Abstract:
The loess deposition in China is an important archive of the Quaternary paleoclimate-paleoenvironmental signals. Other than the Loess Plateau, loess brough by wind deposited in the upper, middle, and lower Yangtze River basin during the Quaternary. Understanding the provenance, transportation dynamics, and post-depositional weathering processes of loess in these humid regions is important for the study of the past changes of the East Asian monsoon in the Yangtze River Basin, and is also of great significance for investigating the carbon sequestration effect during the chemical weathering process of the fine-grained loess in the humid regions. Although much studies have been conducted on loess deposition in various regions of the Yangtze River Basin, the material transport processes in different regions of the Yangtze River Basin, their interconnections, and their roles in carbon sequestration are still unclear. Here, we overviewed the latest understanding of the formation age, sources, and paleoclimatic records of the loesses in the western Sichuan, Jinsha River, Wushan, and Xiashu in the Yangtze River Basin. we found that the formation of loess in the west Sichuan, Wushan and Xiashu regions were tightly linked to the three uplift phases of the Tibetan Plateau, namely the Tibetan Movement B, the Kunlun and Yellow River Movement and the Gonghe Movement. In addition, the weathering degree of loess depositions in the Yangtze River Basin are stronger than that of loess on the Loess Plateau both during the glacial and interglacial periods. We proposed that the influence of the chemical weathering process of loess on terrestrial carbon sequestration and its correlation with paleoclimate changes are the focus of future research on loess in humid regions, e.g., the Yangtze River Basin.