Visualization of the Folds and Thrust Structure of Metamorphic Complexes in the Cover–Basement System Using the AMTS Method (Based on the Example of the Meyer Zone of the Ladoga Region)

The article presents the methodology and results of electromagnetic soundings of the Meyer thrust zone of the Northern Ladoga region, which separates volcanoterrigenous Paleoproterozoic cover complexes with different metamorphism intensity. Obtained in the course of detailed geological mapping, ideas about the structural and material features of the studied fold-thrust forms of this zone were supplemented by depth characteristics and visualization of the latter in the Paleoproterozoic cover–Archean basement system. Owing to the adequate choice of the audio-magnetotelluric sounding method as the main one, combined with magnetic survey, meaningful geoelectric images of the fold–thrust structures to a depth of 1 km were identified. Elements of both “thick-skinned” and “thin-skinned” tectonics, with joint and autonomous deformations of basement and cover complexes, were traced in the constructed electrical conductivity sections. A new dome-shaped structure of the Archean basement, inscribed in the linear series of small highs of the Archean basement of the Sortavala Group, was distinguished.