西藏冈底斯西段银锡铜多金属成矿系列与找矿方向  

The Ag-Sn-Cu polymetallic minerogenetic series and prospecting direction in the western Gangdese belt,Tibet

作　　者：郑有业[1,2] 次琼 高顺宝[4] 吴松[2] 姜晓佳 陈鑫[4] ZHENG Youye;CI Qiong;GAO Shunbao;WU Song;JIANG Xiaojia;CHEN Xin(State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences(Beijing),Beijing 100083,China;School of Earth Sciences and Resources,China University of Geosciences(Beijing),Beijing 100083,China;No.2 Geological Party,Tibet Autonomous Region Geological and Mineral Exploration and Development Bureau,Lhasa 850000,China;Institute of Geological Survey,China University of Geosciences(Wuhan),Wuhan 430074,China)

机构地区：[1]中国地质大学(北京)地质过程与矿产资源国家重点实验室,北京100083 [2]中国地质大学(北京)地球科学与资源学院,北京100083 [3]西藏自治区地质矿产勘查开发局第二地质大队,西藏拉萨850000 [4]中国地质大学(武汉)地质调查研究院,湖北武汉430074

出　　处：《地学前缘》2021年第3期379-402,共24页Earth Science Frontiers

基　　金：国家自然科学基金项目(42072109);国家重点研发计划项目(2017YFC0601506);国家青藏专项(1212011220664)。

摘　　要：作为目前我国规模第一的冈底斯巨型铜多金属成矿带,其东段斑岩铜多金属找矿已取得历史性重大突破,发现了驱龙、甲玛等一系列大-超大型矿床。而西段由于复杂的构造背景、不便的交通条件、极低的地质研究和矿产工作程度,相对于东段具有不同的地壳结构和性质,不均一的地幔属性及壳幔作用方式,以及大面积的火山岩覆盖,使得冈底斯西段的成矿类型、找矿潜力等存在很大的不确定性和争议。在科学技术部、中国地质调查局等大力支持下,通过应用赵鹏大院士的“地质异常成矿预测理论”及开展的一系列技术方法创新、靶区优选与应用示范,在厘清区域成矿规律、发现新矿种、新类型、新矿床等方面均取得重大进展或突破,新发现了帮布勒铅锌银铜、拔隆银铅锌锡、打加错银铅锌、诺仓铅锌银钨、桑莫拉锡金等一批具有中-大型以上找矿前景的银锡金铜铅锌钨矿床,而且还发现冈底斯东、西段成矿存在极大差异:西段除了传统的斑岩型铜钼金、夕卡岩型铁铅锌铜(银)等矿床外,与陆相(次)火山岩有关的浅成低温热液型银锡(金)多金属矿床、特别是银锡或独立银矿床,是冈底斯西段最有找矿潜力的矿床类型(类似于东段的斑岩型),主要受古老基底、逆冲推覆构造、火山机构及次火山岩、晚古生代地体建造等的耦合控制。化探异常元素主要为Ag、Pb、Zn、Sn、Cu、Au、As、Sb、Mn等,其中高强度的Ag、Sn、Au是特征性异常元素,从而可以与单纯的夕卡岩型、岩浆热液型矿床相区别。这些矿床主要分布在冈底斯火山岩浆弧和弧背断隆带,与不同期次和成因的火山岩浆活动密切相关,据此划分出与晚三叠世弧岩浆作用有关的斑岩型铜金、与早白垩世弧岩浆作用有关的夕卡岩-浅成低温热液型铁银铅锌(锡)、与晚白垩世岩浆作用有关的夕卡岩型铁铜铅锌(银)、与古新�The Gangdese belt is the largest copper polymetallic metallogenic belt in China.A historical breakthrough has been made in porphyry-copper polymetallic prospecting by the discovery of a series of large-giant deposits,including the Qulong and Jiama deposits,in the eastern Gangdese belt.In contrast,very little geological research has been done in the western Gangdese belt due to the complex tectonic background and poor road conditions.The western Gangdese belt has different crustal structure and properties from its eastern counterpart,where heterogeneous mantle properties,crust-mantle interaction,and the large volcanic rock cover led to great uncertainty and controversy over its genetic type and ore prospecting potential.In this contribution,with the substantial support of the Ministry of Science and Technology and the China Geological Survey,we made great progress or breakthroughs in clarifying the regional metallogenesis and in the discovery of new rock types,mineral species and deposits,through the application of the geo-anomaly theory developed by academician Zhao Pengda,and through a series of technological innovations,target selection,and target explorations.We discovered a number of Ag-Sn-Au-Cu-Pb-Zn-W deposits with medium to large prospecting prospects,such as the Bangbule Pb-Zn-Ag-Cu,Balong Ag-Pb-Zn-Sn,Dajiacuo Ag-Pb-Zn,Nuocang Pb-Zn-Ag-W,and Sangmola Sn-Au deposits.We also found very different metallogenic processes of the eastern and western Gangdese belt.In the western Gangdese belt,in addition to the traditional porphyry Cu-Mo-Au and skarn Fe-Pb-Zn-Cu(Ag)deposits,the continental(sub-)volcanic rock-related epithermal Ag-Sn(Au)polymetallic deposits(especially Ag-Sn or independent Ag deposits)have the highest prospecting potentials.This deposit type is mainly controlled by the coupling of ancient basement,thrust-nappe structure,sub-volcanic structure,sub-volcanic rocks,and late Paleozoic terrane.The geochemical anomaly elements are mainly Ag,Pb,Zn,Sn,Cu,Au,As,Sb,Mn,and so on,among which the rich elements

关 键 词：成矿作用 成矿系列 找矿新发现 新矿种 新类型 冈底斯西段 西藏 

分 类 号：P611[天文地球—矿床学] P612[天文地球—地质学]