Biomarker features of sabkha-associated microbialites from the Zechstein Platy Dolomite (Upper Permian) of northern Poland

• Published in: Palaeogeography, palaeoclimatology, palaeoecology palaeoclimatology, palaeoecology, 2009-03, Vol.273 (1), p.92-101
• Main Authors: Maliński, Edmund, Gąsiewicz, Andrzej, Witkowski, Andrzej, Szafranek, Janusz, Pihlaja, Kalevi, Oksman, Pentti, Wiinamäki, Kirsti
• Format: Article
• Language: English
• Subjects: Cyanobacterial microbialites; Organic matter; Sabkha; Zechstein (Upper Permian) Platy Dolomite; Łeba Elevation (N Poland)
• ISSN: 0031-0182; 1872-616X
• DOI: 10.1016/j.palaeo.2008.12.005

The Zechstein (Upper Permian) Platy Dolomite deposits of the Łeba Elevation (N Poland) formed a shallow water carbonate platform developed in hypersaline peritidal arid system dominated by various microbialite lithofacies. Extractable hydrocarbons from the Platy Dolomite microbialite carbonate deposits from the Łeba Elevation (N Poland) show a predominance of even carbon numbered n-alkanes within the range of C 20 to C 30 (maximum at n-C 24). Hopanes are represented by the 17α(H), 21β(H) and 17β(H), 21α(H) series, with carbon numbers ranging from C 29 to C 35 plus minor amounts of 17α(H)-22, 29, 30-trisnorhopane, 17β(H)-22, 29, 30-trisnorhopane and gammacerane. Despite the absence of 17β(H), 21β(H) hopanes, an anomalously high content of C 29–C 30 17β(H), 21α(H) hopanes and the extent of epimerization at C-22 below the value of the equilibrium value for the C 31–C 35 compounds of both 17α(H), 21β(H) and 17β(H), 21α(H) hopane series indicate the immaturity of the organic matter. Organic geochemistry data confirm that the organic matter originated from degraded cyanobacterial and bacterial remains.