TECTONIC EVOLUTION OF THE ARCTIC SHELF OF SIBERIA FROM RIPHEAN THROUGH MESOZOIC TIME

Abstract

Paleotectonic structures are a most important factor to be considered during geological exploration for oil, gas, and other mineral resources, particularly for studies in the vast, but poorly accessible Arctic shelves. The authors have treated the paleotectonic evolution of the Arctic shelves of Siberia on the basis, of a three-dimensional tectonic model of the region, which consists of an assemblage of tectonic maps for specific stages, each representing a specific surface within the sedimentary-metamorphic envelope. The surfaces mapped in each case correspond to the top of one of the tectonic megacomplexes (Baykalian, Caledonian, and early Hercynian, late Hercynian, and Mesozoic) and reflect levels of the most significant gross changes in the crustal evolution of Siberia. The megacomplexes in their turn consist of tectonic complexes, separable on the basis of structural-material characteristics, which reflect a particular tectonic regime. As a synthesis of modern geological and geophysical data, the assemblage of tectonic maps depicts the principal features of the evolution of the Arctic shelves in Siberia during the Riphean-Mesozoic interval, that is, prior to the development of the oceanic basins and the formation of a specific syn-oceanic complex of Danian-Quaternary sediments on the shelves. 15 references.