*GEOPHYSICAL RESEARCH*, *2017, vol. 18, no. 3, pp. **27-44. ***DOI: 10.21455/gr2017.3-3**

*UD**C **550.837*

**Abstract References Full text (in Russian)**

**COMBINED INVERSION OF ELECTRIC RESISTIVITY TOMOGRAPHY AND MAGNETOTELLURIC SOUNDING FOR SOLVING TASKS OF ORE GEOPHYSICS**

V.A. Kulikov^{(1)}, A.E. Kaminsky^{(2)}, A.G. Yakovlev^{(1)}

^{(1)}* Lomonosov Moscow State University, Moscow, Russia*

^{(2)} “*Astra Geophysics LTD”, S-Peterburg, Russia*

**Abstract.** The paper presents the results of combined inversion of data of electric resistivity tomography and magnetotelluric sounding in ZONDRES2D code for solving tasks of ore geophysics. It illustrates the advantages of combined inversion for vertical exploration up to a depth of 400-500 m on synthetic models and real field survey data.

Electric tomography as a DC method is hypersensitive to high resistance object and makes it possible to determine more correctly boundaries of different intrusions, quartz core, dykes and other high-resistivity bodies. The principal failure of this method is limitation of the depth of penetration.

The depth of magnetotelluric methods is limited only by the recording time. As a rule, in order to reach the depth of several hundred meters – first kilometers, AMT range is enough. The duration of recording in this mode is less than 1 hour. MT-parameters are more sensitive to conductive bodies and are not shielded by highly resistive layers. In magnetotelluric methods, one can use various independent parameters, which complement each other and constrict the area of inverse solutions.

**Keywords:** electric resistivity tomography, magnetotelluric sounding, two-dimensional inversion, ore exploration.

**References**

Ageeva S.T. Geological position and morphological features of the Severo-Benkalinsk deposit zones (Western Turgai), *Geologiya shtokverkovykh mestorozhdenii medi Urala i Kazahstana, Tr. TsNIGRI *(Geology of the stockwork copper deposits of the Ural and Kazakhstan, Proc. TsNIGRI), 1982, vol. 170, pp. 14-25.

Andreeva, E.V., Bobachev, A.A., Varentsov, Iv.M., Vereshagina M.I., Kulikov V.A., Yakovlev A.G., and Yakovlev D.V. Combining Geophysical Methods for the Prospecting for Copper-Nickel Ores on the Objects of GMK Norilsk Nickel, *Razved. Okhr. Nedr*, 2006, no. 8, pp. 71-79.

Berdichevsky, M.N. and Dmitriev, V.I. *Models and Methods of Magnetotellurics*, Berlin: Springer, 2008.

Kaminskiy A.E., Erokhin S.A., and Shlykov A.A. Joint 2D Inversion of Electrical Resistivity Tomography and Radio/Audio Magnetotelluric data, *Geofizika* (The Russian Geophysics Journal), 2015, no. 4, pp. 32-39.

Kulikov V.A. and Yakovlev A.G. Practical application of the magnetotelluric methods in ore geophysics, in *Razved. Okhr. Nedr,* 2011, no.3, pp. 26-33.

Kulikov V.A., Bobachev A.A., and Yakovlev A.G. Applications of Electrical resistivity tomography in deep mining prospecting *Geofizika* (The Russian Geophysics Journal), 2014, no. 2, pp. 39-46.

*Elektrorazvedka. Uchebnoe posobie po elektrorazvedochnoi praktike dlya studentov geofizicheskikh spetsial’nostei* (Electric Prospecting. Training Manual for Students in Geophysics), Khmelevska, V.K., Modin, I.N., and Yakovlev, A.G., Eds., Moscow: MGU, 2005.

Pedersen L.B. and Engels M. Routine 2D inversion of MT data using the determinant of the impedance tensor, *Geophysics*, 2005, vol. 70, no. 2, pp. G33-G41.

Varentsov Iv.M. Methods of joint robust inversion in MT and MV studies with application to synthetic datasets, *Electromagnetic Sounding of the Earth's Interior: Theory, Modeling, Practice*, Amsterdam: Elsevier, 2015a, pp. 191-229.

Varentsov Iv.M. Arrays of simultaneous EM soundings: design, data processing, analysis, and inversion, *Electromagnetic Sounding of the Earth's Interior: Theory, Modeling, Practice*, Amsterdam: Elsevier, 2015b, pp. 271-299.

Varentsov Iv.M. A General Approach to the Magnetotelluric Data Inversion in a Piecewise-Continuous Medium, *Izv. **Phys. Solid Earth*, 2002, vol. 38, no. 11, pp. 913-934.

Varentsov Iv.M. Resolving Efficiency of the Modern EM Geophysical Methods with Natural Sources, *Razved. Okhr. Nedr*, 2006, no. 8, pp. 66-71.

Varentsov Iv.M., Kovachikova, S., Kulikov, V.A., Logvinov I.M., Tregubenko V.I., and Yakovlev A.G., Simultaneous MT and MV Soundings on the Western Slope of the Voronezh Massif, *Geofiz. Zh.*, 2012, vol. 34, no. 4, pp. 90-107.

Varentsov Iv.M., ivan_varentsov@Kulikov V.A., Yakovlev A.G., and Yakovlev D.V. Possibilities of magnetotelluric methods in geophysical exploration for ore minerals, mail.ru*Izv. Phys. Solid Earth*, 2013, vol. 49, no. 3, pp. 309-328.

Zabelin V.I. Elements of the geological-genetic model of the Ak-Sug copper-molybdenum deposit, *Magmatizm i metallogeniya rudnykh raionov Tuvy* (Magmatism and metallogeny of the Tuva ore regions, Novosibirsk: Nauka, 1992