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Rare earth element geochemistry of columbite-group minerals: LA-ICP-MS data

Published online by Cambridge University Press:  05 July 2018

T. Graupner*
Affiliation:
Federal Institute for Geosciences and Natural Resources (BGR), Stilleweg 2, D-30655 Hannover, Germany
F. Melcher
Affiliation:
Federal Institute for Geosciences and Natural Resources (BGR), Stilleweg 2, D-30655 Hannover, Germany
H.-E. Gäbler
Affiliation:
Federal Institute for Geosciences and Natural Resources (BGR), Stilleweg 2, D-30655 Hannover, Germany
M. Sitnikova
Affiliation:
Federal Institute for Geosciences and Natural Resources (BGR), Stilleweg 2, D-30655 Hannover, Germany
H. Brätz
Affiliation:
GeoZentrum Nordbayern, University of Erlangen-Nürnberg, Schlossgarten 5a, D-91054 Erlangen, Germany
A. Bahr
Affiliation:
Federal Institute for Geosciences and Natural Resources (BGR), Stilleweg 2, D-30655 Hannover, Germany

Abstract

New data on rare earth element (REE) concentrations and distribution patterns of columbite-tantalite minerals from Ta-ore provinces worldwide are presented. The REE geochemistry was studied by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Five major types of chondrite-normalized REE distribution patterns are defined for columbite-group minerals (CGM) from lithium-caesium-tantalum (LCT) pegmatites and rare-metal granites. Features to discriminate between the types include (1) the shape of the pattern (e.g. flat or concave), (2) calculated ratios between groups of the REE (e.g. heavy REEN/middle REEN), and (3) the presence and intensity of anomalies (e.g. Ce*, Eu*). Four pegmatites in central and southern Africa are used as case studies to discuss application of the types of REE patterns in individual deposits. The REE fractionation during progressive evolution of the melt in a pegmatite body (either Nb → Ta or Fe → Mn fractionation lines, or both) results in smaller heavy REEN/middle REEN ratios whereas replacement of primary CGM by secondary CGM produces modifications in the light REEN patterns and the heavy REEN/middle REEN ratios also. Critical features of REE patterns such as highly variable heavy REEN/middle REEN ratios or striking differences in the appearance of Eu anomalies are discussed considering structural data of the host minerals and the differentiation behaviour of the pegmatitic melt. In general, CGM from each individual Ta-ore province are characterized by a predominance of one type of REE distribution pattern. Consequently, these patterns are suitable for tracing the origin of tantalum ore concentrates (e.g. as a forensic tool).

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2010

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References

Anders, E. and Grevesse, N. (1989) Abundances of the elements: Meteoritic and solar. Geochimica et Cosmochimica Acta, 53, 197214.CrossRefGoogle Scholar
Angermeier, H.O., Krauss, U., Kruszona, M. and Schmidt, H. (1974) Zaire. Bundesanstalt für Bodenforschung, Hannover, Rohstoffwirtschaftliche Landerberichte, 3, 120 pp.Google Scholar
Aurisicchio, C, de Vito, C, Ferrini, V. and Orlandi, P. (2001) Nb-Ta oxide minerals from miarolitic pegmatites of the Baveno pink granite, NW Italy. Mineralogical Magazine, 65, 509522.CrossRefGoogle Scholar
