西藏甲玛3000m科学深钻矽卡岩矿物分带及地质意义  

Mineral zoning and geological significance of skarns in the Jiama 3000 m scientific deep borehole,Tibet

作　　者：王梦蝶 唐菊兴[2] 林彬[2] 唐攀 唐晓倩 孙渺 李发桥 祁婧 傅渊慧 张忠坤 崔浩 杨征坤 熊妍 WANG Mengdie;TANG Juxing;LIN Bin;TANG Pan;TANG Xiaoqian;SUN Miao;LI Faqiao;QI Jing;FU Yuanhui;ZHANG Zhongkun;CUI Hao;YANG Zhengkun;XIONG Yan(College of Earth Sciences,Chengdu University of Technology,Chengdu,Sichuan 610059,China;MNR Key Laboratory of Metallogeny and Mineral Resource Assessment,Institute of Mineral Resources,CAGS,Beijing 100037,China;The Key Laboratory of the Ministry of Education on Solid Waste Treatment and Recycling,School of Environment and Resource,Southwest University of Science and Technology,Mianyang,Sichuan 621010,China;Beijing China Mining Federation Consulting Center,Beijing 100044,China;China University of Geosciences,Beijing 100083,China;Tibet Huatailong Ming Corp.Ltd.,Lhasa,Tibet 850200,China)

机构地区：[1]成都理工大学地球科学学院,四川成都610059 [2]中国地质科学院矿产资源研究所,自然资源部成矿作用与资源评价重点实验室,北京100037 [3]西南科技大学环境与资源学院,固体废物处理与资源化教育部重点实验室,四川绵阳621010 [4]北京中矿联咨询中心,北京100044 [5]中国地质大学(北京),北京100083 [6]西藏华泰龙矿业开发有限公司,西藏拉萨850200

出　　处：《地质学报》2023年第6期1956-1971,共16页Acta Geologica Sinica

基　　金：国家重点研发计划(编号2022YFC2905001);国家自然科学基金项目(编号42272093、41902097);中国地质科学院矿产资源研究所基本科研业务费(编号KJ2102,KK2116,KK2017);西藏自治区科技计划项目(编号XZ201901-GB-24);中国地质调查局项目(编号DD20190167)联合资助的成果。

摘　　要：甲玛铜多金属矿床是冈底斯成矿带东段具有重大经济价值及科学研究意义的超大型斑岩-矽卡岩矿床,完整地保存了矽卡岩矿床形成和演化的重要信息。前人研究多集中于矽卡岩的水平分带,而对于矽卡岩矿物垂直分带以及其与金属矿化的耦合关系等方面研究薄弱。本文重点对甲玛3000 m科学深钻中矽卡岩矿体进行了精细的矿物学研究,系统揭示了矽卡岩矿体的矿物学空间分带特征以及与金属矿化的耦合关系。结果表明,矽卡岩从浅部至深部具有清晰的分带现象,即矽卡岩化角岩→透辉石石榴子石矽卡岩→硅灰石石榴子石矽卡岩→石榴子石硅灰石矽卡岩→透辉石石榴子石矽卡岩→石榴子石硅灰石矽卡岩→矽卡岩化大理岩→硅灰石石榴子石矽卡岩→透辉石石榴子石矽卡岩→硅灰石石榴子石矽卡岩→矽卡岩化大理岩→硅灰石石榴子石矽卡岩→透辉石石榴子石矽卡岩→内矽卡岩(含石榴子石花岗闪长斑岩)。金属矿物组合从浅部向深部,变化为辉钼矿±黄铜矿→斑铜矿+黄铜矿±辉铜矿±硫铋铜矿±辉钼矿→辉钼矿±黄铜矿,对应成矿元素变化为Mo±Cu±Au±Ag→Cu(Mo)±Au±Ag→Mo±Cu±Au±Ag。研究表明,侵入岩及围岩的空间位置、构造环境、多期次热液流体叠加是控制矽卡岩矿物分带的重要因素。同时,矿物学特征表明,矽卡岩中高品位金的富集与斑铜矿等铜硫化物密切相关,也可能与多期次流体叠加和富金岩浆源区有关。The Jiama copper polymetallic deposit is a super large porphyry skarn deposit of great economic value and scientific research significance in the eastern part of the Gangdise metallogenic belt,which completely preserves important information on the formation and evolution of skarn deposits.Previous studies mostly focused on the horizontal zoning of skarn,but the vertical zoning of skarn minerals and its coupling relationship with metal mineralization is less understood.This paper focuses on the detailed mineralogical study of skarn ore body in the Jiama 3000 m scientific deep borehole,and systematically reveals the mineralogical spatial zoning characteristics of skarn ore body and its coupling relationship with metal mineralization.The results show that the skarn has clear zoning from shallow to deep,i.e.skarn hornfeld→diopside garnet skarn→wollastonite garnet skarn→garnet wollastonite skarn→diopside garnet skarn→garnet wollastonite skarn→Skarn marble→wollastonite garnet skarn→diopside garnet skarn→diopside garnet skarn→wollastonite garnet skarn→skarn marble→wollastonite garnet skarn→wollastonite garnet skarn→skarn marble→wollastonite garnet skarn→diopside garnet skarn→endoskarn(containing garnet granodiorite porphyry).The metal mineral assemblage changes from shallow to deep,molybdenite±chalcopyrite→bornite+chalcopyrite±chalcocite±wittichenite±(molybdenite) →molybdenite±chalcopyrite.The corresponding metallogenic elements are Mo±Cu±Au±Ag→Cu(Mo)±Au±Ag→Mo±Cu±Au±Ag.The research shows that the spatial location of intrusive and surrounding rocks,tectonic settings and the superposition of multi-stage hydrothermal fluids are important factors controlling the zoning of skarn minerals.At the same time,the mineralogical characteristics show that the enrichment of high-grade gold in skarn is closely related to copper sulfides such as bornite,and may also be related to the superposition of multi-stage fluids and the source area of gold-rich magma.

关 键 词：矽卡岩分带 斑岩-矽卡岩矿床 矽卡岩矿物学 甲玛 西藏 

分 类 号：P618.2[天文地球—矿床学]