Palaeoenvironment of the Late Pleistocene - Holocene interval in the Tanalyk river valley of the Southern Trans-Ural region (Russia)

摘要

Palaeoenvironmental reconstruction of the Tanalyk River valley (Trans-Uralian area, Bashkortostan Republic, Russia) between the Late Pleistocene and the Late Holocene has been established through biostratigraphic investigations. The Tanalyk Bronze Age settlement is located on the first overflood terrace of the Tanalyk River. From the base to the top, this terrace consists of fluvial and lacustrine deposits of the Tabulda horizon, water-slope deposits of the Kudashevo horizon (Late Pleistocene), and subaerial deposits of the Middle and Upper Holocene. During the Late Pleistocene, open landscapes covered by herbs-Artemisia-Chenopodiaceae meadow-steppe associations with Ephedra sp. admixture dominated. Betula and Pinus forests grew in small areas. Picea with Polypodiaceae understory grew in humid valleys. The climate was warm and dry during the Tabulda and cold during the Kudashevo. The subaerial Holocene deposits (soil and cultural layer) were correlated with the Boreal and Subboreal periods of the Blytt-Sernander scale. The late Subboreal climate was cold and dry. The vegetation of this period was represented by Artemisia-Chenopodiaceae steppe and by small Pinus forests with Betula, Tilia and Alnus. The climate of the Subatlantic was wet at the beginning and drier at the end. The vegetation of this period was represented mainly by the Artemisia steppe associations. Small mammals, and land and freshwater mollusc remains have been discovered in the same deposits and complete the palae-oecological characteristic of these periods. A cultural layer has been dated at 2830 ± 110 BP LU-3713 on bones of Equus sp. Numerous Holocene large mammal remains have been found in the cultural layer deposits, dated to Subboreal-3. The large Holocene mammal fauna is constituted of eurybiotic species and species of semi-open landscapes. Bone remains of domestic animals dominate in the collection. Pastoral farming constituted the base of the economy of this ancient people, and the role of hunting was small. The investigated area is now covered by the waters of the Tanalyk water reservoir.