OCE-RIG: Improving Climate Records Through a Mechanistic Understanding of Sub-Micron Proxy Heterogeneity in Spinose Foraminifera

OCE-RIG：通过对刺有孔虫亚微米代理异质性的机械理解来改善气候记录

• 批准号: 1420689
• 负责人: Alexander Gagnon
• 金额: $ 10万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2017-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1420689&HistoricalAwards=false
• 关键词: OCE; RIG; Improving; Climate; Records

Calcite shells of planktonic and benthic foraminifera incorporate minerals and stable isotopes from the surrounding water into their shells as they grow, so the shells provide records of the environmental conditions in which the organisms lived. These shells are often preserved in sediments and are used to provide estimates of paleoclimates. However, many basic questions still remain about the relationship between foraminiferal shell composition and environmental conditions. A better understanding of foraminiferal biocalcification, in particular the relation between changing environmental conditions and the incorporation of trace and minor elements in the carbonate shells, will allow scientists to interpret paleoceanographic records more accurately. This award will support the work of the PI and a graduate student who will investigate biomineralization of foraminiferal shells at a sub-micron scale. The student will also participate in the University of Washington's Project COOL: Chemical Oceanography Outside the Laboratory, a science outreach program for middle school students. This research on the basic mechanics of biomineralization may also be useful for the field of material sciences and for medical applications related to bone growth. Researchers will use new in situ analytical approaches such as SIMS, nanoSIMS, laser-ablation ICP-MS, and new-generation EPMA with advanced element-mapping capabilities to investigate heterogeneous biomineralization of foraminiferal shells at a submicron scale, including apparent diurnal cycles in the Mg/Ca and Na/Ca banding within foraminifera tests. A mechanistic understanding of submicron-spatial scale elemental partitioning within foraminifera should improve our ability to interpret these elemental proxies in the context of paleoceanographic reconstruction.

浮游和底栖有孔虫的方解石壳在生长过程中将周围水中的矿物质和稳定同位素融入到壳中，因此壳提供了生物体生存环境条件的记录。这些贝壳通常保存在沉积物中，用于估计古气候。然而，关于有孔虫壳成分与环境条件之间的关系仍然存在许多基本问题。 更好地了解有孔虫生物钙化，特别是环境条件变化与碳酸盐壳中微量元素和微量元素的结合之间的关系，将使科学家能够更准确地解释古海洋记录。该奖项将支持 PI 和一名研究生的工作，他们将研究亚微米级有孔虫壳的生物矿化。该学生还将参加华盛顿大学的 COOL 项目：实验室外化学海洋学，这是一个针对中学生的科学推广项目。这项关于生物矿化基本力学的研究也可能对材料科学领域和与骨骼生长相关的医学应用有用。研究人员将使用新的原位分析方法，如 SIMS、nanoSIMS、激光烧蚀 ICP-MS 和具有先进元素映射功能的新一代 EPMA，在亚微米尺度上研究有孔虫壳的异质生物矿化，包括有孔虫测试中 Mg/Ca 和 Na/Ca 谱带的明显昼夜循环。对有孔虫内亚微米空间尺度元素分配的机械理解应该提高我们在古海洋重建背景下解释这些元素代理的能力。