Dissertation/ Thesis
Origin, evolution and rare-metal mineralization of the West-African pegmatites ; Origine, évolution et minéralisation en métaux rares des pegmatites de l'Afrique de l'Ouest
| العنوان: | Origin, evolution and rare-metal mineralization of the West-African pegmatites ; Origine, évolution et minéralisation en métaux rares des pegmatites de l'Afrique de l'Ouest |
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| المؤلفون: | Bonzi, Wilédio Marc-Emile |
| المساهمون: | Géosciences Environnement Toulouse (GET), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Centre National de la Recherche Scientifique (CNRS), Université Paul Sabatier - Toulouse III, Université Joseph Ki-Zerbo (Ouagadougou, Burkina Faso), Olivier Vanderhaeghe, Urbain Wenmenga |
| المصدر: | https://theses.hal.science/tel-03701223 ; Géologie appliquée. Université Paul Sabatier - Toulouse III; Université Joseph Ki-Zerbo (Ouagadougou, Burkina Faso), 2021. Français. ⟨NNT : 2021TOU30274⟩. |
| بيانات النشر: | HAL CCSD |
| سنة النشر: | 2021 |
| المجموعة: | Université Toulouse III - Paul Sabatier: HAL-UPS |
| مصطلحات موضوعية: | Pegmatite, West Africa, Mineralization, Afrique de l'Ouest, Minéralisation, [SDU.STU.AG]Sciences of the Universe [physics]/Earth Sciences/Applied geology |
| الوصف: | Rare metals are essential to the development of high-tech industry and to the transition toward a low-carbon energy. The Mangodara district (South West of Burkina Faso, West African Craton) exposes rare metals pegmatites associated with metamorphic, migmatitic and magmatic rocks, in a paleaoproterozoic complex of gneiss-granitoids. We investigate the petrogenesis of these pegmatites, discussed between the partial melting of metasediments and the magmatic differentiation of an enriched pluton, through a multi-disciplinary petrographical, geochemical and geochemical and geochronological approach. The studied zone consists of a regional dome, situated in the middle crust (4-7 kbar, Al in hornblende), cored by a tonalitic-trondhjemitic gneiss rich in plagioclase, and mantled by a granodioritic diatexite hosting rafts of amphibolites, paragneisses (sillimanite-garnet/staurolite) and migmatites of birimian protoliths. Plutonic rocks, forming two geochemical Na-rich and K-rich series, are in diffuse contact gneisses or intrusives within. Four types of pegmatites have been identified in the district. Titanite-allanite type pegmatites and apatite-zircon type pegmatites are metaluminous, few evolved, deriving from the late segregation of the tonalitic-trondhjemitic gneiss. Garnet-columbite type pegmatites (Li, Nb) are peraluminous, from the petrogenetic family Mixed Lithium-Cesium-Tantalum and Niobium-Yttrium-Fluor (LCT+NYF). They come from the partial melting of paragneiss with a control of rare metals fractionation in the source by micas, phosphates and garnet, and a contamination by residual liquids from the metaluminous pegmatites. Garnet-REE type pegmatites are NYF pegmatites, originating from the late segregation of a granodioritic gneiss, with a control of rare metals fractionation in the source by allanite, phosphates and amphibole. Titanite-allanite type pegmatite crystallization is dated at 2094.3 ± 8.8 Ma (U-Pb in situ dating of zircon). Regional cooling below 500 °C is indicated by U-Pb dating of apatite from ... |
| نوع الوثيقة: | doctoral or postdoctoral thesis |
| اللغة: | French |
| Relation: | NNT: 2021TOU30274 |
| الاتاحة: | https://theses.hal.science/tel-03701223 https://theses.hal.science/tel-03701223v1/document https://theses.hal.science/tel-03701223v1/file/2021TOU30274a.pdf |
| Rights: | info:eu-repo/semantics/OpenAccess |
| رقم الانضمام: | edsbas.54644E09 |
| قاعدة البيانات: | BASE |
| الوصف غير متاح. |