ИСТИНА

Anthropogenic soils and soil-sedimentary systems (cultural layer, occupation deposit) in settlement archaeological settings are highly valuable and underappreciated archives of past environments, land-use activities, and life cycles within past residential areas. This study is aimed to reconstruct fire history and paleoenvironment for the early medieval town of Dzhankent located in the Eastern Aral region, Kazakstan as based on the C14 dated stratigraphy, morphology and micromorphology, geochemical data, charcoal morphology, C:N, δC13 and phytolith records. Several sections of cultural layers were studied within excavated areas. Stratigraphic units were thoroughly C14 dated (58 dates). Most 14C dates are between the 7th and 10th centuries, and most of the dates have overlapping intervals of calibrated age although clear up-section trends from older to younger ages may be seen. This demonstrates the slow, progressive accumulation of occupation deposits. The analyzed excavation sections are very well stratified. Stratigraphic units based on char-enriched marker beds could sometimes be traced for long distances. Char enriched layers contain enormous quantities of both grass and wood charcoals. Thin, about 1 m long lenses of ash and charcoals of poor and unified taxonomic variety are thought to be fireplaces. Extended thick char-enriched layers (about 10 meters long and 0,1 m thick), well stratified at macro-, and micro-levels, with sub-parallel oriented charcoals of highly variable taxonomic compositions considered to be traces of big fires. Three fire events were detected based on the stratigraphy, morphology, charcoal amounts, C, N and C13 isotope depth variability. High contents of carbonates, presence of gypsum, high electroconductivity of water extracts (high contents of readily soluble salts), and relatively high mean values of δC13 in more than 4 meters soil-sedimentary sequences indicate persistently arid climate. The regular presence of salt-tolerant Tamarix among identified charcoals testifies salty habitats and desert landscapes. Appearing charcoals of almond wood Ulmus and Hippophae along with slightly risen δC13 in layers dated as the first half of the 10th century indicate relatively less arid conditions than today. Phytolith analysis revealed evidence of initially huge amounts of plant material, Phragmítes in particular, accumulated within habitation deposits. It can be the indirect witness of rather productive phytocoenoses in close vicinities of the settlement. Taking into account geochemical and plant indicators of arid climate this is only possible in water-related environments. Regular occurrence of sponge spicules and diatom shells in the cultural layers also support freshwater reservoirs in close vicinities of the settlement.