Environmental fluctuations in the West of the Tugnui-Suhara valley (on the example of the tri Skaly site in the Western Trans-Baikal) in the late Pleistocene - Holocene

The article presents results of the multidisciplinary studies conducted at the multilayered archaeological site of Tri Skaly in the Tugnui-Suhara valley (Western Trans-Baikal) in 2021. Recognition of the paleoecological conditions of human habitation in this area makes it possible to reconstruct the interconnections between humans and nature at various chronological periods in the Pleistocene - Holocene. The conducted nature-science analyses were based on the derived data on soil pH, soil granulometric structure, calcareousness, and cation-exchange capacity (CEC). The derived results together with the data on the morphology of a particular stratigraphic unit allow revealing noticeable variations of the strata characteristics, which reflect the specific conditions of deposition. Based on cumulative data of archeology and natural sciences, environmental fluctuations have been defined for several chronological periods in Tugnui-Suhara Valley. The upper part of the profile bearing materials of the medieval period and the underlying strata with the Neolithic materials have been dated to the Holocene represented by the soils of dry intermountain depressions. The middle part of the profile demonstrates alternation of short cold / warm periods characteristic for the second part of the terminal Pleistocene. The lower part of the stratigraphic sequence revealed the most abundant archaeological material. The Upper Palaeolithic materials of the Tolbaga blade-based culture have been recovered from this part of deposits. Abundant Palaeolithic artifacts are associated with two lithological layers (4a and 5) representing the Karginian interglacial deposits. The upper part (4a) was considerably redeposied during the Sartanian, the lower part contained buried soil of the Karginian interglacial. Structural elements of the cultural horizon in the form of fire places and artifact and bone concentrations were associated with the lower Karginian layer. The environmental conditions of human habitation at Tri Skaly during the Karginian interglacial have been defined as temperate, landscapes -predominantly steppe.