The Permian lithofacies paleogeographic characteristics and basin-mountain conversion in the Kunlun orogenic belt

Abstract：The Kunlun orogenic belt was basically formed in Paleozoic, resulting from ocean-continent conversion and collision orogenic activity. In the early and middle Permian, the south Kunlun was a multi-island ocean basin, the north Kunlun was an active margin rift and contained mainly shallow sea sediments and partly volcanic basin sediments, the middle part was a seashore-shallow sea, and the Kangxiwa-Muztagh-Animaqing belt contained deep－semi-deep sediments and formed a multi-island ocean basin paleogeographic framework in this period. In the middle and late Permian, convergence took place, ocean basin and active margin rift were closed, uplifting began, and basin-mountain conversion was completed. In the late Permian, the Kunlun orogenic belt entered into another basin-mountain conversion period, sea water came from southeast in the east part and from northwest in the west part, with the deposition of seashore- shallow sea fragmental rocks and carbonate rocks in local areas. Based on field work, analytical tests and integrated studies in association with the 1：250 000 regional geological data and other data available, the authors chose the Permian strata of late Palaeozoic as the study object and discussed the Permian lithofacies characteristics and tectono-paleogeography with the purpose of improving the research level of the Kunlun orogenic belt.