Radio- and controlled-source-tensor magnetotelluric (RMTand CSTMT) methods are used to target hydrothermal veins ofcopper mineralization. The data were acquired along six east-west- and three north-south-trending profiles, covering an area ofabout 500 X 400 m2. The tensor RMT data were collected in the10-250-kHz frequency band. A double horizontal magnetic di-pole transmitter in the 4-12.5-kHz frequency range allowed usto constrain the deeper parts of the resistivity models better. Toobtain optimum field parameters, ground magnetic profiling wasconducted prior to the RMT and CSTMT surveys. Although thestudy area (in Iran) is remote, a number of radio transmitters withacceptable signal-to-noise ratio were utilized. The 2D inversionof RMT data led to unstable resistivity models with large datamisfits. Thus, the RMT data were used to complement and ana-lyze the near-surface resistivity anomalies observed in the 2DCSTMT models. Analyses of strike and dimensionality from theCSTMT data suggests that the low-resistivity structures aremainly three dimensional; therefore, 2D inversion of determi-nant data is chosen. Independent 2D inversion models of the de-terminant CSTMT data along crossing profiles are in good agree-ment. Known copper mineralization is imaged well in theCSTMT models. The thinning of the conductive overburden cor-relates very well with magnetic highs, indicating the bedrock isresistive and magnetic. In this sense, the magnetic and electro-magnetic fields complement each other. Analysis of the 2D resis-tivity models indicates the volcanic rock deepens at the center ofthe study area. This zone is associated with a magnetic low andtherefore is recommended for detailed exploration work.
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