TY - GEN
T1 - Copper hosted in red beds at tambomachay deposit (Cuzco, Peru), Trapped by bacterially reduced sulfur during migration of basinal fluids
AU - Rosas, S.
AU - Fontboté, L.
AU - Salcedo, C.
AU - Robles, M.
AU - Vallance, J.
AU - Sáez, J.
AU - Spangenberg, J.
N1 - Publisher Copyright:
Copyright © 2019 by SME.
PY - 2019
Y1 - 2019
N2 - The Tambomachay ore deposit (13°28'36.78"S, 71°57'35.98"W, about 6 km north of the town of Cuzco, Peru) consists of Cu hosted in arkosic red beds of the Kayra Formation (Lower Eocene). Bornite, chalcopyrite, chalcocite, covelite, digenite, malachite, and chrysocolla occur disseminated in thin layers and in veinlets. The occurrence of the copper ores in a part of the red bed sequence containing green reducing layers, the presence of organic matter in interstices between the hypogene sulfides, and the sulfur composition of the copper sulfides (δ34S values between -16.9 and -12.4%. vs VCDT) pointing to bacterial sulfate reduction, are strong arguments to propose that mineralization was caused by copper-bearing oxidizing saline basinal fluids that precipitate copper sulfides when they meet reduced sulfur in an organic matter-rich horizon. Faults parallel to the regional Tambomachay Fault could have acted as feeders for oxidizing basinal copper-bearing fluids. Fluid migration was probably driven by tectonically-induced topography gradient.
AB - The Tambomachay ore deposit (13°28'36.78"S, 71°57'35.98"W, about 6 km north of the town of Cuzco, Peru) consists of Cu hosted in arkosic red beds of the Kayra Formation (Lower Eocene). Bornite, chalcopyrite, chalcocite, covelite, digenite, malachite, and chrysocolla occur disseminated in thin layers and in veinlets. The occurrence of the copper ores in a part of the red bed sequence containing green reducing layers, the presence of organic matter in interstices between the hypogene sulfides, and the sulfur composition of the copper sulfides (δ34S values between -16.9 and -12.4%. vs VCDT) pointing to bacterial sulfate reduction, are strong arguments to propose that mineralization was caused by copper-bearing oxidizing saline basinal fluids that precipitate copper sulfides when they meet reduced sulfur in an organic matter-rich horizon. Faults parallel to the regional Tambomachay Fault could have acted as feeders for oxidizing basinal copper-bearing fluids. Fluid migration was probably driven by tectonically-induced topography gradient.
UR - http://www.scopus.com/inward/record.url?scp=85084014580&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:85084014580
T3 - 2019 SME Annual Conference and Expo and CMA 121st National Western Mining Conference
BT - 2019 SME Annual Conference and Expo and CMA 121st National Western Mining Conference
PB - Society for Mining, Metallurgy and Exploration
T2 - 2019 SME Annual Conference and Expo and CMA 121st National Western Mining Conference
Y2 - 24 February 2019 through 27 February 2019
ER -