Sediment-hosted lead-zinc deposits in northwestern Guizhou, China, are located on the southwest margin of the Yangtze craton and Youjiang orogenic belt. They are hosted by Proterozoic and Paleozoic carbonate rocks, and consist mainly of sphalerite, galena, and pyrite, with quartz, calcite and dolomite veins. Petrography, microthermometry, laser Raman spectroscopy analyses of fluid inclusions in quartz and sphalerite, and sulfur isotopic compositions of sulfides are used to characterize the ore-forming fluids associated with Pb-Zn mineralization in the northwestern Guizhou. The results show that the fluid inclusions in quartz are two-phase, aqueous inclusion and have higher homogenization temperatures (160 similar to 260 degrees C) and salinities of 10% similar to 22% NaCleqv, with low density of CO2, CH4 and N-2 whereas the homogenization temperatures of two-phase aqueous inclusion in sphalerite range from 160 180 degrees C, with salinities of 3% similar to 23% NaCleqv. Sulfur isotopic compositions of sulfides indicate that reduced sulfur was mainly derived from the host rocks. We proposed that fluid mixing between metal-rich brines and reduced sulfur-bearing sedimentary formation waters is the most efficient process for Pb-Zn ore mineral precipitation.

Publication name	ACTA PETROLOGICA SINICA, 32 (11):3431-3440; 2016
Author(s)	Zhu LuYan; Su WenChao; Shen NengPing; Dong WenDou; Cai JiaLi; Zhang ZhengWei; Zhao Hai; Xie Peng
Corresponding author	ZHU Luyan   zhuluyan.happy@163.com  1. Chinese Acad Sci, Inst Geochem, State Key Lab Ore Deposit Geochem, Guiyang 550081, Peoples R China  2. Univ Chinese Acad Sci, Beijing 100049, Peoples R China

View here for the details