Geothermal system of Despoblados by magnetotelluric data, Valle del Cura, San Juan

Valle delCura develops within a N-S thrust system in the high cordillera of San Juan. This valley has various geothermal manifestations, where the hot springs of Despoblados are highlighted. The aim of the work was to study the geothermal phenomenon by magnetotellurics, in order to obtain the geomet...

Descripción completa

Guardado en:
Detalles Bibliográficos
Autores principales: Barcelona, H., Favetto, A., Peri, G., Pomposiello, C., Ostera, H.
Formato: JOUR
Materias:
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_00044822_v71_n4_p_Barcelona
Aporte de:
Descripción
Sumario:Valle delCura develops within a N-S thrust system in the high cordillera of San Juan. This valley has various geothermal manifestations, where the hot springs of Despoblados are highlighted. The aim of the work was to study the geothermal phenomenon by magnetotellurics, in order to obtain the geometry of the system in depth. High frecuency (1000 – 10 Hz) and broad band (10 – 0.03 Hz) were recorded in 47 and 18 sites. Robust signal processing and standard parameters analysis were performed. 2-D inversion of the data was carried out to obtain the electrical resistivity distribution through 5 models and a single pseudo 3-D model. The models defined 2 conductive anomalies, one directly linked with the hot springs and the other one without superficial manifestation. Both anomalies show structural control and a deep circulation of geothermal fluids. The proposed Despoblados geothermal system has plumes like upwelling zones channeled by faults that surround the valley and downwelling zones linked to the main thrusts, were the meteoric water leaks. Although there is no evidence of shallow lithostratigraphic level as reservoir, is not discarded the existence of one bellow 4000 m depth. The geothermal fluid circulation could be by normal geothermal gradient convection or favored by a remnant thermal anomaly from the Cerro de Vidrio volcanic event (1.5 Ma). Finally, some questions remains about the existence of a main geothermal systems that groups the apparent isolated manifestations on Valle del Cura. © 2014, Revista de la Asociacion Geologica Argentina. All right reserved