投稿时间：2024-11-25
修订日期：2024-12-30
网络发布日期：2025-03-10
中文摘要:自~1350 Ma打开到~250 Ma最终闭合，古亚洲洋经历了11亿年的演化后形成了全球最大的增生型造山带——中亚造山带。研究古亚洲洋的构造演化与成矿可有效揭示中亚造山带的演化与成矿规律，进而指导勘查。中亚造山带发育众多岩浆弧，新元古代岩浆弧主要分布在北侧，而古生代岩浆弧集中在西侧，东侧有少量发育。古亚洲洋在早古生代以大洋俯冲作用为主，晚古生代逐步以弧陆拼贴和碰撞为主导。文章系统梳理了与古亚洲洋板块俯冲相关的31个岩浆弧及37个代表性矿床，厘定古亚洲洋构造体制的6大类成矿类型，包括斑岩型Cu-Au±Mo、浅成低温热液型Au±Ag、岩浆型豆荚状Cr铁矿、岩浆型Ni-Cu-PGE、造山型金矿及VHMS型Cu-Pb-Zn±Au矿床。其中，斑岩型Cu-Au±Mo、造山型金矿及岩浆型Ni-Cu-PGE矿床具有最高的经济价值。斑岩型、浅成低温热液型及VHMS型矿床在早古生代和晚古生代均有产出，而造山型金矿、豆荚状Cr铁矿及岩浆型Ni-Cu矿床则主要形成于晚古生代。这表明，早古生代古亚洲洋板块俯冲与弧岩浆作用占主导地位，形成的构造环境以典型的沟-弧-盆体系为主，有利于在岛弧地区形成斑岩和浅成低温热液系统，并在弧后区域形成VHMS Cu-Pb-Zn±Au矿床。到了晚古生代，随着部分小洋盆的闭合，发生了弧-弧增生与弧陆碰撞作用，导致岩浆型Cr、Ni-Cu矿床及造山型金矿的形成。斑岩型、浅成低温热液型和VHMS及岩浆型Cr矿床与洋壳俯冲关系密切，岩浆型Ni-Cu与碰撞后伸展背景下软流圈上涌直接相关，造山型金矿与弧地体-克拉通边缘拼贴碰撞紧密相关。文章最终建立了由早古生代以斑岩Cu-Au和浅成低温热液矿床为主、晚古生代斑岩-浅成低温热液成矿系统、造山型金矿、岩浆Ni-Cu矿、豆荚状铬铁矿矿、VHMS矿床等多种成矿类型并存的特色古亚洲洋成矿体系。由于蒙古-鄂霍茨克洋闭合与古太平洋板块俯冲的叠加，中亚造山带东段保留了较少的与古亚洲洋有关的岩浆弧和斑岩矿床，寻找被改造错断的隐伏斑岩铜矿床仍有很大潜力。中亚成矿域的成矿特征表明，构造环境越复杂，成矿类型越丰富。反之，成矿类型的多样性也反映了该地区构造演化的复杂程度。这一发现为通过成矿类型揭示区域构造演化提供了新的视角。
Abstract:The Paleo-Asian Ocean, spanning from its opening around 1350 Ma to its closure at approximately 250 Ma, underwent 1.1 billion years of evolution to form the world's largest accretionary orogenic belt——The Central Asian Orogenic Belt (CAOB). Investigating the tectonic evolution and metallogenesis of the Paleo-Asian Ocean is crucial for understanding the formation and metallogenic processes of the CAOB and guiding exploration acti-vities. The CAOB hosts numerous magmatic arcs, with Neoproterozoic arcs predominantly located in the northern region, Paleozoic arcs concentrated in the western region, and a limited number of arcs in the eastern region. During the Early Paleozoic, oceanic subduction-related processes dominated the tectonics, transitioning to arc-continent accretion and collision in the Late Paleozoic.This study systematically reviews 31 magmatic arcs and 37 representative ore deposits related to the subduction of the Paleo-Asian Oceanic plate. It identifies 6 major metallogenic types associated with the Paleo-Asian Ocean’s tectonic regime: Porphyry Cu-Au±Mo, epithermal Au±Ag, podiform chromite, magmatic Ni-Cu-PGE, orogenic gold, and VHMS (volcanogenic massive sulfide) Cu-Pb-Zn±Au deposits. Among these, porphyry Cu-Au±Mo, orogenic gold, and magmatic Ni-Cu-PGE deposits hold the highest economic significance. Porphyry, epithermal, and VHMS deposits formed during both the Early and Late Paleozoic, while orogenic gold, podiform chromite, and magmatic Ni-Cu deposits are primarily Late Paleozoic in age.This temporal and spatial distribution highlights the dominance of Paleo-Asian Oceanic plate subduction and arc magmatism during the Early Paleozoic, characterized by typical trench-arc-basin systems. Such settings favored the formation of porphyry and epithermal systems in island arc environments and VHMS Cu-Pb-Zn±Au deposits in back-arc basins. By the Late Paleozoic, the closure of several small oceanic basins led to arc-arc accretion and arc-continent collision, driving the formation of magmatic Cr, Ni-Cu deposits, and orogenic gold deposits. Porphyry, epithermal, VHMS, and magmatic Cr deposits are closely linked to oceanic subduction processes, while magmatic Ni-Cu deposits are associated with post-collisional extensional environments and asthenospheric upwelling. In contrast, orogenic gold deposits are intimately related to arc terrane-craton margin collisions. This study establishes a distinctive metallogenic system for the Paleo-Asian Ocean, characterized by porphyry Cu-Au and epithermal deposits dominating in the Early Paleozoic, and a coexistence of porphyry-epithermal systems, orogenic gold, magmatic Ni-Cu, podiform chromite, and VHMS deposits in the Late Paleozoic. Due to the superimposed effects of the closure of the Mongol-Okhotsk Ocean and the subduction of the Paleo-Pacific plate, only a limited number of arcs and porphyry deposits associated with the Paleo-Asian Ocean are preserved in the eastern CAOB, there is still great potential in finding concealed porphyry copper deposits that have been transformed and faulted. The metallogenic features of the Central Asian metallogenic domain indicate that more complex tectonic settings yield greater diversity in deposit types. Conversely, the diversity of deposit types also reflects the complexity of tectonic evolution in the region. This finding provides a new perspective for understanding regional tectonic evolution through the lens of metallogenic systems.
keywords:ore deposit types ore-forming characteristics eastern section of the Central Asian Orogenic Belt tectonic evolution of the Paleo-Asian Ocean
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基金项目:本文得到国家重点研发计划“深地资源勘查开采”重点专项“北方东部复合造山成矿系统深部结构与成矿过程”(编号：2017YFC0601306、2017YFC0601302)和深地重大专项（编号：2024ZD1002307）联合资助
引用文本：
秦克章,王乐,朱永峰,田伟,徐备,张晓晖,赵超,庞绪勇,回凯旋,李光明,李文博,申萍.2025.北方东部复合造山成矿：I.古亚洲洋两期构造演化与成矿[J].矿床地质,44(1):35~66QIN KeZhang,WANG Le,ZHU YongFeng,TIAN Wei,XU Bei,ZHANG XiaoHui,ZHAO Chao,PANG XuYong,HUI KaiXuan,LI GuangMing,LI WenBo,SHEN Ping.2025.Composite orogenic metallogenesis of eastern CAOB: Ⅰ. Two phases of tectonic evolution and metallogenesis of Paleo-Asian Ocean[J].Mineral Deposits44(1):35~66
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