Ore-forming material sources of the Baiyangping Cu-Co-Ag polymetallic deposit in the Lanping Basin, western Yunnan Province

The ore-forming material sources of the Baiyangping copper-cobalt-silver polymetallic deposit have been studied in view of the S, Pb, C, O and H isotopic characteristics and the ratio of Co/Ni of cobaltite. The results showed that sulfur in metallic sulfides may have come from a mixed sulfur-source consisting of the sulfur-source from metamorphic rocks in the basin basement with basic volcanic rocks and the sulfur-source from basin sulfates; lead in the ores was provided by the sedimentary rocks and basement rocks; CO2 in ore-forming fluids was derived from thermolysis of altered and normal marine facies carbonates and decarboxylation of sedimentary organic matter respectively; the ore-forming fluids belong to the SO4-Cl- Na-Ca-type basin thermal brines derived from paleo-meteoric waters; cobalt in the deposit may also be derived from the metamorphic rocks in the basin basement with basic volcanic rocks. © Science Press, Institute of Geochemistry, CAS and Springer-Verlag GmbH 2008.