Features of spatial changes in the phosphate content in the cultural deposit as reflecting the infrastructural organization of sites (on the example of the Bronze Age settlement Kamenny Brod)

Occupation layers of ancient settlements have been preserved at many sites of the settlement type. Built into the system of natural horizons, occupation layers serve as objects of both soil studies (soil and subsoil) and archaeology (occupation layers with artifacts). Such layers are anthropogenically transformed horizons that still exist. We have examined the Bronze Age occupation layer at Kamennyy Brod, which is a multi-layer site located in the Arkaim valley in the south of the Chelyabinsk region. This unfortified settlement is a satellite site of the Arkaim fortified settlement, its main archaeological horizon is represented by the eponymous culture. Neolithic layers, thick Bronze Age layers cut across the settlement soil profile, with the topsoil demonstrating modern soil formation processes. The paper describes enrichment of the main occupation layer with organic matter and phosphates and presents distribution of these characteristics across the area of the excavation trench section. It was found that the phosphate enrichment of the layer correlates well with the archaeological schematic drawings of the excavation trench. An elevated content of labile phosphates was identified both inside the dwellings and in the inter-dwelling spaces. Enrichment with organic matter was discovered both near a set of stoves inside the dwellings and outside the dwellings near the walls. At the same time the sections outside the dwellings enriched with phosphates and organic matter do not coincide suggesting different use of these spaces in the past. The clear-cut division of space into sections used for various household and economic purposes is characteristic of both the spacing inside the dwellings and the spacing outside them.