Dhahal structure: an example of transpression associated with the Dead Sea transform in Wadi Araba, Jordan

Abstract

The Dhahal Mountains located at the eastern margin of the northern Wadi Araba sinistral fault represent an example of a transpression associated with the Dead Sea transform, which is a sinistral wrench fault. This structure was formed as a result of right bending of the Humrat Fidan active sinistral fault, which is a parallel strand of the Dead Sea transform located east of the main Wadi Araba fault. The fault bend caused uplift and squeezing of the Cretaceous and Tertiary rocks of the transpression. Positive flower structures, folds, fault-bounded wedge-shaped pop-ups and reverse faults are the main structural elements that characterized the Dhahal transpression. Folds are found as sets or as single anticlines and synclines. The major trend of the fold axes is N50°; the principal stress axis (σ1) is perpendicular to this trend (N140°). This trend deviates 26° anticlockwise from that of the Dead Sea stress system (DSS) (as obtained from fault slip data north of the study area), which is responsible for the formation of the Dead Sea transform. Evidence of active uplift in the Dhahal structure is provided by the sharp topography relative to the surrounding areas, and the low mountain front sinuosity index of the western margin of the Dhahal mountains.