EGU23-12872, updated on 26 Feb 2023
EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

MT data inversion and dimensionality analysis in Varton geothermal central Iran

Mohammad Hajheidari1, Sayyed Mohammad Abtahi Forooshani1, Nader Fathianpour1, Keytash Moshtaghian2, and Hojatollah Tavakoli Harandi1
Mohammad Hajheidari et al.
  • 1Department of Mining Engineering, Isfahan University of Technology, Isfahan, Iran, Islamic Republic of
  • 2Department of Physics, University of Alberta, Edmonton, Canada

The Varton geothermal is located circa 70 kilometers northeast of Isfahan, central Iran. The study area consists of highly fractured rocks with argillic alteration zones and some hot springs. Here, we conduct a magnetic and magnetotelluric data survey to study the effect of the fractures on the hydrothermal convection system. The magnetic data processing exposed two parallel main faults with NW-SE strike in the northern and southern borders of the area. Here, we used nine magnetotelluric (MT) stations along a profile perpendicular to the main faults. Dimensionality analysis of MT impedance and phase tensors in the stations indicated a media with two-dimensional structures. However, 1D MT data inversion revealed a three-layered earth beneath most stations, though the layers' thickness and resistivities varied along the profile. Also, 2D MT data inversion results showed that the resistivity between the two main faults was significantly smaller than zones beyond the faults. However, a large zone with low resistivity was close to the southern fault. Besides,  a shallow layer overlain a thin conductive layer with a resistivity of one ohmm or less. In depths more than 500 m, the resistivity noticeably increased gradually to 1000 ohmm. According to the mentioned results, we deduce that the southern fault is the main feeding fault for the geothermal system. Furthermore, the layer with the lowest resistivity correlates with clay alteration and could be the clay cap of the reservoir. Therefore, the deeper resistive rock is the geothermal reservoir.

How to cite: Hajheidari, M., Abtahi Forooshani, S. M., Fathianpour, N., Moshtaghian, K., and Tavakoli Harandi, H.: MT data inversion and dimensionality analysis in Varton geothermal central Iran, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-12872,, 2023.