Geochemical Characteristics of Technogenic Deposits (Cultural Layer) in the Permafrost Zone

Abstract

The geochemical characteristics of anthropogenic deposits (the cultural layer) of the urbanized area in the permafrost zone are shown on the example of the city of Yakutsk which was founded more than three hundred years ago. The presence of permafrost determined geodynamic and geochemical stability of the thickness of the anthropogenic precipitations, which differ in their chemical and mineral composition, structure, physical and mechanical properties, characteristics of migration and concentration of chemical elements. It is shown that the occurrence of anomalous concentrations of trace elements in the urban soils is determined by technological processes and peculiarities of chemical composition of the alluvial Quaternary deposits. Technogenic salinization and contrasting anomalies of toxic elements in the older parts of the city cover the soils of the cultural layer and penetrate into the upper layers of the alluvial sediments. The thickness of technogenic geochemical halos in the cultural layer depends on the age of the development of the urban area and reaches 8–10 m.