Controlled Source Audio Magnetotelluric (CSAMT) Surveys in the Tucson Mountains

Abstract

Controlled Source Audio-Magnetotellurics (CSAMT) surveys were conducted in 2012 in the Tucson Mountains as a continuation of the 2010 and 2011 Laboratory for Advanced Subsurface Imaging (LASI) field studies in this area. This geologic setting was chosen for its high-resistivity impermeable volcanic layer overlaying porous sedimentary layers. This type of structure has potential for water resources and as a reservoir for compressed air energy storage (CAES). The data from 2,500 meters of CSAMT survey lines generated 900 meter-deep resistivity versus elevation cross-sections and six plan maps of the depth and elevation to the buried conductive layer. Our results are generally in agreement with the geologic cross sections developed by Lipman (1993) and previous TEM data that confirmed the presence of a deep conductive layer beneath a resistive volcanic sequence.