This paper presents the results of magnetotelluric (MT) studies performed within the Western Transbaikalia segment of the Central Asian fold belt along the Selenga River delta-Krasnyi Chikoi Village profile. The data are interpreted using the results of recent geological, petrological, geothermal, tectonic, and geochronological studies of the Mongolia-TransbaikaliAn part of the Central Asian fold belt, including large heterochronous igneous provinces and zones. The studies have shown that the investigated area has a complex geologic and tectonic structure produced by extensive rifting leading to the formation of large crustal blocks and by intense magmatic fluid activity along deep fault zones. The investigated profile is characterized by a combination of blocks with different types of geoelectric section-mountain ranges and intermontane basins separated by long-lived deep fault zones. (C) 2016, V.S. Sobolev IGM, Siberian Branch of the RAS. Published by Elsevier B.V. All rights reserved.

Regional gravity and magnetic anomalies are interpreted with regard to new geodynamic, geological, and tectonic schemes. Integrated analysis of these data confirms the deep origin of the processes which have created the largest igneous areas and zones of the eastern Central Asian Fold Belt.

The magnetotelluric (MT) profile traverses the southeastern edge of the Siberian craton and the adjacent Paleozoic Olkhon collision zone, both being within the influence area of the Baikal rifting. The processed MT data have been integrated with data on the crust structure and composition, as well as with magnetic, gravity, and seismic patterns. Large resistivity lows are interpreted with reference to new geothermal models of rifted crust in the Baikal region. The northwestern and southeastern flanks of the profile corresponding, respectively, to the craton and the collision zone differ markedly in the crust structure and composition and in the intensity of rifting-related processes, the difference showing up in the resistivity pattern. The high-grade metamorphic and granitic crust of the craton basement in the northwestern profile flank is highly resistive but it includes a conductor (less than 50 ohm · m) below 16–20 km and a nearly vertical conductive layer in the upper crust. The crust in the southeastern part, within the collision zone, is lithologically heterogeneous and heavily faulted. High resistivities are measured mainly in the upper crust composed of collisional plutonic and metamorphic complexes. Large and deep resistivity lows over the greatest part of the section are due to Cenozoic activity and rift-related transcrustal faults that vent mantle fluids constantly recharged from deeper mantle.

Profile MTS settles down in Baikal riftzone, including its Transbaikalian part. The primary target of the executed researches is the complex analysis of the geology-geophysical data about the composition and structure of the earth's crust, and also features of a thermal mode and their reflection in an electromagnetic field.