Pore-water indications for the occurrence of gas hydrates in eastern Mediterranean mud dome structures

Abstract

Two mud dome structures were sampled during Leg 160 to the Eastern Mediterranean. Pore waters from the Milano Dome indicate the presence of gas hydrates at relatively shallow depths in the sediment. The deep pore waters of the Napoli Dome indicate that gas hydrates are unlikely to be present >1 meter below seafloor (mbsf), whereas some observations from very shallow pore waters suggest that some gas hydrates must also be present <1 mbsf. In the case of Milano Dome, a massive cap of gas hydrates probably overlies natural gas that cannot escape because of this cap and its shape. Some of the mud-dome pore-water results of Ocean Drilling Program Leg 160 to the Eastern Mediterranean are discussed here in relation to the inferred presence of gas hydrates.