in the garnet stability field. We suggest that the protolith had undergone polybaric...before being subducted to the depth of the diamond stability field. The growing garnets acquired a depleted |
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Ver' "\ ~~ ā¢ THE MINERAL AND ROCK RESOURCES OF GHANA f btYON RALPH Dedicated to my parellfs for not...ISBN 90 6191 597 X paper edition only for sale in Ghana Ā© 1985 A.A.Balkema, P.O.Box I 675, 3000 BR Rotterdam...REPUBLIC OF GHANA- GEOGRAPHY,PHYSIOGRAPHY,GEOLOGY AND GEOHYDROLOGY 6 3. THE MINERALRESOURCESOF GHANA - BACKGROUND...EXPLOITATION IN GHANA 572 12. TABLES OF SUMMARY OF MINERAL AND ROCK RESOURCESOF GHANA 577 13. LEGISLATION...590 APPENDIX 597 INDEX 602 V Preface The Ghana Geological SuJ;"vey DepaJ;"tment in 1.962, published |
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developed in Mali, Mauritania, Senegal, Burkina Faso, Ghana and Cote dāIvoire. 63 The focus of this paper...Birimian Supergroup, as described from studies in Ghana and Page 5 of 87 Burkina Faso by Attoh (1982)...age (Rombouts, 1987), and 109 produced major diamond resources. Long periods of erosion were associated...formation of the 111 Iullemmeden Basin on the south-eastern margin of the craton (Moody and Sutcliffe, 1991)...namely the western 121 Archean domain, and the eastern Paleoproterozoic Yetti and Eglab sub-domains (Sougy |
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the same time diamond-bearing kimberlites developed in Ghana. Another distinct diamond event has been...(KKI) host world-class deposits of gold, important diamond and iron ore concentrations, and manganese, uranium...Orogeny, but there are a number of deposits in Ghana, Burkina Faso and Mali that formed before the Eburnean...granitoids (e.g., Dokrupe in Ghana: Yao et al., 2001; Julie in northern Ghana: Salvi et al., in press ā... Essakane in northwest Burkina Faso; Obuasi in Ghana: Fougerouse et al., in press ā this volume; Siguiri |
| Melton, G.L., McNeill, J., Stachel, T., Pearson, D.G., Harris, J.W. (2012) Trace elements in gem diamond from Akwatia, Ghana and DeBeers Pool, South Africa. Chemical Geology, 314. 1-8 doi:10.1016/j.chemgeo.2012.04.025 | Journal (article/letter/editorial) |
Research paper Trace elements in gem diamond from Akwatia, Ghana and DeBeers Pool, South Africa G.L. Melton...ICPMS Ghana De Beers Pool a b s t r a c t Monocrystalline gem-quality diamonds from Akwatia, Ghana and...elevated LREEN/MREEN and variable LREEN/TiN. One diamond from Ghana is distinct (G103) by having a much steeper...Syngenetic garnet inclusions indicate that the diamond growth medium must have been highly enriched in...trace impurities in gem diamond represent trapped inclusions of the diamond forming ļ¬uid/melt. Mixtures |
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formation event documented on the worldās major diamond producing cratons occurs in Archean lithospheric...diamonds, G10 garnets, and diamond inclusion-type chromites, well used in diamond exploration. Within the...mantle domains of diamond stability, there have been repeated episodes of further diamond crystallization...peridotite. Using improved methods of isotope analysis, diamond formation ages can be correlated with specific...magmatic mantle refertilization. Fibrous cuboid diamond and fibrous coats on SCD are rough-surfaced diamonds |
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Traceāelement geochemistry of diamondāhosted olivine inclusions from the Akwatia Mine, West African Craton: implications...implications for diamond paragenesis and geothermobarometry J. C. M. De Hoog1 Ā· T. Stachel2 Ā· J. W. Harris3...coexisting garnets included in diamonds from the Akwatia Mine (Ghana, West African Craton) were measured to show...similar information about equilibration temperature, diamond paragenesis and mantle processes as garnet. Trace-element...Conventional geothermobarometry indicates that Akwatia diamonds formed and resided close to a 39 mW/m2 |
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Springer-Verlag 1997 Thomas Stachel Ć” JeĀ W. Harris Diamond precipitation and mantle metasomatism Ā± evidence...chemistry of silicate inclusions in diamonds from Akwatia, Ghana Received: 27 January 1996 / Accepted: 5 May...clinopyroxene) included in diamonds from Akwatia (Birim Field, Ghana) were determined using SIMS. Incompatible...CO2bearing melts or ĀÆuids may thus be excluded. Diamond inclusion chemistry and mineralogy also is inconsistent...metasomatism by H2O-rich melts. We therefore favour diamond precipitation by oxidation of CH4-rich ĀÆuids with |
