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

这个研究项目的长期目标，多年来一直保持不变，是发展一个系统收集的相平衡数据体，对玄武岩的起源和地幔地壳的形成施加越来越严格的限制。为了推广结果，并在一个重要的压力范围内建立一个更全面的数据体，建议使用活塞缸装置确定15、25和30 kbar时的相关系以及Na2O对熔化关系的影响。这些数据将对(1)原始洋中脊玄武岩的起源，(2)夏威夷群岛原生拉斑岩岩浆的组成、生成深度和熔融百分比，以及(3)俯冲带高铝玄武岩的起源提供新的约束。此外，本文还提出了利用加拿大阿尔伯塔大学的MA-8仪器研究在250 kbar压力下Mg2SiO4-SiO2体系的熔化关系。这项研究将涉及地球早期历史中非常高压的岩浆过程。

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.