Metallogenic Geochemistry and Physico-Chemical Conditions of Silurian Pb-Zn Mineralization in the Xunyang County, Shaanxi

The Silurian Pb-Zn mineralization zone located in the southern margin of the Paleozoic Zhenan-Xunyang basin of the southern Qinling-Dabie tectonic belt is about 100 km long in EW direction and 10～50 km wide in SN direction.The early exploration has deter mined the Sireng ou-Nanshagou,Yangliu-Renjiagou-Xiaogou and Chang sha-Xiying -Huangshiban Pb-Zn zones in the middle Silurian Shuanghezhen and lower Silurian Maizita formations.About 20 Pb-Zn deposits with Pb and Zn resource reserve of 10×10⁵ t ons have been found in these zones.The study has indicated that ore deposits having basically consistent sulfur origin belong to the mixed type.The primitive Pb was mainly derived from the lower crust and upper mantle; The water source for the hot water deposit may be mixed materials; The metallogenic fluid originated from the building water that is weak-medium acidic in nature and metallogenic temperature is mainly concentrated in 250℃～300℃,belonging to epithermal ore deposit.