DETRITAL ZIRCON PROVENANCE ANALYSIS OF THE LATE TRIASSIC SICHUAN BASIN: IMPLICATIONS FOR SEDIMENT PROVENANCE AND LATE TRASSIC TECTONICS OF CHINA

Late Triassic strata of the Sichuan basin are deposited around the elongate basin, which is bounded by the Qinling orogenic belt and North China block to the north, the Songpan-Ganzi complex to the west, the Qiangtang terrane and Yidun arc terrane to the southwest, and the Jiangnan orogenic belt and Cathyic block to the southeast. The late Triassic is also the very main period for collision between the blocks mentioned above. To analysis the sediment provenance of the Late Triassic strata in each side of the Sichuan basin and the tectonic evolution, paleographic settings of the large blocks during the late Triassic, We conducted a combined study of U-Pb ages and Lu-Hf isotopes for detrital zircons from the sedimentary rocks of the xujiahe formation around the Sichuan basin. Combining with the existing data, we identify the vary sources for the Xujiahe formation in different sides of the Sichuan basin and analye the tectonic frame of the main blocks in the China during the indosinian.