Badanina, E.V., Trumbull, R.B., Dulski, P., Wiedenbeck, M., Veksler, I.V. and Syritsko, L.F. (2006) The behavior of rare-earth and lithophile trace elements in rare-metal granites: a study of fluorite, melt inclusions and host rocks from the Khangilay complex, Transbaikalia, Russia. The Canadian Mineralogist, 44, 667692.CrossRefGoogle Scholar
Baldwin, J.R. (1989) Replacement phenomena in tantalum minerals from rare-metal pegmatites in South Africa and Namibia. Mineralogical Magazine, 53, 571581.CrossRefGoogle Scholar
Baldwin, J.R., Hill, P.G., Finch, A.A., von Knorring, O. and Oliver, G.J.H. (2005) Microlite-manganotanta-lite exsolution lamellae: evidence from rare-metal pegmatite, Karibib, Namibia. Mineralogical Magazine, 69, 917935.CrossRefGoogle Scholar
Barros, R.M. and Vicente, C.A.M. (1963) Estudo dos campos pegmatiticos da Zambezia relatorio da mossao de estudos em Mocambique campanha de 1963. Junta de Energia Nuclear, 1, 133 pp.Google Scholar
Bassot, J.P. and Mono, M. (1989) Morphologie et mise en place de la pegmatite kibarienne a Sn, Nb, Ta, Li de Manono (Zaire). Chronique de la Recherche Miniere, 496, 4156.Google Scholar
Bering, D. (1976) Bericht über eine Vorbereisung der Tantalit-Vorkommen im Raume Akim-Oda in Ghana. German Federal Institute for Geosciences and Natural Resources, Hannover, unpublished report no. 75077, 16 pp. (in German).Google Scholar
Bowden, P. and Kinnaird, J.A. (1984) Geology and mineralization of the Nigerian anorogenic ring complexes. Geologisches Jahrbuch, Reihe B, 56, 68 pp.Google Scholar
BRGM (1987) Plan Minéral du Rwanda (Guillou, Y. and Ziserman, A., editors), République Rwandaise, Ministère de PIndustrie, des Mines et de l'Artisanat, published by BRGM, 580 pp.Google Scholar
Brinckmann, L., Lehmann, B., Hein, U., Hohndorf, A., Mussallam, K., Weiser, T. and Timm, F. (2001) La Géologie et al Minéralisation Primaire de l'Or de la Chaîne Kibarienne, Nord-ouest du Burundi, Afrique Orientale. Geologisches Jahrbuch, Reihe D, 101, 3195.Google Scholar
Brotzen, O. (1959) Outline of mineralization in zoned granitic pegmatites. A qualitative and comparative study. Geologiska Foereningens i Stockholm Foerhandlingar, 81, 398.Google Scholar
Cahen, L., Snelling, N.J., Delhal, J., Vail, J.R., Bonhomme, M. and Ledent, D. (1984) The Geochronology and Evolution of Africa. Clarendon Press, Oxford, UK, 512 pp.Google Scholar
Černý, P. (1989) Characteristics of pegmatite deposits of tantalum. Pp. 195239 in: Lanthanides, Tantalum and Niobium (Moller, P. et al., editors), Springer Verlag, Berlin, Germany.CrossRefGoogle Scholar
Černý, P. (1992) Geochemical and petrogenetic features of mineralization in rare-element granitic pegmatites in the light of current research. Applied Geochemistry, 7, 393416.Google Scholar
Černý, P. (1997) REE trends in rare-element granitic pegmatites: enrichment vs. depletion in granite-to-pegmatite sequences. Journal of the Czech Geological Society, 42, 34.Google Scholar
Černý, P. (2005) The Tanco rare-element pegmatite deposit, Manitoba: Regional context, internal anatomy, and global comparisons. Pp. 127158 in: Rare-element Geochemistry and Mineral Deposits (Linnen, R.L. and Samson, I.M., editors), GAC Short Course Notes 17, St. Catharines, Canada.Google Scholar
Černý, P. and Ercit, T.S. (1989) Mineralogy of niobium and tantalum: crystal chemical relationships, para-genetic aspects and their economic implications. Pp. 2779 in: Lanthanides, Tantalum and Niobium (Möller, P. et al, editors). Springer Verlag, Berlin.CrossRefGoogle Scholar
