青海北祁连成矿带原特提斯洋俯冲期斑岩-浅成低温热液成矿系统的发现及其找矿意义  

The discovery of the porphyry-epithermal metallogenic system during the subduction of the Proto-Tethys Ocean in northern Qilian metallogenic belt, Qinghai Province and its implications for mineral exploration

作　　者：王旭辉 郎兴海[1] 叶紫枫 陈庚户 董维财 王登科 向佐朋 李善财 WANG XuHui;LANG XingHai;YE ZiFeng;CHEN GengHu;DONG WeiCai;WANG DengKe;XIANG ZuoPeng;LI ShanCai(College of Earth and Planetary Sciences,Chengdu University of Technology,Chengdu 610059,China;MNR Key Laboratory of Geochemical Exploration,Institute of Geophysical and Geochemical Exploration,CAGS,Langfang 065000,China;Sichuan Xinshun Mining Co.,LTD,Chengdu 610041,China;Qinghai Second Nonferrous Geological Exploration Institute,Xining 810007,China)

机构地区：[1]成都理工大学地球与行星科学学院,成都610059 [2]自然资源部地球化学探测重点实验室,中国地质科学院地球物理地球化学勘查研究所,廊坊065000 [3]四川鑫顺矿业股份有限公司,成都610041 [4]青海省有色第二地质勘查院,西宁810007

出　　处：《岩石学报》2025年第5期1584-1605,共22页Acta Petrologica Sinica

基　　金：国家重点研发计划(2022YFC2905002);新一轮找矿突破战略行动科技支撑项目(ZKKJ202405、ZKKJ202427);西藏自治区科技计划项目(XZ202401YD0066);四川省自然科学基金项目(2024NSFSC1954、2025ZNSFSC1196);深地国家科技重大专项(SQ2024AAA060124-6);威海市能源资源调查评价重点实验室开放课题(LDKF-2023WH-04);物化探所中央级公益性科研院所基本科研业务费专项资金资助项目(AS2022P03);成都理工大学珠峰科学研究计划(2020ZF11407)联合资助详细信息。

摘　　要：松树南沟金矿区位于北祁连成矿带中部, 目前发现有东、西两个矿床, 金资源量分别达中型和大型规模。尽管其为青海北祁连成矿带上的重要金矿床, 但其研究极为薄弱, 矿床地质特征不清, 矿床成因类型存在较大争议, 严重阻碍了矿区下一步矿产勘查工作部署和找矿突破。为了查明松树南沟矿区东、西矿床的地质特征及矿床成因类型, 指导矿区勘查工作部署, 本研究在野外地质调查和岩心精细编录的基础上, 进行了系统岩矿鉴定和能谱分析。研究表明: 西矿床主要赋存于晚奥陶世石英闪长斑岩及其接触带附近的上奥陶统扣门子组玄武安山岩中, 蚀变类型为钾化、青磐岩化和绢云母-绿泥石化, 金矿化主要产于钾化和青磐岩化蚀变带中;金属矿物主要为黄铜矿、斑铜矿、自然金、磁铁矿、黄铁矿以及少量方铅矿、闪锌矿、辉钼矿、黝铜矿, 金主要以自然金的形式赋存于石英-黄铜矿-斑铜矿脉中, 少部分以不可见金的形式赋存于黄铁矿中;西矿床的地质特征表明其属于斑岩型金矿床。东矿床主要产出于上奥陶统扣门子组晶屑凝灰岩、流纹质凝灰岩与玄武安山岩中, 围岩蚀变主要为绢云母-绿泥石化, 局部发育绢英岩化;金属矿物主要包括方铅矿、低铁闪锌矿、黝铜矿、砷黝铜矿、黄铜矿、黄铁矿、自然金及少量银金矿, 金主要以自然金和少量银金矿的形式产于碳酸盐-石英-多金属脉中, 少部分产于碳酸盐-石英-黄铁矿脉中;东矿床的地质特征表明其属于中硫化型浅成低温热液金矿床。结合上述地质特征和已有的地质年代学结果, 本文认为东、西矿床构成一个晚奥陶世(~455Ma)斑岩-中硫化型浅成低温热液金成矿系统, 其形成与原特提斯洋北向俯冲作用诱发的岩浆活动密切相关, 是目前特提斯成矿域发现的最古老的斑岩-浅成低温热液成矿系统。这一认识为在�The Songshunangou Au district is located in the central part of the northern Qilian metallogenic belt. Currently, the eastern and western deposits have been identified in the district, with gold resources reaching medium and large scales, respectively. Despite being an important Au deposit in the northern Qilian metallogenic belt in Qinghai Province, it is extremely lack of research, and as a result, its geological characteristics and genetic type remain unclear, which also seriously hindered further breakthroughs in prospecting within the district. To investigate the geological characteristics and genesis of the eastern and western deposits in the Songshunangou district and guide the deployment of exploration in the district, this study conducted systematic petrographic and mineralogical identification along with energy spectrum analysis on the basis of detailed field investigations and core logging. The results indicate that the western deposit is primarily hosted in Late Ordovician quartz diorite porphyry and Upper Ordovician Koumenzi Formation basaltic andesite near their contact zones. Hydrothermal alterations include potassic, propylitic and sericite-chlorite alterations, with Au mineralization primarily occurring in the potassic and propylitic alteration zones. Metallic minerals mainly consist of chalcopyrite, bornite, native gold, magnetite, pyrite, and minor galena, sphalerite, molybdenite and tetrahedrite. Gold mineralization is mainly present as native gold within quartz-chalcopyrite-bornite veins, with a smaller portion occurring as invisible gold within pyrite. These geological characteristics suggest that the western deposit is a porphyry gold deposit. The eastern deposit is primarily hosted in the Upper Ordovician Koumenzi Formation crystal tuff, rhyolitic tuff and basaltic andesite. Hydrothermal alterations are dominated by sericite-chlorite alteration, with localized development of phyllic alteration. Metallic minerals include galena, sphalerite, tetrahedrite, tennantite, chalcopyrite, pyrite, na

关 键 词：松树南沟 斑岩-浅成低温热液成矿系统 北祁连成矿带 早古生代 斑岩型金矿 中硫化型浅成低温热液金矿 

分 类 号：P611.1[天文地球—矿床学] P618.51[天文地球—地质学]