Cenozoic mountain building of the West Qinling and its correlation with formation of the earliest eolian red clays in the Chinese Loess Plateau

The earliest eolian deposits in large-scale eolian depositional regions are typically regarded as the indicators of the initial aridification and reorganization of the atmospheric pattern. However, eolian deposition is influenced not only by climatic changes in source regions, but also by the topography evolution along dust transportation pathways, a factor often overlooked. The Chinese Loess Plateau (CLP) is the largest dust accumulation region in East Asia, which is bounded by boomerang-shaped mountains. Here, we used apatite (UTh)/He thermochronology and thermal modeling to reconstruct the uplift history of the West Qinling, an orogenic belt adjacent to the earliest (25–22 Ma) eolian red clays in the CLP. Our findings indicate that the West Qinling experienced tectonic uplift during the late Oligocene-early Miocene, coeval with the formation of the earliest eolian red clays in the CLP. Considering the tectonic activities surrounding the CLP and updated climatic records in Central Asia and Pacific Ocean, we propose that the appearance of the late Oligocene-early Miocene eolian red clays in the CLP likely reflects the formation of geomorphologic conditions conductive to dust accumulation and preservation. This phenomenon is not limited to East Asia, but is also commonly observed in other active orogenic belts. Thus, it ought to be cautious to assess the geological significance of the initial eolian deposition, particularly in active orogenic belts.