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.

Abstractoce-0624777OCE-0624443OCE-0624704氧化还原反应主导了架子海床的动员，以动员或隔离生物学上的基本要素。 但是，关于导致该特定铁源的输送速率或地铁边界条件的相对较少的信息。 因此，很难预测区域水文周期和风化的变化如何影响未来的沿海铁递送率，以响应全球气候变化，并量化沿海缺氧的增加（或减少）如何影响铁供应。 因此，俄勒冈州立大学，南加州大学和加利福尼亚大学河畔大学的研究人员将确定来自小河流河流大陆架子沉积物的铁的成岩递送率（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运送生物可用铁的重要过程，以及是否从底栖成岩发生的铁的同位素签名与其他铁源不同。 该研究的第一部分将是在上升季节，期间和之后评估细粒河衍生的货架沉积物中铁的​​底栖外排。 第二个组成部分是测试以下想法：在沉积物中经历了多种氧化还原反应的地铁改变的陆生铁具有独特的同位素特征。 如果是真的，那么铁同位素就可以被证明是货架来源的铁的有价值的示踪剂，在整个太平洋盆地中，它已被认为是铁的重要来源。 除了这项工作的智力优点外，这项研究还将加强与同事和英国南安普敦国家海洋学中心的研究生合作，他们正在南大西洋（Crozex）进行类似的研究。 该项目的一部分将为俄勒冈州立大学的两名本科生和一名来自南加州大学的研究生和一名本科生。