地质论评2018，Vol.64Issue(3)：723-736,14.DOI:10.16509/j.georeview.2018.03.017
东昆仑那更康切尔沟银矿床银矿物特征及成矿元素沉淀机制浅析
Characteristics of Silver Minerals of Nagengkangqieergou Silver Deposit in Eastern Kunlun Orogenic Belt and a Brief Analysis of the Precipitation Mechanism of Ore-forming Elements
摘要
Abstract
Objectives:Nagengkangqieergou silver deposit,situated in the eastern section of Eastern Kunlun orogenic belt and to the north of Kunzhong Fault,is a large-scale structurally-controlled hydrothermal vein-type deposit,newly discovered in Qinghai Province in recent years. The characteristics of silver minerals and the precipitation mechanism of ore-forming elements of Nagengkangqieergou silver deposit has been first studied in this paper. Methods:Mineragraphy observation,scanning electron microscopy-energy dispersive spectrometry analysis, electron microprobe analysis,and microthermometry of fluid inclusions trapped in quartz were carried out to investigate the characteristics of silver minerals of Nagengkangqieergou silver deposit and precipitation mechanism of ore-forming elements. Results:It is preliminarily ascertained that silver minerals,occurred in Elashan Formation,include native silver, acanthite, proustite, pyrostilpnite, miargyrite, argentian tetrahedrite, freibergite, andorite, diaphorite, teremkovite,all of which contain high content of I. By contrast,silver minerals,hosted in Jinshuikou Group,are principally composed of native silver and argentite,both of which are spatially connected closely with arsenopyrite, sphalerite,stannite and contain scarcely any I. Besides,homogenizaion temperature of quartz fluid inclusions occurred in the Jinshuikou Group are clustered in the interval of 275~295℃,while in the interval of 155~215℃for those occurred in Elashan Formation. Moreover,there is slight difference in the salinity of ore-forming fluid for both strata. Ore-forming fluid salinity values are clustered in the interval of 4.5~6.5% for the Jinshuikou Group, while in the interval of 5.5~6.5% for the Elashan Formation. Conclusions:Precipitation mechanism of ore-forming elements in the Jinshoukou Group and that in the Elashan Formation are remarkably different,indicated by the significant difference of wall rock alteration,category and chemical composition of silver minerals as well as the ore-forming fluid temperature. Therefore,this study provides guiding significance for ore-prospecting in both strata.关键词
东昆仑那更康切尔沟/银矿物/电子探针/矿物学特征/均一温度Key words
Nagengkangqieergou of Eastern Kunlun Mountains/silver minerals/electron microprobe/mineralogical characteristics/homogenization temperature引用本文复制引用
李敏同,陈晓东,许远平,谢万洪,周洪兵,孙崇波,刘宏..东昆仑那更康切尔沟银矿床银矿物特征及成矿元素沉淀机制浅析[J].地质论评,2018,64(3):723-736,14.基金项目
本文为青海省地勘基金(编号:青地调勘[2017]72号)的成果.This study is financially supported by the geological prospecting foundation of Qinghai Province([2017]No.72).We would like to extend our sincere thanks to WangYue from Institute of Multipurpose Utilization of Mineral Resources and Gong Tingting from Chengdu University of Technology for their help in the test process as well as Professor Xue Chunji for his sincere comments and proposals during the revising process. （编号:青地调勘[2017]72号）
