TY - JOUR
T1 - The Bepkong gold deposit, Northwestern Ghana
AU - Amponsah, Prince Ofori
AU - Salvi, Stefano
AU - Béziat, Didier
AU - Baratoux, Lenka
AU - Siebenaller, Luc
AU - Nude, Prosper Mackenzie
AU - Nyarko, Richard Scriven
AU - Jessell, Mark W.
N1 - Publisher Copyright:
© 2015 Elsevier B.V.
PY - 2016/10/1
Y1 - 2016/10/1
N2 - The Bepkong gold deposit is located in the Wa–Lawra belt of the Paleoproterozoic Baoulé-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 D3 deformational event, denominated DB1 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 forms euhedral crystals surrounding arsenopyrite, but does not contain gold, suggesting that it formed at a late stage, from a gold-free hydrothermal fluid.
AB - The Bepkong gold deposit is located in the Wa–Lawra belt of the Paleoproterozoic Baoulé-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 D3 deformational event, denominated DB1 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 forms euhedral crystals surrounding arsenopyrite, but does not contain gold, suggesting that it formed at a late stage, from a gold-free hydrothermal fluid.
KW - Bepkong deposit
KW - Gold mineralization
KW - Northwestern Ghana
UR - http://www.scopus.com/inward/record.url?scp=84936971714&partnerID=8YFLogxK
U2 - 10.1016/j.oregeorev.2015.06.022
DO - 10.1016/j.oregeorev.2015.06.022
M3 - Article
AN - SCOPUS:84936971714
SN - 0169-1368
VL - 78
SP - 718
EP - 723
JO - Ore Geology Reviews
JF - Ore Geology Reviews
ER -