Evidence for metallogenic geochemistry of volcano-hot spring deposition in Xiqiu copper deposit, Zhejiang Province, China

There were strong volcanic and hot spring activities in Late Proterozic in the Xiqiu mining district, Zhejiang Province. The volcanic rocks and hydrothermal sedimentary cherts have high contents of the major metallogenic elements. Their atomic percentage of Cu:Zn:Pb is similar very much between volcanic rock, hydrothermal sedimentary chert and ore. Therefore, the metallization has a direct bearing on the volcanic and hot spring activities in the Xiqiu area. The δ³⁴S values vary from ?6.5‰ to 2.8‰, the δ³⁰Si values from ?0.2‰ to 0.6‰, and the δ¹⁸O values from 8.14‰ to 22.32‰ Lead isotopes were derived mainly from the lower crust. The ores have high contents of As, Sb, bi, Ga, Zn, and Ba, and low Al/(Al + Fe+ Mn) ratios, with Zn/(Zn+ Pb) ratios approximate to unity. Therefore, the Xiqiu massive copper sulfide deposit can be ascribed to volcano-hot spring deposition.