Tectonic evolution of the NE Palmyride mountain belt, Syria: the Bishri crustal block

摘要

Investigation of the Bishri block, centrally positioned amid the diverse tectonic and structural zones of Syria, reveals details of the intraplate Phanerozoic development of the northern Arabian platform. The Bishri block is a broad NE-plunging inverted basin located at the NE portion of the Palmyride mountain belt where the mountains intersect the Euphrates fault system. Well and seismic data show that subsidence and sedimentation in the Bishri area was generally continuous from Carboniferous to Paleocene time, with the Bishri block part of the extensive Palmyride–Sinjar trough. Major bounding faults and a rift-type environment are documented in the Permo-Triassic, Jurassic and Cretaceous. The present Bishri structural and topographic high has been formed through transpressive structural inversion since the Mid-Miocene; high-angle Mesozoic bounding normal faults now have net reverse offsets with a significant dextral strike-slip component. East of the Bishri block, towards the Euphrates fault system, NNW–SSE-striking normal faults exhibit less reverse movement. This deformation history correlates with the opening and closing of the nearby NeoTethys ocean that has driven the evolution of intracontinental Syria.