Planktonic Foraminiferal Biostratigraphy of the Late Eocene and Oligocene in the Palmyride Area, Syria

Three deep exploration wells in the Palmyride area (Syria) have been drilled through Oligocene and Eocene deposits. A detailed micropalaeontological investigation has been performed on the planktonic foraminiferal assemblage from drill cuttings. Standard planktonic foraminiferal zones from P15 to P22 (E15 to O6) have been identified. The test morphology and diversity of the foraminiferal assemblage indicate a general cooling trend during the late Eocene and Oligocene. The specialized Eocene forms (K-mode life strategy) such as turborotaliids, globigerinathekids and hantkeninids become extinct in the uppermost late Eocene. The Oligocene is characterized by the dominance of cooler, opportunistic planktonic foraminifera (r-mode life strategy), such as pseudohastigerinids, chiloguembelinids, globigerinids and tenuitellids. A very low number of benthic foraminifera in late Eocene cuttings implies sedimentation in a deep, open sea environment. A gradual increase of the benthic foraminiferal proportion through the Oligocene indicates shallowing of the sedimentary environment