Kinetic and Thermodynamic Controls on Mg and Sr Contents during Calcite Growth: Establishing a Baseline for Biological Mineralization

方解石生长过程中镁和锶含量的动力学和热力学控制：建立生物矿化的基线

基本信息

批准号：
0083173
负责人：
Patricia Dove
金额：
$ 30.01万
依托单位：
Virginia Polytechnic Institute and State University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2000
资助国家：
美国
起止时间：
2000-12-15 至 2004-11-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=0083173&HistoricalAwards=false
关键词：
Kinetic Thermodynamic Controls Mg Sr

项目摘要

Trace elements, especially those that may be used as paleoproxies, behave as lattice impurities that regulate biomineralization and provide critical information on crystal growth history. For example, incorporation of Mg2+ has been shown to modify the morphology, solubility and polymorphic expression of CaCO3 biominerals. In addition, Mg2+ is the principal inhibitor of calcite growth in natural waters, thereby influencing the size and reactivity of the biogeochemically significant carbonate reservoir. However, the fundamental mechanistic interactions of Mg2+ with calcite surfaces remain controversial. For this reason, the PI will use an experimental approach that integrates techniques from aqueous geochemistry and surface sciences to quantify the kinetic and thermodynamic controls on Mg and Sr contents of calcite grown in 0.1 M NaCl and synthetic seawater solutions. The PI also will determine the mechanism(s) by which Mg and Sr modify calcite growth properties and morphology and construct a quantitative and mechanistic model of calcite growth that provides a baseline for understanding the complexity of the influences of biological processes on the elemental composition of carbonate minerals. Results from this research will provide a baseline for understanding the influence of trace elements incorporated into calcite. This information is needed to interpret the compositions of biogenic calcite and in understanding paleotemperature data.

痕量元素，尤其是那些可以用作古倍的元素，表现为调节生物矿化的晶格杂质，并提供有关晶体生长历史的关键信息。例如，已显示MG2+的掺入可以改变CACO3生物衬里的形态，溶解度和多态性表达。此外，MG2+是天然水中有方解石生长的主要抑制剂，从而影响生物地球化学意义的碳酸盐储层的大小和反应性。但是，MG2+与方解石表面的基本机械相互作用仍然有争议。因此，PI将使用一种实验方法，该方法将水溶液和表面科学水的技术整合在一起，以量化在0.1 M NaCl和合成海水解决方案中生长的方解石的MG和SR含量上的动力学控制和SR含量。 PI还将确定MG和SR修饰方解石生长特性和形态的机制，并构建一个定量和机械模型的变解生长的定量和机械模型，该模型为理解生物过程对碳酸盐矿物质元素组成的影响的复杂性提供了基线。这项研究的结果将为理解纳入方解石中的痕量元素的影响提供基线。需要此信息来解释生物学方解石的组成和理解古温度数据。