Abstract: Structural Fabric of the Palmyride Fold-Thrust Belt in Syria: Evolution Since the Proterozoic

Dogan Seber, Muawia Barazangi, Robert Litak, Tarif Sawaf, Wasif Alyoussef

The intracontinental Palmyride fold-thrust belt, located in central Syria, is bounded by the Aleppo plateau to the north and the Rutbah uplift to the south. The 400 × 100 km belt merges with the Dead Sea fault system in the southwest and gradually ends near the Euphrates depression in the northeast. Hydrocarbon exploration within the belt has provided excellent seismic reflection data coverage for the entire mountain belt, augmented by tens of drill holes, as well as seismic refraction profiles and gravity observations. These data are utilized to understand present-day structures within the Palmyrides and to infer the tectonic and structural evolution of this transpressional mountain belt.

The Palmyrides are recognized as the site of an early Mesozoic aulacogen-type depression that was linked to the Levantine rifted continental margin in the eastern Mediterranean. The existence of a Precambrian suture (or shear zone) at the Palmyrides' location is inferred from the analysis of gravity data. Uplift of the Palmyride depression initiated in the late Cretaceous and intensified since the late Oligocene/early Miocene. These tectonic episodes can be related to specific tectonic events along the Arabian plate boundaries. The style and the intensity of the inversion process vary considerably along the strike of the Palmyrides and involve shortening by both folding and reverse faulting. Different structural styles are observed within the Palmyrides: short-wavelength folding in th southwestern Palmyrides contrasts with very broad anticlines of the northeast. No regional decollement is observed in the seismic data. However. local detachment surfaces are evident along the Triassic anhydrite units. Possible deeper decollement surfaces within the Paleozoic rocks (or deeper) are also inferred. Total thickness of the Phanerozoic sedimentary rocks within the Palmyrides proper varies from 12 km in the southwest to 9 km in the northeast.

AAPG Search and Discovery Article #90986©1994 AAPG Annual Convention, Denver, Colorado, June 12-15, 1994