Dataset on spatial variability of soil properties: Tokhmeyevo archaeological site of the Bronze Age, Chuvashia (southern fringe of the forest zone, the Russian Plain)

Geoarchaeological and palaeopedological studies focusing on the reconstruction of the Holocene paleoenvironments require a detailed knowledge of the spatial variability of soil properties both for the surface soils and paleosols buried under archaeological constructions. However, such studies are often carried out at unique sites where it is difficult to ensure the representativeness of the data obtained. In this paper, we report original data on 15 soil profiles which shows the range of spatial variability of soil properties (рН H(2)O, рН KCl, particle size distribution, depth of genetic horizons, colour codes) for both surface and buried soils at the Tokhmeyevo kurgan cemetery, located in the Middle Volga region, Chuvash Republic, Russia. The data supplement the original research [1] and also give additional detailed information on pollen and spore analysis by plant species for the humus horizons in four buried and one surface soils. All soils developed from the same lithology (mantle loam), at the same elevation, in a similar topographic position (levelled upland slope) and in proximity to each other. Both buried and surface soils, classified as Retisols [1], show slight variability in morphology and particle size distribution that varies in a similar range. However, the two soil groups (buried and surface) differ in two striking features: buried soils exhibit dark humus horizon and black humic cutans in the middle part of the soil profile; these features are absent in the surface soils. The values of рН in water and 1 M KCl suspension in the buried soils and soils of the kurgan mounds are lower than in the surface soils. The data on the spatial variation of the properties of the surface and buried soils increase the reliability of the results, making it possible to assess the extent to which the differences in soils are associated with the environmental evolution. The presented data can provide one the context for further work in paleoenvironmental studies and also be compared with other already published datasets increasing the reliability of conclusions about the trends of environmental evolution in the second half of the Holocene.