Exploration for Gas Generation Potential and Geochemical Signatures of Neogene Clastic Deposits from Gavdos Island, Greece, Eastern Mediterranean

The latest exploration developments and discoveries from the eastern Mediterranean documented that Neogene formations can act as source-rocks for hydrocarbon generation and their exploitation delivered large amounts of mostly biogenic gas to the market. Examples of such offshore gas-fields include the Zohr-Egypt, Leviathan/Tamar-Israel, and Aphrodite-Cyprus. Having attracted the oil majors’ attention for hydrocarbons exploration in southern Greece (e.g., Exxon-Mobil, Chevron), by using onshore geologic analogs, we suggest relevant perspectives in the country’s offshore sector. Our study focuses on Miocene marine deposits exploration, from Gavdos Island, southern Greece, evaluating their characteristics as potential source-rocks affected by a paleodepositional framework. By integrating fieldwork, organic (Rock-Eval VI-pyrolysis, CHNS) and inorganic geochemical data (XRF), the current results indicate gas-prone organic matter with variable preservation status, reflecting a few oxidation episodes during deposition under generally dysoxic-to-suboxic conditions. Paleoclimatic weathering indices (CIA, C.I., Sr/Cu, Rb/Sr) suggest predominantly arid to semi-arid regimes punctuated by short-lived humid phases that locally enhance organic accumulation and nutrient supply. Variations in paleosalinity and stratification, particularly within the Messinian section, are interpreted as precursors to the Messinian Salinity Crisis. Our findings highlight the potential for hydrocarbon-prone intervals in the deeper-offshore Eastern Mediterranean basins, where most favorable conditions for organic-carbon preservation and maturation are documented by the discoveries.