Structure/property Relations in Silicate-C-O-H-N Melts Melts and Fluids Characterized Experimentally, In-situ, at Mantle Redox Conditions, Pressure, and Temperature

硅酸盐-C-O-H-N熔体和流体的结构/性质关系在地幔氧化还原条件、压力和温度下通过实验、原位表征

• 批准号: 1212754
• 负责人: Bjorn Mysen
• 金额: $ 21.4万
• 依托单位: Carnegie Institution of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-15 至 2018-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1212754&HistoricalAwards=false
• 关键词: Structure; property; Relations; Silicate; Melts

Intellectual merits. An experimental study is proposed to advance our understanding the processes that govern the budget and recycling of volatile components in the system C-O-H-N in the Earth?s interior. Relationships between structure and transport, volume, and thermodynamic properties of silicate melts and C-O-H-N fluid and fluid/melt element and stable isotope fractionation will be examined while samples are at temperature, pressure, and redox conditions primarily using a hydrothermal diamond anvil cell (HDAC). Major objectives are to: [1] Use vibrational spectroscopy to characterize structure and properties in silicate-C-O-H-N melt, mineral, and fluid systems as proxies to model the behavior of fluids and melts in natural magmatic systems. [2] Determine fractionation of structural species, and of isotopes between minerals, melts, and fluids in silicate-COHN systems using vibrational spectroscopy and microbeam analyses of quenched materials. [3] Develop structure-property models to explain the behavior of natural magmatic systems at P-T conditions corresponding to the upper mantle of the Earth. Current knowledge of structure of solubility and solution mechanisms of C-O-H-N volatile components in silicate melts is based largely on analytical and structural examination of quenched melts (glasses). However, this information does not precisely reflect properties of actual melts. Conversely, the proposed experiments will enable measurements of samples while they are being held at temperature, pressure and redox conditions representative of the Earth?s upper mantle. Characterization how melt structure affects mineral/melt element partitioning will be addressed by combining melt structural data with trace element partitioning experiments (relying on electron microprobe and ion probe analysis of run products). Partitioning of structural species between melts and fluids will be accomplished with vibrational spectroscopic techniques and will be compared with elemental analyses as a means to calibrate the partitioning of the structural species determined by vibrational spectroscopy. Protocols will also be developed for use of vibrational spectroscopy to determine D/H fractionation between fluid and melt while at desired pressure, temperature, and redox conditions. The proposed work will also provide new information on rheology, compressibility, and thermodynamics of component mixing for magmatic systems (melts and fluids) at deep crust and upper mantle conditions. Broader Impacts. The PI typically has one high school student and one undergraduate student (funded by the Geophysical Laboratory) working in his laboratory. This will continue as a part of the proposed research. These programs have been very successful resulting, for example, in seven articles in the peer reviewed literature from the work done in the PIs laboratories during the last several years with undergraduate and high school students as co-authors. In this regard, the PI contributes time to judge and supervise projects by middle and high school students. Winners of this fair proceed to national science competitions such as the International Science Fair and the Siemens Foundation's competition in Math-Science-Technology.

智力上的优点。 提出了一个实验研究，以促进我们的理解的过程中，管理的预算和循环系统中的挥发性成分的碳氧氢氮在地球上？的内部。硅酸盐熔体和C-O-H-N流体和流体/熔体元素和稳定同位素分馏的结构和运输，体积和热力学性质之间的关系将被检查，而样品在温度，压力和氧化还原条件下，主要使用热液金刚石砧室（HDAC）。主要目标是：[1]使用振动光谱来表征硅酸盐-C-O-H-N熔体、矿物和流体系统的结构和性质，作为模拟天然岩浆系统中流体和熔体行为的替代物。[2]确定分馏的结构物种，矿物，熔体和流体之间的同位素在硅酸盐COHN系统使用振动光谱和微束分析淬火材料。 [3]发展结构-性质模型来解释自然岩浆系统在对应于地球上地幔的P-T条件下的行为。目前对硅酸盐熔体中C-O-H-N挥发组分的溶解度结构和溶解机理的认识主要是基于对淬火熔体（玻璃）的分析和结构检查。然而，这些信息并不能精确地反映实际熔体的性质。相反，拟议的实验将使测量样品，而他们被关押在温度，压力和氧化还原条件代表地球？的上地幔。 熔体结构如何影响矿物/熔体元素分区的表征将通过结合熔体结构数据与微量元素分区实验（依靠电子探针和离子探针分析运行产品）来解决。熔体和流体之间的结构物种的分区将完成与振动光谱技术，并将与元素分析作为一种手段，以校准振动光谱确定的结构物种的分区进行比较。协议也将开发使用振动光谱，以确定D/H分馏之间的流体和熔体，而在所需的压力，温度和氧化还原条件。拟议的工作也将提供新的信息流变学，压缩性和热力学的组分混合的岩浆系统（熔体和流体）在地壳深部和上地幔条件。更广泛的影响。PI通常有一名高中生和一名本科生（由地球物理实验室资助）在他的实验室工作。这将继续作为拟议研究的一部分。这些计划已经非常成功，例如，在同行评议的文献中的七篇文章，从在过去几年中与本科生和高中生作为合著者在PI实验室所做的工作。在这方面，PI贡献时间来评判和监督初中和高中学生的项目。本次博览会的获奖者将参加国家科学竞赛，如国际科学博览会和西门子基金会的数学科学技术竞赛。