The Isotopic Composition of Carbon in Soil Lipids in the Oil and Gas Development Area in Volgograd Oblast, Russia

Research data on the isotopic composition of carbon in soil lipids in the Zhirnovskoe and Bakhmet’evskoe oil and gas fields in the Medveditsa River basin, Volgograd oblast, Russia, are analyzed. Oil and atmospheric soil pollution is recorded. The variations in the isotopic composition are determined by both anthropogenic factors and the diversity of natural conditions. The isotopic composition of carbon in the lipids of the interfluvial soils (chernozems) is heavier (–26.9 to –29.2‰) than that in the alluvial soils (–29.4 to –31.3‰) because of the differences in the moistening and temperature conditions. Oil pollution appears as a lighter isotopic composition (–29.3 to –29.8‰) since oil isotopic composition is in general somewhat lighter (–28.4 to –30.6‰) as compared with unpolluted soils. Urban and transport infrastructure makes the isotopic composition of atmospheric CO2 lighter, thereby influencing the δ13С values of plants and soils.