Geophysical exploration for geothermal energy mapping in Taftan Volcanic area

Renewable energy resources have an important role in sustainable development, especially in impoverished areas like south west of Iran. This paper is a part of a plenary and large project funded by= electric and power company of Sistan and Baluchestan province. Electric resistivity tomography (ERT) method and radial basis function modeling were used to detect fractured rock geothermal aquifers in hard rock volcanic environments. The most important task of a survey concerning the exploitation and protection of a thermal spring is the understanding of the mechanism of the outflow of thermal fluids. In this concept, geophysical methods are conscripted to contribute to the understanding of the hydrogeological model, since they can provide information without interferences which could potentially react on the flow of the hot water. In the most of the cases, the occurrence of such springs is related to the local faulting system that allows the upwards flow of the thermal fluids. The resistivity maps and twodimensional geoelectric models indicated a relative conductive region ( 50ohm-m) in east and south east part of Taftan mountain, toward Sangan village. Favorable areas were located where the intense fracturing of the basement volcanic rocks has produced extensive or local thickening of overburden material. Two fault zones have been detected by compilation of several isoresistivity maps for different depths. The reservoir is intersected by some sub-vertical faults/fractures that probably play an significant role in convoying the thermal water up to the surface. On the basis of the results of this method, three locations are proposed for drilling in these conductive zones.