Abstract
Abstract
The aim of the present study is to establish the biogeochemical characteristics of the primary soil formation, separately for natural conditions (protected areas) and urban environment (with incoming technogenic aerosols) for pedogenesis models when there is no parent rock (“upward soil growth”). This makes it possible to assess the contribution of the still poorly studied pedogenesis factors that can form the specific geochemical features of the material composition of soils non-inherited from the parent rock, and without the involvement of biogenic bottom-up migration of elements. We have studied two contrasting regions to perform a comparative analysis of pedogenesis conditions. We have compared embryonic soils on megalithic gabbro-diabase blocks in a 17th century defence wall located on the territory of a natural reserve, 1 km away from the Black Sea coast (ecologically clean area) and a 45-year solid bitumen cover between a thermal power plant and a busy railway (an industrial zone in the central part of the city). In the natural reserve, the average dust deposition rate was 0.82 um yr1 (0.082 mm/100 yr) due to stardust, atmospheric aerosols and biogenic processes of pedogenesis. The mineral part of soils, which had formed on the solid bitumen in 45 years in the city’s industrial zone, differs from the soil developed in 320-350 years without the involvement of the parent rock in the protected area by higher content of V (9 times) and Cr (2 times), as well as CaO, SiO2 and Pb. In the industrial zone of the city, emission dust mostly contributes to the accumulation of V, Cr and Cu in comparison with the pedogenesis conditions in the ecologically clean area, where the rate of solid-phase soil matter accumulation is twice lower due to background aerosols and biogenic factors.