On the left bank of the Dnister River between the villages of Mezhyhirtsi and Dubivtsi (Halych district, Ivano-Frankivsk region, Ukraine) there are several large mechanized quarries, where raw materials (marl, limestone, gypsum) are mined for PJSC “Ivano-Frankivsk Cement”. It is quarries of limestones and marls of Dubivtsi Suite of the Upper Cretaceous in a lower part of a slope, and gypsum of Tyrassian Suite of the Neogene nearly in a watershed. The amplitude of maximum points of the relief above the Dnister River bed reaches 145 m and it varies in the range of 50-60 m above the oldest terraces of the Dnister River (Loyeva level), which are developed on it right bank (Dnister-Lukva interfluve). Well stratified thick (more than 20 m) Pleistocene loess-soil sequence covering almost all the Brunhes palaeomagnetic chron developed over the gypsum. In particular, it is worth noting that the covering series of sediments in the Mezhyhirtsi section does not lie on the alluvium of the Dnister, but directly on the bedrocks, i.e. outside the Dnister valley. The first general description of the Pleistocene loess-soil series in the Mezhyhirtsi section is given and the fossil malacofauna found in a number of horizons and sub-horizons is presented. There are almost all the stratigraphic horizons of the Pleistocene (from the upper horizon of the Upper Pleistocene loesses (MIS 2) to the palaeosol complex of Zahvizdia (MIS 17-21) and the sediments, which it was formed on) in the section. It is reasoned that the Mezhyhirtsi section requires a comprehensive study. It may become a key section for the Pleistocene of Halych-Dnister region – an area with a well-developed complex of Dnister terraces, a number of Upper and Middle Palaeolithic sites (Mezhyhirtsi, Yezupil I-IX, Kolodiiv, Mariampil I, V, Halych I, II and many others). There are many interdisciplinary studied sections of the Pleistocene deposits (for instance, the Kolodiiv section with a fossil Eem (Horokhiv) peatland or the Halych section with a 50-meter thick covering loess-soil series on the fifth (Halych) terrace of the Dnister River) in the region. The Mezhyhirtsi section is important because it contains the oldest part of the section of the Pleistocene in the Halych-Dnister region, as well as a few palaeobasins (above the Korshiv and Zahvizdia palaeosol complexes), the study of which may provide many new data for reconstruction of the palaeogeographical conditions of the Pleistocene within the Dnister valley and beyond it. Key words: Pleistocene, loess-soil series, key section, palaeobasin, the Matuyama-Brunhes boundary, Halych-Dnister region.
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