DBPapers
DOI: 10.5593/SGEM2014/B11/S5.061

GEOELECTRICAL METHODS APPLIED FOR PROSPECTING AN AREA WITH GEOTHERMAL POTENTIAL

F. Chitea, D. Ioane, I. Airinei, A. Serban, A. Dorobantu
Wednesday 1 October 2014 by Libadmin2014

References: 14th International Multidisciplinary Scientific GeoConference SGEM 2014, www.sgem.org, SGEM2014 Conference Proceedings, ISBN 978-619-7105-07-0 / ISSN 1314-2704, June 19-25, 2014, Book 1, Vol. 1, 459-466 pp

ABSTRACT
Non-invasive prospecting methods were deployed in an area with geothermal potential, not enough exploited. Occurrences of thermal springs were known to exist in the Toplita area, due to the existence of two old spa and geothermal gradient data maps. In order to locate a new borehole, geophysical investigations consisting in apparent resistivity measurements were carried out in two areas within Toplita City. Due to the local constrains (private properties, infrastructure, fences) measurements were performed mainly in areas where exploitation of new thermal springs would have been possible. The recent geophysical measurements included apparent electrical resistivity investigations. Techniques deployed for field data acquisition were Electrical Resistivity Tomography (ERT) and Vertical Electrical Sounding (VES). Following the low apparent resistivity anomalies, evidences of high permeability zones were noticed on resulted sections and models. Three locations were delineated as possible bearing thermal groundwater. Despite their close locations, differences in electrical resistivity data were noticed both on ERT and VES data. After advanced data processing on ERT data, it was concluded that only one of them was bearing mineralized and moderate temperature water. In the selected location, a borehole (210m) was drilled and successfully located a thermal spring, having the highest temperature among known thermal water occurrences in the City area.

Keywords:geothermal resources, geophysical investigations, Toplita, Romania, electrical resistivity measurements