3D geoelectric model MT/MV methods anomalies of conductivity deep structure experimental electromagnetic studies Golovanivsky suture zone Kirovograd electroconductivity anomaly Southern side of the Dnieper-Donets Basin Ukrainian shield anomalies of electro-conductivity anomalies of electroconductivity collision conductivity anomalies electrical conductivity anomalies electromagnetic experimental study fault zones magneto-variational profiling magnetotelluric and magnetovariational methods magnetotelluric sounding mineral deposits oil and gas prospecting area the Bragin-Love ledge the Chernihiv block of the Dnieper-Donets depression the Crimean region the Earth's crust and upper mantle the Golovaniv suture zone the Golovanivsk suture zone zones of deep faults zones of metasomatism