MARGIN: 0cm 0cm 0pt" class=MsoNormal> mary name="EnDivSummary">Based on an analysis of sedimentary sequence, regional unconformity, lithologic character and distribution of Paleogene-Neogene sediments, the authors hold that the Paleogene-Neogene sediments can be divided into four upward-shallowing sequences of Tuotuohe Formation, Yaxicuo Formation, Wudaoliang Formation and Quguo Formation, which constitute two complete continental orogenic molasses formation sequences. The analysis shows that the Paleogene-Neogene Tuotuohe Basin has experienced such evolutionary stages as foreland basin evolution stage (56.5man’; mso-hansi-font-family: ’Times New Roman’">~45.0 Ma)→strike-slip pull-apart basin stage (45.0man’; mso-hansi-font-family: ’Times New Roman’">~30.0 Ma)→overall uplift and intermountain residual basin stage (23.5man’; mso-hansi-font-family: ’Times New Roman’">~16.0 Ma)→foreland basin-confined basin-intermountain residual basin stage (16man’; mso-hansi-font-family: ’Times New Roman’">~2.6 Ma).mas-microsoft-com:office:office" />