Schlumberger Sounding Results over the Newberry Volcano Area, Oregon

Abstract

Schlumberger soundings were made in the Newberry volcano area of Oregon to categorize the electrical properties of possible Cascade geothermal system's An east-west geoelectric cross section constructed from the interpreted soundings show a low resistivity zone in the caldera, that corresponds to the increase in thermal gradient observed in the U.S. Geothermological Survey (USGS) test well. Another low resistivity zone a out 600 m deep is present just to the west of the caldera boundary. A north-south geoelectric cross section shows the configuration of the western low resistivity zone. Maps of interpreted resistivity at depths of 750 and 1000 m show that the main low resistivity area west of the caldera has two tongues, one oriented easterly and the other oriented southerly. On the 750 m depth map, the western low resistivity zone has an areal extent of about 16 km2. This zone is interesting enough that at least one company has drilled it.