A Geoelectrical Model of the Southern Ladoga Region on the Basis of 3D Magnetotelluric Data Inversion

—The paper presents results of magnetotelluric sounding performed in the South-Eastern Ladoga Region in 2018–2021 for the purpose of studying the deep geoelectrical structure of the basement of the East-European Platform (EEP). The area of the study covers the territory south and south-east of Lake Ladoga to the latitude 58°45′ S and the longitude 35°37′ E. In the west, the territory is confined to the Saint Petersburg — Murmansk electric railway. The data gathered by the LADOGA working group and the most solid findings of the previous studies were used to make a 3D inversion and to build a three-dimensional geoelectrical model of the area under study. More detailed electrical resistivity models were obtained for specific profiles on the basis of a two-dimensional inversion. We traced the continuation of the southern branch of the Ladoga electrical conductivity anomaly and clarified its deep structure. Also, we established completely new zones of the crustal electrical conductivity anomaly, which are presumed to mark first-order tectonic boundaries between the South-Baltic belt and the central Russian orogen.