Geochemical Soil Analysis and Environmental Reconstructions at the Neolithic and Chalcolithic Settlement Kochegarovo-1 in the Forest-Steppe Zone of Western Siberia

Geochemical Soil Analysis and Environmental Reconstructions
at the Neolithic and Chalcolithic Settlement Kochegarovo-1
in the Forest-Steppe Zone of Western Siberia

DOI: 10.17746/1563-0110.2017.45.2.035-044

L.R. Bikmulina¹, A.S. Yakimov^{1, 2}, V.S. Mosin³, and А.I. Bazhenov^1
1Earth Cryosphere Institute, Siberian Branch, Russian Academy of Sciences, Malygina 86, Tyumen, 625026, Russia
²Tyumen State University, Volodarskogo 6, Tyumen, 625003, Russia
³South Ural Department of the Institute of History and Archaeology, Ural Branch, Russian Academy of Sciences, Pr. Lenina 76, Chelyabinsk, 454080, Russia

This article outlines the results of the analysis of cultural layers and natural soil horizons at the Neolithic and Chalcolithic settlement Kochegarovo-1, and of the modern soil in its vicinity. The distribution of chemical elements and the associated geochemical ratios in the archaeological profile were compared to the background values. Six chemical elements (phosphorus, potassium, calcium, magnesium, manganese, and strontium) form distinct concentration-zones within the Neolithic and Chalcolithic cultural layers, especially within the latter. The most informative geochemical ratios are CIA (Chemical Index of Alteration), Rb/Sr, Ba/Sr, MnO/Al₂O₃, (CaO+MgO)/Al₂O₃, and Zr/TiO₂. They allow us to reconstruct environmental conditions and subsistence activities at the site, which evid ently emerged in the Neolithic when the hydrological situation of the region had changed. After the channel of the Miass River had migrated, new areas of land with semi-hydromorphic landscapes were exposed. The seasonal Neolithic camp was located on the river bank. In the Chalcolithic, the Miass River had continued to recede, and new areas of land appeared near the settlement. The environment remained semi-hydromorphic. The peak of subsistence activities, evidenced by maximal settlement area and largest estimated population size, coincided with the Chalcolithic, when occupation became permanent. Indicators of anthropogenic impact are present at all stages of occupation, especially at the Chalcolithic stage. The analysis confirmed that Neolithic and Chalcolithic populations of the region subsisted by hunting, gathering, and fishing.

Keywords: Cultural layer, soil, chemical elements, geochemical ratio, Neolithic, Chalcolithic, forest-steppe, Western Siberia.