Mesozoic–Cenozoic evolution of the intraplate Euphrates fault system, Syria: implication for regional tectonics

Abstract: A lack of dramatic surface geological structures along the Euphrates River in Syria belie a complex tectonic history revealed by newly released seismic reflection and well data. We document the intraplate Euphrates fault system, characterize the variation in structural style along its 350 km length in Syria, and infer its Mesozoic–Cenozoic tectonic and deformational history. We then relate the defor-mation of the Euphrates system and other proximate intraplate structures to nearby Arabian plate boundary processes in order to develop a new model for the tectonic evolution of the northern Arabian plate. Throughout most of Mesozoic time, the Euphrates area experienced minor deposition compared to the Palmyride trough to its southwest, and the Sinjar trough to its northeast. During latest Cretaceous time, however, significant sinistral transtension occurred along the length of the Euphrates fault system in Syria, with graben formation especially noteworthy in southeastern Syria. This episode was probably related to events at nearby plate boundaries, and may have reactivated a zone of weakness formed during Pan-African accretion of the Arabian plate. A Palaeogene sag basin formed over the graben system in southeastern Syria. Neogene continental collision along the northern and eastern Arabian plate bound-aries caused minor reactivation of the Euphrates fault system in a dextral transpressional sense, in concert with significant inversion and the main phase of uplift of the nearby Palmyride and Sinjar mountains