Lithostratigraphic and structural controls of 'tsavorite' deposits at Lemshuku, Merelani area, Tanzania

Julien Feneyrol (1) , Gaston Giuliani (1, 2) , Daniel Ohnenstetter (1) , Elisabeth Le Goff (3) , Elias P.J. Malisa (4) , Mark Saul , Eric Saul , John Saul , Vincent Pardieu

1 CRPG - Centre de Recherches Pétrographiques et Géochimiques
2 LMTG - Laboratoire des Mécanismes et Transfert en Géologie
3 BRGM - Bureau de Recherches Géologiques et Minières (BRGM)
4 University of Dar-es-Salaam - Department of Geology

The first study of the Lemshuku ‘tsavorite' mining district is presented. From bottom to top, the lithostratigraphic column corresponds to a metasedimentary sequence composed of quartzite, fine-grained graphitic gneiss, kyanite-graphite gneiss, biotite-almandine gneiss, metasomatized graphitic gneiss and dolomitic marble. ‘Tsavorite' occurs in quartz veins and rarely as nodular concretions. Two factors control mineralization: (1) lithostratigraphy, with ‘tsavorite' in association with pyrite and graphite confined to quartz veins within the metasomatized graphitic gneiss; and (2) structure, with the mineralized veins characteristically controlled by tight isoclinal folds associated with shearing.

Mots clés: ‘Tsavorite; Tanzania; Lemshuku Mine; ‘Tsavorite'; Quartz vein; Lithostratigraphic and structural controls

Domaines: Sciences de la Terre

Julien Feneyrol, Gaston Giuliani, Daniel Ohnenstetter, Elisabeth Le Goff, Elias P.J. Malisa, et al.. Lithostratigraphic and structural controls of 'tsavorite' deposits at Lemshuku, Merelani area, Tanzania. Comptes Rendus Géoscience, 2010, 342 (10), pp.778-785. ⟨10.1016/j.crte.2010.06.003⟩. ⟨hal-00563709⟩