Paleo-Tethys Orogenic Process And Gold Metallogenesis Of The East Kunlun

Paleo-tethys orogen of the East Kunlun shows special tectonic position, complex tectonic setting, frequent magmatic activities and varying degrees metamorphism. It records the orogenic cycle process of the strongest tectonism-magmatism-mineralization, and contains rich in mineralization type and mineral resources. The gold belt is an ideal area to study the anomalous concentration of large amounts of ore materials in the orogenic process and a window to reveal the relationships between thecrust-mantle interaction and metallogenesis. Through the studying of geology,isotopic dating and geochemistry, we rebuilt the evolution process of tectonism,magmatism and mineralization, and highlight the coupling between the major tectonic events and the large scale mineralization, with the purpose of recognizing the geodynamic setting of the gold mineralization in the Paleo-tethys orogenic process of the East Kunlun, to resolve the mystery of gold metallogenesis of the East Kunlun.Paleo-tethys orogenic process of the East Kunlun can be classified: spreading and subduction of Paleo-tethys ocean (278?240 Ma),the main collision (240?228 Ma)and post-collision (228?210 Ma) of the East Kunlun. Two major events of tectonism and magmatism can be identified: -240 Ma acid-intermediate magmatic activity of syn collision setting, and -228 Ma mafic magmatic activity of post collision setting.Precise geochronological data show that there are two periods of large-scale mineralization during Paleo-tethys orogenic process of the East Kunlun (?240 Ma and?228 Ma). The belt form a series of deposits: Dachang,Wulonggou,Kengdenongshe and Tuoketuo deposits. Dachang gold deposit of the Bayan Har is Carlin-like type, the product of mineralization in post-collision extension setting. Kengdenongshe gold polymetallic deposit of the South Kunlun is sedimentary exhalative type, the product of mineralization in oceanic subduction and syn-collision tectonic conversion.Wulonggou gold deposit of Central Kunlun is orogenic-type, the product of mineralization in many stages of minerals into the superposition. Their formation epochs are 220?237 Ma,which take the same period of ductile-brittle shear zone. The ore-bodies of skam type are mainly in 240?244 Ma. Tuoketuo copper-gold(molybdenum) deposit of Central Kunlun is porphyry type (232 Ma), the product of mineralization in metasomatism of fluid of slab subduction. The porphyry-skarn deposits of North Kunlun mainly occur in the period of Middle-Late Triassic(210?248 Ma).The metallogenesis from the East Kunlun is characterized by the concentrated distribution, multiple types and multiple mineralization. The period of large-scale mineralization during Paleo-tethys orogenic process of the East Kunlun are accordant with tectonic framework transformation of syn-collision, post-collison and post-orogenic extension. Based on the chronological data of magmatism and mineralization suggest that the transition of tectonic regime and underplating and magma mixing may be important factors of control the large-scale tectonics -magmatism - metallogenic event during the Paleo-tethys orogenic process.