Document Type

Article

Publication Date

1993

Journal / Book Title

Organic Geochemistry

Abstract

Lacustrine and marine sediments from the Permian rift-basins of southwestern Poland were analysed using GC-MS and petrographic techniques. High Pr/Ph ratios, gamma- and beta-carotanes and gammacerane in the lacustrine sediments indicate deposition under elevated water salinities. The primary organic matter is represented by bacterial and algal lipids with variable terrestrial input. Marine algal lipids with minor bacterial and cyanobacterial lipids are the primary source of organic matter in the marine sediments. Extended hopanes, n-alkanes with even-odd predominance and low Ts/Tm ratios are consistent with deposition in a closed, evaporitic basin with substantial carbonate sedimentation.

Comments

The Sudetes area of southwestern Poland consists of two major rift basins of Permian age: the Intrasudetic Basin and the North Sudetic Basin. The basins, which now occur as small NW-SE trending synclinal units, are a result of Variscan orogenic movements on the periphery of the Bohemian Massif. The Permian sediments analysed are from the continental Rotliegendes deposits of the Intrasudetic Basin and the Zechstein marine transgressive sequence from the Fore-Sudetic Monocline. The Lower Rotliegendes within the lntrasudetic Basin have three fining-upward sequences at its base, each capped by organic-rich shales of lacustrine origin, with some intercalations of limestones and coals. These lacustrine shales are known as the Lower Anthracosia, Upper Anthracosia and Walchia shales, with the Walchia being the youngest of the three (latest Autunian-earliest Saxonian).

DOI

https://doi.org/10.1016/0146-6380(93)90044-C

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