中-哈-吉-乌天山变形带容矿金矿床:成矿环境和控矿要素与找矿标志

Deformed zone hosted gold deposits in the China-Kazakhstan-Kyrgyzstan-Uzbekistan Tian Shan:metallogenic environment,controlling parameters,and prospecting criteria

天山是全球第二大金矿富集区,世界级和大型-超大型金矿床东西成带横贯中国新疆中部-哈萨克斯坦东南部-吉尔吉斯斯坦-乌兹别克斯坦,构成巨型跨境金成矿带。天山巨型跨境金成矿带和重要金矿床形成的地质环境、成矿的控制要素、找矿勘查的标志都是学术界和工业界高度关注的重大地质和找矿问题。通过广泛、深入地文献调研和境内外天山较全面野外地质矿产调查与研究,本文认为中-哈-吉-乌天山大规模金成矿主体形成于晚石炭世-早二叠世古亚洲洋闭合后的陆块拼贴变形过程,部分形成于中-晚二叠世陆内走滑变形过程。中天山南、北缘古缝合带及其附近的大型脆性/韧-脆性变形带是巨量金成矿的关键控制因素,多期叠加复合成矿是天山变形带容矿金矿床的显著特征。地壳初始富集、构造变形活化、岩浆热液叠加是天山变形带容矿金矿床的主控因素。"碳质细碎屑岩+脆韧性变形带+海西末期岩体"是中-哈-吉-乌天山变形带容矿大型-超大型金矿的找矿标志组合。

Tian Shan is the world’s second largest gold ore cluster and hosts an array of world-class and large/superlarge gold deposits.It constitutes a giant cross-border gold metallogenic belt that extends westward from Central Xingjiang,China to Uzbekistan,via southeastern Kazakhstan and Kyrgyzstan.What metallogenic settings have been responsible for the large-scale gold mineralization of the Tian Shan giant gold belt?What are the key factors controlling gold mineralization?What are the criteria for gold prospecting in Tian Shan giant gold belt?All of these are crucial geological and prospecting problems that have become the focus of the academics and mining industry.Based on an extensive and thorough literature review,along with comprehensive field investigations on the geology and gold deposits of Tian Shan orogen,this paper suggests that the large-scale gold mineralization of Tian Shan had formed during a terrane assembling deformation subsequent to the final closure of the paleo-Asian Ocean in the Late CarboniferousEarly Permian.On the other hand,minor gold mineralization had formed during intracontinental strike-slip deformation in the Middle-Late Permian.The large brittle/ductile-brittle deformation zones,situated near the tectonic sutures of the northern and southern margins of the Middle Tian Shan,are the key factors controlling the large-scale gold mineralization of Tian Shan.Multistage overprinting mineralization is a significant feature of the Tian Shan deformed zone-hosted gold deposits.The crustal initial enrichment,structural deformation activation,and magmatic-hydrothermal overprinting are the main factors controlling the Tian Shan deformed zone-hosted gold deposits.Fine-grained carbonaceous clastic rocks,ductile-brittle deformed zones,and late Hercynian granitic intrusions are the key prospecting criteria for the deformed zone-hosted gold deposits in the China-Kazakhstan-Kyrgyzstan-Uzbekistan Tian Shan gold ore belt.