High Pressure Phase Equilibrium Studies Bearing on the Generation and Crystallization of Basaltic Magmas

玄武质岩浆生成和结晶的高压相平衡研究

• 批准号: 8816044
• 负责人: Dean Presnall
• 金额: $ 49.43万
• 依托单位: University of Texas at Dallas
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-04-01 至 1994-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8816044&HistoricalAwards=false
• 关键词: Pressure; Phase; Equilibrium; Studies; Bearing

The long-term objective of this research program, which has remained the same over the years, is to develop a systemically collected body of phase equilibrium data that imposes progressively tighter constraints on the origin of basalt and the formation of the earth's crust from the mantle. In order to generalize results and to develop a more comprehensive body of data in an important pressure range, it is proposed to determine, using a piston-cylinder apparatus, the phase relationships at 15, 25, and 30 kbar and the effect of Na2O on melting relationships. The data would provide new constraints on (1) the origin of primary mid-ocean ridge basalts, (2) the composition, depth of generation, and percent melting of primary tholeiitic magmas in the Hawaiian Islands, and (3) the origin of high-alumina basalts in subduction zones. In addition, it is proposed to study melting relations in the system Mg2SiO4-SiO2 up to pressures of 250 kbar using an MA-8 apparatus at the University of Alberta. This study would bear on very high pressure magmatic processes in the early history of the earth.

该研究计划的长期目标多年来一直保持不变，是开发一个系统收集的相平衡数据体，对玄武岩的起源和地幔从地幔的形成施加逐渐严格的限制。 为了概括结果并在重要压力范围内开发更全面的数据体，建议使用活塞气缸装置确定 15、25 和 30 kbar 下的相位关系以及 Na2O 对融化的关系。 这些数据将为以下方面提供新的约束：(1) 原生洋中脊玄武岩的起源，(2) 夏威夷群岛原生拉斑玄武岩的成分、生成深度和熔化百分比，以及 (3) 高浓度玄武岩的起源。 -俯冲带中的氧化铝玄武岩。 此外，还建议使用阿尔伯塔大学的 MA-8 装置研究 Mg2SiO4-SiO2 系统在 250 kbar 压力下的熔化关系。 这项研究将研究地球早期历史中的高压岩浆过程。