Geological Structure Identification from Gravity Data in Baños de Cuenca Geothermal Prospect, Ecuador

Abstract

Located south of Ecuador, Baños de Cuenca, is a geothermal prospect which lies out of the northern active volcanic zone of the Andes, however with several hot springs with temperatures up to 75°C. Geothermal manifestations are developed over Oligocene volcanic deposits, Miocene sedimentary rocks from the Cuenca basin and Mio-Pliocene volcanic tephra from the extinct Quimsacocha volcanic center. Previous geological and geochemical studies categorized it as a low to medium enthalpy prospect. Nonetheless the heat source and the direction of geothermal fluids to flow up at Baños de Cuenca town are still in discussion. In order to define geological structures, 220 gravity stations were deployed on approximately 150 km2. The analysis of Bouguer anomaly without topographic distortion and inversion of gravity data allowed finding out information related to possible geothermal system with negative flower termination, as well as several geological structures which segment the western part of Cuenca basin. These faults would be the pathways of geothermal fluids and Baños de Cuenca town the outflow of the system. The structural setting could improve the permeability of the area; consequently the geothermal potential could probably be higher than expected. In order to constrict the interest area, 42 MT stations are suggested to deploy in Baños de Cuenca geothermal prospect.