Donbas Electrical Conductivity Anomaly

Abstract

Summary This work is devoted to electromagnetic (EM) studies of the electrical conductivity of Earth crust by the methods of magnetic variation profiling (MVP) and magnetotelluric sounding (MTS). The MVP data reveal the intense Donbas electrical Conductivity Anomaly (DCA) which runs along the main anticline of the folded Donbas. Profile curves of anomalous fields give an estimation of maximum possible depth of the anomalous currents center h=18±2 km. Frequency response maximum of the anomalous field T0≈3600 s yields the total longitudinal conductance G = (8±2)×108 S×m. 70 MTS at periods 0. 1-3000 s yield two conductive stripes, which upper edge varies from 0. 3 to 5 km. The stripes are parallel to the DCA axis and considered as part of DCA. A very large value of G leads to assumption that the anomalous body extends to considerable depth. DCA axis spatially coincides with intense (up to 90 mW/m2) deep heat flow anomaly. This fact suggests that the nature of the DCA lower part can be a partial melting of fluid-enriched heated local rocks or intrusion of mantle magma. In both cases ecology-friendly geothermal energy would be very useful for the restoration and development of the region.