新疆西天山松湖铁矿床叠加成矿过程--来自矿床地质和矿物地球化学的约束  

Superposition Mineralization Process of the Songhu Iron Deposit in West Tianshan,Xinjiang:Constraints from Deposit Geology and Mineral Geochemistry

作　　者：徐洋[1,2] 杜杨松[2] 喻志勇[2] 欧阳学财 王明阳 

机构地区：[1]中国地质科学院矿产资源研究所,北京100037 [2]中国地质大学(北京),北京100083 [3]江西省核工业地质局266大队,南昌330038

出　　处：《地质学报》2017年第9期1971-1984,共14页Acta Geologica Sinica

基　　金：中国地质调查局项目“西天山阿吾拉勒铁成矿带典型矿床研究”(编号1212011120497)资助成果

摘　　要：松湖铁矿床是新疆西天山阿吾拉勒铁成矿带中的典型中型铁矿床,该矿床铁矿石资源量5506万吨,矿体品位22%~54%,平均品位42%。本文对松湖铁矿床进行了矿床地质和矿物地球化学特征研究,查明了蚀变和矿化特征,划分了矿石类型以及成矿期和成矿阶段,探讨了矿床的形成过程。对松湖铁矿区围岩蚀变分带特征进行了仔细的划分,根据矿物相互穿插关系以及矿物组合和结构构造特征,将成矿过程分为3个成矿期6个成矿阶段。矿浆期成矿温度500~650℃,而热液期成矿温度为接近400℃,蚀变矿物绿泥石的形成温度平均为312℃。两种成因类型磁铁矿稀土元素特征具有专属性,矿浆期磁铁矿ΣREE值明显高于火山热液期磁铁矿,表明热液演化过程中稀土元素分馏程度较高。耦合矿床地质和矿物地球化学特征,初步判断新疆松湖铁矿为矿浆-火山热液叠加型铁矿床。The Songhu iron deposit is a typical iron deposit in the Awulale iron metallogenic belt in West Tianshan,Xinjiang,This iron ore resources of 55.06 million tons,ore body grade of 22% ~54%,the average grade of 42%.Study of deposit geology and mineral geochemistry has been carried out in the deposit,with the focuses on alteration and mineralization characteristics,ore types,mineralization periods and mineralization processes.Based on veins penetrating relation,mineral assemblage and texture and structure,wall rock alteration zoning features of the Songhu iron deposit have been classified in detail into three mineralization periods and six mineralization stages.Pulp ore period mineralization temperature ranges from 500 to 650 ℃,and volcanic hydrothermal period is up to 400 ℃,The average temperature of the formation of altered mineral chlorite is 312 ℃.REE characteristics of the two types of magnetite have their specificity,with ore pulp magnetite ΣREE value obviously higher than volcanic hydrothermal magnetite,suggesting a high fractionation degree of hydrothermal rare earth elements in the evolution process of hydrothermal fluids.Coupling ore deposit geology and mineral geochemical characteristics,the Songhu iron deposit can be preliminarily ascertained as an ore pulp-volcanic hydrothermal superpositiontype iron deposit.

关 键 词：矿床地质 矿物地球化学 矿浆-火山热液叠加成矿作用 松湖铁矿 新疆西天山 

分 类 号：P618.31[天文地球—矿床学]