Mid-Pleistocene vermiculated red soils in southern China as an indication of unusually strengthened East Asian monsoon

A paleosol unit, referred to as vermiculated red soil (VRS), widely distributes in the region south of the Yangtze River. It is characterized by red and white veins, easy to be identified in the fields, and is usually considered a stratigraphic marker. VR…

Mid-pleistocene vermiculated red soils in southern China as an indication of unusually strengthened East Asian monsoon

The mid-Pleistocene vermiculated red soils (VRS) from Xuancheng (Anhui Province) and Bose (Guangxi) are studied through soil micromor- phological, mineralogical and chemical approaches. The results indicate a polygenetic nature of the VRS, having experienced multiple soil-forming stages. Three main stages have been recognized, attribut- able to distinct climate regimes. They include the formation of the homogeneous matrix of a red soil (stage 1), development of the white veins within the soil profile (stage 2), and formation of juxtaposed textural features (stage 3). The white veins, resulting from iron-depletion in the groundmass of the homo- geneous matrix of a red soil, required abundant rainfall without significant seasonal desiccations. The geographically widely spread VRS south of the Yangtze River in China implies a Mid-Pleistocene extreme East Asian summer monsoon. This climate extreme might be closely linked with the changes in the strength of NADW.