Preliminary Evaluation of the Aquarius Mountains Hot Dry Rock Geothermal Prospect, Arizona

Abstract

Los Alamos Scientific Laboratory is currently evaluating several sites nationwide for future Hot Dry Rock geothermal wells similar to the prototype system at Fenton Hill, New Mexico. One such prospect if the Aquarius Mountains of northwest Arizona which lie on the southwest margin of the Colorado Plateau at the boundary with the Basin and Range tectonic province, Compilation of geophysical data suggests that a regional positive thermal anomaly underlies the area northeast of the Aquarius Mountains. No Quaternary volcanic rocks are exposed at the surface to indicted the presence of magma at depth, although at least three episodes of silicic to intermediate volcanism occurred in Miocene time. A survey of the few thermal waters has revealed no indication of conventional geothermal systems of large volume or high temperature (>150°C). Existing sparse geothermal gradient data indicate that the potential reservoir rocks of Precambrian basement have a minimum temperature of 170°C at about 4 km depth.