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