Natural environment of MIS 5 and soil catena sequence along a loess slope in the Seret River valley: Evidence from the Pronyatyn Palaeolithic site (Ukraine)

Abstract

The Middle Palaeolithic site in Pronyatyn village is situated on the Ternopil Plateau, on the eastern, long and straight slope of the Krucha Gora hill (369.5 m a.s.l.). The structure of loess cover in this area was investigated in the series of archaeological excavations to a depth of 5–6 m in 1977–1985, 2010 and 2011. Lithological, palaeomagnetical and palynological analyses, as well as TL dating were carried out in the selected profiles. In all profiles, under thin cover of loess from the last aeolian deposition sub-cycle (MIS 2), a set of soils of S1 = Gorohiv s.l.; (MIS 5 complex) exists. This complex is composed of interglacial and interstadial units. Forest and forest-steppe vegetation, followed by a rich steppe with the continuous occurrence of trees and shrubs and without subarctic elements, developed during the stages of its formation. Based on the investigations of loess cover carried out over a large area, it was found that all sequences are spatially diversified in the profiles located along and across the slope in the middle part of this area. This diversity resulted from the development of pedogenetic and slope processes, depending on morphological features of individual slope segments. In the southern part of the study area, outside the extent of artifact occurrence, the deposits representing MIS 5 are undisturbed or slightly disturbed and contain a loess-soil sequence, which is composed of the interglacial Cambisol (with evidence for the Blake palaeomagnetic event) and 2–3 interstadial soils. Artifacts were discovered in the northern and northwestern parts of the study area, within a solifluctionally redeposited chernozem occurring on a denuded Luvisol. Based on the analysis of the artifact collection, the flint industry is the Western-Podolian, Levallois, radial-parallel, flakes-and-blades, without two-sided tools and with domination of knife-like products on Levallois blanks. This suggestion of the flint industry age as within the younger part of MIS 5 is supported by TL dates. It is most possible that this settlement took place in MIS 5c. Based on spatial distribution of artifacts, state of their preservation, and the features of solifluction deposits representing the younger part of MIS 5, we conclude that the site was originally located on the slope above the excavation area, about 30–50 m to the west.

Introduction

Pedons as indicators of environment features and dynamics of its functioning are one of the sources of information about natural environments and enable us to reconstruct their development in space and time. The analysis of spatial variability of soil cover, which is influenced by other environmental components, is of essential importance. The analysis of linear objects, i.e. catena patterns of soil cover, is of great importance to palaeogeographical studies of past environments. A catena is the sequence of soils that developed from similar parent material under similar climatic conditions along a slope, and soil variability in a catena mostly depends on relief and relief-related environmental features such as relative height, slope angle, and water circulation, which influence soil-forming processes (Milne et al., 1935, Wieder et al., 1985, Kowalkowski, 2000, Degórski, 2003). In this paper, we report the results of a research on the fossil soil catena sequence from MIS 5 developed along loess slope in the Middle Palaeolithic site at Pronyatyn on the Seret River (Podolia Upland) (Fig. 1).

The Pronyatyn site is located within a hill with loess mantle where years ago a brickyard existed. Exploitation was abandoned in 1976. The first archaeological finds were discovered in this site in 1969: mammoth tusk, bones of primitive horse, and reindeer occurred at a depth of 3–4 m. In 1977, O. Sytnyk discovered the redeposited Middle Palaeolithic artifacts at a distance of 60–80 m from the mentioned bone finds. That discovery was the reason for undertaking regular archaeological excavations in 1977–1981 (Sytnyk, 2000, Sytnyk et al., 2011a, Sytnyk et al., 2011b).

Rich archaeological materials were discovered only within the disturbed or redeposited deposits of the Gorohiv pedocomplex (MIS 5) so the problems arose with the determination of geological position and age of the Middle Palaeolithic cultural layer at Pronyatyn. As the stratigraphic situation of the archaeological materials was unclear, we undertook new research (with the use of different geological methods) in 2010. Based on all investigations, the middle part of the catena (110 m long and 30 m wide) was described. We found undisturbed layers of deposits corresponding to MIS 5, so it was possible to reconstruct the palaeogeographical conditions of deposition and pedogenesis (Sytnyk et al., 2011b). The purpose of the present study is to reconstruct spatial and temporal changes in the examined part of the catena, and to use this data for determination of the original situation and stratigraphic position of the archaeological materials.