Černý, P. and Ercit, T.S. (2005) The classification of granitic pegmatites revisited. The Canadian Mineralogist, 43, 20052026.CrossRefGoogle Scholar
Cooper, D.G. (1964) The Geology of the Bikita pegmatite. Pp. 441461 in: The Geology of some Ore Deposits in southern Africa (Haughton, S.H., editor). Horters, Johannesburg, South Africa.Google Scholar
Correia Neves, J.M., Lopes Nunes, J.E. and Lucas, D.B. (1971) Mineralogy and structure of some pegmatites from Mozambique (P.E.A.) — A Review. Revista de Ciências Geológicas U. L. M., Série A, 4, 3542.Google Scholar
Cronwright, M.S. (2005) A review of the rare-element pegmatites of the Alto Ligonha Pegmatite Province, northern Mozambique and exploration guidelines. M.Sc, unpubl. Dissertation, Rhodes University, Grahamstown, South Africa, 139 pp.Google Scholar
De Vito, C, Pezzotta, F., Ferrini, V. and Aurisicchio, C. (2006) Nb-Ti-Ta oxides in the gem-mineralized and “hybrid” Anjanabonoina granitic pegmatite, Central Madagascar: A record of magmatic and post magmatic events. The Canadian Mineralogist, 44, 87103.CrossRefGoogle Scholar
Dewaele, S., Tack, L., Fernandez-Alonso, M., Boyce, A., Muchez, P., Schneider, J., Cooper, G. and Wheeler, K. (2008) Geology and mineralization of the Gatumba area, Rwanda: present state of knowledge. Etudes Rwandaises, 16, 624.Google Scholar
Diehl, B.J.M. (1990) Pegmatites of the Cape Cross-Uis pegmatite belt, Namibia: Geology, mineralisation, rubidium-strontium characteristics and petrogenesis of rare metal pegmatites. Ministry of Mines and Energy of Namibia. Open File Report EG 083. 29 pp.Google Scholar
Diehl, B.J.M. (1992) Niobium and tantalum. Pp. 3.5-1—3.5-15 in: The Mineral Resources of Namibia (Hoal, B.G., editor), Ministry of Mines and Energy of Namibia. Geological Survey, Namibia.Google Scholar
Diehl, M. (1993) Rare metal pegmatites of the Cape Cross-Uis pegmatite belt, Namibia: geology, mineralisation, rubidium-strontium characteristics and petrogenesis. Journal of African Earth Sciences, 17, 167181.CrossRefGoogle Scholar
Drake, MJ. and Weill, D.F. (1975) Partition of Sr, Ba, Ca, Y, Eu2+, Eu3+, and other REE between plagio-clase feldspar and magmatic liquid: an experimental study. Geochimica et Cosmochimica Ada, 39, 689712.CrossRefGoogle Scholar
Ercit, T.S. (1994) The geochemistry and crystal chemistry of columbite-group minerals from granitic pegmatites, southwestern Grenville province, Canadian Shield. The Canadian Mineralogist, 32, 421438.Google Scholar
Felix, M. and Kiessling, R. (1990) Characteristics of the pegmatite-bearing area east of Marropino (Zambesia Province, P.R. of Mozambique). Zeitschrifi für Geologische Wissenschaften, 18, 431441.Google Scholar
Fernandez-Alonso, M., Lavreau, J. and Klerkx, J. (1986) Geochemistry and geochronology of the Kibaran granites in Burundi, central Africa: implications for the Kibaran orogeny. Chemical Geology, 57, 217234.CrossRefGoogle Scholar
Fetherston, J.M. (2004) Tantalum in Western Australia. Mineral Resources Bulletin, 22, Geological Survey of Western Australia, 153 pp.Google Scholar
Friese, A. (2010) Development of a fingerprint of columbite group minerals from the Kenticha rare-element pegmatite, Ethiopia, on the basis of trace element geochemistry. Unpublished Diploma thesis, University of Erlangen-Nürnberg, Germany, 151 pp.Google Scholar
Gavrilenko, B.V. (2001) Ore potential of acidic rocks of the Archaean Kolmozero-Voronya zone, NE Baltic Shield. Pp. 421424 in: Mineral Deposits at the Beginning of the 21s’ Century (Piestrzynski, A. et al., editors), Swets and Zeitlinger Publishers, Lisse, The Netherlands.Google Scholar
