Eocene tectonic lithofacies paleogeography of the Tibetan Plateau

On the basis of the data obtained from 1:250000 geological mapping conducted by China Geological Survey during 1996- 2008 as well as other data available concerning the Cenozoic strata, and through integrated researches on the tectonic setting and lithostratigraphic sequence of remnant basins in Eocene, the authors investigated the evolution of Eocene tectonic lithofacies paleogeography in the Tibetan Plateau. In the Eocene period, uplift and erosional areas existed in Songpan-Garze and Gangdise, depressed basins(lakes and pluvial plain) lay in eastern Tarim, Qaidam, Qiangtang and Hoh Xil, and Neo-Tethys Sea was located in western and southern Tibetan Plateau. Based on researches on the tectonic-lithofacies paleogeographic evolution in Eocene and its response to the tectonic uplift of the Tibetan Plateau, the authors recognized two major uplift events, which happened during 55-51Ma and 45-34Ma respectively.