The pollution of the environment by technogenic hydrocarbons (TH) represents one of the most complicated ecological problems of recent decades (especially for northern territories).

The oil-gas condensate deposits at the north of Western Siberia are the most powerful pollution "suppliers" for forest-tundra landscapes, of which the soil cover is predominated by peat and tundra gley soils with active reduction and freezing processes.

The oil-gas condensate deposits possess the greatest number of different types of technogenic flows with TH in various concentration among all the possible types of hydrocarbons fields.

The analysis of the data of TH content in vertical profile of polluted soils shows:

1. Just after the start of pollution, the maximum concentrations of pollutants are observed in the upper organic horizons of peat and tundra gley soils, reaching (due to the composition and volumes of pollution and genetic properties of horizons) values up to .7 - 46.2% and even more of the air dry soil weight.
2. The radial migration of TH into lower horizons (H) of these soils leads to a gradual increase in their contents up to .6 - 16.5% of the air dry soil weight, which, in turn, can increase pollution concentrations in the upper horizons.
3. The wide-spread permafrost in the profile of the peat soils of forest- tundra landscapes encourages the active pollutant accumulation above the low-temperature permafrost barrier, where the TH quantity can exceed the content in upper horizons 1.7-13 times.
4. In the tundra gley soils with active reduction processes in mineral horizons, in the initial stage of pollution an intense accumulation of pollutants is observed at the boundary with gley (G) horizons. The hydrocarbon content within the gley layer does not exceed the background concentrations (.005-.08% of air dry soil weight).
5. While "processing" the soil mass by technogenic flows a gradual penetration of hydrocarbons into gley layers takes place, and their content in these horizons may increase more than 4.3 times.
6. The revealed peculiarities of TH distribution through the vertical profile of polluted peat and tundra gley soils of forest-tundra landscapes of Western Siberia show a good correlation with data obtained for other regions (Solntseva, 1995) with comparable soil types.

Alexandr P. Sadov
Department of Landscapes Geochemistry
Faculty of Geography
Moscow Lomonosov State University
Moscow, 119899, Russia
Phone: (095) 939-2131
Fax: (095) 939-0126
E-mail: boch@imb.imb.ac.ru