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

Tectonic subsidence analysis of five major sedimentary basins of the E ast European platform reveals two episodes of rapid downward motion si nce the Devonian. The mechanisms of basin evolution are examined to ex plain the rapid subsidence of the basins. Models of these mechanisms a re compared with seismic, gravity, heat flow and Devonian magmatism ob servations from the Timan-Pechora, Pre-Ural, Pre-Caspian, Dnieper-Done ts and Moscow basins. The models assume that the post-Devonian develop ment of the basins has been affected by one or more of the following p rocesses: stretching of the lithosphere and thermal decay, mineralogic al phase transition in the crust, magmatism and eclogitization-induced mantle flow in the uppermost mantle, subduction under the platform an d continental collision. While some features of basin evolution are in good agreement with one of the mechanisms, no specific model can expl ain all features of the platform basins. Magmatism-eclogitization mech anisms are likely to be responsible for the Devonian subsidence of the Dnieper-Donets, Timan-Pechora, and Pre-Caspian basins, whereas the su bduction-induced mantle flow may explain the Devonian to Permian subsi dence of the Moscow basin and Pre-Ural depression. (C) 1998 Elsevier S cience Ltd. All rights reserved.