Oil of the volcano Uzon caldera, Kamchatka

There are reported gas chromatography, gas chromatography/mass spectrometry and carbon isotopic data on the oils sampled in caldera of the Uzon volcan o (East Kamchatka). The Uzon volcano is located in the west of the eastern Kamchatka basin which is made up of thick Paleogene-Neogene sedimentary roc ks. Its caldera is made up of lacustrine volcanogenic-sedimentary formation s of Pleistocene age (38-70 thousand years), lying on dense basalts. Two sa mples studied were heavy oils (0.915 g/ml) and contained 2% sulfur; 2.5% pa raffin, 9.3% waxes; 1.4 wt% olefinic hydrocarbons. Their eas chromatograms show a mono-modal distribution for n-alkanes with a maximum at C-18. Prista ne/Phytane concentration ratios were measured to be 0.48-0.52. Olefinic hyd rocarbons were interpreted to be of hydrothermal origin. Sterane and triter pane biomarkers indicated a low maturation degree and a lacustrine origin o f the initial organic matter. The Uzon oil was found to be isotopically hea vy with a delta(13)C value of -21 parts per thousand. C-14 isotope was dete cted, which indicates that recent plant organic matter was significantly in volved in oil generation process. (C) 1998 Elsevier Science Ltd. All rights reserved.