Collaborative Research (USC/Caltech): Evaluation of Opal Dissolution Kinetics and Factors That May Regulate Opal Accumulation in Margin Sediments

合作研究（南加州大学/加州理工学院）：评估蛋白石溶解动力学和可能调节边缘沉积物中蛋白石积累的因素

• 批准号: 0351169
• 负责人: William Berelson
• 金额: --
• 依托单位: University of Southern California
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-03-15 至 2008-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0351169&HistoricalAwards=false
• 关键词: Collaborative; Research; USC; Caltech; Evaluation

ABSTRACTOCE - 0351169 / OCE - 0351498The marine biogeochemical cycles of carbon and silicon are directly linked through the activities of diatoms, so the behavior of the carbon cycle cannot be predicted without a firm understanding of what factors regulate the oceanic Si budget. It is clear that Si removal from the ocean occurs primarily through opal (bSi = biogenic silica) burial, and several algorithms that relate bSi burial to bSi rain rate have been proposed, based on observations in deep sea environments. Unfortunately, these algorithms have limited utility because we do not have a mechanistic understanding of the factors linking bSi dissolution to the bSi rain reaching the seabed, and because they fail to work in margin environments. Margin environments have recently been recognized as the sink for 30-45% of the bSi buried in the entire ocean. The relative rates of sediment accumulation and the kinetics of bSi interaction with aluminosilicates appear to be critical factors that regulate bSi dissolution, although other factors may play a role.In this study, researchers at the University of Southern California and the California Institute of Technology will use a relatively new technique, stirred flow reactors, to measure the kinetics of bSi dissolution and Al release from margin sediments, in an effort to evaluate how these factors may govern bSi burial. Measurements will be made on freshly collected samples (planktonic material, particles falling into traps, and the sediments) representing the entire particle export pathway in two California borderland basins. Results will be compared with kinetics deduced from modeling pore water profiles of silicic acid and dissolved Al. The goal is to develop an algorithm based on readily measured characteristics of sediments that will provide a reliable measure of bSi burial susceptibility. This information will be of value for interpreting the significance of the bSi sedimentary record and for developing biogeochemical models that incorporate the effect of the Si cycle on carbon dynamics. The project will also provide for the support and training of graduate and undergraduate students.

摘要 - 0351169 / OCE - 0351498碳和硅的海洋生物地球化学循环与硅藻的活动直接相关，因此，如果不充分了解调节海洋硅收支的因素，就无法预测碳循环的行为。很明显，海洋中的硅去除主要是通过蛋白石（bSi = 生物二氧化硅）埋藏进行的，并且根据深海环境中的观测，已经提出了几种将 bSi 埋藏与 bSi 降雨率联系起来的算法。不幸的是，这些算法的实用性有限，因为我们对 bSi 溶解与到达海底的 bSi 雨之间的联系因素缺乏机械性的理解，而且它们无法在边缘环境中发挥作用。最近，边缘环境被认为是埋藏在整个海洋中 30-45% 的 bSi 的汇。沉积物积累的相对速率以及 bSi 与铝硅酸盐相互作用的动力学似乎是调节 bSi 溶解的关键因素，尽管其他因素也可能发挥作用。 在这项研究中，南加州大学和加州理工学院的研究人员将使用一种相对较新的技术，即搅拌流反应器，来测量 bSi 溶解和边缘沉积物中 Al 释放的动力学，以评估这些因素如何影响 可以管理 bSi 埋葬。将对新收集的样本（浮游物质、落入捕集器的颗粒和沉积物）进行测量，这些样本代表加利福尼亚州两个边境盆地的整个颗粒输出路径。结果将与硅酸和溶解铝的孔隙水剖面建模推导出的动力学进行比较。 目标是开发一种基于易于测量的沉积物特征的算法，为 bSi 埋藏敏感性提供可靠的测量。这些信息对于解释 bSi 沉积记录的重要性以及开发包含 Si 循环对碳动力学影响的生物地球化学模型具有重要价值。 该项目还将为研究生和本科生提供支持和培训。