Sedimentary microfacies and evolution of Cenozoic Liupanshan Basin

In order to study the characteristics of Cenozoic sedimentary microfacies and sedimentary evolution of Liupanshan Basin, the Cenozoic sedimentary microfacies and sedimentary evolution of Liupanshan Basin are studied based on the lithology, sedimentary structure and sedimentary microfacies characteristics of outcrops around the basin. The results show that the Cenozoic in Liupanshan Basin developed the Sikouzi Formation of Eocene, the Qingshuiying Formation of Oligocene, the Zhangenbao Formation of Miocene and the Ganhegou Formation, which were in unconformity with the underlying strata of different ages. The Cenozoic sedimentary facies in Liupanshan Basin are alluvial fan, braided river, delta, lake and desert deposits. According to the combination characteristics of sand and mud deposition in the longitudinal direction, four kinds of sedimentary filling styles are identified: sand and mud thin interlayer type, thick mud and sand thick type, thin mud and sand thick type. Influenced by the uplift of the Tibetan Plateau, the Sikouzi Formation was dominated by braided river-alluvial fans during the initial filling period of the Liupanshan Basin, which varied greatly in both transverse and longitudinal aspects. During the peak period, the Qingshuiying Formation was dominated by lacustrine sediments characterized by clastic rocks such as salt and salt. During the decline period, the Zhangenbao Formation was dominated by lacustrine facies in the south and fluvial facies in the north. The whole Cenozoic sedimentary microfacies reflects the Cenozoic sedimentary evolution of Liupanshan Basin, mainly fluvial facies. The results of this study provide a new understanding of the sedimentary microfacies and sedimentary evolution of the Cenozoic in Liupanshan Basin, and provide reference for the study of different strata and sedimentary basins.