投稿时间：2024-01-21
修订日期：2024-06-24
网络发布日期：2024-08-23
中文摘要:晚古生代是地球历史上一个重要时期，蕴含着潘吉亚超大陆、规模最大冰期、最严重的生物大灭绝以及巨量矿产资源形成的关键信息。地处欧亚大陆腹地的中亚成矿域是全球最大的显生宙大陆增生区，以晚古生代大规模成矿为显著特色，尤其早二叠世（270~290 Ma）在中亚成矿域西部天山及邻区巨量金、镍爆发性集中成矿作用，造就出世界第二大金成矿省，形成了超过10000 t金，造就出具有世界特色的造山带岩浆型镍矿集区，形成了包括8个大型-超大型矿床在内的东天山、额尔齐斯、北山3个重要镍矿床集中区，镍资源达250万t，是一次全球罕见的金-镍时间耦合重大成矿事件。文章基于最新研究成果，系统论述了中亚成矿域西部早二叠世金、镍大规模成矿的时空分布和基本地质特征，探讨了该重大成矿事件的区域动力学背景和可能成矿机制。研究认为，早二叠世金矿床产于天山古缝合带附近的脆/韧性构造变形带，构成独具特色的大陆变形带金成矿系统，已有成矿理论难以涵盖，含碳碎屑岩系、地块抬升导致的大规模区域变质作用、多来源的流体作用、多期构造活化富集、多种因素耦合叠加等，可能是大规模金成矿的关键条件；早二叠世镍矿床沿天山、北山、阿尔泰地区深大断裂附近的镁铁-超镁铁质岩体线性展布，是全球造山带镍成矿作用最强烈、发现矿床数量最多的地区，俯冲熔/流体的交代岩石圈地幔/软流圈发生高程度部分熔融、区域超壳深断裂为玄武质岩浆提供快速运移的通道、壳源物质加入触发硫化物熔离、硫化物与多幕脉动侵位的岩浆反应是造山带岩浆型镍大规模成矿的关键。整体上，中亚成矿域西部早二叠世金、镍重大成矿事件表现为“时间耦合、西金东镍”的时空格局，但大规模成矿的全球和区域动力学背景、金与镍富集机制及成矿响应机理还是未解之谜。
中文关键词:早二叠世 大陆变形带金成矿系统 造山带岩浆型镍成矿系统 重大成矿事件 中亚成矿域西部
Abstract:The Late Paleozoic is an important period in Earth's history, containing key information about the supercontinent Pangaea, the Great Ice Age, the most severe mass extinction, and the formation of vast mineral resources. The Central Asian Metallogenic Domain, located in the heartland of the Eurasian continent, is the largest Phanerozoic continental accretion zone. It is characterized by extensive mineralization event in the Late Paleozoic, particularly during the Early Permian (270~290 Ma), when significant gold and nickel mineralization occurred in Tianshan and adjacent areas, western part of Central Asia. This event resulted in the formation of over 11,000 tons of gold, which created the world's second-largest gold mineralization province. Meanwhile, 2.5 million tons of nickel was formed in the eastern Tianshan, Irtysh, and Beishan clusters, which contain eight large to super-large-sized deposits. This represents a globally rare coeval gold-nickel mineralization event. Based on the latest researches, this article provides a preliminary and systematic discussion of the temporal-spatial distribution and fundamental characteristics of the large-scale gold and nickel mineralization in the western part of the Central Asian Metallogenic Domain during the Early Permian. The dynamic background and mineralization mechanisms of this major mineralization event were also investigated. The study suggests that the Early Permian gold deposits are associated with brittle/ductile deformation zones near the Tianshan suture zone, forming a unique continental deformation belt gold mineralization system, which cannot be fully explained by the existing metallogenic theories. The key factors for large-scale gold mineralization may include thick carbonaceous clastic rock sequences, regional metamorphism induced by block uplift, multiple sources of fluids, multi-stage tectonic activation and gold enrichment, and the coupling and superposition of multiple factors. The Early Permian nickel deposits hosted by mafic-ultramafic intrusions are linearly distributed along the major faults in the Tianshan-North Altai region. This region exhibits the strongest nickel mineralization among global orogenic belts and provides the most discovered deposits. Key factors for significant magmatic nickel mineralization in orogenic belts include high-degree partial melting of the subducted melt/fluid-modified lithospheric mantle/asthenosphere, regional deep faulting providing pathways for basaltic magma migration, sulfide segregation caused by the addition of crustal materials, and reactions between the sulfides and multiple episodes of magma. Overall, the major gold-nickel mineralization event during the Early Permian in the western part of the Central Asian Metallogenic Domain exhibits a "temporal-spatial coupling, with gold in the west and nickel in the east" pattern. However, there are still many mysteries regarding the regional and global dynamic background of significant mineralization, the mechanisms of gold and nickel enrichment, and the mechanisms of mineralization.
keywords:Early Permian continental deformed zone hosted gold mineralization system magmatic nickel mineralization system in orogenic belts major metallogenic event Central Asian Orogenic Belt
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基金项目:本文得到国家重点研发计划重点专项资助(编号：2017YFC0601202)、国家自然科学基金(编号：42372090)、新疆维吾尔自治区人民政府国家 305 项目办公室、新疆维吾尔自治区“天池英才”引进计划联合资助
引用文本：
薛春纪,赵晓波,赵云,赵伟策,莫宣学,肖文交,马华东,朱炳玉,Nikolay Pak,Bakhtiar Nurtaev,邓军,侯增谦.2024.中亚成矿域西部早二叠世金、镍重大成矿事件[J].矿床地质,43(4):749~784XUE ChunJi,ZHAO XiaoBo,ZHAO Yun,ZHAO WeiCe,MO XuanXue,XIAO WenJiao,MA HuaDong,ZHU BingYu,Nikolay Pak,Bakhtiar Nurtaev,DENG Jun,HOU ZengQian.2024.Early Permian Au-Ni major metallogenic events in western Central Asian metallogenic domain[J].Mineral Deposits43(4):749~784
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