Mineral chemistry of the Xiasai Ag-Pb-Zn deposit in the central Yidun Terrane, SW China: Insight into Ni-Ag-Bi mineralization and formation conditions

摘要

Sulfides and sulfosalts are major ore minerals for most of Ag-Pb-Zn deposits and can be used to study enrichment and distribution of ore-forming elements and formation conditions. The Xiasai Ag-Pb-Zn deposit (Zn 0.141 Mt @ 4.30%, Pb 0.132 Mt @ 4.03%, Ag 1028 t @ 337.8 g/t, Cu 10058 t @ 0.56%, and Sn 20000 t @ 0.75%) is a hydrothermal vein-type deposit in the central Yindun Terrane, SW China. It consists of proximal quartz-cassiterite veins and distal Ag-Pb-Zn sulfide veins to a Cretaceous monzogranite. Three successive mineralization sub-stages are recognized for Ag-Pb-Zn veins, i.e., arsenopyrite + coarse-grained pyrite (Py1) + pyrrhotite, sphalerite + chalcopyrite + fine-grained pyrite (Py2), and silver-minerals + native bismuth + galena.