Pore Water Estimates of the Radiocarbon Age of Calcite Dissolving at the Sea Floor

海底方解石溶解的放射性碳年龄的孔隙水估计

• 批准号: 9810962
• 负责人: William Martin
• 金额: $ 22.24万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-10-01 至 2001-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9810962&HistoricalAwards=false
• 关键词: Pore; Water; Estimates; Radiocarbon; Age

ABSTRACTOCE-9810962One of the ways scientists try to understand the the history of biological production in the ocean and its relationship to climatic history through the carbon cycle is through examination of the sedimentary record of marine carbonates. Interpretation of changes in glacial/interglacial carbonate accumulation rates requires that we understand the mechanism(s) of calcite dissolution, and until now investigators have tried to approach this problem indirectly by estimating the amount of CaCO3 remaining after dissolution. The two candidate mechanisms most widely considered are chemical erosion, in which the carbonate sediment uniformly dissolves, and non-homogeneous dissolution, in which the dissolution is not uniform. In this project, the PIs will develop and use a direct method for determining the dissolution mechanism by determining radiocarbon ages of inorganic carbon in sediment porewaters generated by CaCO3 dissolution and by the oxidation of organic matter. A full suite of carbon and carbon isotopic measurements will be made on solids and porewaters in sediments from the Eastern Equatorial Atlantic and the Western Equatorial Pacific to give a fresh evaluation of the mechanism of dissolution.

科学家们试图通过碳循环来了解海洋生物生产的历史及其与气候历史的关系，其中一种方法是通过检查海洋碳酸盐的沉积记录。 解释冰期/间冰期碳酸盐累积速率的变化需要我们了解方解石溶解的机制，到目前为止，研究人员一直试图通过估计溶解后剩余的CaCO 3量来间接解决这个问题。 最广泛考虑的两种候选机制是化学侵蚀，其中碳酸盐沉积物均匀溶解，以及非均匀溶解，其中溶解不均匀。在本项目中，项目研究员将开发和使用一种直接方法，通过测定CaCO 3溶解和有机物氧化产生的沉积物孔隙水中无机碳的放射性碳年龄，确定溶解机制。 将对东赤道大西洋和西赤道太平洋沉积物中的固体和孔隙水进行一整套碳和碳同位素测量，以重新评价溶解机制。