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a t e / l i t h o s Evaluation of kimberlite diamond potential using FTIR spectroscopy of xenocrystic...2009 Keywords: Kimberlite Infrared spectroscopy Diamond grade Olivine Hydroxyl a b s t r a c t Xenocrysts...spectral features associated with good diamond carrying and diamond preservation potential. As an exploratory...inclusions in diamond, olivine coexisting with diamond in peridotite xenoliths and olivine from diamond-free peridotite...kimberlites with widely variable diamond grades and reconciliation with diamond resorption features may permit |
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silicate phases by a metasomatic agent during diamond formation unlike other trace elements like REE...rights reserved. Keywords: Lithium; Inclusions in diamond; Eclogites; Peridotites; Websterites; Majorite...chemgeo.2003.08.001 ed at the time and place of diamond formation and carry information on the chemistry...signatures of diamonds and their inclusions unravelled diamond formation processes, the magmatic, metamorphic...incompatible elements presumably at the time of diamond formation (e.g., Stachel et al., 2000a,b and references |
| (Fanus) Viljoen, K.S., Dobbe, RenƩ, Smit, Braam, Thomassot, Emilie, Cartigny, Pierre (2004) Petrology and geochemistry of a diamondiferous lherzolite from the Premier diamond mine, South Africa. Lithos, 77 (1) 539-552 doi:10.1016/j.lithos.2004.03.023 | Journal (article/letter/editorial) |
a diamondiferous lherzolite from the Premier diamond mine, South Africa K.S. (Fanus) Viljoen a,*, ReneĢ...diamondiferous peridotite xenolith from the Premier diamond mine in South Africa. The xenolith is altered with...6 x to 1.3x. These are broadly correlated with diamond nitrogen content as determined by infrared spectroscopy...Metasomatism occurred prior to, or accompanied, diamond growth. D 2004 Elsevier B.V. All rights reserved...reserved. Keywords: Peridotite; Lherzolite; Diamond; Kimberlite; Lithosphere; Infrared 1. Introduction This |
| Gunn, A.G., Dorbor, J.K., Mankelow, J.M., Lusty, P.A.J., Deady, E.A., Shaw, R.A., Goodenough, K.M. (2018) A review of the mineral potential of Liberia. Ore Geology Reviews, 101. 413-431 doi:10.1016/j.oregeorev.2018.07.021 | Journal (article/letter/editorial) |
of iron ore is currently restricted to a single mine, Yekepa, in the Nimba Range. Other important deposits...Goe Fantro. There is a long history of alluvial diamond production in western and central Liberia, together...diamonds since the 1960s and 1970s. Further detailed field and laboratory 1 investigations using modern techniques...Senegal, Guinea, Sierra Leone and Mali in the west to Ghana and Niger in the east. The western part of the Leo-Man...domain) comprises Archaean gneisses, whereas the eastern part (the BaoulƩ-Mossi domain) is largely Paleoproterozoic |
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2007 Available online 22 April 2008 Keywords: Diamond formation Peridotitic Eclogitic Websteritic Subcratonic...suites and used to establish the characteristics of diamond source rocks in the subcratonic lithospheric mantle...(Kalahari Craton) is by far the best studied diamond source region in the world but appears to be unique rather...and trace element characteristics of peridotitic diamond sources indicate polybaric melt extraction proceeding...mounting evidence from xenolith studies, eclogitic diamond sources are linked to subducted oceanic protoliths |
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inclusions in alluvial diamonds from the Kankan region of Guinea in West Africa are mainly of lherzolitic...exclusively lherzolitic garnets document that the diamond source experienced a previous stage of melt extraction...from the Monastery mine. Subsequently, the discovery of diamonds from the Brazilian mine SaĆo Luiz, which...the present study on diamonds from the Kankan district in Guinea, we will examine the major and trace...lithospheric inclusion parageneses and then evaluate diamond populations derived from the asthenosphere and |
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47 Gabon . . . . . . . . . . . . . . . . . . 51 Ghana . . . . . . . . . . . . . . . . . . 57 Guinea ....of diversified experience in mineral exploration, mine design, development, and operations, as well as...early 1993 and for a number of African and Middle Eastern countries since then. George A. Morgan is Chief...ranked by portion of world production in 1993, were diamond, cobalt, chromite, gold, phosphate rock, manganese...and zircon. Several of these-chromite, cobalt, diamond, and manganese- were not produced in the United |
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homepage: www.elsevier.com/locate/precamres Type Ib diamond formation and preservation in the West African...Available online 22 September 2016 Keywords: Type Ib Diamond ReāOs Sulphide West Africa Cratonic lithosphere...diamonds from the Zimmi (West Africa) alluvial diamond locality were analysed for their bulk FeāCuāNiāCo...features characteristic of eclogitic sulphides. Each diamond has 3ā4 individual inclusions. 187Re/188Os and...mineral isochrons for each diamond ā unambiguously dating the time of diamond formation. The 650 Ma age |
