Crustal Evolution And Endogenic Metallic Metallization In Eastern Tianshan Orogenic Belt

Based on analyzing and studying the achievements made by others, this dissertation concludes that:(1) The East-Tianshan tectonic belt is an intercontinent orogenic belt located between the Junggar and Tarim basin and formed through convergence of the two plates;(2)The Arqikekuduk-Shaquanzi fault was an early Paleozoic sutur resulted from collision between the Junggar plate and the Meso-Tianshan microplate rather than subduction of Tianshan paleo-ocean towards the Tarim Plate;(3)tectonomagmatic activities did not stop because of convergent effect between the plates in East Tianshan region, and post-orogenic extension is very common with large scale of intraplate magmatism and nonferrous and noble metallic mineralization related to magmatism;(4) the author and his co-workers carried out systematical isotopic chronologic study and got a series of high-precision isotopic data for diagenetic mineralization, such as the quartz diorite, gabbro-diorite and gabbro from the Baishiquan Cu-Ni orefield has a zircon SHRIMP U-Pb age of 285±10Ma, 284Ma±9Ma (95% confidence) and 284±8Ma (95% confidence), respectively;the biotite plagiogranite body of the Baishan Rhenium-Molybdenum Mine has a zircon SHRIMP U-Pb age of 181±3Ma and the ore-bearing quartz veins in the Baishan orefield have a Rb-Sr isochron age of 187±7 Ma (95% confidence;MSWD=3.52) and a 40Ar-39Ar plateau age of 182±1.6Ma;the mineralized plagiogranite porphyry in the Chihu molybdenum-copper orefield has a zircon SHRIMP U-Pb age of 322±10Ma. The isotopic data mentioned above futher ulteriorly approve that large scale of post-orogenic diagenetic mineralization and indicate an excellent metallogenetic geological condition and prospecting perspective, which is of important significance for instructing prospecting and prognosticating of mineral resources in East Tianshan Orogenic belt;(5) the author discussed regional metallogenetic space-time regularities of the studied area, analyzed the relationships between the Crustal evolution and mineralizations, briefly stated mineralization during different Crustal evolution stages, and systematicallysummed up the metallogeny and chronological achievements of some representative deposits in the studied region. According to metallogenetic chronologic data, mineralization in East Tiansan region was approximately divided into the Precambrian, Early Paleozoic, late Paleozoic and Mesozoic-Cezozoic period. (6) analyzing the potential of endogenetic metallic resources, discussing the main mineralization features of some potential concentrated mineralization areas, put forward further prospecting directions;choosing and identifying the prospecting targets of main endogenetic metallic deposits (porphyry copper deposits, Cu-Ni sulfide deposits and tenacity-shering zone type gold deposits) in eastern Tianshan region, which is of great important significance for directing further exploration ofmineral resources in the studied area.