Inland jump of the Arabian northwest plate boundary from the Levant continental margin to the Dead Sea Transform

Abstract

While the breakup of Arabia and Africa began in the early Oligocene, the northwestern boundary of the Arabian Plate along the Dead Sea Transform (DST) formed 10–15 Myr later (early–middle Miocene). During the early stage of breakup the Red Sea Rift continued propagating northwestward, forming the Suez Rift. The present ∼45° northward twist of the plate boundary from the Red Sea toward the Gulf of Eilat (Aqaba) still did not exist. What happened at the northern tip of the Suez Rift at that time? How was strain distributed to its surroundings, and where did the plate boundary continue from there? Here we describe an abandoned segment of the Arabian northwestern plate boundary that extended from the northern tip of the Suez Rift northeastward, along the Levant margin. Seismic data collected offshore Israel support a subsurface, deep‐rooted fault zone running along the base of the continental slope. These faults indicate Oligocene transpressional lateral shearing. We propose that during the early stage of continental breakup a left‐lateral strike‐slip motion of ∼10 km took place along this embryonic plate boundary. Such deep‐rooted tectonism implies that unlike the passive situation of the Israel‐Sinai continental margin witnessed presently and before the Oligocene, during the early stage of the Africa‐Arabia breakup this part of the continental margin was reactivated. We further suggest that the inland jump of the plate boundary toward the DST was not immediate and that during the transitional period the Israel‐Sinai triangular block was an independent subplate with deformation all around it.