Microfacies evidence for a Late Cretaceous Apulian-type carbonate platform paleoenvironment in Kephalonia (Western Greece, Ionian Sea)

This study aims to investigate the presence of Cretaceous carbonate platform facies on the island of Kephalonia, which was previously thought to belong entirely to Pre-Apulian slope domains. Such presence may have a deep impact on the regional oil and gas exploration, since Mediterranean Cretaceous reefs have often proved to be excellent reservoir units (e.g., Zohr Field). Micropalaeontologic, sedimentologic, microfacies and geochemical indicators all show that, on the westernmost part of the island, Campanian-age inner platform to platform margin facies are present (Area 1 or “Argostoli platform”), with a shift to progressively more distal time-equivalent Pre-Apulian units eastwards (Areas 2-4). The Argostoli Platform, in western Kephalonia, is characterized by clear evidence of inner platform to platform margin facies, including possible peritidal cycles and redded palaeosol layers intercalated with thick-massive limestone beds, with above-background concentration of Fe2O3, Al2O3, TiO2, SiO2. In this area, microfacies are attributable to inner platform to platform edge, including wackestones/floatstones (FZ7, SMF9), grainstones-grapestones (FZ7, SMF 16, 17), oolitic rudstones/grainstones (FZ6, SMF15) and boundstones (FZ5, SMF7), with bryozoans, mollusks and miliolidae. The Argostoli Platform may represent the easternmost edge of the Apulian Platform and may belong to the Apulian Domain rather than to transitional Pre-Apulian units.