Tectonic evolution of northeast Syria: Implications for regional tectonics and hydrocarbons

Abstract

We present the Phanerozoic tectonic evolution of northeast Syria and incorporate the results into regional deformation models of the northern Arabian Platform and nearby Arabian Plate boundaries. Based on analysis of extensive seismic reflection profiles and well data, we interpret that the Sinjar-Abd el Aziz area in northeast Syria was subsiding under extension at various rates from the Carboniferous until the end of the Mesozoic, most markedly during the latest Cretaceous. The predominant basin through most of the Late Paleozoic and Mesozoic was southwest-northeast trending; this formed the northeast extension of the major Palmyride Basin to the southwest. During the Late Cretaceous, extension in eastern Syria initiated along southeast-northwest and then eastwest trends - possibly as a result of changing subduction geometries and plate motions in the Neo-Tethys to the northeast. The east-west striking faulting resulted in syntectonic deposition of up to approximately 1,600 meters of Late Campanian-Maastrichtian marly limestones in the Sinjar-Abd el Aziz area. The area was subjected to horizontal shortening throughout the Cenozoic, primarily during Plio-Pleistocene time, resulting in structural inversion along some of the faults. Although crustal shortening through the Syrian Sinjar and Abd el Aziz structures is relatively minor (approximately 1%), this has been critical to hydrocarbon trap formation in Mesozoic and Cenozoic strata through the formation of fault-propagation folds. We present regional models that show the interrelated tectonic history of northeast Syria, the Palmyrides, and the Euphrates Fault System are all inseparably linked to the polyphase opening and closing of the nearby Neo-Tethys Ocean.