Study on paragenesis-separation mechanism and source of ore-forming element in the Baiyangping Cu-Pb-Zn-Ag polylmetallic ore deposit, Lanping basin, southwestern China
兰坪盆地白秧坪Cu-Pb-Zn-Ag多金属矿集区元素共生分异机制及物质来源

Baiyangping Cu-Ag polymetallic ore district is located in the northern part of the Lanping-Simao foreland fold belt between the Jinshajiang-Ailaoshan and Lancangjiang faults, and the deposit can be divided into eastern and western ore zones. Based on electron microprobe analysis of ore minerals, ore-forming element content and S isotope composition, we included that (1) The type of ore minerals combination and trace elements characteristics are significantly different in two ore zone, the feature in eastern part is simple, whereas in western part is complex (occurring Pb, Zn and Cu independent mineral, in addition, having Co and Bi minerals); (2) In eastern ore zone, the enrichment of Ag, As, Cd, Pb, Sb and Zn is weakened, enrichment of Bi and Cu is enhanced from south to north, moreover, the depletion of Co, Cr, Ni and V are appear in this area. In western ore zone, the enrichment of Ag, Pb and Zn are strong in Wudichang and Liziping. Cu is enriched in Xiaoyakou and Baiyangping. Otherwise, Ba, Co, Cr, Ni and V are depleted in different ore zones; (3) Co, Ni and Cr contents are higher in western ore zone, on the contrary, Sr, Pb, Zn and Ba contents are higher in eastern ore zone. These characteristics are consistent with their mineral assemblages' rules. There existed a certain relationship between the paragenesis-separation mechanism and tectonic zonation; (4) The volcanic rocks in Lanping basin have provided the main ore-forming source. The characteristics of Mo, Co and Ni indicated that the mineralization may have a close connection with mafic-ultramafic magma. S isotope features implied that the source of sulfur is mainly mantle source.