LATE MIDDLE PLEISTOCENE SEDIMENTARY SEQUENCES AND TIME EVIDENCE IN HONGSHUICHUAN REGION, EAST KUNLUN MOUNTAINS

Buqingshan Mountains have already begun to rise abruptly on a large scale in the late Middle Pleistocene. The Quaternary deposit is more than 100 m thick in Chaganerige, northern slope of the Buqingshan Mountains, Kunlun Mountain Ranges. This deposit layer is defined as the multivariant complex formation of pluvial-alluvial fans, in the relatively fine sedimentary layers of which occur abundant sporomorphs. The analysis of plant sporopollen assemblage in the alluvial and pluvial formations is used to determine that the Quaternary pluvial-alluvial deposit occurred in the Middle Pleistocene. In addition, the plant type at that time reflected by the sporopollen assemblage is determined to be a mixed_forest_desert steppe. The thermoluminescent dating of the pluvial-alluvial deposit is (302±22)?ka. The paleomagnetic measurement is used to identify two subtimes: Biwa reverse polarization No.1 and Biwa reverse polarization No.2, and also to identify the late Middle Pleistocene.