Tectonic characteristics of the Eratosthenes Seamount and its periphery: Implications for evolution of the eastern Mediterranean

Abstract

A comprehensive tectonic analysis of the Eratosthenes Seamount (ESM) and its surrounding domains covered by our seismic data, contributes to better understanding of the evolution of the eastern Mediterranean. Tectonic origins of the ESM and the Zohr-like sub-Messinian salt highs between the ESM and the Nile delta are both continental fragments detached from the African-Arabian plate. These continental fragments form a NE-SW striking tectonic belt acting as the western margin of the Levant basin. After the Neotethyan rift, isolated carbonate platforms grew on these continental fragments and existed until the Miocene with alternations of shallow-water and deep-water carbonates caused by sea-level variation in the eastern Mediterranean. The subduction beneath the Cyprus arc beginning in the Early Miocene triggered onset of tectonic inversion of the deep-water area of the eastern Mediterranean. The ESM shielded the Zohr-like platforms from deforming by assimilating compressional stress from the Miocene subduction and the Messinian-present collision through its own folding, which led to tectonic evolutionary discrepancy between the Eratosthenes and the Zohr-like platforms since the Early Miocene. In addition, syn-sedimentary folding deformations related to the subduction were recognized in the southern Levant basin, the Herodotus eastern sub-basin, and the Cyprus arc. These deformations were all intense in the Early Miocene, attenuated gradually in the Middle and Late Miocene, and terminated at the very beginning of the Messinian. The weakening of these deformations could be associated with an increase in the subduction angle which also induced the development of the Mid-Late Miocene normal faults in the northern Levant basin. The initial African–Eurasian collision in the Messinian terminated these subduction-related deformations. Finally, we proposed a new evolutionary model of the deep-water area of the eastern Mediterranean, consisting of four stages, i.e. the Neotethyan rift stage from the Late Permian to the Early Jurassic, the post-rift tectonic stability stage from the Middle Jurassic Bajocian to the Oligocene, the subduction-related compression stage during the Miocene, and the collision-related compression-transpression stage from the Messinian to the present.