Lithological and Structural Control of the Geothermal System in the Nereidas Valley, Caldas-Colombia

Abstract

The Nereidas Valley was described in the 60´s. Its located in the SE of the municipal set of Villamaría, Caldas-Colombia, nearby to Rio Claro river in the confluence with the Nereidas river. There are a several geothermal manifestations like hot Waters, steams and formation of new minerals. These manifestations are located to West from Botero Londoño area in the Nereidas Valley. They are characterized by having high patterns of deformative processes in the zone. There are several hidrothermal alterations like silicification, sericitization, epidotization as a product of the ascension of the hydrothermal fluids. This area is influenced by a structural control. These structural controls are produced by the existence of the Santa Rosa, La Telaraña and Nereidas faults mainly. Using kinematic indicators, it is observed that La Telaraña and Santa Rosa faults have a right-lateral strike slip with an NNE-SSW orientation while the Nereidas fault has a left-lateral strike slip with a NW-SE orientation. These faults have a geomorphological evidence like triangular facets and the deflection of the Rio Claro river. In the area of survey, the ascension of the geothermal fluids it is posed as a product of the secondary porosity by the brittle deformation due to the tectonic activity. Therefore, structural control is proposed throughout the thermal system. In addition, the area is affected by the emplacement of felsic intrusions probably associated with the volcanic system of Nevado del Ruiz (NRV).