Scientific Quarterly Journal of Geosciences

Scientific Quarterly Journal of Geosciences

Geoelectric Structure of Meshkinshahr Geothermal Area Deduced from 2D Magnetotelluric Models

Document Type : Original Research Paper

Authors
Mohammad Kazem Hafizi 1
Abdolmahdi Rahimi 1
Mehrdad Aiobi 2
1 Institute of Geophysics, Tehran University, Tehran , Iran
2 Dept. of Geophysics, Iranian National Oil Co., Tehran, Iran
Abstract
A 2D inversion of magnetotelluric data was carried out from geothermal resources at Mount Sabalan  in the north west of Iran. The algorithms used in the MT study are the 2D models of Occam’s inversion. Profile ِA with 13 MT stations was passed through Gheynarge village and aligned NW-SE around the west flank of the volcanic mountains of Sabalan. 2D inversion of magnetotelluric indicates a zone of very low resistivity nearby Gheynarge springs. The geothermal model was considered with a 100 ohm-m cap overlaying a 5 ohm-m reservoir in a 400 ohm-m half-space. The response of the regarded model confirms the 2D Occam’s inversion obtained from MT data in the west of Mount Sabalan. The Combination of 2D inversion from three profiles, which crossed on the A profile, indicates a 2.5D interpretation of Meshkin-Shahr’s geothermal site’s reservoir
Keywords
Geothermal
2D Inversion
Meshkin-Shahr
Magnetotelluric
Resistivity

Subjects

Bromly,C.,Khosravi,K. & Talebi,B.,2000- Geophysical Exploration of Sabalan Geothermal Prospects in Iran, Proceedings of the world Geothermal Congress, Japan.
DeGroot-Hedlin, C. & Constable, S., 1990- Occam’s Inversion to Generate Smooth, Two-dimensional Models from Magnetotelluric Data, Geophysics, Vol. 55, No.12.
Emami, M. H. & Amini, B., 1994- 1:100000 Geological map of Iran, sheet 5566 (Meshkinshahr), Geological Survey of Iran.
Galanopoulos, D., E. Lagios, Dawes, G.J.K., Hobbs, B.A., 1998- Geoelectric Structure of Sousaki Geothermal Area (Greece) deduced from Two Dimensional Magnetotelluric  Studies, Journal of the Balkan Geophysical Society, Vol. 1, No. 4, pp. 60-74.
Hafizi, M. K., Aiobi, M., Rahimi, A., 2002- Combination of 2D and 1D inversion for 2.5D interpretation of  Magnetotelluric Geothermal Sites, EAGE 64th Conference, Florence, Italy. 
Kaufman, A. A. & Keller, G.V.,1981- The Magnetotelluric Sounding Method, Elsevier Scientific Publishing Company.
Kingston-Morrison Limited, Renewable Energy Organization of Iran, SUNA, 1999- Sabalan Geothermal Project, Stage 1- Surface Exploration, Vol. 4, MT Resistivity Layered Models.
Ross,W.,Groom,W.&Baily,C.,Decomposition of Magnetotelluric impedance Tensor in the presence of 3-D galvanic disturtion.
Wannamaker, P.E., Wright, P.M., Zi-Xing, Z.et al., 1991- Magnetotelluric transect of Long Vally caldera-resistivity cross-section, structural implications, and the limits of a 2-D analysis. Geophysics, 56, 926-940. 
Wright P. M., Ward S. H., Ross H. P., West R. C., State-of-art geophysical exploration for geothermal resources., Geophysics., Vol. 50., No. 12., 2666-2699.
Yungul , S. H., 1996- Electrical Methods in Geophysical Exploration of Deep Sedimentary Basins, Chapman & Hall.
Scientific Quarterly Journal of Geosciences
Volume 14, Issue 54
Winter 2005, Vol. 14, No.54
Winter 2005
Pages 20-27