Constrains on the origin and history of the Eastern Mediterranean basin

Abstract

The basin formed along the northern passive margin of Gondwanaland as a relict of the Mesozoic Neotethys in early Mesozoic time. Though direct information from the basin itself is meagre, the geology of its passive margins and the regional framework of the Tethys evolution constrain the formation and history of the basin. The Eastern Mediterranean and its passive margins are interpreted to have formed as a result of several faulting and continental breakup phases from Early Permian to Middle Jurassic times, before Pangaea's complete disintegration. This led to the detachment of the Eratosthenes and Tauride blocks from the margins of the Levant and Herodotus basins, respectively. The latter merged in the northeast with the Cyprus basin that extended along Arabia's northern margin. The main rifting probably occurred in the Triassic, leading to seafloor spreading in the Herodotus and Cyprus basins, while along the Levant margin important rifting also occurred in the Jurassic. During the initial rifting stages extension perpendicular to the Levant margin was important, but subsequently the Tauride block drifted mainly northward. The existence of the passive margins and slopes of the Eastern Mediterranean is documented at least from the end of the Middle Jurassic. Until then the basin was probably narrow (≤200–300 km?), but during the main phase of the Africa–Laurasia separation it grew to twice its present width, or more. This scenario depends critically on the interpretation that the Tauride block was originally located next to northeastern Africa on the western side of the Eratosthenes block. Plate convergence and consumption of the northern portion of the basin have taken place since mid-Cretaceous times, but the active convergent boundary on its northern side formed only in the Neogene by modification of earlier structures. Some intra-plate deformation also took place, especially in the Neogene, but it hardly changed the original configuration of the remaining portion of the basin.