Etude métallogénique du district aurifère de Syama (Mali) : analyse comparative de gisements situés sur une même structure lithosphérique éburnéenne

Abstract : This thesis presents a comparative study of the Syama, Tabakoroni and Tellem gold deposits, located in the N-S trending Bagoé greenstone belt of Mali. Mineralization is found preferentially along the edges of millimetre- to centimetre-sized quartz, quartz-albite, quartz-ankerite, dolomite-quartz veins developed in tension gaps that formed during brittle deformation. Gold mineralization is mostly associated with pyrite in the three deposits, and also with arsenopyrite at Tabakoroni and Tellem. These sulphides are zoned with (i) an arsenic-rich core containing several albite, ankerite and rutile inclusions (less commonly, pyrrhotite) and (ii) a clear border of finely alternating As-rich and As-poor bands. Gold occurs in the form of i) invisible gold included in their crystal lattices, ii) small individual grains bound to these sulphides, frequently accompanied by sulphoantimonides, mainly tetrahedrite and chalcostibite and iii) free gold associated with quartz. The arseniferous pyrites and arsenopyrites of the Bagoé belt deposits are among the richest in invisible gold in all gold deposits in West Africa and are quite comparable to those of the Ashanti Belt in Ghana.
Document type :
Theses
Complete list of metadatas

Cited literature [297 references]  Display  Hide  Download

https://tel.archives-ouvertes.fr/tel-01900948
Contributor : Abes Star <>
Submitted on : Monday, October 22, 2018 - 3:25:07 PM
Last modification on : Friday, January 10, 2020 - 9:09:57 PM
Long-term archiving on: Wednesday, January 23, 2019 - 3:16:52 PM

File

2017TOU30087b.pdf
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-01900948, version 1

Collections

Citation

Yollande Traoré. Etude métallogénique du district aurifère de Syama (Mali) : analyse comparative de gisements situés sur une même structure lithosphérique éburnéenne. Minéralogie. Université Paul Sabatier - Toulouse III, 2017. Français. ⟨NNT : 2017TOU30087⟩. ⟨tel-01900948⟩

Share

Metrics

Record views

102

Files downloads

833