Characterization of a geothermal system in the upper Arkansas Valley, CO

Summary: The past four years, geophysics students and faculty from Col- orado School of Mines and Boise State University have studied the subsurface in the Upper Arkansas Valley, Colorado, using a combination of geological and geophysical methods. Here, we present and integrate their results from seismic, self-potential and gravity data, as well as water temperature measurements in local wells to ascertain the overall basin structure and in- vestigate a geothermal system in the Mt. Princeton area. We conclude that a shallow orthogonal fault system in this area appears to be responsible for the local geothermal signature at and near the surface. The extent to which high temperatures exist throughout the deeper basin is still under investigation.