Tectonic uplift of the Tibetan Plateau: Impacts on the formation of landforms, climate changes and ancient human migration in China

Abstract：It is imperative to build the geochronological sequence for key and important Cenozoic events based on studies of tectonic deformation, geochronological data of uplifting and general tectonic framework, so as to get an overall recognition of the Cenozoic tectonic-geomorphological framework of China's mainland. Several key issues on the continental tectonics and geomophological framework, although widely discussed, remain unresolved, e.g., the uplifting of the Tibetan Plateau which is the highest mountain range on the earth, and the formation of the WNW-trending basin-range system in Northwest China as well as the development of the stepped NNE-trending basin-range system in East China. Through studies of the Tibetan Plateau since the 1970's, lots of geochronological data on the uplifting and paleao-elevation have been obtained, which makes it possible to conduct quantitative analysis. The problem when the plateau was formed has been the subject of studies for decades. The authors have conducted continued studies of the Qaidam Basin and neighboring regions for more than 20 years since 1980's and, as a result, found that the Qaidam Basin, as a basin-in-plateau, has experienced the entire uplifting history of the plateau. There exists complete sedimentary and structural evidence recording the Cenozoic geological events and variation of the environment during the uplifting of the plateau. The evidence can be utilized as a temporal-spatial reference for the subdivision of various stages of plateau uplifting. It is therefore suggested that the plateau was not uplifted in Paleogene (55-24 Ma), and the initial uplifting of a Tibet-Fujian-Guangdong plateau occurred in early-middle Miocene (23-17 Ma). The present plateau was configured by a final uplift in late Pliocene or early to middle Pleistocene (3.6-0.8 Ma). The uplift of the Tibetan Plateau and the formation of the tectonic-geomorphologic framework of China led to the variation of the environment of China and of the World, and also affected the paths of migration of ancient people. Joint studies by geologists, paleoclimatologists and paleoanthropologists will contribute to the deep understanding of the paleaogeomorphologic evolution and variation of paleaoclimate as well as the birth of ancient people and their migration. The present paper focuses on the relationship between the uplifting of the plateau, the formation of the geomorphological framework of China and the variation of paleaoclimate. The possible migration paths of ancient Chinese are discussed.