西昆仑塔什库尔干赞坎铁矿成矿物质来源的锶钕同位素约束  

Sr-Nd Isotope Constraints on the Source of Ore-forming Elements of Zankan Iron Deposit in the Taxkorgan Terrane of West Kunlun Orogen

作　　者：周振菊[1,2] 陈衍景[2] 汤好书 吴艳爽[4] 陈正乐[1] ZHOU Zhenju;CHEN Yanjing;TANG Haoshu;WU Yanshuang;CHEN Zhengle(Institute of Geomechanics,Chinese Academy of Geological Sciences,Beijing 100081,China;Key Laboratory of Orogen and Crustal Evolution,Peking University,Beijing 100871,China;State Key Laboratory of Ore Deposit Geochemistry,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550002,Guizhou,China;Xinjiang Research Center for Mineral Resources,Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences,Urumqi 830011,Xinjiang,China)

机构地区：[1]中国地质科学院地质力学研究所,北京100081 [2]北京大学造山带与地壳演化教育部重点实验室,北京100871 [3]中国科学院地球化学研究所矿床地球化学国家重点实验室,贵州贵阳550002 [4]中国科学院新疆生态与地理研究所矿产资源研究中心,新疆乌鲁木齐830011

出　　处：《黄金科学技术》2018年第4期454-464,共11页Gold Science and Technology

基　　金：国家自然科学基金项目"西南天山阿沙哇义造山型金矿构造-流体控矿作用研究"(编号:41772085);"西昆仑塔什库尔干赞坎铁矿成矿作用研究"(编号:41402061);"帕米尔地区塔什库尔干铁矿带黄铁矿-石膏/重晶石-磁铁矿建造成因研究"(编号:41672086);"中-新生代天山造山带再造过程与砂岩型铀矿成矿作用"(编号:U1403292);"十二五"国家科技支撑计划项目"西南天山金锑矿成矿系统与靶区优选评价"(编号:2015BAB05B04)联合资助

摘　　要：西昆仑赞坎铁矿是塔什库尔干地区新发现的大型富铁矿,其赋矿围岩为布伦阔勒群火山—沉积变质岩系。矿体主要呈层状和似层状分布,矿石具有条带状、浸染状和块状构造。通过研究该矿床赋矿地层、矿石的硫化物钕和锶同位素组成特征,获得矿石硫化物ISr=0.7100~0.7111,平均值为0.7103;(143Nd/144Nd)i=0.511555~0.512223,平均值为0.511827;赋矿围岩布伦阔勒群(143Nd/144Nd)i=0.511552。Sr-Nd同位素特征表明,成矿物质来源具有壳幔混合特征,主要来自海底火山喷发活动。赞坎铁矿属与海底热液有关的铁矿床,形成于早古生代原特提斯洋向南俯冲的岛弧环境。Zankan iron deposit is a recently discovered large iron deposit in the Taxkorgan terrane of the west Kunlun Orogen.The deposit is hosted in the metamorphosed volcanic and sedimentary rocks of the Bulunkuole Complex.The orebodies are stratiform or stratoid.The ores are uniquely composed of magnetite,pyrite and anhydrite at various ratios,and show banded,disseminated and massive structures.This paper reports Sr and Nd isotopic composition of ores and ore-hosting rocks of Bulunkuole Group to constrain sources of ore-forming material.The ores yield ISr of 0.7100~0.7111,with an average of 0.7103;(143Nd/144Nd)i of 0.511555~0.512223,with an average of 0.511827.The biotite-quartz schists of Bulunkuole Group yield(143Nd/144Nd)i of 0.511552.The Sr-Nd isotope systematic shows a source of mixing crust and mantle.Therefore,it is concluded that the ore-forming materials mainly originated from volcanic rocks in the Bulunkuole Complex,and Zankan iron deposit was formed froman Early Cambrian seafloor hydrothermal systemrelated to southward subduction of Proto-Tethyan plate.

关 键 词：SR-ND同位素 成矿物质来源 硫化物 矿石 布伦阔勒群 赞坎铁矿 塔什库尔干 西昆仑 

分 类 号：P618.31[天文地球—矿床学]