Landform evolution of the Qilian Shan since 120 Ma revealed by Apatite fission track data

The Cenozoic uplift of the Qilian Shan is intimately connecting with the collision of India and Eurasian Plates, while the deformation mechanism is still a mystery for its far distance from the collision boundary. The first requirement for answering this question is to obtain the uplift process of this range, which remains debate. In this study, we compiled apatite fission track data from previous studies on the range, aims to reveal the spatial and temporal disparities or similarities for the exhumation process. Most age-evolution profiles and thermo-modeling results show a low exhumation rate during 80-20 Ma, corresponding to shorter track lengths, indicating a lower erosion rate and lower relief across the whole Qilian Shan region. The result also reveals two stages of rapid exhumation, during Cretaceous (120-80 Ma) and since Miocene (20-0 Ma). The exhumation history of the Qilian has no significant spatial difference, and the outward growth was limited at the southern and northern edge after 5 Ma. This temporal and spatial pattern for the exhumation of the Qilian Shan suggests that there was probably no obvious uplift at the initial collision of India-Tibet plates, and support the proposal that the whole Qilian range uplifted synchronously since 20 Ma. Thematic collection: This article is part of the Mesozoic and Cenozoic tectonics, landscape and climate change collection available at: https://www.lyellcollection.org/topic/collections/mesozoic-and-cenozoic-tectonics-landscape-and-climate-change Supplementary material: https://doi.org/10.6084/m9.figshare.c.7224863