Collaborative Research: Measurement of Transport Properties of Silicate Melts with Application to Crustal Anatexis

岩石圈内的热质传递受岩石圈的输运性质、导热系数和粘度的控制。关于这些物理性质的现有数据不足以对造山和地壳融化期间岩石圈不断演变的热结构进行可信的建模。岩石圈热结构模型通常假定导热系数不变，尽管这一性质与温度和岩石成分密切相关。这一合作项目的目的将是产生关于天然和合成硅酸盐熔体以及化学等价物玻璃、矿物和岩石的粘度和导热系数的新数据。特别是，研究活动将提供高温导热系数测量，并测试现有的水合硅酸盐熔体粘度模型。此外，这项工作将通过将新数据整合到大陆碰撞造山带热演化的数值模型中，将新数据应用于地壳熔融产生淡花岗岩。该项目将支持三名研究生接受激光闪光分析测量导热系数以及平行板和同心圆柱体技术测量粘度的培训。这项研究将影响目前对大规模岩石圈过程的理解，包括热流和岩浆运输，以及火山灾害，其中岩浆的运输性质起着关键作用。

Heat and mass transfer within the lithosphere are governed by the transport properties, thermal conductivity and viscosity. Available data on these physical properties are inadequate for confident modeling of the evolving thermal structure of the lithosphere during mountain-building and crustal melting. Models of lithospheric thermal structure typically assume constant thermal conductivity, although this property is known to depend strongly on both temperature and rock composition. The purpose of this collaborative project will be to produce new data on the viscosity and thermal conductivity of natural and synthetic silicate melts and chemically equivalent glasses, minerals, and rocks. In particular, the research activities will be to provide high-temperature thermal conductivity measurements, and test existing models for the viscosity of hydrous silicate melts. Additionally, the work will entail the application of the new data to leucogranite generation by crustal melting, by integrating the new data into numerical models for the thermal evolution of continental collisional orogenic belts.This project will support the training of three graduate students in thermal conductivity measurements by laser-flash analysis, and viscosity measurements by the parallel-plate and concentric-cylinder techniques. This study will impact current understanding of large-scale lithospheric processes, including heat-flow and magma transport, and also volcanic hazards, in which the transport properties of magmas play a key role.