Thermodynamics of Aluminous Amphiboles

铝角闪石的热力学

• 批准号: 9706326
• 负责人: Bernard Evans
• 金额: $ 12.65万
• 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: 1997
• 资助国家: 美国
• 起止时间: 1997-07-15 至 2001-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9706326&HistoricalAwards=false
• 关键词: Thermodynamics; Aluminous; Amphiboles

9706326 Evans This project will extend the PIs work on the crystallographic and thermodynamic properties of the aluminum-free "quadrilateral" amphiboles into the Al-bearing orthorhombic gedrite series and the monoclinic hornblende series, both of which occur widely in crystalline rocks. X-ray single crystal structure refinements will be done on suites of natural samples encompassing a range of Mg/Fe ratios and Al-contents, prior to and after equilibration at 700o-1000oC and high pressure. Site scattering and bond length data will be incorporated with compositional data to provide a description of octahedral and tetrahedral site order-disorder as a function of temperature. The Gibbs energy of these complex amphiboles is written to explicitly include the measured configurational entropy, as well as end-member, reciprocal and reciprocal-ordering terms. Experimental, thermochemical and natural phase equilibrium data provide additional constraints. These data allow calculation of phase diagrams for magmatic and subsolidus systems involving amphiboles and other minerals for which there are previously developed consistent thermodynamic models.

9706326 Evans该项目将把PI关于无铝“四边形”角闪石的晶体学和热力学性质的工作扩展到含铝斜方晶晶菱晶岩系列和单斜角闪岩系列，这两种系列都广泛存在于结晶岩中。 将在700 - 1000 ℃和高压下平衡之前和之后，对一系列天然样品进行X射线单晶结构精修，包括一系列Mg/Fe比和Al含量。 网站散射和键长数据将与成分数据，以提供一个描述的八面体和四面体网站的有序无序作为温度的函数。 这些复杂的角闪石的吉布斯能被写入明确地包括测量的构型熵，以及端员，倒数和倒数排序项。 实验，热化学和自然相平衡数据提供了额外的限制。 这些数据允许计算相图的岩浆和subsolidus系统，涉及角闪石和其他矿物，有以前开发的一致的热力学模型。