Sedimentary model of the Staiky loess plateau, Pridniprovs'ka Upland, Ukraine

Abstract

There is still a considerable gap between sedimentologic investigations of great geologic intervals and modern sedimentary environments. which especially concerns the continental formations. Elaboration of sedimentogenic models for the small depositional bodies of the Quaternary sequence and spanned in scale from a year to 100,000 years can assist to fill up this gap. A selected study object was a complex of the Staiky Plaleau (Pridniprovs'ka Upland, the Ukraine) which has developed after the last glaciation in this area, i.e. 210-250 ka BP. This complex consists mainly of lacustrine, aeolian (loess and sand), slope wash and alluvial deposits. They form regular bodies of suites and groups of suites. defined by a spatial pattern, mode of occurrence, facies composition and lithologic features, which allow correlating. There are three sedimentary zones in the examined region. The first is a proper plateau. with a local lacustrine and then, a stable aeolian (loess) deposition. The second zone is plateau slopes with a sheet and locally, gully erosion, but prevailing aeolian and slope wash deposition. Predomination of down cutting combined with transit intermittent alluvial accumulation is the characteristics of the third zone, i.e. plateau valleys. Clastic material was derived from the areas adjoining the Staiky Plateau and from local sources. The Quaternary and the pre-Quaternary deposits were subjected to erosion, products of which were transported to lower levels of the plateau, and then they were carried out along the plateau val1eys to the Dnieper valley.