A NEW HOMOLOGOUS SERIES OF HOPANOIDS (hydrocarbon biomarkers) IN OILS AND NATURAL BITUMENS OF THE NORTHEASTERN SLOPE OF THE ALDAN ANTECLISE
V.A. Kashirtsev1,2, I.N. Zueva2, O.N. Chalaya2
1A.A. Trofimuk Institute of Petroleum Geology and Geophysics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
2Institute of Oil and Gas Problems, Siberian Branch of the Russian Academy of Sciences, Yakutsk, Russia
Keywords: Oil, natural bitumen, hydrocarbon biomarkers, Aldan anteclise
Abstract
Oil and bitumen shows with previously unknown hydrocarbon biomarkers - 9-methyl, 8-14-secohopanes - were encountered in the sections of hydrogeological wells on the northeastern slope of the Aldan anteclise. Shows of biodegraded asphaltites are confined to the cavernous horizon in the middle Cambrian limestones of the Tankhai Formation. The relatively high residual concentrations of the “new” biomarkers are due to their very high resistance to biologic oxidation processes. Geologic materials and geochemical data on the studied naphthides suggest that in the region under consideration there is a typical oil deposit sealed in the “head” of the cavernous horizon by highly viscous bitumens.
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