Tectonic and geoelectric structures of rift basins in the Baikal region

Abstract

The article summarizes results of tectonophysical and geoelectric studies of rift basins in the Baikal region. Their sedimentary cover is intersected by faults, which induce shallow soft deformations in Late Cenozoic sediments. The faults observed in the internal part of the basins correlate with zones of contrast change in the deep structures of the crystalline basement and sedimentary layers. They offset the top of the basement and bottom of the sedimentary layers, and constitute zones of lower resistivity values. Significant variations of electrical parameters can be due to redistribution of conducting fluids in a geological massif, which allows discriminating water-bearing faults from water-free ones. Taken as a whole, the tectonic structure of the basins is best defined by the presence of shallow deformation zones, an asymmetrical morphology and fault-block pattern of both the sedimentary infill and basement of the basins.