Revisiting clay‐sized mineral and elemental records of the silicate weathering history in the northern Tibetan Plateau during the late Cenozoic: The role of aeolian dust

Abstract

AbstractExceedingly strong aeolian dust activity has occurred in inland Asia. Comparisons of the late Cenozoic sedimentation rates between aeolian and fluvial‐lacustrine sequences around the northern Tibetan Plateau suggest that aeolian process has played an important role in the erosion, weathering and deposition of sediment. However, recognizing dust as an important source in fluvial‐lacustrine sequences is a vital but difficult task. Here, clay‐sized mineral and elemental records of regional silicate weathering histories are revisited during the period of Asian dust expansion at ~9–8 Ma. The aeolian dust input from the Tianshan‐Altay Orogens into the Jiuquan Basin is identified using the Th/Sc ratio while that from the Qilian Shan into the Xining Basin is identified based on inconsistent fine‐grained silicate weathering proxies. Our study suggests that the use of appropriate dust provenance tracers and recognition of wind transport‐induced changes in dust grain size and chemistry can provide useful aeolian dust discrimination approaches.