Hydrothermal Mineralogy and Isotopic Geochemistry in the Cerro Prieto Geothermal Field, Mexico, III: Practical Applications

Abstract

Our studies of rock samples from geothermal boreholes use a combination of mineralogy, light stable isotopes, fluid inclusions and other methods of geothermometry. This approach has proved cost effective and rapid when applied to practical problems of exploration at Cerro Prieto. We were ale to predict temperatures and make qualative statements about permeability during drilling. Our predictions were largely substantiated when the boreholes were subsequently tested. This kind of timely information helps determine final depth and the siting of future wells. We can also identify zones of different permeability, and distinguish between the natural recharge, discharge, and heating regimes of the geothermal system. Thus the effective hydrology and its evaluation in the natural state can be described. Although theses concepts were developed as a result of our studies in the Salton Trough, we believe that, with suitable modifications, they can be applied to various different types of geothermal fields elsewhere.