Collaborative Research (UCR, OSU and ASU): Combined Fe-S Stable Isotopes in Modern Anoxic Environments and the Effect of Fe versus S Limitation

合作研究（UCR、OSU 和 ASU）：现代缺氧环境中的组合 Fe-S 稳定同位素以及 Fe 与 S 限制的影响

• 批准号: 0551716
• 负责人: Silke Severmann
• 金额: $ 21.33万
• 依托单位: University of California-Riverside
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-03-01 至 2009-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0551716&HistoricalAwards=false
• 关键词: Collaborative; Research; UCR; OSU; ASU

ABSTRACT Severmann, Anbar, McManus (0551716, 0551732, 0551605)Intellectual merit: The biogeochemical cycles of iron and sulfur are closely coupled, and their combined influence impacts the evolution of the global carbon and oxygen cycles as well as the ocean's proton balance over geologic time. Our preliminary data show that Fe isotope compositions of dissolved and particulate species unambiguously reflect their depositional conditions in modern aqueous environments. This research determines the isotopic expressions of these cycles as specifically linked to the primary sources and sinks of Fe and S in oxygen-deficient aqueous settings. Specific questions to be addressed are: (1) how does the relative availability of Fe and S influence the isotopic expression of their cycling and (2) does benthic Fe recycling on oxic continental shelves influence the Fe isotope composition within anoxic basin sediments. Samples from two modern anoxic lake environments with contrasting sulfate levels will be analyzed (the Black Sea sulfate enriched, and Lake Tanganyika sulfate poor). This work leverages off on-going NSF-funded studies and all samples come with rich ancillary data sets, providing essential information regarding S isotope compositions, Fe speciation and general sediment diagenetic parameters. The proposed work will provide information essential to our interpretation of the Fe cycle in both the modern and ancient ocean as well as the evolution of the Earth's atmosphere and the redox balance of the modern atmosphere-ocean system. Fe and S will be extracted from sediment samples by sequential leaching. Fe and S isotopes will be measured using a multi-collector ICP-MS or isotope ratio mass spectrometry. Standard wet chemistry will be used to determine Fe and S speciation in the associated pore waters and mineral leachates.Broader impacts: This work funds investigators at institutions in three states: California, Oregon, and Arizona and involved international collaborations with scientists in Germany and Turkey. The research supports a young, female principal investigator and a graduate student, the latter who will spend time learning analytical techniques in the collaborating institutions. It will also allow participation of the lead PI and her student to participate in the field program in Africa. US, as well as African undergraduates will be involved and mentored in paleoclimate research.

摘要 Severmann, Anbar, McManus (0551716, 0551732, 0551605)学术价值：铁和硫的生物地球化学循环紧密耦合，它们的综合影响影响全球碳和氧循环的演变以及地质上海洋的质子平衡时间。我们的初步数据表明，溶解和颗粒物质的铁同位素组成明确反映了它们在现代水环境中的沉积条件。这项研究确定了这些循环的同位素表达，这些循环与缺氧水环境中 Fe 和 S 的主要来源和汇特别相关。 需要解决的具体问题是：（1）铁和硫的相对可用性如何影响其循环的同位素表达；（2）含氧大陆架上的底栖铁循环是否影响缺氧盆地沉积物内的铁同位素组成。 将分析来自两个具有对比硫酸盐水平的现代缺氧湖泊环境的样本（黑海硫酸盐富集，坦噶尼喀湖硫酸盐贫乏）。 这项工作利用了正在进行的 NSF 资助的研究，所有样本都附带丰富的辅助数据集，提供有关 S 同位素组成、Fe 形态和一般沉积物成岩参数的基本信息。 拟议的工作将为我们解释现代和古代海洋中的铁循环以及地球大气的演化和现代大气-海洋系统的氧化还原平衡提供重要的信息。 Fe 和 S 将通过顺序浸出从沉积物样品中提取。 Fe 和 S 同位素将使用多接收器 ICP-MS 或同位素比质谱法进行测量。 标准湿化学将用于确定相关孔隙水和矿物渗滤液中铁和硫的形态。更广泛的影响：这项工作为加利福尼亚州、俄勒冈州和亚利桑那州三个州的机构的研究人员提供了资金，并涉及与德国和土耳其科学家的国际合作。 该研究支持一名年轻的女性首席研究员和一名研究生，后者将花时间在合作机构学习分析技术。 它还将允许首席 PI 和她的学生参与非洲的实地项目。 美国和非洲的本科生将参与古气候研究并接受指导。