Tectonic Evolution of the Palmyra Zone, Syria

F. X. O'Keefe, A. M. C. Sengor

The Palmyra foldbelt extends approximately 350 km northeast from its intersection with the Dead Sea transform near Damascus. The surface expression of this feature is a southeast-verging fold-and-thrust belt that brings rocks as old as Triassic to the surface in fault contact with Upper Cretaceous and Tertiary rocks. The Palmyra region is first recognized as a subsiding trough from at least Triassic and possibly Permian time through middle Tertiary. This subsidence increases southwestward, reaching a reported maximum of 6 km of sediment north of Damascus, and is related to right-lateral motion along the eastern margin of the opening southern branch of the Neotethys sea as the Cimmerian continent moved northward away from northeast Africa during Permian-Triassic time. Exte sion and subsidence continued through the Jurassic and Cretaceous, interrupted by uplift and erosion from Late Jurassic to Early Cretaceous in the northeastern part of the zone.

Compression and inversion of the Palmyra zone begin during Miocene time with the initiation of left-lateral displacement on the Dead Sea transform system related to the continued opening of the Red Sea and the failure of the Gulf of Suez rift system. Approximately 105 km of offset are reported for the Dead Sea transform along the Jordan-Israel border segment, while 60 km are reported in Syria north of Lebanon. The Palmyra foldbelt accommodates this discrepancy through oblique shortening, possibly utilizing pre-existing extensional fault systems.

AAPG Search and Discovery Article #91032©1988 Mediterranean Basins Conference and Exhibition, Nice, France, 25-28 September 1988.