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.
