Chemical data on ashy soils as an information basis for dating archaeological sites.

As a special type of parent rock associated with human activities both in antiquity and nowadays, ash widely occurs in the settlements' functional zones and their cultural layers. Soils developed on ash deposits of various genesis can be presented as soil chronosequences, which forms an information basis for determining the time at which settlements and their economic zones went out of use ("Archaeological ash deposits and soils formed on ash in the south of the East European Plain. Quaternary International" [1]). Studies of ash deposits and soils formed on ash were conducted in three regions of the East European Plain which differ in extent of forest cover. Geochemical associations of accumulated and dispersed elements in the upper horizon of soils of different age in relation to the original ash were determined. This makes it possible to calculate the time of biogeochemical transformation of ash in the course of pedogenesis, thus offering a new dating technique for archaeologists.