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Multi-channel seismic reflection data and borehole information were used to study the structure and stratigraphy of the Levantine basin, offshore Israel. A new, 2D seismic survey that covers the southeastern Mediterranean Sea from the Israeli coast to the Eratosthenes Seamount shows the entire Phanerozoic sedimentary fill down to a depth of 14-16 km. The basin-fill is subdivided into six seismo-stratigraphic units interpreted as low-order, major depositional cycles (supersequences A-F). Correlation and mapping of these units allowed an investigation of the geological history of the basin and the analysis of two important tectonic phases: Neotethyan rifting, and Syrian Arc inversion and contraction. The Neotethyan rifting phase is recorded by the strata of supersequences A and B. Faulting took place during the Anisian (Mid-Triassic), continued through the Liassic and ceased during the Mid-Jurassic. The basin opened in a NW-SE direction, between the Eratosthenes Seamount and the Levant margin of the Arabian Massif, at an angle of about 30 ~ to the present-day shoreline. No indications for sea-floor spreading were found in the present study. Late Triassic to Liassic volcanic rocks of assumed intraplate origin accumulated in the northeastern part of the basin. It is hypothesized that the basin originated as an intracontinental rift associated with the nucleation of an oceanic spreading centre, but reached only an early magmatic phase. An inversion and contraction phase, associated with closing of the Neotethyan ocean system, is recorded by supersequences C and D. The contractional structures of the Syrian Arc extend in a wide and elevated fold belt along the eastern edge of the deep-marine basin. These structures were formed by the inversion of pre-existing normal faults. The folding occurred in several pulses starting in the Senonian and ending in the Miocene. The western limit of the main fold belt, located 50-70 km west of the coastline, is defined by a transition in crustal properties. Supersequences E and F record the Late Cenozoic history of the basin. A Messinian, evaporitic basin was limited to the east by the elevated and uplifted Syrian Arc fold belt composed of older, Oligocene to Mid-Miocene strata. During highstand episodes, the Messinian evaporites were deposited on the entire slope and within canyons incised into the shelf. High sedimentation rates of Nilotic and locally derived sediments during the Plio-Pleistocene resulted in the development of extensive submarine deltas and basinward progradation of the Levant shelf break.

At the time of the opening of the Tethys Ocean the northern edge of Gondwana was affected by several rifting events. In this study, we used data from deep exploration wells, seismic profiles, and seismic depth maps to reconstruct the pattern of Tethyan rifting in the Levant region and to investigate its effects on the evolution of the Levant crust.The results show a several hundred kilometre wide deformation zone, comprised of graben and horst structures that extend from the inner part of the Levant to the marine basin offshore Israel. The structures are dominated by sets of NE–SW and NNE–SSW oriented normal faults with vertical offsets in the range of 1–8 km. Rifting was associated with a NW–SE direction of extension, approximately perpendicular to the present-day Mediterranean coast. Faulting activity progressed over a period of 120 Ma and took place in three main pulses: Late Palaeozoic (Carboniferous to Permian); Middle to Late Triassic; and Early to Middle Jurassic. The last, and the most intense, tectonic phase post-dates the activity in other rifted margins of northern Gondwana.Rifting was associated with the modification and stretching of the Levant crust. Our results demonstrate an extension discrepancy between the brittle deformation in the upper crust and the amount of total crustal thinning. Seismic reflection data shows that the Levant Basin lacks the characteristics of typical rifted margins, either volcanic or non-volcanic. The evolution of the basin may be explained by depth-dependant stretching, associated with the upwelling of divergent mantle flow and removal of lower crustal layers by decoupling along deep detachment faults.

A 600 m thick conglomerate, the Erez conglomerate, was penetrated in the Helez Deep borehole, drilled in the Coastal Plain of Israel. This conglomerate is underlain by a 40 m thick sandy shale of probable Early Triassic age, and is overlain by 190 m of Late Triassic peritidal dolomites. This sedimentary sequence is underlain by metamorphic Precambrian basement.The Erez conglomerate is polymictic, consisting of various types of carbonate frag-

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