ИСТИНА

The results of interpretation of MT data acquired on north-west slope of Voronezh crystalline core-area in 2007 - 2014 are presented. It was a part of the international project, which main issue was survey of Baryatinskaya and Kurskaya crustal high-conductive anomalies. Scientists from Lomonosov Moscow State University, Geoelectromagnetic Research Center of The Schmidt Institute of Physics of the Earth of the RAS, Subbotin Institute of Geophysics of the NAS of Ukraine and Nord-West Ltd. took part in this project. MT survey of this area started in 1990th when high-conductive anomaly in the crust was found. From 2007 the survey of this anomaly was supported by Russian Foundation for Basic Research (RFBR). Since then the MT data was acquired in 142 sites along 12 lines using two type of equipment: MTU (Phoenix Geophysics) with magnetic coils and LEMI with flux-gate magnetometers. The range of periods for the most of sites is from 300 Hz to 10 000 sec. The analysis of impedance (Z) and tipper (W) was carried out. It showed, that northern part of area has close to 2D structure and on the south it more likely 3D, because two conductive zones with different direction join there. 2D inversion for MT lines on the northern part of area was carried out in 2012. In 2017 3D inversion of all MT data (Z and W) was carried out using ModEM software and supercomputer «Lomonosov» (Research Computing Center of Lomonosov Moscow State University). Resistivity image obtained from 3D inversion shows the boundaries of the Baryatinskaya and Kurskaya crustal high-conductive anomalies, their deep resistivity structure and their connection with well-known high-conductive areas of Ukrainian craton. The resistivity images were compared with geological, gravity and magnetic data. Some interesting features connected with the main geological structures were discovered.