THE DEVONIAN TO PERMIAN SUBSIDENCE MECHANISMS IN BASINS OF THE EAST-EUROPEAN PLATFORM

Abstract

Tectonic subsidence analysis of five major sedimentary basins of the East European platform reveals two episodes of rapid downward motion since the Devonian. The mechanisms of basin evolution are examined to explain the rapid subsidence of the basins. Models of these mechanisms are compared with seismic, gravity, heat flow and Devonian magmatism observations from the Timan-Pechora, Pre-Ural, Pre-Caspian, Dnieper-Donets and Moscow basins. The models assume that the post-Devonian development of the basins has been affected by one or more of the following processes: stretching of the lithosphere and thermal decay, mineralogical phase transition in the crust, magmatism and eclogitization-induced mantle flow in the uppermost mantle, subduction under the platform and continental collision. While some features of basin evolution are in good agreement with one of the mechanisms, no specific model can explain all features of the platform basins. Magmatism-eclogitization mechanisms are likely to be responsible for the Devonian subsidence of the Dnieper-Donets, Timan-Pechora, and Pre-Caspian basins, whereas the subduction-induced mantle flow may explain the Devonian to Permian subsidence of the Moscow basin and Pre-Ural depression.