Late Miocene (10.0~6.0 Ma) rapid exhumation of the Chinese South Tianshan: implications for the timing of aridification in the Tarim Basin

Abstract

Cenozoic exhumation in the Tianshan is controlled by a complex interaction between tectonics and climate. However, the timing and magnitude of exhumation of the Tianshan and its contribution to climate change in Central Asia remains debated. In this study, we report new apatite fission track and (U-Th)/He ages for granite samples from the roof of the South Tianshan that are significantly younger than those published for other parts of the South Tianshan. Inverse and forward modeling reveals two phases of accelerated cooling at 10∼6∼Ma and since ∼3∼Ma, which can be linked to (1) the reactivation of strike-slip faults and hot asthenospheric upwelling during India- Eurasia convergence and (2) the interplay between tectonics and glaciation, respectively. The 10∼6∼Ma exhumation phase further corresponds to the timing of climate change, suggesting that this exhumation phase significantly contributed to the enhanced aridification of the Tarim Basin