Investigation of the electrical resistivity and geological structures on the hot springs in Markazi rovince of Iran using magnetotelluric method

The Mahalat region of Markazi province in Iran is a popular tourist spot due to the occurrence of hot springs and having the greatest geothermal fields in Iran. We chose a 6 km profile with 12 sites across the hot springs for carrying out a magnetotelluric (MT) survey on July 2011. A 2D inversion was applied on the determination MT data to resolve the subsurface conductive structures using a 2D inversion routine of Occam approach. The 2D model significantly illustrates the geothermal structures at depth, including cap rock (from 100 to 600 m), reservoir (from 500 to 2000 m) and the heat source (starting from 1000 m), and it shows a good correlation with the geological features. One of the interesting results is distinguishing the main faults, which are acting as the preferential paths to circulate the hydrothermal fluids. The resistivity model fits on the geological section along the MT profile.