The Eastern Mediterranean Mesozoic basin extends from northwestern Egypt to southeastern Turkey. The basin originated in the Triassic and Early Jurassic as continental blocks separated from North Africa and Arabia, forming a zone of extension. Clastics, carbonates, and evaporites were deposited in an extensional sag basin and in grabens. Triassic carbonate reservoirs, sealed by evaporites, are oil and gas productive in Syria and Iraq. Jurassic paralic and shaly beds and basinal limestones, deposited in the widening basin and in grabens, are oil sources in Egypt and Israel. From the Middle Jurassic to the Late Cretaceous the extensional basin became a passive margin on which clastics alternated cyclically with carbonate platforms. This sequence provided sandstone and carbo ate reservoirs sealed by shale and marl. Late Cretaceous convergence along the Taurus-Zagros front, and compression and shear in the platform and basin area coincided with regional high sea level. Organic-rich chalk, marl, shale, and limestone were deposited from the Late Cretaceous into the early Tertiary over most of the basin area. The greater part of known reserves in the region is derived from these beds, which generated oil into multiple faulted reservoirs in deep grabens and downwarps from Egypt to Syria, and into Upper Cretaceous to Paleocene reef limestones in Syria, Iraq, and Turkey.