Geochronology of Yulekenhalasu porphyry copper deposit in northtern Junggar area,Xinjiang,China

Yulekenhalasu copper deposit is a medium-sized porphyry deposit found in recent years in Kalaxiange'er porphyry copper metallogenic belt in northtern Junggar area.Study on its geochronology will help further set up metallogenic model and summarize regional ore-forming pattern.Mang intrusive rocks are exposed in the ore district.The Cu mineralized mainly occurs in the diorite porphyry with subordinate porphyroid biotite quartz monzonite and volcanic rocks and volcaniclastic rocks of Beitashan Formation.This paper studies geochronology of intrusive rocks and mineralization using zircon LA-ICP-MS U-Pb and molybdenite Re-Os method.Based on our and other people data,magma intrusion events in the Yulekenhalasu ore district can be divided into five stages:Quartz diorite invading at 382Ma,ore-bearing diorite porphyry forming at 379Ma,porphyroid biotite quartz monzonite forming at 375 to 374Ma,biotite quartz porphyry invading at 348Ma,and quartz monzonite porphyry forming at 266Ma.Three stages before are formed during the subduction of plate,and other stages corresponds to a period of postcollision during Late Paleozoic.Seven samples of molybaenite Re-Os isochron age is 373.9±2.2Ma,suggesting the Cu-Mo mineralization occurred in the Late Middle Devonian,and relating to the diorite porphyry.