Gorzhevskaya, S.A., Sidorenko, G.A. and Ginzburg, A.I. (1974) Titano-tantalo-niobaty (Svoistva, osobennosti sostava i usloviya obrazovaniya). Nedra, Moscow, 343 pp. (in Russian).Google Scholar
Guenther, M. and Ngulube, A. (1992) The lithium-pegmatite at Manono, Zaire. Pp. 91—99 in: Metallogeny of the Kibara Belt Central Africa, 1GCP Project No. 255 Bulletin- Newsletter, 4 (Pohl, W. and Delhal, J., editors). BWK, Leuven, Belgium.Google Scholar
Giinther, M.A., Dulski, P., Lavreau, J., Lehmann, B., Moller, P. and Pohl, W. (1989) The Kibaran tin granites: hydrothermal alteration versus plate tectonic setting. Pp. 21—27 in: Metallogeny of the Kibara Belt Central Africa, 1GCP Project No. 255 Bulletin- Newsletter, 2 (W. Pohl and J. Delhal, editors). BWK, Leuven, Belgium.Google Scholar
Harlov, D.E., Forster, H.J. and Nijland, T.G. (2002) Fluid-induced nucleation of (Y+REE)-phosphate minerals within apatite: nature and experiment. Part I. Chlorapatite. American Mineralogist, 87, 245261.CrossRefGoogle Scholar
Helba, H., Trumbull, R.B., Morteani, G., Khalil, S.O. and Arslan, A. (1997) Geoehemieal and petrographie studies of Ta mineralization in the Nuweibi albite granite complex, Eastern Desert, Egypt. Mineralium Deposita, 32, 164179.CrossRefGoogle Scholar
Höll, R., Borisenko, A., Obolenskiy, A., Grechistchev, O. and Shcherbakov, Yu. (2000) Sn and Ta granitoid-related ore-magmatic systems: Deputatsky and Ulug-Tanzek deposits, Russia. Pp. 127141 in: Ore-bearing Granites of Russia and Adjacent Countries. INTAS-93 and IGCP-373 Projects (Kremenetsky, A.A. et al, editors). IMGRE, Moscow.Google Scholar
Horbe, A.M.C. and da Costa, MX. (1999) Geoehemieal evolution of a lateritic Sn-Zr-Th-Nb-Y-REE-bearing ore body derived from apogranite: the case of Pitinga, Amazonas — Brazil. Journal of Geoehemieal Exploration, 66, 339351.CrossRefGoogle Scholar
Hunting Geology and Geophysics Ltd (1985) Rare metal and rare earth deposits in Mozambique — Mineral Development Study. Internal report Instituto Nacional de Geologica, Republica Popular de Mocambique, J615 Rel, Mozambique, 222 pp.Google Scholar
Irber, W. (1999) The lanthanide tetrad effect and its correlation with K/Rb, Eu/Eu*, Sr/Eu, Y/Ho, and Zr/ Hf of evolving peraluminous granite suites. Geochimica et Cosmochimica Ada, 63, 489508.CrossRefGoogle Scholar
Kontak, DJ. (2003) Geology of the southern lobe of the Brazil Lake LCT-type pegmatite (NTS 21 A/04), Yarmouth County, Nova Scotia. Pp. 41—68 in: Mineral Resources Branch, Report of Activities 2003. Nova Scotia Department of Natural Resources, Report 2004-1.Google Scholar
Kontak, DJ. (2006) Nature and origin of an LCT-Suite pegmatite with late-stage sodium enrichment, Brazil Lake, Yarmouth County, Nova Scotia. I. Geological setting and petrology. The Canadian Mineralogist, 44, 563598.CrossRefGoogle Scholar
Kiister, D., Romer, R.L., Tolessa, D., Zerihun, D., Bheemalingeswara, K., Melcher, F. and Oberthür, T. (2009) The Kenticha rare-element pegmatite, Ethiopia: internal differentiation, U-Pb age and Ta mineralization. Mineralium Deposita, 44, 723750.CrossRefGoogle Scholar
Lachelt, S. (2004) The geology and mineral resources of Mozambique. Council for Geoscience, Direccao Nacional de Geologia, Mozambique, 515 pp.Google Scholar
