藏南马扎拉金-锑矿床:成矿流体性质和成矿物质来源  

Mazhala Gold-Antimony Deposit in Southern Tibet: The Characteristics of Ore-Forming Fluids and The Origin of Gold and Antimony

作　　者：谢玉玲[1] 杨科君 李应栩[3] 李光明 曲云伟 董磊[3] Xie Yuling;Yang Kejun;Li Yingxu;Li Guangming;Qu Yunwei;Dong Lei(Civil and Resource Engineering School,University of Science and Technology Beijing,Beijing 100083,China;Beijing Jinyou Exploration Limited Compajiy,Beijing 100010,China;Chengdu Center,China Geological Survey,Chengdu 610081. China)

机构地区：[1]北京科技大学土木与资源工程学院,北京,100083 [2]北京金有地质勘查有限责任公司,北京100010 [3]中国地质调查局成都地质调查中心,四川成都610081

出　　处：《地球科学》2019年第6期1998-2016,共19页Earth Science

基　　金：国家重大基础研究项目(No.2011CB403100);中国地质调查局地质调查项目(No.DD20190147);国家重点研发计划项目(No.2016YFC0600308)

摘　　要：马扎拉金-锑矿床是藏南巨型金-锑成矿带的重要组成部分,其矿床成因目前仍存在不同认识.通过主要矿石和蚀变围岩的岩相学、矿相学、流体包裹体和稳定同位素分析,探讨了马扎拉金-锑矿床的成矿流体性质、矿质迁移和沉淀机制.结果表明,马扎拉金-锑矿床成矿流体主要来自岩浆水,主成矿期流体为中温(约255℃)、低盐度(2.8%~3.5%NaCleqv)、富CO2流体,成矿压力约150 MPa,流体演化过程中的CO2与水的不混溶是造成矿质沉淀的主要原因,成矿金属主要来源于地层,特别是区域广泛分布的海相火山岩地层.The genesis of Mazhala Au - Sb deposit, which is one of the most important Au - Sb deposits in South Tibet Au - Sb metallogenic belt, is still open to debate. Based on field observation, petrography, microscopy, fluid inclusions, and stable isotopic results, in this paper, it discusses the characteristics of ore-forming fluid, the transportation, and the precipitation mechanism of Au and Sb. It can be concluded that the ore-formng fluid has a dominant magmatic origin, and is of moderate temperature (ca.255 ℃), low salinity (ca.2.8%-3.5% NaCleqv) and rich in CO2. The estimated ore-forming pressure is about 150 MPa. The unmixing between CO2 and aqueous during the fluid evolution leads to the ore precipitation. The Au, Sb may have been sourced from wall rocks, especially the submarine volcanic rock of them.

关 键 词：藏南金-锑成矿带 马扎拉金-锑矿床 流体包裹体 成矿金属来源 矿床 

分 类 号：P611[天文地球—矿床学]