Paleostress analyses in NW Syria: constraints on the Cenozoic evolution of the northwestern margin of the Arabian plate

Abstract

Fault analysis between the Dead Sea Transform and the Euphrates region in northern Syria shows two main directions of compression connected to the recent evolution of the northwestern wedge of the Arabian plate. E–W open folds due to N–S compression gently deform the Cretaceous to Tortonian successions of the Aleppo Plateau and the eastern termination of the Palmyrides west of the Euphrates. Conjugate sets of strike-slip and normal faults, pre- as well as post-dating folding occur in the plateau and are still consistent with the same stress field. N–S normal faults cross recent deposits and control Quaternary volcanoes along the Euphrates, suggesting the persistence of this stress regime. A NW–SE compression related to the Syrian segment of the Dead Sea Transform (DST) was detected in the western part of the study area. The activation of large N–S left-lateral strike-slip and WNW–ESE right-lateral faults follows in time the growth of in-line folds and thrusts. Permutation of the σ 1 and σ 2 stress axes is related to activation of NW–SE normal faults, which generally accompany strike-slip faults and post-date E–W folds within the plateau. Recent E–W extension in the Euphrates region is consistent with a horizontal N–S maximum direction of compression and seems to be partially coeval with the stress regime induced by the DST. This stress pattern can be explained by the superposition of the northward push of the Arabian plate to the N–S left-lateral shearing along the DST.