PALEOGEOGRAPHY FEATURES OF TOURNASIAN-VISEAN TIME OF THE AREA OF MECHEDIVSKO-SVIRIDIVSKA SADDLE AND ADJACENT TERRITORIES.

Abstract

For detailing of Tournasian-Visean paleogeographic patterns of the north-western tectonic segment of the Dnipro-Donets depression data of quantitative spectral analysis of core samples have been used. Distribution of the groups of elements Ti, V, Mn, Ni, Co, Cr and Sr, Ba, Mn inside main lithological rocks types (sandstones-siltstones-argillites-carbonates) with taking into account factor of mono-minerality, are show the rate of intensity the physical/chemical weathering and allow to trace contours of catchments. The ratio Sr/Ba was used for definition of paleo-shore borders and delta-avandelta facies. Absorption of alkaline-earth elements (in particular Ba) from aqueous solutions in areas of mixing of saline and fresh waters is reflected in sporadic peak concentrations last ones in cement of sandstones and siltstones and, to a greater extent in higher background concentrations in argillites. Containing in solutions Ba were transported from feeding areas including as well magnetite ore fields of Voronezh anteclise, as evidenced by the established. Paleogeographic sketches were supplemented by analysis of textures by core samples and petrographic descriptions of thin sections. The conducted studies allowed to supplement and substantially elaborate the existing no-tions about the lithology and paleogeography of the north-western tectonic segment of the Dnipro-Donets depression during Tournasian-Visean. The alluvial plains on the territory of the axial and side parts of Dniprо-Donets depression were widely distributed in this time as well the presence of a desalinated sea basin on the territory of the Srebninska and Zhdanovska depressions has noted. Last one in particularly have been testified by presence of alluvial-delta and avandelta deposits of Mеchedivsko-Svуrуdivska saddle.