造山带环境钴岩浆成矿作用——以夏日哈木镍钴硫化物矿床为例  

Cobalt magmatic mineralization in orogenic settings——A case study of the Xiarihamu nickel cobalt sulfide deposit

作　　者：包亚文 蔡楠 张铭杰 徐文博 张宏福[3] 胡沛青 乔玉财 BAO Yawen;CAI Nan;ZHANG Mingjie;XU Wenbo;ZHANG Hongfu;HU Peiqing;QIAO Yucai(Gansu Key Laboratory of Mineral Resources in Western China,School of Earth Sciences,Lanzhou University,Lanzhou,Gansu 730000,China;Kunlun Study Center of Critical Metals Resources,Qinghai Huanghe Mining Co.,Ltd,Xining,Qinghai 810016,China;State Key Laboratory of Continental Dynamics,Department of Geology,Northwest University,Xi'an,Shaanxi 710069,China)

机构地区：[1]兰州大学地质科学与矿产资源学院,西部矿产资源甘肃省重点实验室,甘肃兰州730000 [2]青海黄河矿业有限责任公司昆仑关键金属资源研究中心,青海西宁810016 [3]西北大学地质学系,大陆动力学国家重点实验室,陕西西安710069

出　　处：《地质学报》2023年第11期3604-3621,共18页Acta Geologica Sinica

基　　金：国家自然科学基金项目(编号91962212、42272069、41872075、41872073);国家重点研发计划项目(编号2022YFC2903504)联合资助的成果。

摘　　要：东昆仑造山带新发现的夏日哈木和石头坑德等岩浆镍钴硫化物矿床伴生有钴资源,它们与区域上火山-热液型、喷流沉积型等钴独立矿床共同指向早古生代镁铁质岩浆活动相关的钴成矿作用,表明镁铁质岩浆是区域钴富集成矿的重要载体,并预示东昆仑造山带的钴成矿潜力巨大。夏日哈木超大型镍钴硫化物矿床为造山带环境镍钴岩浆成矿作用的产物,本文在现有岩石地球化学数据甄别的基础上,分析了不同岩相和矿物Co、Ni和Cu等成矿元素的含量变化特征,探讨了镁铁质岩浆钴富集机制和控制因素。镁铁—超镁铁质岩具有较高的钴含量,随空间位置(期次)、岩石与矿物类型钴含量变化较大。在MgO含量最高的橄榄岩、辉石岩相中钴富集,在硫化物矿物中钴含量较高。钴含量与全岩MgO、硫、镍和铜含量正相关,这些规律表明夏日哈木镁铁质岩浆富集钴金属,不同期次岩浆中钴的富集程度不同,硫化物熔体是钴富集的主要途径之一,岩浆演化过程中钴在矿物中的富集机制需要原子层面钴赋存状态的系统认识。The newly discovered Xiarihamu and Shitongkende magmatic nickel-cobalt sulfide deposits in the East Kunlun orogenic belt(EKOB),China are associated with cobalt resources.The cobalt mineralization of these magmatic Ni-Co deposits,combined with different types of independent cobalt deposits such as hydrothermal and sedimentary deposits found in the EKOB,were related to early Paleozoic mafic magmatism to varying degrees.These illustrate the huge metallogenic potential of early Paleozoic mafic magmatism in the EKOB.The Xiarihamu super-scale Ni-Co sulfide deposit has become a typical deposit of Ni-Co large-scale magmatic mineralization in the orogenic settings.Based on the screened existing rock geochemical data,this paper determines the variation characteristics of Co,Ni and Cu etc.metallogenic elements in different lithofacies,and discusses the mafic magmatic cobalt enrichment mechanism and controlling factors.The mafic-ultramafic rocks in the Xiarihamu deposit show higher cobalt contents that varies greatly with different locations(magmatic period),rock and mineral types.The cobalt content is rich in peridotite and pyroxenite facies rocks with high MgO contents.The cobalt content in sulfide ore is the highest.The cobalt content in different types of rocks is positively correlated with the sulfur,nickel and copper content.These results indicated that the Xiarihamu magmas were enriched in Co,and sulfide melt is the main mechanism of cobalt enrichment.The mechanism of cobalt enrichment in minerals during magmatic evolution requires systematic understanding of cobalt occurrence at the atomic level.

关 键 词：钴富集 镁铁质岩浆 夏日哈木镍钴硫化物矿床 东昆仑造山带 

分 类 号：P618.63[天文地球—矿床学] P618.62[天文地球—地质学]