Paleoweathering and paleoenvironmental change recorded in lacustrine sediments of the early to middle Eocene in Fushun Basin, Northeast China

作者：Zuoling Chen, Zhongli Ding, Zihua Tang, Shiling Yang, Xu Wang, Linlin Cui · 发表于：Geochemistry Geophysics Geosystems · 年份：2016 · DOI：10.1002/2016gc006573 · 被引用次数：26 · 研究领域：Geology and Paleoclimatology Research、Paleontology and Stratigraphy of Fossils、Geochemistry and Elemental Analysis

Abstract Deciphering the long‐term interaction among continental silicate weathering, global climate, and atmospheric CO 2 concentrations is helpful in understanding the mechanisms of the Cenozoic climate change and accessing the future climatic and environmental response to anthropogenic carbon emissions. The Eocene, which is characterized by the Early Eocene Climatic Optimum (EECO) and the following global cooling, represents an ideal test case. Here we generate geochemical data of the Eocene lacustrine sediments from the Fushun Basin, northeast China, to explore the regional climatic response to the global climate change. The chemical index of alteration (CIA) and plagioclase index of alteration (PIA) consistently show a gradual, long‐term decrease, indicating a climatic transition from warm and humid to relatively cold and arid during the Eocene in the Fushun Basin. This climatic trend is broadly coincident with the global cooling and decreasing CO 2 concentration, implying that the regional climate is closely correlated with the global climate change over geological time scales. Additionally, the extreme silicate weathering and high lake productivity as reflected by relatively positive δ 13 C values of lacustrine organic matter are associated with the EECO. This consistency may demonstrate that enhanced continental weathering and lake productivity had served as effective sinks to lower atmospheric CO 2 across the EECO. Collectively, our new geochemical data add supportin...