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.

多年来，该研究计划一直保持不变的长期目标是开发一个系统收集的相位平衡数据，该数据对玄武岩的起源和地幔的地壳形成逐渐更严格的限制。 为了概括结果并在重要的压力范围内开发更全面的数据体，建议使用活塞缸设备确定15、25和30 kbar的相位关系以及NA2O对NA2O对熔融关系的影响。 数据将对（1）原发性中山脊的起源提供新的限制，（2）夏威夷群岛的原代质岩浆的成分，发电深度和百分比融化，以及（3）俯冲底座中高铝层的起源。 此外，建议在艾伯塔大学使用MA-8设备中研究系统MG2SIO4-SIO2中的熔融关系，直至250 kbar的压力。 这项研究将在地球早期历史上的高压岩浆过程中进行。