Constrains on the origin and history of the Eastern Mediterranean basin

The basin formed along the northern passive margin of Gondwanaland as a rel ict of the Mesozoic Neotethys in early Mesozoic time. Though direct informa tion from the basin itself is meagre, the geology of its passive margins an d the regional framework of the Tethys evolution constrain the formation an d history of the basin. The Eastern Mediterranean and its passive margins a re interpreted to have formed as a result of several faulting and continent al breakup phases from Early Permian to Middle Jurassic times, before Panga ea's complete disintegration. This led to the detachment of the Eratosthene s and Tauride blocks from the margins of the Levant and Herodotus basins, r espectively. 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 t he Jurassic. During the initial rifting stages extension perpendicular to t he Levant margin was important, but subsequently the Tauride block drifted mainly northward. The existence of the passive margins and slopes of the Ea stern Mediterranean is documented at least from the end of the Middle Juras sic. Until then the basin was probably narrow (less than or equal to 200-30 0 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 t he interpretation that the Tauride block was originally located next to nor theastern Africa on the western side of the Eratosthenes block. Plate conve rgence and consumption of the northern portion of the basin have taken plac e since mid-Cretaceous times, but the active convergent boundary on its nor thern 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 o f the basin. (C) 1998 Elsevier Science B.V. All rights reserved.