Restraining bend deformation at the northern termination of the Wadi Araba Fault: Insights from reflection seismic data and focal mechanism solutions

Abstract

This study examines subsurface deformation at the northern end of the Wadi Araba Fault (WAF), focusing on the Amman-Hallabat Fault (AHF) and the Wadi Shueib Fault (WSF). While surface evidence shows their tectonic impact from the Late Cretaceous to the present, research on their subsurface structures, contributing to the WAF, is limited. Using seismic data and well report, five seismo-stratigraphic units with significant unconformities were identified. The seismo-structural interpretation reveals a complex deformational fault zone with numerous reverse and normal faults intersecting strata from post-Precambrian rocks to the uppermost Cretaceous deposits, forming a composite flower structure with positive and negative flower characteristics. These structures show significant folding and thrusting of deposits from the uppermost Cretaceous to recent times. Seismic evidence indicates that the AHF and WSF extend upward to the Earth's surface. Fault mechanism analysis suggests a NE-SW transpressional deformation pattern, with fault formation and associated structures influenced by the Syrian Arc stress field since the Turonian. Changes in stress field orientation have significantly affected their reactivation. At its northern termination, the WAF may intersect or terminate against pre-existing faults like the AHF and WSF, influencing the WAF's behavior by accommodating strain, dissipating energy, or being reactivated as restraining bends due to the NNW-SSE-trending Dead Sea stress, leading to a complex network of distributed movement.