This is a collaborative project for making magnetotelluric measurements and three dimensional interpretations in California that will concentrate on determining the lower crust and upper mantle resistivities. These measurements and their interpretation will be helpful in trying to understand the conditions that exist in the lower crust of this region which must play a role in the ongoing tectonics, and which are presently the subject of a good deal of debate. These measurements should also be able to detect any unusual thermal conditions in the upper mantle which could be related to mantle deformation processes. The ability to determine crustal resistivities from magnetotelluric measurements is due to the fortunate circumstance that the oceanic conductivity-resistivity structure allows the oceanic current system to be brought up onto the California upper crust, and therefore, magnetotelluric measurements can follow the way in which these currents work their way back into the mantle through the lower crust.
