现代地质2012，Vol.26Issue(3)：453-463,11.
藏南扎西康铅锌锑多金属矿床流体包裹体研究及地质意义
Fluid Inclusions in the Zhaxikang Pb-Zn-Sb Polymetallic Deposit,South Tibet, and Its Geological Significance
摘要
Abstract
The Zhaxikang Pb-Zn-Sb polymetallic deposit, which is located in the south Tibetan detachment system , is one of the few large Pb-Zn-Sb-Ag symbiotic deposits in Tibet that characterized by great variety of sulfosalt minerals. The deposit occurs in Lower Jurassic Ridang Formation, with the rocks being carbon-bearing calcareous slate, calcareous slate, sericite slate, shale and quartz sandstone. The ore bodies in Zhaxikang deposit are mainly controlled by SN and NE-SW striking tensional faults. The deposit was subjected to two stages: medium-low temperature hydrothermal period and hypergenesis period. The inclusions in siderite, calcite and quartz of the medi- um-low temperature hydrothermal period are dominantly vapor-liquid two-phase inclusions, including a small amountof pure vapor inclusions, pure vapor CO2-type inclusions and CO2-H2O three-phase CO2 inclusions. In the medium-low temperature hydrothermal period, homogenization temperatures of inclusions vary from 184 to 329℃. with peak temperature of 255℃, the salinities from 2. 07% to 12. 05% , the densities from 0. 65 to 0. 86 g/cm3. The ore-forming fluid is a medium-low temperature, low salinity, low density H2O-NaCl system, with minor or trace amounts of CO2 and CH4. The ξDV-SMOW and ξ18OH2O values of the fluids in quartz and calcite inclusions varied from - 165‰ to - 131‰ and from - 13. l‰ to 10. 21‰, respectively, therefore, the water in the ore-forming fluids derived from precipitation. The immiscibility which was marked by the escape of gases from the fluid occurred during the mineralization, whereas this immiscibility resulted in sulfide mineralization. The genesis of this deposit belongs to medium-low temperature hydrothermal type formed during groundwater convection cycle driven by sedimentary-structural-geothermal activity.关键词
铅锌锑多金属矿床/流体包裹体/成矿作用/扎西康/藏南Key words
Pb-Zn-Sb polymetallic deposit/ fluid inclusion/ mineralization/ Zhaxikang/ south Tibet分类
天文与地球科学引用本文复制引用
朱黎宽,顾雪祥,李关清,章永梅,程文斌,卞孝东..藏南扎西康铅锌锑多金属矿床流体包裹体研究及地质意义[J].现代地质,2012,26(3):453-463,11.基金项目
西藏自治区矿产资源潜力评价项目(1212010813025) （1212010813025）
国家自然科学基金项目(40930423,40873036) （40930423,40873036）
国家重点基础研究发展计划项目(2009CB421003-01) （2009CB421003-01）
高等学校学科创新引智计划项目(B07011). （B07011）
