title: Calcium Nodules as a Proxy for Quaternary Paleoclimate Change on China's Loess Plateau.
abstract: Different proxies have been used to investigate Quaternary paleoclimate change. Here, we used weathering of calcium nodules in paleosols on China's Loess Plateau as a proxy for Quaternary paleoclimate changes to provide an alternative indicator of these changes. Paleosol and carbonate nodules were collected from Luochuan and Lantian counties in Shaanxi Province, China. We found that this approach allowed quantitative reconstruction of temperature, rainfall, soil mineral composition, and the effects of weathering and leaching. The changes in carbonate content in the loess and paleosol sequences were controlled by alternating dry and wet climatic conditions. Nodule formation conditions were directly affected by the leaching and migration of elements. The loess and paleosol sequences developed calcium nodules, and their formation was closely related to the rainfall and leaching characteristics of the paleoclimate. The paleoclimate and soil minerals affected the vegetation types and directly influenced changes in the soil. During formation of the calcium nodules, the surface vegetation evolved slowly, and the number of species and quantity of vegetation both decreased.
authors.affiliation: School of Chemistry and Environment, Jiaying University, Meizhou, Guangdong, China.|State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau, Northwest Agriculture & Forestry University, and Institute of Soil and Water Conservation; Chinese Academy of Sciences & Ministry of Water Resources, Yangling, Shaanxi, China.
authors.forename: Wenming
authors.initials: W
authors.lastname: He
authors.affiliation: State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau, Northwest Agriculture & Forestry University, and Institute of Soil and Water Conservation; Chinese Academy of Sciences & Ministry of Water Resources, Yangling, Shaanxi, China.
authors.forename: Hongming
authors.initials: H
authors.lastname: He
authors.affiliation: State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau, Northwest Agriculture & Forestry University, and Institute of Soil and Water Conservation; Chinese Academy of Sciences & Ministry of Water Resources, Yangling, Shaanxi, China.|Department of History and Sociology, Minnan Normal University, Zhangzhou, Fujian, China.
authors.forename: Mingyong
authors.initials: M
authors.lastname: Zhu
mesh_terms: D002118:Calcium / Q000032:analysis*; D002681:China; D057231:Climate Change; D019015:Geologic Sediments / Q000737:chemistry*
chemical_list: D002118:Calcium