LANDSCAPES OF EARLY DEVONIAN SEAS IN SIBERIA

Abstract

Based on the analysis of spatial-temporal distribution of Tabulata and other benthic organisms, organogenic buildups, and lithologic data, position and configuration of seas and continents are depicted for Early Devonian Siberia. Paleolandscape maps of Siberian seas are compiled for the Lochkovian and Emsian ages. The Salair, West Siberian, Taimyr, and Middle Siberian seas were characterized by nine landscape types in the Lochkovian and twelve landscape types and several landscape areas in the Emsian. Their characteristics are inferred from data on the distribution and boundaries of paleolandscapes, peculiarities in sea bottom morphology and substrates, location of zones with active tectonic movements and intense volcanism, hydrodynamics, salinity, temperature and illumination of bottom waters, and on the peculiarities of the benthic population. Formation zones of organogenic buildups are outlined, and the Siberian sea is shown to have been a part of the subtropical belt. Four correlative intervals, each of which is characterized by similar Tabulata species, correspond to the early Lochkovian, late Lochkovian, early Emsian, and late Emsian time ranges.