Mariusz J. Rospondek

Biomarker geochemistry of a foreland basin: the Oligocene Menilite Formation in the Flysch Carpathians of Southeast Poland

Black shales of the Menilite Formation, the source rock for oils in the Carpathian overthrust belt, display a large variability in their bulk and molecular geochemical parameters. Biomarker and stable carbon isotope analyses indicate a variable contribution from different algae (particularly dinoflagellates and diatoms) and cyanobacteria. This is reflected by specific, predominantly sulfurised biomarkers (e.g. C35 homohopanoids, C25 highly branched isoprenoids and marine n-alkanes) and by particular distributions of steranes and 4-methylsteranes comprising 24-nor- and 24-methyl-27-norcholestanes, and related, novel steranes with a methylation at C-23. The presence of hopanoids of methanotrophic origin (δ13C up to −57‰) implies a temporarily enhanced full methane cycle in a marine environment which affected the isotopic composition of organisms dwelling in the upper photic zone. The presence of isorenieratene derivatives indicate periods of euxinic conditions within the photic zone in all investigated sub-basins.

Phenyldibenzofurans and phenyldibenzothiophenes in marine sedimentary rocks and hydrothermal petroleum

Abstract The phenyl derivatives of dibenzo[ b , d ]furan and dibenzo[ b , d ]thiophene, so far not reported in geological samples, have now been identified in some sedimentary rocks, bitumen and hydrothermal petroleum through a comparison of their retention times and mass spectra with those of authentic standards. All four possible positional isomers were detected for each phenyldibenzo[ b , d ]furan (PhDBF) and phenydibenzo[ b , d ]thiophene (PhDBT). Their elution sequence is 1-, 4-, 2- and 3-phenyldibenzo[ b , d ]furan and 1-, 4-, 2- and 3-phenyldibenzo[ b , d ]thiophene on apolar stationary phases. In contrast to phenyldibenzofurans, the distributions of the thiophene series is controlled mainly by the organic matter maturity. In the most mature samples 4-, 2- and 3-PhDBTs prevail over 1-PhDBT, while less mature samples contain mainly 4-PhDBT or 1-PhDBT and 2-, 3-PhDBTs occur at comparable concentrations. However, in samples of low maturity, in addition to the phenyldibenzo[ b , d ]thiophene C 18 H 12 S series, other structural isomers of C 18 H 12 S possessing very similar mass spectra were detected. These are likely to be either naphthylbenzo[ b ]thiophenes and/or phenylnaphtho[ b ]thiophenes. PhDBFs and PhDBTs are likely to be intermediate products in the formation of more condensed heterocyclic polycyclic aromatic compounds like triphenyleno[1,12 −bcd ]thiophene and triphenyleno[1,12 -bcd ]furan, and benzobisbenzofurans and benzobisbenzothiophenes, which are commonly detected in geological samples.

The role of organically bound sulphur in stratiform ore sulphide deposits

Abstract Low- and high-molecular-weight organic sulphur compounds were analyzed in a selected number of samples of the Permian Kupferschiefer (Poland). Their significant presence in these mature samples supports the hypothesis that during deposition, and shortly thereafter, labile organic sulphur compounds must have been very abundant. This assumption has led to a new model for metal accumulation, based on a slow and gradual release of sulphur from these labile organic sulphur compounds during increasing diagenesis.

Novel C26 highly branched isoprenoid thiophenes and alkane from the Menilite Formation, Outer Carpathians, SE Poland

A novel C26 HBI alkane [2,6,10,13,14-pentamethyl-7-(3′-methylpentyl)pentadecane] and C26 highly branched isoprenoid (HBI) thiophenes, possessing the same carbon skeleton, have been tentatively identified in sediments of the Oligocene Menilite Formation of the Outer Carpathians, SE Poland. The structural identity of these compounds has been assigned by mass spectral and relative retention time data, and by desulfurization followed by hydrogenation of the C26 HBI thiophenes. The C26 HBI compounds show structural similarities to known C25 HBIs but possess an additional methyl group at C-13. The identical thiophene isomer distribution and similar stable carbon isotope compositions of the C25 and C26 HBI thiophenes point towards a biological HBI precursor polyene with double bonds in the same position, probably originating from the same diatom species.