Palaeocurrent Data: Evidence for the Source of the Langjiexue Group in Southern Tibet

Forty-three paleocurrent data recorded in flute structures of the Upper Triassic weakly metamorphosed Langjiexue Group are sampled and analyzed at 37 locations of the Qiongguo and Gongga areas, Shannan of Tibet, which are tectonically asserted into the northern subzone of the Tethys Himalayas. Calibration of these data using the stereographic projection method shows two main paleocurrent directions: one is dominantly southeastward (140°- 160°), the other chiefly southwestward (190°-210°). It is supposed that the clastic composition of the Upper Triassic Langjiexue Group could be derived from the northern unidentified block instead of the ancient Indian plate. This idea can provide geologists a clue for understanding the evolution of sedimentary basin and tectonic plates in the Himalayas and the Tibetan Plateau.