Evolution of Late Paleozoic sedimentary provenance of Lhasa block: Detrital zircons from Yongzhu Formation in Cuoqin area, Tibet

The Late Paleozoic is an important transition period for the geological evolution of the Lhasa block, so there are some disputes on key geological issues, such as the origin of the Lhasa block. In this paper, the Upper Carboniferous Yongzhu Formation in the Cuoqin region of Tibet was selected as the study object. The U-Pb dating data of detrital zircons in quartz sandstone show the peak ages of 523Ma and 920Ma. Based on a comparison with the Lhasa block and the detrital zircons formed before the Lhasa blockin the Late Carboniferous glacial period, the authors hold that the 920Ma agepeak of the Yongzhu Formation in the Lhasa block is more characteristic of the provenance on the Indian side of the Gondwana opening, and that the Nanqiangtang, Lhasa and Himalayan microlandmasses were significantly related before splitting. The source information of western Australia (about 1180Ma age peak) in the Laga and Laigu groups containing ice raft debris suggests that ice rafts from western Australia might have drifted to the Lhasa block through ocean currents and then deposited ice raft debris.