A comparative organic geochemical study of oils seeps in Western GreeceA comparative organic geochemical study of oils seeps in Western Greece Peer-Reviewed Journal Publication Δημοσίευση σε Περιοδικό με Κριτές 2018-10-222016enSamples from three oil shows in Western Greece were studied following a suite of analytical geochemical procedures, aiming to reveal the origin of the organic matter and characterize its depositional environment. The authors findings were compared, and confirmed to a great extent, to geochemical results from previously published studies. Certain compositional differences exist between the three oil shows, reflecting different source rock and/or different facies. The influence of different analytical methodologies commonly used to separate compound groups (saturates, aromatics, resins, asphaltenes) on the obtained geochemical indices was also examined. The results demonstrate that bulk composition of maltenes, as well as most biomarker indices, are not affected significantly by the employed group-type separation procedures.http://creativecommons.org/licenses/by/4.0/Energy Sources, Part A383362-369 Pasadakis Nikos Πασαδακης Νικος Ntagounaki Vithleem Νταγκουνακη Βηθλεεμ Chamilaki Eleni Χαμηλακη Ελενη Taylor & Francis Biomarkers Gas chromatography Ionian zone Oil seeps Western Greece Mass spectrometry