Revised stratigraphy and palaeogeography of the Rostan Hills in northwestern Ukraine

Abstract

This paper presents a new approach to stratigraphy and palaeogeography of NW Ukraine. So far, the glacial landforms near the Rostan area have been interpreted as end moraines derived from the Saalian ice-sheet. Sedimentological and petrographic analyses conducted at the Rostan site shed new light on the dynamics and age of the ice-sheet that formed the examined glaciogenic forms. Sedimentological analysis of glacial deposits documented the sedimentary environment of a glaciofluvial fan deposited by the ice-sheet front characterised by varying dynamics, i.e. advancing, stationary and retreating. Petrographic analysis proved an older age of deposits, i.e. Elsterian, and not Saalian as interpreted so far. These results shed new light on palaeogeography and stratigraphy of this area. The occurrence of the Elsterian deposits on the surface gives evidence of the absence of younger – Saalian – glaciation in this area, which relates to the recently announced new approaches to palaeogeography and stratigraphy of neighbouring areas in eastern Poland.