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、热导率和粘度的控制。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热结构的演变进行可靠的模拟。岩石圈热结构模型通常假设恒定的热导率，尽管已知这种性质在很大程度上取决于温度和岩石成分。这个合作项目的目的是产生关于天然和合成硅酸盐熔体以及化学等效玻璃、矿物和岩石的粘度和导热性的新数据。特别是，研究活动将提供高温导热系数测量，并测试现有的含水硅酸盐熔体粘度模型。此外，这项工作还需要将新数据整合到大陆碰撞造山带热演化的数值模型中，从而将新数据应用于地壳熔融形成的浅花岗岩。本项目将支持培训三名研究生进行激光闪光热导率测量和平行板和同心柱技术粘度测量。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.