Part of #Investigation of Sabalan geothermal field structure using Magnetotelluric data# :
Publishing year : 2010
Conference : 14th Iranian Geophysical Conference
Number of pages : 5
Abstract: Sabalan geothermal field is a high potential geothermal system in the Ardebil province of N-W of Iran, which is now under investigation for electricity generation. In this paper, the fourteen MT stations of the 1998 MT data set were used along a profile perpendicular to the main geological structures in order to evaluate the three main elements of the Sabalan geothermal field namely cap-rock, reservoir and heat source. TE and TM mode data and skew parameters show that the earth dimensionality differs from site to site, so we examine the 2D inversion along the profile. The two-dimensional inversion has been done using a code from Siripunvaraporn and Egbert (2000). The resulting model shows a pattern of high-low-low resistivity with depth. The high resistive layer at the surface is largely controlled by basalt, andesitic and old trachyandesitic flows and other impermeable rocks that have thermal conductivity and acts as a cap-rock of the system. The second layer is a very conductive layer and interpreted as a reservoir with thermal convection and hot fluids contained in its fractured and pores. The resistive basement is a hot and solid magmatic intrusion and is interpreted as a heat source which produces a conductive heat flow toward the reservoir. As a result, the shallow resistivity model of the Sabalan area is in good correlation with geological features and the common conceptual resistance method for geothermal reservoir structure.