Collaborative Research (OSU, USC, UCR): Continental Shelf Diagenesis: The Importance of Fresh Continental Material Degradation and Seasonal Diagenesis to Coastal Iron Supply

合作研究（OSU、USC、UCR）：大陆架成岩作用：新鲜大陆物质降解和季节性成岩作用对沿海铁供应的重要性

• 批准号: 0624704
• 负责人: Silke Severmann
• 金额: $ 6.77万
• 依托单位: University of California-Riverside
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-10-01 至 2008-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0624704&HistoricalAwards=false
• 关键词: Collaborative; Research; OSU; USC; UCR

ABSTRACTOCE-0624777OCE-0624443OCE-0624704The oxidation-reduction reactions that dominate the shelf seabed act to mobilize or sequester biologically essential elements. However, relatively little information is known about the delivery rates or diagenic boundary conditions that lead to this specific iron source. Thus, it is difficult to predict how changes in the regional hydrological cycle and weathering might impact future coastal iron delivery rates in response to global climate change, as well as quantify how increases (or decreases) in coastal hypoxia influence iron supply. For this reason, researchers at Oregon State University, the University of Southern California, and the University of California-Riverside will determine the diagenetic delivery rate (effux) of iron from small river-dominated continental shelf sediments deposits. They will assess whether or not diagenesis of fresh continental material is an essential process for delivering bio-available iron to the Northeast Pacific coastal upwelling system, and if the isotopic signature for iron that is derived from benthic diagenesis is distinct from other iron sources. The first part of the study will be to evaluate the benthic efflux of iron in fine-grained river-derived shelf deposits prior to, during, and after the upwelling season. The second component will be to test the idea that diagenetically altered terrestrial iron, which has undergone multiple oxidation-reduction reactions within sediments, has a unique isotope signature. If true, iron isotopes could then prove to be a valuable tracer for shelf-derived iron, which has been hypothesized to be an important source of iron throughout much of the Pacific basin. In addition to the intellectual merit of this work, this study will strengthen collaboration with colleagues and a graduate student from the National Oceanographic Center in Southampton, United Kingdom, whom are working on a similar study in the South Atlantic (CROZEX). Two undergraduate students from Oregon State University and one graduate and one undergraduate student from the University of Southern California will be supported and trained as part of this project.

在陆架海底起支配作用的氧化-还原反应是生物必需元素的流动或隔离。 然而，相对较少的信息是已知的交付率或成岩边界条件，导致这种特定的铁源。 因此，很难预测区域水文循环和风化的变化如何影响未来沿海铁的输送率，以应对全球气候变化，以及量化如何增加（或减少）沿海缺氧影响铁的供应。 出于这个原因，俄勒冈州州立大学、南加州大学和南加州大学河滨分校的研究人员将确定来自小型河流为主的大陆架沉积物矿床的铁的成岩输送率（effux）。 他们将评估新鲜大陆材料的成岩作用是否是向东北太平洋沿海上升流系统提供生物有效铁的重要过程，以及来自海底成岩作用的铁的同位素特征是否与其他铁来源不同。 研究的第一部分将是评估底栖流出的铁在细粒河流衍生的陆架沉积之前，期间和之后的上升流季节。 第二个组成部分将是测试这样一种想法，即在沉积物中经历了多次氧化还原反应的成岩蚀变的陆地铁具有独特的同位素特征。 如果这是真的，那么铁同位素就可以被证明是一种有价值的大陆架铁的示踪剂，而大陆架铁被认为是太平洋盆地大部分地区铁的重要来源。 除了这项工作的智力价值外，这项研究还将加强与联合王国南安普顿国家海洋学中心的同事和一名研究生的合作，他们正在南大西洋进行一项类似的研究。 作为本项目的一部分，将支助和培训来自俄勒冈州州立大学的两名本科生以及来自南加州大学的一名研究生和一名本科生。