投稿时间：2015-10-01
修订日期：2018-06-05
网络发布日期：2018-11-03
中文摘要:铁格隆南是班公湖-怒江成矿带西段重要的斑岩-浅成低温热液铜（金、银）矿床，也是西藏地区首个铜资源量超过1000万吨的超大型铜（金、银）矿床，其蚀变与矿化结构的精细解剖，对完善区域成矿理论和指导找矿实践有重要的指导意义。文章基于详细的野外地质调查、钻孔编录和镜下鉴定，识别出铁格隆南矿床具有斑岩和浅成低温热液叠加成矿作用特征。其中，斑岩成矿作用主要位于矿床深部及外围，以细脉状、脉状、浸染状黄铁矿、黄铜矿、斑铜矿及少量辉钼矿等为主，蚀变为钾硅化、青磐岩化、黄铁绢英岩化，发育A、B、D型脉体。浅成低温热液成矿作用主要产于矿床中-浅部，叠加于斑岩成矿作用之上，以浸染状-脉状黄铁矿、硫砷铜矿、斑铜矿、铜蓝、蓝辉铜矿、斯硫铜矿、雅硫铜矿、久辉铜矿等Cu-S体系矿物为特征，蚀变为高级泥化，广泛发育N脉（即高岭石或明矾石-硫化物脉）。蚀变、矿化特征及脉体穿切关系揭示，矿床成岩成矿作用可细分为岩浆期（Ⅰ）、岩浆-热液期（Ⅱ）和表生期（Ⅲ）。成岩成矿年代学结果揭示，矿区内闪长玢岩侵位时代较早（123 Ma），代表岩浆活动上限；花岗闪长斑岩（122~120 Ma）是主要的含矿斑岩，与成矿作用关系最为密切；火山岩覆盖于地表，喷发时代较晚（111 Ma），代表成矿后岩浆活动的产物。钾硅化的黑云母和黄铁绢英岩化的绢云母40Ar-39Ar年龄分别（121.1±0.5） Ma、（120.8±0.9） Ma与斑岩成矿作用的辉钼矿Re-Os年龄（（121.2±1.2） Ma）一致，而高级泥化的明矾石40Ar-39Ar年龄为（117.9±1.6） Ma与浅成低温热液矿化的黄铁矿Rb-Sr年龄（（117.5±1.8）Ma）一致。所以，依据时空关系，铁格隆南超大型矿床成矿作用可细分为岩浆热液成矿作用（123~119 Ma）、浅成低温热液成矿作用（118~117 Ma）和火山岩覆盖保存（111~110 Ma） 3个阶段。
Abstract:Tiegelongnan, an important porphyry high sulfidation epithermal Cu (Au, Ag) deposit in the west of Bangong Co-Nujiang metallogenic belt, is the first giant deposit with over 10 million tons of Cu reserves in Tibet. The investigation of detailed characteristics of alteration, mineralization, and ore-forming process of the Tiegelongnan deposit is of great significance for improving the regional metallogenic theory and exploration. Based on detailed field geological survey, drilling logging and microscopy, the authors identified two kinds of mineralization, with the early porphyry mineralization overlapped by the later epithermal mineralization. Veinlet, vein and disseminated pyrite, chalcopyrite, bornite and minor molybdenite seem to constitute typical mineralizations in the depth and the outer part. Potassic, prophylitic, and phyllic alterations constitute the main alterations and A, B, D types of vein occurred during the porphyry mineralization. Epithermal mineralization was mainly produced in the intermediate-shallow part, superimposed upon the porphyry mineralization and characterized by disseminated-vein pyrite, enargite, bornite, covellite, digenite, spionkopite, yarrowite, djurleite and other Cu-S series minerals. Advanced argillic alteration is typical alteration with widely developed N type veins(kaolinite or aluminum sulfide veins). The diagenesis and mineralization of the Tiegelongnan deposit can be subdivided into magmatic stage (Ⅰ), magmatic hydrothermal stage (Ⅱ) and supergene stage (Ⅲ), according to characteristics of alteration and mineralization as well as the crosscutting relationship of veins. The intrusion of diorite porphyry occurred early (123 Ma), which represents the upper limit of magmatic activity. The granodiorite porphyry (122~120 Ma) was the main ore-bearing intrusion, which had the closest relationship with mineralization. These volcanic rocks, andesite or dacite, which erupted late (111 Ma) and covered the surface, are the products of postmineralization magmatism. Geochronologic studies show that the 40Ar-39Ar ages of potassic biotite and phyllic sericite are (121.1±0.5) Ma and (120.8±0.9) Ma respectively, consistent with Re-Os ages ((121.2±1.2) Ma) of molybdenite formed during porphyry mineralization. 40Ar-39Ar age of advanced argillic alunite is 117.9±1.6 Ma, consistent with the Rb-Sr age ((117.5±1.8) Ma) of pyrite from epithermal mineralization. In summary, the oreforming process of the Tiegelongnan giant deposit can be divided into three stages:① porphyry mineralization (123~119 Ma), ② epithermal mineralization (118~117 Ma) and ③ cover and protection of volcanic rocks (111~110 Ma).
文章编号：
中图分类号：P618.42
文献标志码：
基金项目:本文得到国家重点研发计划-深地专项（编号：2018YFC064101）、公益性行业科研专项（编号：201511017、201511022-05）、中国地质科学院院基本科研业务费（YYWF201608）、国家自然基金科研项目（编号：41402178）、中国地质调查局二级项目（编号：DD20160026）和中国地质调查局中国矿产地质与成矿规律综合集成和服务（矿产地质志）项目（编号：DD20160346）联合资助
引用文本：
林彬,陈毓川,唐菊兴,宋扬,王勤,贺文,刘治博,王艺云,李彦波,杨超,杨欢欢,张乐骏,李玉彬.2018.西藏铁格隆南超大型铜(金、银)矿床地质、蚀变与矿化[J].矿床地质,37(5):917~939LIN Bin,CHEN YuChuan,TANG JuXing,SONG Yang,WANG Qin,HE Wen,LIU ZhiBo,WANG YiYun,LI YanBo,YANG Chao,YANG HuanHuan,ZHANG LeJun,LI YuBin.2018.Geology, alteration and mineralization of Tiegelongnan giant Cu (Au, Ag) deposit, Tibet[J].Mineral Deposits37(5):917~939
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