Paleoelevation of the Qilian Mountain inferred from carbon and oxygen isotopes of cenozoic strata

Located at the northeast edge of the Tibetan Plateau, the Qilian Mountain is a key region where the whole Plateau expands to the interior of the continent, and hence the paleoelevation estimated by paleo-altimetry based on carbon and oxygen isotopes of Cenozoic strata is of great significance for understanding the uplift of the Tibetan Plateau. In this paper, such a paleo-altimetry was used to calculate the paleo-annual temperature and paleo-elevation of middle Qilian Mountain based on carbon and oxygen isotopes of Cenozoic sediments formed in the Eocene, Oligocene, Miocene and Mid-late Pleistocene. The results show that the Qilian Mountain was uplifted to 2711 m in Paleogene, to ~2848 m in the early Miocene, to ~3586 m in the mid-late Miocene, and to 3790~3890 m in the Middle-late Pleistocene. The paleo-elevation of the Qilian Mountain in Paleogene was not very high, but had already formed the northeastern margin of the Tibetan Plateau. The Qilian Mountain was uplifted considerably in Mid-late Miocene, forming basins-mountains tectonic landforms. In Quaternary the earth crust of the Qilian Mountain was activated again and uplifted intermittently. The paleoelevation of the Qilian Mountain inferred from carbon and oxygen isotopes of Cenozoic strata provides a reference for better understanding of the uplifting process of the Tibetan Plateau. ©, 2015, Science Press. All right reserved.