Organic geochemistry of the Upper Miocene-Lower Pliocene sedimentary rocks in the Hellenic Fold and Thrust Belt, NW Corfu island, Ionian sea, NW Greece
The northwestern margin of the Hellenic Fold and Thrust Belt situated along the southern edge of the Dinarides – Albanides - Hellenides continental convergent zone, has been studied in terms of its hydrocarbon generating potential. More than a hundred (100) samples of the Upper Miocene-Lower Pliocene sedimentary rocks from several sites in Corfu Island were analyzed using Rock-Eval VI pyrolysis, while a selected representative group was further analyzed using bitumen extraction, open column chromatography and gas chromatography-mass spectrometry. Results of this investigation revealed units with sufficient organic material of good enough quality and quantity to be considered as potential source rocks. A general Type III kerogen was identified, indicating terrestrial origin of the organic matter. Tmax and Production Index values further indicate that the most promising parts of the sediments are immature with respect to oil generation and have not experienced high temperature during burial. n-alkanes distribution for selected samples of the Northern Miocene to Pliocene mudstones present dominance of the long-chain components. Immaturity of the organic matter is also evident by the low Pr/Ph and 20S/(20S + 20R) steranes ratios.