Intraplate Deformation in the Northern Arabian Platform, Syria: Implications for Hydrocarbon Accumulations

Robert Litak, Muawia Barazangi, Tarif Sawaf, Anwar Al-Imam, Wasif Al-Youssef

Syria lies almost entirely within the Arabian plate, but contains several zones of significant intraplate deformation, including the Palmyride mountains, Euphrates fault system, and Sinjar uplift. These areas have a long and complex tectonic history that is primarily responsible for the location of known hydrocarbon accumulations within Syria. Ongoing analysis of an extensive database of over 13,000 km of seismic reflection data, over 150 wells, digital topography, gravity, and satellite information, and refraction and geologic data elucidates the scope and style of deformation throughout Syria. The SW-trending Palmyride mountain belt in western Syria represents the (mostly Neogene and Quaternary) inversion of a Mesozoic aulacogen, which itself may have reactivated a Prot rozoic suture. Analysis of refraction data indicate the presence of up to 11 km of sediments beneath the partially inverted Palmyrides. Structural style varies dramatically along the Palmyrides: in the SW, thin-skinned thrusting is associated with Triassic salt and evaporite deposits; large gas accumulations have been found in Upper Triassic carbonate reservoirs in thrust-related anticlines. Thick-skinned, near-vertical, transpressional structures dominate in the NE Palmyrides, where broad, gentle uplifts and buried fault traps yield oil and gas.

The NW-trending Euphrates depression/fault system probably formed as a sinistral tear in Late Cretaceous time in response to Arabian plate boundary events, followed by Tertiary subsidence and Neogene reactivation as dextral transpression. Major oil production, primarily from Early Cretaceous sandstones, occurs in a number of upthrown fault traps. In northeast Syria, the Sinjar uplift, an inverted Mesozoic trough like the Palmyrides, also hosts significant quantities of oil, as do the Zagros foothills in far northeast Syria. In spite of these widespread hydrocarbon occurrences, many areas remain relatively unexplored, including the thick Paleozoic section.

AAPG Search and Discovery Article #91020©1995 AAPG Annual Convention, Houston, Texas, May 5-8, 1995