The Crust and Upper Mantle Structure of the Southern Sikhote Alin from Magnetotelluric Sounding Data along the Abrazheevka-Valentin Profile

摘要

Based on the results of magnetotelluric soundings carried out in the southern part of the Sikhote Alin Fold System in the frequency range from 10 kHz to 0.001 Hz, the geoelectric section was constructed down to a depth of 150 km. The electrical parameters have been obtained and the crust and upper mantle structure has been studied. The crust has a high resistivity ranging from 1000 to 20 000 Ohm m and is divided into fault-bordered blocks according to low resistivity zones. Two zones with abnormally low resistivities of 100-200 Ohm m and lower have been distinguished in the crust and upper mantle. The structure of the geoelectric section is related to the subduction of an ancient plate and the formation of a slab window.