Late Miocene (10.0∼6.0 Ma) Rapid Exhumation of the Chinese South Tianshan: Implications for the Timing of Aridification in the Tarim Basin

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 similar to 6 Ma and since similar to 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 similar to 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. Plain Language Summary The tectonic uplift of the Mountains is closely related to climate change in nearby areas, e.g. the uplifting of the Tibetan Plateau plays an important on the aridification of the Tarim Basin since the Cenozoic. This study reported a new set of low-temperature thermochronological data from the high-elevation area of the Tianshan. They revealed the rapid exhumation of the central Chinese South Tianshan during 10.0-6.0 Ma, simultaneous with the enhanced aridification of the Tarim Basin. Therefore, we speculated that the uplift of the central South Tianshan have effectively blocked the humid westerlies from the Atlantic and Indian Oceans to enter the Tarim Basin and enhanced the aridification in the Tarim Basin during the late Miocene.

Automated summary

The exhumation of the Tianshan Mountains is controlled by a complex interaction between tectonics and climate. New low-temperature thermochronological data reveals rapid exhumation in the central South Tianshan during 10-6 million years ago, contributing significantly to the aridification of the Tarim Basin.