西藏班公湖-怒江成矿带中段达若洛陇斑岩-矽卡岩型铜(金)矿床成岩成矿时代及其地质意义  

The magmatism and metallogenetic ages of the Daruoluolong porphyry-skarn copper (gold) deposit in the central segment of the Bangonghu-Nujiang metallogenic belt, Tibet, and their geological significance

作　　者：李海峰 宋扬[3] 方向 李发桥 熊妍 高轲 朱磊 LI HaiFeng;SONG Yang;FANG Xiang;LI FaQiao;XIONG Yan;GAO Ke;ZHU Lei(China 19th Metallurgical Group Corporation Limited,Chengdu 610031,China;State Key Laboratory of Deep Earth and Mineral Exploration,Chinese Academy of Geological Sciences,Beijing 100037,China;Institute of Mineral Resources,Chinese Academy of Geological Sciences,Beijing 100037,China;Chengdu Center,China Geological Survey,Chengdu 610081,China)

机构地区：[1]中国十九冶集团有限公司,成都610031 [2]中国地质科学院,深地探测与矿产勘查全国重点实验室,北京100037 [3]中国地质科学院矿产资源研究所,北京100037 [4]中国地质调查局成都地质调查中心,成都610081

出　　处：《岩石学报》2025年第5期1644-1663,共20页Acta Petrologica Sinica

基　　金：国家重点研发计划项目(2022YFC2905001);中国科协青年人才托举工程项目(2022QNRC001);国家自然科学基金青年基金(42402110);中国地质调查局地调项目(DD20230054、DD20243483);四川自然科学基金项目(2023NSFSC0798)联合资助详细信息。

摘　　要：达若洛陇矿床位于班公湖-怒江成矿带中段北缘高保约地区, 是该成矿带近年来新发现的铜多金属矿床。为查明其矿床类型、成矿时代、成矿地质背景等地质特征, 本文基于详细的野外地质调查和钻孔岩心编录, 开展了岩/矿相学、年代学和全岩地球化学等测试分析。研究结果显示, 达若洛陇矿床以铜矿化为主, 伴生金、银矿化, 金属矿物主要赋存于花岗闪长斑岩及与围岩接触带的外矽卡岩, 为典型的斑岩-矽卡岩型铜(金)矿床。同位素测年显示, 含矿花岗闪长斑岩锆石U-Pb年龄为153.2±0.9Ma, 成矿后花岗闪长岩形成于147.1±1.2Ma, 辉钼矿Re-Os年龄为153.8±1.6Ma, 表明矿化形成于中生代, 是班-怒带首次发现的晚侏罗世斑岩-矽卡岩型铜(金)矿床。岩石地球化学特征表明, 含矿花岗闪长斑岩富集大离子亲石元素、亏损高场强元素, 形成于班-怒洋洋壳北向俯冲过程的活动大陆边缘, 具有洋壳熔融型埃达克质岩特征。综上, 本文认为班-怒带具有寻找晚侏罗世斑岩-矽卡岩型铜(金)矿床的潜力。The Daruoluolong deposit, located in the Gaobaoyue area at the northern margin of the central Bangonghu-Nujiang Metallogenic Belt (BNMB), is a newly discovered Cu-polymetallic deposit. This study integrates detailed field investigations, drill core logging, petrography, mineralogy, geochronology and whole-rock geochemistry studies to constrain its genetic type, metallogenic age and tectonic setting. Results show that the deposit is dominated by Cu mineralization with associated Au-Ag. Ore minerals are mainly hosted in granodiorite porphyry and exoskarn zones, defining it as a typical porphyry-skarn Cu(Au) system. Zircon U-Pb dating of the ore-bearing granodiorite porphyry yields an age of 153.2±0.9Ma, and post-ore granodiorite and molybdenite Re-Os dating give ages of 147.1±1.2Ma and 153.8±1.6Ma, respectively. This is the Late Jurassic porphyry-skarn Cu (Au) mineralization reported for the first time at the BNMB. Geochemical data reveal that the ore-related granodiorite porphyry is enriched in LILEs and depleted in HFSEs, being of adakitic affinities derived from the oceanic crust melting, suggesting the intrusion was emplaced in an active continental margin setting. During this period, the Bangong-Nujiang oceanic slab was subducting northward beneath the Qiangtang Terrane. These findings highlight the potential for hunting the additional Late Jurassic porphyry-skarn Cu(Au) deposits in the BNMB.

关 键 词：成岩成矿时代 构造地质背景 斑岩-矽卡岩型铜矿 达若洛陇 班公湖-怒江成矿带 西藏 

分 类 号：P588.13[天文地球—岩石学] P597.3[天文地球—地质学] P618.41