Speaker: Nikolay Palshin
“EM methods besides seismic tomography are an efficient tool for studying lithosphere structure. The East European Craton has been intensively investigated by various geophysical methods for several decades. Several array and profile EM studies have been carried out on the territory of Finland, Sweden, Norway, Denmark, Poland, Russia and Ukraine.
Studies were carried out in several interconnected and complementary directions, which included (1) organization of long-term measurements of the electric field; (2) theoretical researches, including construction of prognostic models and mass EM calculations as well as their transfer function; (3) analysis of the data available and its preliminary joint interpretation.
The main result obtained in the East European Craton is absence of asthenopshere as low viscosity layer and high conductive layer underlay the lithosphere. Interpretation of conductivity structure suggests low temperature and low hydrogen contents in the upper mantle at East European Craton.
Interpretation of MT data on the territory of Finland, Russia and Ukraine (within boundaries of Fennoscandia and Sarmatia) suggests that there existed a genetic relation of elongated crustal anomalies of electric conductivity confined to the boundaries of Archean and Proterozoic blocks and tectonic processes that took place on Ar-Pt boundary.”