SAMTEX: The electrical lithosphere of Southern Africa

摘要

The Southern African Magnetotelluric Experiment (SAMTEX) is imaging the properties and geometries of the lithosphere below southern Africa to depths of 200+ km. Electrical conductivity is highly sensitive to ambient temperature, e.g. (Ledo and Jones 2005) and to the presence of an interconnected conducting phase, such as a solid phase like graphite or sulphides, e.g. (Ducea and Park 2000; Jones et al. 2003) or a fluid phase like partial melt, e.g.(Park and Ducea 2003), or bound water through hydrogen diffusion, e.g. (Hirth et al. 2000). Thus one primary geometrical piece of information that can be readily obtained from lithospheric-scale MT experiments is the depth to the lithosphere-asthenosphere boundary (LAB).