投稿时间：2025-05-30
修订日期：2025-09-05
网络发布日期：2025-10-31
中文摘要:滇西北地区位于特提斯-喜马拉雅构造域东缘，是西南三江成矿带的重要组成部分，以丰富的铜、钼、钨、铅锌等多金属矿产资源而著称。红山-红牛铜钼矿床作为该区域的典型代表，近几年在其铜钼矿体中发现显著的白钨矿矿化，引起广泛关注。文章以红牛-红山铜钼矿床中新发现的钨矿（化）体为研究对象，开展了矿床地质、矿物学和白钨矿微量元素分析、与白钨矿共生的石榴子石U-Pb定年等方面的研究。通过对与白钨矿共生的石榴子石进行LA-SF-ICP-MS U-Pb定年，获得石榴子石U-Pb年龄为(76.8±2.7)Ma、(86.5±5.5)Ma，表明白钨矿的形成时代为晚白垩世。这与矿区晚白垩世成岩成矿事件年龄（76~81 Ma）基本一致，表明红牛-红山铜钼矿床白钨矿成矿作用与同期花岗岩具有密切的成因联系。对白钨矿开展激光剥蚀和面扫描分析表明，红牛-红山铜钼矿床白钨矿属于岩浆-热液白钨矿，REE3+（稀土元素）主要以3Ca2+=2REE3++□Ca的替换机制进入白钨矿；Eu的价态和Mo质量分数均表明在白钨矿成矿阶段成矿流体以氧化性流体为主，Mo元素的分布由核部到边部经历了降低再升高的过程，指示在结晶过程中流体环境经历了氧逸度降低再升高的变化，但从整体上仍是氧化性流体；出溶的富钨成矿流体在向外运移过程中与围岩接触发生反应，导致富钙的碳酸盐岩围岩发生热接触变质作用，含矿流体中的WO42-结合围岩释放出的Ca2+，形成白钨矿（CaWO4），最终导致红牛-红山铜钼矿床燕山晚期花岗岩体接触带中白钨矿的形成。
Abstract:The northwestern Yunnan region is located in the eastern margin of the Tethys-Himalayan tectonic domain. It is an important part of the “Sanjiang” metallogenic belt in Southwest China. It is famous for its rich polymetallic mineral resources such as copper, molybdenum, tungsten, lead and zinc. As a typical representative of this area, the Hongshan-Hongniu copper-molybdenum deposit has found significant scheelite mineralization in its copper-molybdenum ore body in recent years, which has attracted wide attention. In this paper, the newly discovered tungsten ore body in the Hongniu-Hongshan copper-molybdenum deposit is taken as the object, and the geology, mineralogy, geochemical composition of scheelite, and garnet U-Pb dating of scheelite are studied. By LA-SF-ICP-MS U-Pb dating of garnet associated with scheelite, the U-Pb ages of garnet are (76.8±2.7) Ma and (86.5±5.5) Ma, which limit the formation of scheelite in late Cretaceous. This is basically consistent with the age of the Late Cretaceous diagenesis and mineralization event in the mining area (76~81 Ma), indicating that the scheelite mineralization of the Hongniu-Hongshan copper-molybdenum deposit is closely related to the same period of granite. The analysis of laser ablation and surface scanning of scheelite shows that the scheelite of Hongniu-Hongshan copper-molybdenum deposit belongs to magmatic-hydrothermal scheelite, and REE3+ (rare earth elements) mainly enters the scheelite with the substitution mechanism of 3Ca2+=2REE3++□Ca. The valence state of Eu and the mass fraction of Mo indicate that the ore-forming fluid in the scheelite mineralization stage is mainly oxidizing fluid. The distribution of Mo element experienced a process of decreasing and then increasing from the core to the edge, indicating that the fluid environment experienced a change of decreasing and then increasing of oxygen fugacity during the crystallization process, but it is still an oxidizing fluid as a whole. The exsolved tungsten-rich ore-forming fluid reacts with the surrounding rock in the process of outward migration, resulting in thermal contact metamorphism of the calcium-rich carbonate surrounding rock. The WO42- in the ore-bearing fluid combines with the Ca2+ released by the surrounding rock to form scheelite (CaWO4), which eventually leads to the formation of scheelite in the contact zone of the Late Yanshanian granite body in the Hongniu-Hongshan copper-molybdenum deposit.
keywords:geochemical characteristics in-situ U-Pb dating LA-ICP-MS surface scanning genesis of deposit Tungsten ore Hongniu-Hongshan deposit
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基金项目:本文得到国家自然科学基金项目(编号：42362010)、云南省高层次科技人才及创新团队选拔专项(编号：202305AT350004-4)和云南省三江成矿系统与评价顶尖团队培育项目(编号：202305AS350015)联合资助
引用文本：
刘学龙,李文昌,周云满,赵成峰,陶兴雄,张娜,周杰虎,陆波德,魏志毅,李守奎,王涛,罗聪.2025.滇西北红牛-红山铜钼矿床新发现的白钨矿特征及成因研究[J].矿床地质,44(5):1053~1076LIU XueLong,LI WenChang,ZHOU YunMan,ZHAO ChengFeng,TAO XingXiong,ZHANG Na,ZHOU JieHu,LU BoDe,WEI ZhiYi,LI ShouKui,WANG Tao,LUO Cong.2025.Study on characteristics and genesis of newly discovered scheelite in Hongniu-Hongshan copper-molybdenum deposit, Northwest Yunnan Province[J].Mineral Deposits44(5):1053~1076
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