The early evolution of the Neotethys in the eastern Mediterranean area: implication of new evidence from the Levant basin and margin

Analysis and re-evaluation of recently obtained data from seismic reflection surveys and deep offshore and onland boreholes from the continental margin of Israel and the adjacent Levant basin, combined with pre-existing data, provide significant new insight into their early, Triassic to Middle Jurassic, development. Thick Middle Jurassic and older sediments in the Levant basin next to Israel cover a substantial relief of a pre-existing thin crust that was shaped in the Middle Triassic or earlier times. In the Levant margin near the present-day coastal area and further onshore the early development of the basin was accompanied by two major deformation phases, in the Triassic and in the Middle Jurassic, separated by a period (much of the Late Triassic and Early Jurassic) in which deformation and subsidence slowed down considerably or ceased. In contrast, in the Mt Carmel area conspicuous faulting and magmatism took place in the Late Triassic (older history unknown); that is, during the period of tectonic quiescence farther south, implying significantly different evolution of this and the more southern parts of the margin. Few Triassic igneous rocks are known onshore Israel, but widespread Late Triassic submarine volcanic rocks, associated with deep-marine sediments, were documented in the remnants of the northern extension of the Levant basin in the present-day area of Turkey and Cyprus, which probably represent the same regional tectonic phase. Renewed subsidence of the Levant margin and adjacent lands since the late part of the Early Jurassic was associated with renewed faulting along the Levant margin and in the adjacent lands, involving significant changes in the deformation pattern. A Middle Jurassic continental slope, >1 km high from top to base, developed along the Levant margin and deep-water conditions in the adjacent basin were established. This configuration is expected to have existed also in earlier times, in association with the formation of the basin’s thin crust next to the much thicker crust beneath the bordering continental area, but evidence for the earlier depositional history is limited by the lack of deep seismic and well data. In view of the extensive evidence presented here, a Cretaceous age for the formation of the Levant basin and margin that was recently suggested appears to be unlikely.