Adams S. J. auteur aut IRD Van Lichtervelde Marieke auteur aut IRD Amponsah P. O. auteur aut IRD Nude P. M. auteur aut IRD Asiedu D. K. auteur aut IRD Dampare S. B. auteur aut IRD text journalArticle eng text/pdf born digital access In southern Ghana, the region along the coast between Accra and Cape Coast hosts a large number of pegmatites mineralized in lithium, niobium-tantalum and tin. The pegmatites occur in many distinct groups, each extending over several kilometers. They intrude metasedimentary units of the Birimian Supergroup, and are associated with early to late orogenic granite intrusions which are metaluminous, sterile, and too old to be potential parental granites for the pegmatites. In this study, we characterized the Winneba-Mankoadze group of geographically coeval pegmatites, using field description, petrography, rare-metal mineralogy and accessory mineral geochemistry on micas, garnet and Nb-Ta-Sn minerals, in order to determine its rare-metal potential and to investigate its origin. The results indicate that the pegmatites are part of the albite-spodumene type of the Lithium-Cesium-Tantalum (LCT) family. The rare metal mineral assemblages are particularly complex and display relevant oxide species such as columbite- and wodginite-group minerals, tapiolite, microlite, cassiterite and rutile, which are evidences of an extremely evolved magmatic system. Based on mineral assemblages, wholerock geochemistry, and mineral geochemistry on garnet, micas and the CGM, two pegmatite fields are distinguished in the Winneba-Mankoadze group, and an anatectic origin is proposed. For the first time in West Africa, we fully describe a highly fractionated LCT-family pegmatite field comparable to the most evolved pegmatite bodies in the world. specialized Rare-element pegmatites Spodumene Columbite-group minerals Extreme fractionation GHANA 064 207 105049 [18 p.] 2023 1464-343X https://www.documentation.ird.fr/hor/fdi:010090323 10.1016/j.jafrearsci.2023.105049 1464-343X [F B010090323] https://www.documentation.ird.fr/hor/fdi:010090323 https://www.documentation.ird.fr/intranet/publi/2023-11/010090323.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2023-11-10 2025-02-24 fdi:010090323 fre