Is Island Park a Hot Dry Rock System?

Abstract

The Island Park Yellowstone National Park region comprises a complex caldera system which has formed over the last 2 m.y. The caldera system has been estimated to contain 50% of the total thermal energy remaining in all young igneous systems in the United States. Although development is not permitted within the national park, neither exploration nor development is progressing in the caldera complex outside the park. Environmental concerns have in part caused this, but the lack of surface thermal manifestations and the lack of evidence for hydrothermal systems with the Island Park part of the caldera complex is also responsible. As the result of a reexamination of the data and recent electrical work in the area, we now postulate that much of the area where the first and second stage calderas developed is underlain by a solidified but still hot pluton. We postulate that the pluton represents a significant hot dry rock resource of the United States.