What are the sources and mechanisms of iron enrichments during oceanic anoxic event 2? - Evidence from iron stable isotopes

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。本项目将通过对1994年以来中国大陆沉积物中全铁的铁同位素（d56 Fe）分析，研究第二次海洋缺氧事件（OAEII，~94 Ma）的古地质历史。 原北大西洋和接壤的西部内陆航道，包括几个从DSDP和ODP。OAEII沉积物的特点是有机碳（OC）浓度高，这可能是由于1）全球缺氧条件导致OC保存增加，或2）表层海洋生产力增加。OAEII期间铁对海洋生产力和整体碳循环的影响是本研究的主要目的。为此，本研究将调查铁的相对输入，从热液输入与从陆架沉积物，应携带一个明显低于d56 Fe值比热液源再活化的富氧沉积物。OAEII的富氧沉积物中沉积铁的d56 Fe值和FeT/Al比值反映了热液来源的相对贡献。这项研究将试图限制OAEII期间海洋中铁的整体质量平衡，从而扩大使用Fe同位素分析古环境assessment.Broader影响：这项研究支持一名本科生，一名博士后和一名早期职业女性科学家。作为罗格斯大学海洋科学教育卓越中心的一部分，PI将与该中心合作？的主任将研究成果纳入针对K-12教师，K-16学生和沿海管理人员的在线教育材料。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). This project will investigate the paleo-geological history of Ocean Anoxic Event II (OAEII, ~94 Ma) by iron isotopic analyses (d56Fe) of total iron in archived sediment cores from the proto North Atlantic and bordering Western Interior Seaway, including several from DSDP and ODP. OAEII sediments are characterized by concentrations of high organic carbon (OC) which might have resulted either from 1) increased preservation of OC resulting from more anoxic conditions globally, or 2) increased surface ocean productivity. The effects of iron on ocean productivity and the overall carbon cycle during OAEII is a major aim of this research. To this end, the research will investigate the relative inputs of Fe to euxinic sediments from hydrothermal inputs versus that remobilized from shelf sediments that should carry a distinctly lower d56Fe value than the hydrothermal source. The d56Fe values and FeT/Al ratios of sedimentary iron in euxinic sediments of OAEII will reflect the relative contribution from hydrothermal sources. This research will try to constrain the overall mass balance of iron in the ocean during OAEII and thus expand the use of Fe isotopic analyses for paleo-environmental assessment.Broader impacts: The research supports an undergraduate student, a postdoc, and an early career female scientist. As part of the Center for Ocean Science Education Excellence at Rutgers University, the PI will work with the Center?s Director to incorporate the research results into online educational materials directed at K-12 teachers, K -16 students, and coastal managers.