Modelo geológico y evaluación del campo geotérmico La Primavera, Jal., México

Abstract

La Primavera Volcanic Field (PVF) (Jalisco State, Mexico) is located west of Guadalajara. In this area Quaternary volcano-tectonic activity has given rise to a convective hydrothermal system. 13 deep wells were drilled in the central part of the PVF. Ten of these wells were evaluated for geothermic potential. Lithostratigraphic sequences are pre- and syncalderic, pre-caldera sequence including the granitic basement, andesites, lithic tuffs and rhyolites. The geotermal sequence is located in the andesitic formation. The contact between intrusives and andesites is not metamorphic suggesting that the heat source and the intrusive are not related. Rhyolites at the top of the pre-caldera sequence might be the earliest flows related to caldera formation. Syn-caldera sequence is represented by the highly permeable Tala tuff and rhyolites. The post-calderic sequence includes volcanic-sedimentary products, lacustrine sediments and rhyolitic domes. The groundwater flows from SE to NW. The geothermal potential Nas evaluated by geochemical, thermic, and mineralogic parameters. It is estimated at about 100 MWe, projected to last for about 17 years.