Are the Jurassic Source Rocks Contributing to Oils in Western Peloponnese and Ionian Islands? New Evidence

The multiple hydrocarbon indications throughout Western Greece, the Katakolo oil field offshore west Peloponnese, and the well documented source rocks (SR) all suggest an active petroleum charge system. However, the complex geology (thrust and fold belt) and the salt tectonic movements make the oil-to-source rock correlation substantially challenging. The subject of the present study is to challenge the existing interpretation and assess potential kitchens. The examined SR samples are from wells and outcrops covering the period from upper Triassic to upper Miocene. Hydrocarbon samples include oils from shallow wells on Zakynthos, asphalts, and extracts from Eocene impregnated limestones from outcrops along the west coast of Peloponnese. The rock samples were studied by applying Rock-Eval 7S and organic petrography, whereas GC/GC-MS were applied for the oils/asphalts and extracts. The results of this study suggest a strong correlation of the examined oils/asphalts with the Jurassic SR intervals of the Ionian basin and the most external part of the fold and thrust belt (FTB). No correlation to Miocene SR intervals was observed. The study also grouped the oils from Zakynthos and Kyllini into the same family. The high SI and the organic sulfur-rich kerogen low activation energies suggest a low-temperature oil generation.