Amponsah P. O., Salvi S., Beziat D., Baratoux Lenka, Siebenaller L., Nude P. M., Nyarko R. S., Jessell Mark. (2016). The Bepkong gold deposit, Northwestern Ghana. Ore Geology Reviews, 78, p. 718-723. ISSN 0169-1368.
Titre du document
The Bepkong gold deposit, Northwestern Ghana
Année de publication
2016
Auteurs
Amponsah P. O., Salvi S., Beziat D., Baratoux Lenka, Siebenaller L., Nude P. M., Nyarko R. S., Jessell Mark
Source
Ore Geology Reviews, 2016,
78, p. 718-723 ISSN 0169-1368
The Bepkong gold deposit is located in the Wa-Lawra belt of the Paleoproterozoic Baoule-Mossi domain of the West African Craton, in NW Ghana. It occurs in pelitic and volcano-sedimentary rocks, metamorphosed to greenschist facies, in genetic association with zones of shear interpreted to form during the regional D-3 deformational event, denominated D-B1 at the deposit scale. The ore zone forms a corridor-like body composed of multiple quartz +/- carbonate veins surrounded by an alteration envelope, characterized by the presence of chlorite, calcite, sericite, quartz and disseminated pyrite, arsenopyrite plus subordinate pyrrhotite and chalcopyrite. The veins contain only small proportions of pyrite, whereas most of the sulphides, particularly arsenopyrite, occur in the altered host rock, next to the veins. Pyrite is also common outside of the ore zone. Gold is found in arsenopyrite, where it occurs as invisible gold and as visible - albeit micron-size - grains in its rims, and as free gold within fractures cross -cutting this sulphide. More rarely, free gold also occurs in the veins, in fractured quartz. In the ore zone, pyrite formseuhedral crystals surrounding arsenopyrite, but does not contain gold, suggesting that it formed at a late stage, from a gold-free hydrothermal fluid.
Plan de classement
Géologie et formations superficielles [064]
Description Géographique
GHANA
Localisation
Fonds IRD [F B010067626]
Identifiant IRD
fdi:010067626
