Abstract

Geothermal resources in the form of thermal springs were the first geological energy resource readily available to humans in the Southern Rocky Mountains/Rio Grande Rift region. Geothermal resources are once again making a contribution to the energy resources of the region for recreation, therapy, space heating, and commercial uses, including greenhouse heating and aquaculture. We catalogue these resources and speculate on possible heat sources for the thermal waters, including the obvious association with young volcanism in the Valles Caldera in northern New Mexico. The main heat transport mechanism in the upper crust is thought to be physical transport of heat by water flow (thermal convection).

Current uses of geothermal energy in the region are restricted to direct use of heat in thermal waters where the energy is used without conversion. Evidence from the chemistry of some thermal spring waters indicates that they may have a source at depth much hotter than the surface waters, perhaps a source sufficiently hot to generate electricity. With the exception of the Valles Caldera, none of the areas have yet been drilled to sufficient depth to test whether these indications are valid and whether there are adequate temperatures with sufficient water for electricity generation. Direct use of geothermal resources in the region is slowly increasing. There is continuing interest in generating electricity from geothermal resources, but the feasibility of this proposition awaits testing by drilling one or more areas in the region to test the predictions of the geochemistry.