DETRITAL ZIRCON U-PB AGES AND ITS SIGNIFICANCE FROM YINGJISU SAG IN TARIM BASIN

According to the appliance of the new U-Pb isotopic age analysis of zircon by LA-ICP-MS from clastic rocks of Yingjisu sag,there are three groups sedimentary source ages of Jurassic:350-500Ma,760-970Ma,1400-1600Ma,and there are two groups sedimentary source ages of Cretaceous:320-354Ma,1400-1800Ma.The date of zircon ages from the clastic rocks indicated that Altun Tagh is the Jurassic sedimentary province of Yingjisu sag, and the igneous rocks of late Ordovician – early Silurian were the main source. It is demonstrated that Altun Tagh Mountain had intense uplift in Jurassic and its rehandling sedimentary sources of the area. On the contrary, the sediments comes from the northern Kuruktag Mountain in Cretaceous. It is also showed that the oldest source rocks originated from Mesoproterozoic. The alternation of detrital zircon ages reflected the basin-mountain coupling of the area.