Lagache, M. and Quéméneur, J. (1997) The Volta Grande pegmatites, Minas Gerais, Brazil: an example of rare-element granitic pegmatites exceptionally enriched in lithium and rubidium. The Canadian Mineralogist, 35, 153165.Google Scholar
Larsen, R.B. (2002) The distribution of rare-earth elements in K-feldspar as an indicator of petroge-netic processes in granitic pegmatites: Examples from two pegmatite fields in southern Norway. The Canadian Mineralogist, 40, 137151.CrossRefGoogle Scholar
Lehmann, B. (1982) Metallogeny of tin: magmatic differentiation versus geochemical heritage. Economic Geology, 77, 5059.CrossRefGoogle Scholar
Lehmann, B., Melcher, F., Sitnikova, M. and Rudzindana Munana, J. (2008) The Gatumba rare-metal pegmatites: chemical signature and environmental impact. Etudes Rwandaises, 16, 2540.Google Scholar
Linnen, R.L. and Cuney, M. (2005) Granite-related rare-element deposits and experimental constraints on Ta-Nb-W-Sn-Zr-Hf mineralization. Pp. 45-68 in: Rare-Element Geochemistry and Mineral Deposits (Linnen, R.L. and Samson, I.M., editors). Geological Association of Canada, Short Course Notes, 17. Google Scholar
Liu, C.-Q. and Zhang, H. (2005) The lanthanide tetrad effect in apatite from the Altay No. 3 pegmatite, Xingjiang, China: an intrinsic feature of the pegmatite magma. Chemical Geology, 214, 6177.CrossRefGoogle Scholar
Liu, Y., Hu, Z., Gao, S., Giinther, D., Xu, J., Gao, C. and Chen, H. (2008) In situ analysis of major and trace elements of anhydrous minerals by LA-ICP-MS without applying an internal standard. Chemical Geology, 257, 3443.CrossRefGoogle Scholar
London, D. (2005) Granitic pegmatites: An assessment of current concepts and directions for the future. Lithos, 80, 281303.CrossRefGoogle Scholar
Lumpkin, G.R., Chakoumakous, B.C. and Ewing, R.C. (1986) Mineralogy and radiation effects of mierolite from the Harding pegmatite, Taos Country, New Mexico. American Mineralogist, 71, 569588.Google Scholar
Martin, HJ. (1964) The Bikita tinfield. Southern Rhodesia Geological Survey Bulletin, 58, 114131.Google Scholar
Masau, M., Černý, P., Cooper, M.A. and Chapman, R. (2002) Monazite-(Sm), a new member of the monazite group from the Annie Claim #3 granitic pegmatite, southeastern Manitoba. The Canadian Mineralogist, 40, 16491655.CrossRefGoogle Scholar
Melcher, F., Sitnikova, M.A., Graupner, T., Martin, N., Oberthür, T., Henjes-Kunst, F., Gäbler, E., Gerdes, A., Bratz, H., Davis, D.W. and Dewaele, S. (2008) Fingerprinting of conflict minerals: columbite-tantalite (“coltan”) ores. SGA News, 23, 114.Google Scholar
Melcher, F., Graupner, T., Sitnikova, M.A., Henjes-Kunst, F., Oberthiir, T., Gäbler, E., Bähr, A., Gerdes, A., Bratz, H. and Rantitsch, G. (2009) Ein Herkunftsnachweis für Niob-Tantalerze am Beispiel Afrikanischer Selten-Element-Pegmatite. Mitteilungen der Österreichischen Mineralogischen Gesellschaft, 155, 231267.Google Scholar
Mishra, K.S., Jagadeesan, P., Pandey, K.K., Saxena, V.P. and Sinha, R.M. (2008) REE geochemistry of uranium-bearing columbite-tantalites and multiple oxide phases from Proterozoie rare metal pegmatites of Pandikimal and adjoining areas, Jharsuguda district, Orissa. Journal of the Geological Society of India, 71, 313320.Google Scholar
Miyawaki, R. and Nakai, I. (1996) Crystal chemical aspects of rare earth minerals. Pp. 2140 in: Rare Earth Minerals: Chemistry, Origin and Ore Deposits (Jones, A.P., Wall, F. and Williams, C.T., editors). Mineralogical Society Series, 7, Chapman & Hall, London.Google Scholar
