GEOCHEMISTRY OF THE ORGANIC MATTER OF ULUG-KHEM BASIN COALS
D.A. Bushnev1, S.A. Ondar2, N.S. Burdel'naya1
1Institute of Geology, Komi Science Center, Ural Branch of the Russian Academy of Sciences, ul. Pervomaiskaya 54, Syktyvkar, Komi Republic, 167982, Russia
2Tuvinian Institute for Exploration of Natural Resources, Siberian Branch of the Russian Academy of Sciences, ul. Internatsional’naya 117a, Kyzyl, 667007, Russia
Keywords: Organic matter, coal, Ulug-Khem Basin, Tyva
Abstract
The composition of the organic matter (OM) of coals in the Ulug-Khem Basin has been studied. According to Rock-Eval pyrolysis data, this OM is a type III kerogen, sometimes significantly oxidized. The coal of low-grade metamorphism has a high hydrocarbon potential. Based on the gas-liquid chromatography and chromatography-mass spectrometry data on the distribution of n-alkanes, isoprenoids, polycyclic biomarkers, and aromatic hydrocarbons, we have established the composition of the primary OM of the coals and the grade of OM metamorphism. The primary OM of the coals consists mainly of remains of aquatic vegetation and terrigenous OM. The latter includes conifer remains, which are identified from the presence of 4β(H)-19-norisopimarane in the aliphatic fraction of bitumen and from the domination of retene over cadalene and 6-isopropyl-1-isohexyl-2-methylnaphthalene in the aromatic fraction.
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