中国及境外天山铅锌成矿作用与找矿方向

中国及境外天山铅锌矿床多有发现,如哈萨克斯坦Tekeli、Shalkiya和Achisai,乌兹别克斯坦Kurgashinkan和Uchkulach,塔吉克斯坦Altyntopkan,中国新疆乌拉根、彩霞山、阿齐山、阿尔恰勒等大型—超大型铅锌矿床,构成了天山巨型铅锌成矿带.这些铅锌矿床形成于怎样的地球动力学背景?铅锌成...

Zn-Pb Metallogeny and Prospecting Orientation of Tianshan in China and Abroad

There are many Zn-Pb deposits in Tianshan of China and abroad,forming a giant Zn-Pb metallogenic belt.Why so many Zn-Pb deposits are located here?how geodynamic setting results in their formation?What is the regional ore-forming types and the key to the Zn-Pb metallogeny?Where is the future prospecting orientation?All these significant geological and exploration problems are attracted much more attentions.Based on investigating the regional geology and Zn-Pb deposits in Tianshan and consulting various references,the important metallogenic environments,geological characteristics of typical Zn-Pb deposits and their ore-forming types were demonstrated,and tectonic-metallogenic evolution of Tianshan orogen and prospecting direction of Zn-Pb mineral resources were then discussed.The results show that Tianshan orogen experiences four geodynamic processes,namely the formation of Precambrian continent,ocean-continent subduction accretion,continent-continent collision orogeny,and intraplate deformation,and four corresponding metallogenic environments,including Proterozoic paleo-continent margin rift basin,Paleozoic ocean-continent subduction accretion island arc,Late Paleozoic continent-continent collision orogeny and Meso-Cenozoic depression basin.Accordingly,four important metallogenic systems and ore-forming types are formed as follow.The SEDEX Zn-Pb deposits are formed in Proterozoic paleo-continent margin rift basin environment,and controlled by contemporaneous faults and reduced fine-grained clastic rocks or carbonate rocks.The skarn,magmatic hydrothermal vein and VMS Zn-Pb deposits are formed in island arc of Paleozoic ocean-continent subduction accretion environment,and controlled by arc-related magmatism,faults and favorable strata.The MVT Zn-Pb deposits are formed in Late Paleozoic continent-continent collision orogeny environment,and controlled by marine carbonate in passive margin,extensional faults and thrust nappe structures.The sandstone-hosted Zn-Pb deposits are formed in Meso-Cenozoic depression basin environment,and controlled by basinal structure,infilling of oil and gas,bleaching of red beds,and sulfate.The Paleozoic subduction accretion island arc Zn-Pb system and skarn,magmatic hydrothermal vein and VMS types play a more important role in Zn-Pb mineral resources of Tianshan orogen compared to other parts of the world,which should be paid more attentions.North Tianshan island arc belt,the northern and southern margins of Kazakhstan-Yili block and central Tianshan block are all favorable for Paleozoic subduction accretion island arc Zn-Pb system,and show promising potential for ore prospecting of more large-scale Zn-Pb deposits.Meanwhile,the northern margin of Kazakhstan-Yili block and central Tianshan massif of East Tianshan for Proterozoic paleo-continent margin rift basin Zn-Pb system and SEDEX type,the northern margin of foreign central Tianshan and South Tianshan orogen for Late Paleozoic continent-continent collision orogenic Zn-Pb system and MVT,and the piedmont/intermontane basins along South Tianshan orogen for Meso-Cenozoic depression basin Zn-Pb system and sandstone-hosted type are all favorable,which should continue to be concerned about.These results may provide reference and indication for regional Zn-Pb metallogenic understanding and future Zn-Pb ore exploration.