Petroleum Systems of Syria
We propose a reconstruction of the tectonostratigraphic evolution since Paleozoic of the northeastern Arabian platform and margin in Syria and Levant. The Mesozoic and Cenozoic evolution is illustrated through a series of palinspastic reconstructions. During the Paleozoic, depositional setting in NW Arabia is an east-facing, clastic-dominated continental platform that developed in northern Gondwana. Then, a 110 my-long tectonostratigraphic cycle lasted from Middle Permian to Late Jurassic. In the Early Mesozoic, the sedimentation changed from clastic to carbonate deposition with the initiation of rifting in the Levant Basin. Widespread Triassic to Liassic sediments accumulated in the subsiding Palmyride and Sinjar Troughs associated with normal faulting. The rifting aborted in the Palmyride Trough and Levant Basin in Mid-Jurassic. Then, overlying a major regional unconformity, a 60 my-long cycle lasted from the Late Jurassic to the Turonian. The Early Cretaceous is marked by an extensional tectonic event, widespread all around the East Mediterranean Basin. Early Cretaceous regressions originated a major stratigraphic gap with emersion. The Cenomanian – Early Turonian interval is a major transgressive period characterized by a subsiding carbonate platform. In Senonian a general subsidence, associated with an increase in water depth, resulted from the opening of the NW-WNW-oriented major Senonian grabens. The main pulse of rifting is Campanian in age. This extensional tectonics is coeval with the obduction of the Neo-Tethyan ophiolites onto the Northern Arabian platform. Within the upper-most Maastrichtian to Paleocene times, a discreet inversion occurred, evidenced by local unconformities in the Mesozoic basins. In Eocene-Oligocene, a sub-meridian extension prevailed in Levant pre-dating the Africa-Eurasia collision. The Neogene period is dominated by compressive deformations related to the closure of Eastern Mesogea, and the Arabia/Anatolia collision that initiated in the Early Miocene. This period is marked by the inversion of the Mesozoic basins in Baer-Bassit, Afrin, Palmyrides, and Lebanon. Finally, in the Late Miocene the Levant fault cuted all the older structures. Finally, we provide a review of the petroleum systems of Syria. During the last 60 years exploration in Syria mainly developed in the major Late Paleozoic and Mesozoic sedimentary basins. Source and reservoir rocks were deposited during major regional extensional periods in the Late Paleozoic and Mesozoic. Main traps were created in Senonian block-faultings, and anticlines associated to the Cenozoic inversions of inherited normal faults. There is a relationship between the hydrocarbon traps and the main Mesozoic rifts later inverted during the Cenozoic compressions. However, some formations, as well as entire regions, were still poorly or not explored. New targets in Paleozoic and Mesozoic petroleum systems can be explored. New traps, other than the NE-trending Palmyrides and E-W Sinjar anticlines, and Euphrates Graben tilted fault blocks may be imagined. Stratigraphic traps may include the Paleozoic siliciclastic succession, isolated Cretaceous carbonate build-ups, or Jurassic-Cretaceous carbonate platforms and karsts, and offshore siliciclastic basin-floor fans.