Moller, P. (1989) REE(Y), Nb, and Ta enrichment in pegmatites and carbonatite-alkalic rock complexes. Pp. 103144 in: Lanthanides, Tantalum and Niobium (Moller, P., Černý, P. and Saupé, R, editors). Springer, Berlin.CrossRefGoogle Scholar
Moller, P. and Muecke, G.K. (1984) Significance of europium anomalies in silicate melts and crystal-melt equilibria: a re-evaluation. Contributions to Mineralogy and Petrology, 87, 242250.CrossRefGoogle Scholar
Morel, S.W. (1979) The geology and mineral resources of Sierra Leone. Economic Geology, 74, 15631576.CrossRefGoogle Scholar
Nakajima, T. and Kurosawa, M. (2006) Rare-element mineralogy of the Uzumine granitic pegmatite, Abukuma mountains, north-eastern Japan. The Canadian Mineralogist, 44, 3144.CrossRefGoogle Scholar
Obaje, N.G. (2009) Geology and mineral resources of Nigeria. Lecture Notes in Earth Sciences, 120. Springer Verlag, Heidelberg, 221 pp.Google Scholar
Pearce, N.J.G., Perkins, W.T., Westgate, J.A., Gorton, M.P., Jackson, S.E., Neal, C.R. and Chenery, S.P. (1997) A compilation of new and published major and trace element data for NIST SRM 610 and NIST SRM 612 glass reference materials. Geostandards Newsletter, 21, 115144.CrossRefGoogle Scholar
Pedro, A.M.A. (1986) The Alto Ligonha Pegmatites (Mineral Exploration Guidelines). M.Sc, unpubl. Dissertation, Imperial College of Science and Technology, London, 190 pp.Google Scholar
Pinna, P., Jourde, G., Calvez, J.Y., Mroz, J.P. and Marques, J.M. (1993) The Mozambique Belt in northern Mozambique: Neoproterozoic (1100 — 850 Ma) crustal growth and tectogenesis, and superimposed Pan-African (800—550 Ma) tectonism. Precambrian Research, 62, 159.CrossRefGoogle Scholar
Prakash, K.S. (2007) Tantalite exploration in “Block-A” of Uis region, Namibia. Trabajos de Geologia (Universidad de Oviedo), 27, 4169.Google Scholar
Romer, R.L. and Lehmann, B. (1995) U-Pb columbite age of Neoproterozoic Ta-Nb mineralization in Burundi. Economic Geology, 90, 23032309.CrossRefGoogle Scholar
Romer, R.L. and Smeds, S.-A. (1996) U-Pb columbite ages of pegmatites from Sveconorwegian terrains in south-western Sweden. Precambrian Research, 76, 1530.CrossRefGoogle Scholar
Safiannikoff, A. (1955) Classification des pegmatites du Congo Beige et du Ruanda-Urundi. Annales de la Societe Geologique de Belgique, 78, 5770.Google Scholar
Schwartz, M.O., Rajah, S.S., Askury, A.K., Putthapiban, P. and Djaswadi, S. (1995) The Southeast Asian tin belt: Earth Science Reviews, 38, 95293.CrossRefGoogle Scholar
Semenov, E.I. (1958) Relationship between composition of rare earths and composition and structures of minerals. Geochemistry, 5, 574586.Google Scholar
Shannon, R.D. (1976) Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides. Ada Crystallographica, A32, 751767.Google Scholar
Shmakin, B.M. (1992) Mineralogy and geochemistry of REE in granitic pegmatites, Baikal region, eastern Siberia, Russia. Applied Geochemistry, 7, 459468.CrossRefGoogle Scholar
Simmons, W.B., Lee, M.T. and Brewster, R.H. (1987) Geochemistry and evolution of the South Platte granite-pegmatite system, Jefferson County, Colorado. Geochimica et Cosmochimica Ada, 51, 455472.CrossRefGoogle Scholar
Sosa, G.M., Augsburger, M.S. and Pedregosa, J.C. (2002) Columbite-group minerals from rare-metal granitic pegmatites of the Sierra de San Luis, Argentina. European Journal of Mineralogy, 14, 627636.CrossRefGoogle Scholar
