Stable isotope records of Cenozoic climate and topography, Tibetan plateau and Tarim basin

We seek to better understand growth of the Tibetan plateau and associated climate change by presenting the first regionally extensive set of ox isotope data obtained from ca. 40 m.y. of Cenozoic strata from a 700,000 km(2) area ranging from the northern edge of the Tibetan plateau northward across the entire Tarim basin. Our results reveal a previously unrecognized large positive isotope shift from Eocene to Oligocene which we suggest results from initial topographic growth of the Himalayan-Tibetan system and attendant reorganization of climate by this growing mountain belt. A negative isotopic shift recorded in Miocene strata may reflect retreat of the Neotethyan Sea from the Tarim basin, as well as enhanced elevation of the Himalaya/Tibetan plateau region and the rise of the Tian Shan, which diverted moisture-bearing Westerlies and deepened aridity in the Tarim basin and the northern Tibetan plateau.