ASGP (2023), vol. 93: 447–466

GEOCHEMICAL CHARACTERIZATION AND PALAEOENVIRONMENTAL IMPLICATIONS OF LIPIDS IN NEOGENE LIGNITES AND LIGNITIC SHALES IN NW POLAND

Franciszek CZECHOWSKI (1*), Marzena POLOWCZYK (2), Bernd R. T. SIMONEIT (3), Cezary GRELOWSKI (4) & Marek HOJNIAK (5)

1) University of Wrocław, Faculty of Earth Sciences and Environmental Management, Maksa Borna 9, 50-204 Wrocław, Poland; e-mail: franciszek.czechowski@uwr.edu.pl
2) Wroclaw University of Science and Technology, Faculty of Environmental Engineering, Grunwaldzki 13, 50-377 Wrocław, Poland; e-mail: polowczyk.marzena@gmail.com
3) Department of Chemistry, College of Science, Oregon State University, Corvallis, OR 97331, USA; e-mail: simonebe@oregonstate.edu
4) Polish Oil and Gas Company, Zielona Góra Branch, Staszica 9, 64-920 Piła, Poland
5) University of Wrocław, Faculty of Chemistry, F. Joliot-Curie 14, 50-383 Wrocław, Poland; e-mail: marek.hojniak@uwr.edu.pl
*) Corresponding author

Czechowski, F., Polowczyk, M., Simoneit, B. R. T., Grelowski, C. & Hojniak, M., 2023. Geochemical characterization and palaeoenvironmental implications of lipids in Neogene lignites and lignitic shales in NW Poland. Annales Societatis Geologorum Poloniae, 93: 447–466.

Abstract: The lipophilic biomarker distributions in lipids of Neogene lignites and lignitic shales in western Pomerania and the midlands of Poland are presented. Twenty-six lignite samples and seven lignitic shales were obtained from twenty-four boreholes. Their extracts were separated, using thin-layer chromatography, and the saturate and aromatic fractions were analyzed by gas chromatography-mass spectrometry. The molecular compositions of n-alkanes, isoprenoids, n-alkylcyclohexanes, n-alkylbenzenes, tri- and tetracyclic diterpenoids, pentacyclic triterpenoids, as well as polycyclic aromatic hydrocarbons (PAHs) with up to five rings, were determined. The samples displayed n-alkane distributions in the range of C14–C35 and high odd-over-even carbon number predominances (CPI(25–33) from 2.9 to 7.9). Diterpanes consisted primarily of phyllocladane, abietane, isopimarane, labdane, and kaurane structures, although their abundances varied among the samples. Hopanes exhibited the biological and geochemical characteristics of low-maturity organic matter. Minor oleanane triterpenoids from angiosperms were also found. A few samples displayed evidence of biodegradation on the basis of the advanced isomerization of αβ-hopanes and the presence of short-chained n-alkanes, n-alkylcyclohexanes, and n-alkylbenzenes. A more mature stage of the above biomarkers also may have resulted in part from the oxidation of organic matter. The lignite source materials were derived from conifer and angiosperm flora as well as microbial remnants. The contribution from marine phytoplankton was excluded on the basis of the lack of C27 steroids. PAHs were predominantly perylene or phenanthrene, with minor other analogues. Thus, the data support progressive lacustrine/lagoonal sedimentation in the palaeoenvironmental mires.

Manuscript received 23 February 2023, accepted 5 September 2023