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THE PRESSURES AND TEMPERATURES OF FORMATION OF DIAMOND BASED ON THERMOBAROMETRY OF CHROMIAN DIOPSIDE INCLUSIONS...temperature (T) and pressure (P) of formation of natural diamond has generally relied on thermobarometry of rare...potential re-equilibration of touching minerals after diamond growth and possible disequilibrium between non-touching...inclusions of chromian diopside (mostly isolated) in diamond crystals containing inclusions of peridotitic material...conditions and relative timing of diamond genesis. Inclusions in diamond and xenoliths from the same source |
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0 Ga) and hence an unconventional setting for diamond exploration. Buffalo Hills diamonds formed during...2006 Elsevier B.V. All rights reserved. Keywords: Diamond inclusions; Carbon isotopes; Nitrogen aggregation;...Majorite; Off-craton 1. Introduction Traditionally diamond exploration has focused on cratons stabilized in...an empirically derived association of primary diamond deposits with Archean cratons as summarized by...in the discovery of the Buffalo Hills kimberlite field in northern Alberta. It was discovered in 1997 by |
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of early Archean cratonie rocks in Liberia and eastern Sierra-Leone. They consist of a complex assemblage...scattered relics within the Archean craton in eastern Sierra Leone, Liberia and Guinea. These include... A greater part of the West African craton in eastern Sierra Leone, Liberia, Guinea and Ivory Coast is...1968). In the Ivory Coast and to the east as far as Ghana (Fig. 2), the Archean basement complex is overlain...Guinea has been correlated with Birrimian rocks in Ghana (HAuGItTON, 1963; H~-WKES,1972). The Marampa Group |
| Stachel, Thomas, Aulbach, Sonja, Brey, Gerhard P., Harris, Jeff W., Leost, Ingrid, Tappert, Ralf, Viljoen, K.S.(Fanus) (2004) The trace element composition of silicate inclusions in diamonds: a review. Lithos, 77 (1) 1-19 doi:10.1016/j.lithos.2004.03.027 | Journal (article/letter/editorial) |
eclogitic diamond sources. The trace element composition of an āāaverage eclogitic diamond sourceāā based...about 10% of a partial melt in the garnet stability field and that subsequently experienced only minor reenrichment...inclusion. This suggests that sublithospheric diamond sources may be linked to old oceanic slabs, possibly...can provide the redox gradients necessary for diamond precipitation in an otherwise reduced sublithospheric...V. All rights reserved. Keywords: Inclusion in diamond; REE; Metasomatism; Lithosphere; Garnet; Majorite; |
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Coast. DIAMONDS: FROM BIRTH TO ETERNITY A diamond is rarely found embedded in kimberlite rock. This...update its diamond mining and reeovery inlormation, we asked the assistance ol John Roux, Diamond Information...to present Arthur Wilsonās compilation on the diamond and its origins. Richard T. Liddicoat, Jr. CONTENTS... 413 Index . 449 i\ LIST OF ILLUSTRATIONS Diamond (Color Plate).Frontispiece Lord Rutherford. 4 Radiometric...Radiometric dating. 5 Hannay's experiment. 11 Graphite-diamond equilibrium . 13 Convection cells . 15 Snider-Pelligrini |
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Akademika Osipāyana 4, Chernogolovka, 142432, Moscow Region, Russia b Science Facilities Department, Natural...set of trace elements (TE) in the partly molten diamond-forming peridotiteāeclogiteā carbonatite system...Model TE partition coefficients for the natural diamond-producing carbonatite melts of mantle chambers...minerals of peridotite and eclogite parageneses of diamond inclusions, on the one hand, and on the experimental...āmetasomatic agentsā in the formation of chambers of diamond-forming carbonatite magmas. Ā© 2015, V.S. Sobolev |
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Accepted: 7 January 1998 Abstract Syngenetic diamond inclusions from the Mwadui kimberlite reveal that...pairs suggests successive iron enrichment during diamond formation, e.g. leading to the presence of harzburgitic...harzburgitic garnet and lherzolitic olivine in the same diamond. Apart from the dominant peridotitic inclusion...association Fe-FeO-Fe3O4 in one single diamond indicates diamond formation over a large range of fO2 conditions...harzburgitic garnet and a SiO2-phase in the same diamond. Alternatively the formation of the SiO2phase may |
Akwatia Mine, Birim diamond field, Denkyembour District, Eastern Region, Ghana