Incorporation of Minor and Trace Elements in Coral Skeletal Aragonite: An X-Ray Absorption Spectroscopy and Microstructural Study

珊瑚骨骼文石中微量元素和微量元素的结合模式及其随之的流动性是研究人员关注的问题，他们从珊瑚的化学代用物中获得全球和局部变化的记录。我们正在使用基于同步加速器的x射线吸收光谱来确定各种珊瑚和其他钙质分类群的骨骼碳酸盐中Sr， U, Ba， Mg和Pb等元素在原子水平上的结构位置（例如钙的替代，缺陷的占领，离散相）。利用透射电镜和分析电镜以及电子探针显微分析，我们还将对我们最近在珊瑚文石中记录的锶矿相进行微观结构和微化学表征。结构结合的知识是开发和验证来自Mg， U, Pb， Cd和Ba的新数据集的基础。该项目的结果将对研究海洋表面温度、海洋环流、海洋污染、生物矿化和碳酸盐岩石学的研究人员感兴趣。由于碳酸盐矿物在地表非海洋环境中的重要性，我们的研究结果也将对放射性核素和有毒金属迁移问题产生影响。

9814336Pingitore The mode of incorporation and consequent mobility of the trace and minor elements in coral skeletal aragonite are a concern to researchers who derive records of global and local change from chemical proxies in corals. We are using synchrotron-based x-ray absorption spectroscopy to determine the structural site location at the atomic level (e.g., substitution for calcium, occupation of defects, discrete phase) of such elements as Sr, U, Ba, Mg, and Pb in the skeletal carbonate of a variety of corals and other calcareous taxa. Using transmission and analytic electron microscopy and electron probe microanalysis, we also will perform microstructural and microchemical characterization of the strontianite phase which we recently documented in coral aragonite. Knowledge of structural incorporation is fundamental to the development and validation of new data sets being derived from Mg, U, Pb, Cd, and Ba. The project results will be of interest to researchers studying sea surface temperatures, ocean circulation, marine pollution, biomineralization, and carbonate petrology. Because of the importance of carbonate minerals in surficial non-marine environments, our results also will have bearing on problems in radionuclide and toxic metal migration.