中亚南天山穆龙套型金矿地质背景、成矿特征和找矿策略

中亚南天山是世界上最重要的金矿带,以浅变质含碳质碎屑岩系为容矿岩石的穆龙套型金矿最为发育且规模巨大。将境内外南天山作为整体开展研究,有助于推进中国新疆南天山地区金矿的找矿持续突破。南天山是南天山洋在石炭纪末闭合时在Karakum—塔里木板块北缘形成的褶皱冲断带。南天山地区穆龙套型金矿的容矿地层为一套浅变质、变形强烈的含碳质细碎屑岩建造,对金矿化有明显预富集;区域内的大型韧-脆性变形带,剪切带及相关断裂系统是穆龙套型金矿的控矿构造;金矿区岩浆活动虽然较弱,但岩浆活动与成矿具有紧密的时空联系。矿体呈脉状、板状、透镜状,常以黄铁矿和毒砂为主要载金矿物,围岩蚀变以硅化、黄铁矿化、碳酸盐化最为发育。成矿年龄多为晚古生代,同位素示踪指示成矿流体、硫及成矿金属物质具有壳幔混源特征。"碳质岩系+构造变形+岩浆热液"是穆龙套型金成矿的关键控制因素。按照总体控矿特征,探讨了中国新疆南天山地区穆龙套型金矿床的主要找矿策略。

Metallogenic background, characteristics and prospecting strategy of Muruntau-type gold deposit in Southern Tianshan, Central Asia

The Southern Tianshan area in Central Asia is the most important gold metallogenic belt in the word and the shallow metamorphic carbonaceous metamorphic rock-hosted Muruntau-type gold deposits are widely developed here.Generally such type of gold deposit is gigantic.Taking the whole Southern Tianshan as the study area,both areas inside and outside the border of China will help to make breakthrough of gold prospecting in the Southern Tianshan area of Xinjiang.The whole Southern Tianshan area was a fold thrust belt at the North margin of Karakum-Tarim Plate formed during the Southern Tianshan ocean closure in Late Carboniferous Period.Gold is pre-enriched in the host rock (the shallow metamorphic but strongly deformed carbonaceous metamorphic fine-grained clastic rock) of Muruntau-type gold deposit.Such type gold deposit in the area is controlled by large ductile-brittle deformation zone,shear zone and related fault system.Mineralization is closely related in time and space although magmatism in the mining area looks weak.Ore body is generally vein like,tabular and lenticular.Pyrite and aesenopyrite are the main gold-carriers.The mostly developed wallrock alteration is silicification,pyritization and carbonation.Most age data fall in Late Palaeozoic Era.Isotope tracing is characterized by crut-mantle mixture source of ore fluid,sulfur and ore metals.Prospecting strateg is discussed on basis of the comprehensive control factor,i.e.Carbonaceous rock+structure deformation+magmatism.