Content of Natural Hydrocarbons in Arctic and Subarctic Soils

The assessment of the natural background of the hydrocarbon (HC) content in soils is an urgent task, the solution of which will allow us to objectively determine soil pollution and promptly introduce restrictions on industrial technologies of oil production, transportation and refining. The purpose of this work is to assess the background content, to establish patterns of accumulation of HCs in the arctic and subarctic soils, taking into account the landscape–geochemical characteristics of the territories. The concentration of HCs in soil samples was determined based on the values of the fluorescence intensity of the hexane extract. It has been established that the accumulation and distribution of HCs in the soil cover depend on several factors: the relief of the territory and the nature of the soil formation, the particle size distribution of the soil-forming rocks and the content of soil organic matter. The maximum HC content was detected in the soils of accumulative landscapes and the minimum in soils of eluvial territories. Differentiation of HCs over genetic horizons is more flagrant in soils formed on loams and less on sandy rocks. We created a database and a map for the distribution of the natural HCs in the soils of Komi Republic.