Two-dimensional resistivity imaging in the Kızıldere geothermal field by MT and DC methods

Magnetotelluric (MT) and Schlumberger (DC) surveys were conducted to identify conductive zones inside metamorphic complex in the easternmost part of B. Menderes Graben. In this study, using these surveying data, creation of some two-dimensional images of the shallow and deeper parts of the area was aimed. Broadband (200–0.002 Hz) MT and Schlumberger data were acquired along four profiles crossing the B. Menderes Graben with a total of 18 MT and 19 DC stations. These data were modeled using two-dimensional inverse techniques. The main findings are: (1) presence of wide conductive regions with very low resistivity (< 3 Ω m) are imaged at depth of ~ 100 m, extending to maximum ~ 2000 m depth, and these conductive regions signify potential geothermal resource in the area, (2) presence of deep conductive regions (< 75 Ω m) at a depth from ~ 15 km to 35 km, which reflects the shallow asthenosphere, could be correlated with the presence of high enthalpy geothermal system and its heat source.

Research highlights
► Wide very conductive regions (< 3 ohm m) extending to ~ 2000 m depth, signify potential geothermal resource in the Kızıldere.
► Our study shows high conductance values (around 1000 S) which indicate the field is part of an active tectonic province.
► 2-D MT resistivity models indicate that shallow conductive electrical asthenosphere is present in western Turkey.
► Deep conductive regions (< 75 ohm m) could be correlated with the presence of geothermal system and its heat source.
► Since this study covers also some neighbouring areas, it might shed light on further development activities.