Organic geochemistry and petroleum source rock potential of Late Paleozoic lacustrine sediments: Examples from the Sudetic basins, Poland and the Stellarton Basin, Nova Scotia, Canada

The primary goal of this study was to identify the geochemical characteristics of Late Paleozoic lacustrine sediments and to determine their petroleum source quality. This goal was accomplished through detailed organic geochemical profiling of individual lacustrine sequences. Large lacustrine deposits of late Paleozoic age, associated with the supercontinent Pangae, are found in South America, eastern Canada, NW Europe, western China and east Africa. From these known present-day geographic locations, the Sudetes area of southwestern Poland, and the Stellarton Basin of northern Nova Scotia, were chosen as study areas for this project because the sequences in Poland had not been previously studied geochemically while there was exclusive availability of core material from Nova Scotia and limited geochemical studies.;The results of this dissertation showed that major differences exist in the various geochemical signatures of lacustrine and marine sedimentary rocks, which can aid in distinguishing between the two types of rocks and their paleoenvironments. The preserved organic matter in lacustrine sedimentary rocks is a mixture of both aquatic and terrestrial plant detritus. The former can occur either as algal lipids or bacterial lipids while the latter represents bordering vegetation that was transported into the lake. The results also highlighted the dangers of indiscriminately applying previously published interpretations when using specific biological markers as indicators of either organic matter input or paleoenvironment. The water chemistry of lakes is highly variable, due partly to their immediate and drastic response to both climatic change and seasonal variations in hydrological input. Organofacies within lacustrine sequences can therefore be expected since lake-level fluctuations can control both productivity and preservation potential. The source rock potential of lacustrine sediments as a whole is promising as they have been shown to contain mostly hydrogen-rich, oil-prone kerogen. (Abstract shortened by UMI.).