Sedimentary response to the uplift of the Liupan Shan since the Late Pleistocene and its environmental effects

Liupan Shan lies between the Tibetan plateau and Ordos block and has been under the remote effect of the northeastward extension of the Tibetan plateau. The former research about the uplift of Liupan Shan mainly focused on the petrology, structural deformation or tectonic evolution study from the Cretaceous to early period of Cenozoic. However, the Late Pleistocene geological study closely connected with the human activities was rarely mentioned. In this study, we carried out systematic sedimentary research in the Qingshuihe basin adjacent to the Liupan Shan tectonic belt, re-determine the sedimentary sequence at first, then reverse the uplift history of Liupan Shan tectonic belt since the Late Pleistocene, and predict the possible environmental effect in the future at last. According to the research, there developed two ancient lakes in the Qingshuihe basin during the early to middle stage of the Late Pleistocene while the environment was dominated by warm and moist climate. At the end of the Late Pleistocene, ancient lakes gradually disappeared from the Qingshuihe valley and the environment deteriorated as a result of the rapid uplift of Liupan Shan. What's more, alluvial fan in the front area of mountains lie in the middle part of Liupan Shan tectonic belt, continuously developed since the Late Pleistocene. The alluvial fan is expanding eastward along the Qingshuihe valley until now. Hence, there is a high risk that the Qingshuihe would be intercepted and dammed lake could be created. This research not only make up the deficiency of the uplift study of the Liupan Shan since the Late Pleistocene, but also provide solid geological basis for the comprehensive treatment of the Qingshuihe valley.