The Thermodynamics, Fluid Dynamics and Chemistry of Deep Mantle Melts: Models of Archean Magmatism

火山熔岩具有极高的喷发温度，提供了太古宙地幔的独特信息。太古宙科马长岩主要元素组成的简单模型表明，在非常高的温度和压力下（潜在温度大于1800℃，深度至少250 km）熔融，但这些区域的上升流、熔融和熔体提取的动力学尚不清楚。PI提出将地幔对流和熔融的数值模型与高压熔融实验的熔体成分参数化相结合。这些模型将用于系统地探索太古宙地幔中缺乏约束的性质和条件（温度、组成、粘度、熔体迁移渗透率、岩石圈厚度）对所产生的熔体的主要元素和微量元素组成的影响。超镁铁质和其他太古宙岩石的组成将用于约束模型的假设和假设。一个灵活有效的模型可以确定流体动力学和地幔熔融化学之间的依赖关系和相互作用，这将为了解太古宙地幔动力学和确定未来实验计划的优先级提供指导。

9614178 Sparks Komatiite lavas, with extremely high eruption temperature provide unique information about the Archean mantle. Simple models of the major element compositions of Archean komatiites indicate melting at very high temperatures and pressures (potential temperatures greater than 1800C and depths of at least 250 km), but the dynamics of upwelling, melting and melt extraction in these areas of the mantle are not understood. The PI proposes to integrate a numerical model of mantle convection and melting with parameterizations of melt compositions from high pressure melting experiments. These models will be used to systematically explore the effects of poorly constrained properties of and conditions in the Archean mantle (temperature, composition, viscosity, melt migration permeability, lithospheric thickness) on the major and trace element composition of the melts that are produced. The compositions of ultramafics and other Archean rocks will be used to constrain the hypotheses and assumptions of the models. A flexible and efficient model that can determine the dependencies and interactions between the fluid dynamics and chemistry of mantle melting will provide both insight into the dynamics of the Archean mantle and guidance in setting the priorities of future experimental programs.