Chemical Diffusion in Multicomponent Anhydrous Silicate Melts

多组分无水硅酸盐熔体中的化学扩散

• 批准号: 8720631
• 负责人: Mark Ghiorso
• 金额: $ 12.93万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-06-01 至 1991-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8720631&HistoricalAwards=false
• 关键词: Chemical; Diffusion; Multicomponent; Anhydrous; Silicate

In this project chemical diffusion will be investigated experimentally in silicate melts of basaltic composition. The flattened and polished ends of capsules containing dissimilar materials will be joined by a Pt sleeve and welded shut during initial heating by a thread of gold wire wrapped around the join at the top and bottom of the sleeve. Diffusion profiles will be determined after quenching the couple by longitudinal sectioning and microprobe "linescan" for all eleven major elements. The data on numerous "linescans" corresponding to various diffusion times and initial concentration profiles will be fitted to an appropriate multicomponent solution of the diffusion equation. The aim of this exercise is to extract the off-diagonal (coupling) terms of the diffusion matrix for basaltic magmas. The calibrated diffusion matrices will be used to resolve certain intriguing aspects of crystal growth in magmatic systems ( such as whether oscillatory zoning is a natural consequence of the coupling of diffusion to the crystal liquid interface and the kinetics of interface growth) and to suggest possible melt "species" predominant in basaltic systems.

在该项目中，化学扩散将在玄武岩组成的硅酸盐融化中进行实验研究。胶囊的胶囊的扁平和抛光末端将通过PT套筒连接，并在初始加热过程中通过包裹在套筒顶部和底部的连接的金属丝上加热时焊接。 在所有11个主要要素的纵向截面和微探针“线can”淬灭后，将确定扩散曲线。 对应于各种扩散时间和初始浓度曲线的许多“线cans”的数据将拟合到扩散方程的适当多组分解决方案中。 本练习的目的是提取玄武岩岩浆扩散矩阵的非对角线（耦合）术语。 校准的扩散矩阵将用于解决岩浆系统中晶体生长的某些有趣的方面（例如振荡性分区是否是扩散与晶体液体界面和界面生长动力学的偶联的自然结果），并建议在底层系统中可能“物种”蛋白质。