Phys. Geog. Geom. 2025, 48(2): 50–59

https://doi.org/10.17721/phgg.2025.48.2/130.05

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The Zhydachiv section and its significance in understanding morpholithogenic processes in the Dniester basin

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Andriy M. Yatsyshyn, Roman Ja. Dmytruk, Andriy A. Kyrylchuk, Maria V. Lialiuk  

Ivan Franko National University of Lviv, 41, P. Doroshenka St, Lviv, 79000, Ukraine

 

Abstract

The publication analyses the current state of research into the structure of fragments of the Dniester and Stryi valleys within the Stryi-Zhydachiv basin. The new section of terrace deposits we have studied, Zhydachiv, provides unique opportunities to establish: 1) the patterns of the structure of loose accumulations of one of the Pleistocene terraces of the Stryi River; 2) the location (number) of the studied terrace in the general nomenclature of terraces of the Dniester River basin; 3) improve our understanding of the course of morphogenetic processes in the basin, in particular in the Stryi and Dniester valleys in general. The upper part of the terrace deposits, represented by loess-soil cover and alluvium of floodplain and oxbow facies, is exposed in the section. The loess-soil cover consists of Holocene soil developed on Dubno (Vytchiv) fossil soil (MIS 3), which directly lies on deposits formed during the fifth oxygen isotope stage (MIS 5), namely, interlayering of interstadial soils with loess formations, which are underlain by interglacial (Eemian) forest soil. The illuvial horizon of the Eemian fossil soil is developed on loess-like deposits, which stratigraphically correspond to the upper horizon of the Middle Pleistocene (MIS 6) loess, underlain by alluvium of the floodplain facies. The alluvium of the channel facies, which is exposed by exploratory wells drilled near the quarry, is represented by an 18-metre thick layer of boulder and pebble material. The structure of the terrace's forest-soil cover provides grounds for confidently identifying it as a Middle Pleistocene fourth floodplain (Yezupil). The warm alluvium of this terrace probably accumulated during the Kaidak period (MIS 7), and the accumulation of alluvium was completed in the cold conditions of the Tiasmyn paleoclimatic stage (MIS 6). The results of studies of the Golobut, Zhydachiv and other sections indicate that the northern part of the Stryi-Zhydachiv basin is filled with alluvium, which has been deposited since the Middle Pleistocene.

Keywords

Terrace, loess, fossil soils, alluvium, Stryi Valley, paleoclimaticstage

 

Received: November 21, 2025 / Accepted: December 27, 2025 / Published online: December 30, 2025