Commencing uplift of the Liupan Shan since 9.5 Ma: Evidences from the Sikouzi section at its east side

The Cenozoic evolution of the Liupan Shan, situated at the northeast of the Tibetan Plateau, will provide constraints to test the models and mechanisms of the evolution of the plateau. In this contribution, the Sikouzi section, at the east of the Liupan Shan, has been selected to study Liupan Shan's uplift history. At around 9.5 Ma, constrained by the magnetostratigraphy, the sediment and depositing architecture characteristics obviously changed. Synchronously. flow direction changed from E -> W to W -> E, and accumulation rate increased to more than double. All these evidences suggest that the Liupan Shan initiated uplifting at around 9.5 Ma. Subsequently, a stage of intense uplift happened during 8.2-7.3 Ma, indicated by the apatite fission-track (AFT) data across the Liupan Shan. Regional comparison indicates that this stage of uplift is not only with local but also regional significance. The Miocene uplift of the Tibetan Plateau triggered the intensification of the East Asian Monsoon and Asian intercontinental aridity, which has been implied by the pollen results of the Sikouzi section. (C) 2009 Elsevier Ltd. All rights reserved.