大陆风化在地质尺度上消耗大气CO2，稳定地球气候的长期宜居性。但是，大陆风化如何响应气候驱动还存在较大争议，尤其是大洋记录中不同地球化学指标重建的大陆风化通量互相矛盾。近些年建立的宇宙成因核素10Be（降水输入）和稳定核素9Be（风化输入）比值（10Be/9Be）的指标研究揭示，大陆风化通量在第四纪气候旋回中基本稳定，这与Sr、Pb、Os和Nd等同位素指标的显著变化形成对照。10Be/9Be指标的主要不确定性在于入海沉积物中的9Be在大陆边缘的循环过程和机制缺少实测数据约束。本项目以代表性的长江口-东海内陆架环境梯度断面为研究对象，分析沉积物不同化学相态和孔隙水的元素及Be同位素地球化学组成，探讨Be在沉积物-水界面交换的时空变化特征及环境控制。项目将深化海洋Be同位素记录对陆源风化输入通量的指示研究，为重建第四纪东亚大陆风化通量提供科学借鉴。

Chemical weathering of silicate minerals removes CO2 from the atmosphere over geological timescales, and maintains the long-term habitability of Earth’s climate. However, how global silicate weathering responds to climate change is under debate, because the continental weathering fluxes reconstructed from different geochemical proxies in oceanic records are contradictory. Specifically, the ratio of meteoric cosmogenic 10Be to stable 9Be, where 10Be is delivered by rainfall and 9Be is released from rock weathering, suggests constant continental weathering fluxes over Quaternary climatic cycles, in contrast to the distinct temporal variability recorded in Sr, Pb, Os and Nd isotopes. One major uncertainty in the 10Be (meteoric)/9Be framework is the lack of direct observations on 9Be release from continental margin sediments, which is the major 9Be input to the oceans. This project will study the Changjiang estuary-inner East China Sea Shelf system with a prominent gradient of water environment and analyse different chemical phases of shelf sediments and pore water for Be isotopes and other geochemical proxies. This project will probe into the spatial and temporal variability of Be behaviors at the sediment-water interface and the environmental controls. This project aims to strengthen the link between seawater Be isotopic records and continental weathering input, and provide valuable instructions on reconstruction of East Asian continental weathering fluxes over Quaternary climatic cycles.