Spear, F.S. and Pyle, J.M. (2002) Apatite, monazite and xenotime in metamorphic rocks. Pp. 293335 in: Phosphates: Geochemical, Geobiological, and Materials Importance (Kohn, MJ., Rakovan, J. and Hughes, J.M., editors). Reviews in Mineralogy and Geochemistry, 48, Mineralogical Society of America, Chantilly, Virginia, USA.CrossRefGoogle Scholar
Sweetapple, M.T. and Collins, P.L.F. (2002) Genetic framework for the classification and distribution of Archaean rare metal pegmatites in the North Pilbara Craton, Western Australia. Economic Geology, 97, 873895.CrossRefGoogle Scholar
Tack, L., Liegeois, J.P., Deblond, A. and Duchesne, D.C. (1994) Kibaran A-type granitoids and mafic rocks generated by two mantle sources in a late orogenic setting (Burundi). Precambrian Research, 68, 323356.CrossRefGoogle Scholar
Tack, L., Fernandez-Alonso, M., De Waele, B., Tahon, A., Dewaele, S., Baudet, D. and Cutten, H. (2006) The northeastern Kibaran belt (NKB): a long-lived Proterozoic intraplate history. 3 pages in: Abstracts of 21s’ Colloquium on African Geology, Maputo, Mozambique.Google Scholar
Tack, L., Wingate, M., De Waele, B., Meert, J., Griffin, B., Belousova, E.A., Tahon, A., Fernandez-Alonso, M., Baudet, D., Cutten, H. and Dewaele, S. (2009) The Proterozoic Kibaran belt in Central Africa: intracratonic 1375 Ma emplacement of a LIP. P. 52 in: Abstracts of the Fermor meeting of the Geological Society of London, Edinburgh, UK.Google Scholar
Teertstra, D.K., Schindler, M., Sherriff, B.L. and Hawthorne, F.C. (1999) Subsolidus rubidium-dominant feldspar from the Morrua pegmatite, Mozambique: paragenesis and composition. Mineralogical Magazine, 63, 313320.CrossRefGoogle Scholar
Varlamoff, N. (1954) Repartition des types de pegmatites autour de la partie nord-ouest du grand massif granitique de Nyanza (Ruanda, Afrique). Annales de la Société Géologique de Belgique, 78, 125.Google Scholar
Vasil'ev, N.V., Chevychelov, V.Yu., Zaraisky, G.P., Borodulin, G.P. and Udoratina, O.V. (2008) Peculiarities of tantalum-niobium mineralization of Taikeusky ore cluster (the Polar Urals). Zapiski Rossiiskogo Mineralogitsheskogo Obshestva, 137, 116.(in Russian).Google Scholar
Vasil'ev, N.V., Chevychelov, V.Yu., Zaraisky, G.P., Borodulin, G.P. and Udoratina, O.V. (2009) Tantalum-Niobium mineralization of the Taikeu ore cluster, the Polar Urals. Geology of Ore deposits, 51, 537548.CrossRefGoogle Scholar
Veksler, I.V., Dorfman, A.M., Kamenetsky, M., Dulski, P. and Dingwell, D.B. (2005) Partitioning of lanthanides and Y between immiscible silicate and fluoride melts, fluorite and cryolite and the origin of the lanthanide tetrad effect in igneous rocks. Geochimica et Cosmochimica Ada, 69, 28472860.CrossRefGoogle Scholar
von Backstrom, J.W. (1976) Geology and Mineral Deposits of Tantalite Valley, Warmbad District, South West Africa. Atom Energy Bd., South Africa, PER-3, 23 pp.Google Scholar
Walker, R.J., Hanson, G.N., Papike, J.J., O'Neil, J.R. and Laul, J.C. (1986) Internal evolution of the Tin Mountain pegmatite, Black Hills, South Dakota. American Mineralogist, 71, 440459.Google Scholar
Wise, M.A. and Černý, P. (1990) Primary compositional range and alteration trends of microlite from the Yellowknife pegmatite field, Northwest Territories, Canada. Mineralogy and Petrology, 43, 8398.CrossRefGoogle Scholar
Wright, J.P., Hastings, D.A., Jones, W.B. and Williams, H.R. (1985) Geology and Mineral Resources of West Africa. Georg Allen and Unwin, London, 187 pp.Google Scholar

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