The Structure of an Inverted Early Mesozoic, Intra-Continental Rift and Its Implications for Hydrocarbon Exploration: The Levantine Basin, Southeastern Mediterranean

Gardosh, Michael, Yehezkeel Druckman, Geophysical Institute of Israel, Lod, Israel

Interpretation of 4,000 km of 2D, multi-channel, deep seismic reflection data offshore Israel reveal the internal structure of the Levantine Basin, an Early Mesozoic rift system, filled with up to 15 km of sediments on the northern margin of the African-Arabian plate. Six seismic packages were mapped above the basement; their boundaries are extensive reflec­tors in the deep basin, correlated to regional unconformities in wells onshore and offshore Israel. Two tectonic phases are identified: (a) Large-scale rifting during Anisian to Late Jurassic and extension in a NW-SE direction between the Eratosthenes Seamount and the Levant margin, with no indications for sea-floor spreading (b) Inversion and contraction in several pulses during Senonian to Late Miocene, thrusting and folding within an elevated Syrian Arc type fold belt, extending along the eastern Levant margin. Its western limit, 50­70 km west of the coastline may be controlled by the transition in basement properties. Implications for hydrocarbon exploration are: (a) Sub-commercial oil and gas shows indi­cate matured, Triassic-Early Jurassic source rocks in the shallow, eastern margin while Late Cretaceous-Neogene source rocks may be thermally matured at depth of 4-7 km in the basin center (b) Abundant extensional and contractional structures in Early Mesozoic to Miocene levels provide excellent traps (c) Extensive submarine channels and deepwater fans are potential conduits and reservoirs for hydrocarbons, as evident by significant biogenic gas accumulations in Pliocene sands (d) No evidence was found for major, post Liassic mag­matic events that could have destructed hydrocarbon accumulations.