Intensified climate-driven exhumation along the South Himalayan Front since one million years ago

Abstract

This paper builds a database of apatite fission track (AFT) ages and thermal-modeling results covering the whole southern Tibetan Plateau, providing detailed information on the cooling and erosion process of the modern landscape evolution and comparing with the distribution of climatic factors. Large-scale AFT age distribution and thermal-history modeling results indicate extraordinarily intense erosion along the South Himalayan Front and relatively weak erosion in the interior of the plateau. AFT samples from different regions plot into different partitions on the elevation vs AFT age diagram, and there is an excellent coupling between AFT ages and climatic factors. Based on AFT thermal-history modeling results, an intensified erosion event since ∼1Myr ago has been identified along the South Himalayan Front. The varied AFT ages along the South Himalayan Front are probably induced by differential intensity of erosion in the same cooling event rather than the time when the rapid cooling event began. Meanwhile, the spatiotemporal coupling of climatic factors and the intensified erosion belt suggests that climatic transition is the key factor dominating the rapid exhumation event since ∼1Myr.