25th International Meeting on Organic Geochemistry IMOG 2011

P-107
Caldera of the Uzon volcano as a natural laboratory of the
modern oil formation
Alexey Kontorovich 1 , Svetlana Bortnikova 1 , Gennadii Karpov 2 , Vladimir Kashirtsev 1 ,
Elena Kostyreva 1 , Alexander Fomin 1
1 Institute of Petroleum Geology and Geophysics SB RAS, Novosibirsk, Russian Federation, 2 Institute of
Volcanology and Seismology FEB RAS, Petropavlovsk-Kamchatsky, Russian Federation
The advocates of abiogenic origin of oil
frequently give examples of naphthide occurrence in
the craters of modern volcanoes. Authors selected
and examined oil shows from the caldera of the Uzon
volcano (Kamchatka). The hydrocarbon type content
of oil shows is dominated by hydrocarbons (HC) (90-
93%). The concentration of saturated hydrocarbons
by weight in them is two times as much as that of
aromatic ones. The concentration of heterocyclic
compounds is 7-10%. Few asphaltenes are present in
the examined samples (< 0,3%). The composition of
saturated and aromatic hydrocarbons of oil shows in
the Uzon volcano caldera shows that they have been
derived from lipids of land plant remains brought into
sediments (the ratio of sterane concentrations
С29/С27>2,5, tricyclane index 2(С19+С20)/ΣСi (i = 23,
24, 25, 26)>1,5, relatively high concentration of
triaromatic steroids), aquabionts, inhabitants of
caldera sediments and bottom waters (the ratio n-
С27/n-С17