Electrical conductivity: the story of an elusive parameter, and of how it possibly relates to the Kapuskasing uplift (Lithoprobe, Canada)

Abstract

Possible sources of crustal conductivity are reviewed, with special emphasis on shield environments. Typical lower crustal conductivities are interpreted in terms of brines and/or graphite films precipitated at grain-boundaries under cooling after peak metamorphism. The nature of the conductive films may strongly depend on the age of the crust. Electromagnetic investigations of the Kapuskasing Uplift confirm that exposed lower crustal rocks are very resistive. -from Author