A Fluid Inclusion Study of Vein-type Copper Mineralization in the East Wulasigou Pb-Zn-Cu Deposit,Altay,Northwestern China
A Fluid Inclusion Study of Vein-type Copper Mineralization in the East Wulasigou Pb-Zn-Cu Deposit,Altay,Northwestern China作者机构:University of Science and Technology Beijing Beijing 100083 China
出 版 物:《Acta Geologica Sinica(English Edition)》 (地质学报(英文版))
年 卷 期:2016年第90卷第5期
页 面:1754-1767页
核心收录:
学科分类:081803[工学-地质工程] 08[工学] 0818[工学-地质资源与地质工程]
基 金:funded by National Nature Science Foundation of China(41372096)
主 题:Wulasigou vein copper mineralization H2O-CO2 fluids metamorphic fluids stable isotopes
摘 要:The Wulasigou Cu-Pb-Zn deposit,located 15 km northwest of Altay city in Xinjiang,is one of many Cu-Pb-Zn polymetallic deposits in the Devonian Kelan volcanic-sedimentary basin in southern *** mineralizing periods can be distinguished:the marine volcanic sedimentary PbZn mineralization period,and the metamorphic hydrothermal Cu mineralization period,which is further divided into an early bedded foliated quartz vein stage(Q1) and a late sulfide-quartz vein stage(Q2) crosscutting the *** types of fluid inclusions were recognized in the Q1 and Q2 quartz from the east orebodies of the Wulasigou deposit:H2O-CO2 inclusions,carbonic fluid inclusions,aqueous fluid inclusions,and daughter mineral-bearing fluid *** studies show that solid CO2 melting temperatures(T(m,CO2)) of H2O-CO2 inclusions in Ql are from-62.3℃ to-58.5C,clathrate melting temperatures(T(m,clath)l) are from 0.5 C to 7.5 C,partial homogenization temperatures(T(h,CO2)) vary from 3.3℃ to 25.9℃(to liquid),and the total homogenization temperatures(T(h,tot)) vary from 285℃ to 378℃,with the salinities being 4.9%-15.1%NaCl *** the CO2-phase densities being 0.50-0.86 g/cm-3.H2O-CO2 inclusions in Q2 have T(m,CO2) from-61.9℃ to-56.9℃,T(m,clath)from 1.3℃ to 9.5℃,T(h,CO2) from 3.4℃ to 28.7℃(to liquid),and T(h,tot) from 242℃ to 388℃,with the salinities being 1.0%-15.5%NaCl *** the CO2-phase densities being 0.48-0.89 g/*** minimum trapping pressures of fluid inclusions in Q1 and Q2 are estimated to be 260-360 MPa and180-370 MPa,*** δ-(34)S values of pyrite from the volcanic sedimentary period vary from2.3‰ to 2.8‰(CDT),and those from the sulfide-quartz veins fall in a narrow range of-1.9‰ to 2.6‰(CDT).The δD values of fluid inclusions in Q2 range from-121.0‰ to-100.8‰(SMOW),and theδ-(18)O(H2O) values calculated from δ-(18)O of quartz range from-0.2‰ to 8.3‰(SMOW).The δD-δ-(18)O(H2O)data are close to the magmatic and metamorphic *** fluid inclusion