The Geochemistry of Rare-Earth Elements in Estuarine and Coastal Waters

本次更新建议的重点是河口和沿海水域、沉积物和孔隙水中的稀土元素地球化学。切萨皮克湾和亚马逊河陆架将是主要的研究区域。根据私家侦探在目前的研究中，稀土元素的通量、循环和分馏在河口带经历了主要的生物地球化学扰动。切萨皮克湾研究结果表明，在深盆地缺氧条件发育过程中，轻稀土元素在溶解相富集。在拟议的研究中，将在切萨皮克湾季节性缺氧盆地（水柱和沉积物）进行时间序列研究，以量化这种通量和分异的程度和动力学。孵化实验也将跟踪REE成岩作用。还建议与大型多学科研究（“AmasSeds”项目）合作开展亚马逊货架研究。亚马逊河口的季节性研究将重点关注河口水体中稀土元素的再矿化和去除以及与铁和有机质动态循环相关的沉积物中稀土元素的成岩作用。亚马逊河河口的研究将为一个主要河流/河口系统提供急需的REE数据。

The geochemistry of rare earth elements (REE) in estuarine and coastal waters, sediments, and pore waters in the main focus of this renewal proposal. The Chesapeake Bay and Amazon River shelf will be the main study areas. Based on the P.I.'s current grant, the flux, cycling and fractionation of REE undergo major biogeochemical perturbations in the estuarine zone. Results from the Cheseapeake Bay show that light REE as being enriched in the dissolved phase during the development of anoxic conditions in the deep basins. In the proposed research, a time-series study in a Chesapeake Bay seasonally anoxic basin (water column and sediments) will be carried out to quantify the extent and kinetics of such fluxes and fractionation. Incubation experiments will also follow the diagenesis of REE. Collaboration with a large multi-disciplinary study ("AmasSeds" project) of the Amazon shelf is also proposed. A seasonal study of the Amazon estuary will focus on the remineralization and removal of REE in the estuarine waters and REE diagenesis in the sediments associated with dynamic cycling of Fe and organic matter. The Amazon River estuary study will provide much needed data on REE for a major river/estuary system.