Intraplate deformation by block rotation and mesostructures along the Dead Sea Transform, northern Israel

Abstract

Combined analysis of mega‐ and meso‐structures yield the strain, inferred stress and tectonic history of the margin of the Sinai sub‐plate in northern Israel, along the Dead Sea transform. Three major stress regimes were developed and have affected the region since the middle Miocene: one is regional and controlled the left‐lateral shear along the Dead Sea transform. This one has been active since post‐early Miocene, is characterized by σ1 trending c. 345° and deformed the plate margin by horizontal shear and contemporaneous block rotation. This style of deformation is similar to simple shear. The second one was local and may be subdivided into distinct stress and strain domains. It was characterized by σ1 trending E‐W and σ3 trending N‐;S, which produced a conjugate set of strike‐slip faults. The region underwent N‐S elongation by horizontal shear and block rotation similar to the pure shear mechanism. This stress regime was active in late Miocene to early Pliocene time. The third and youngest stress regime is extentional with σ1 vertical and σ3 oriented N‐S. This one has been active since post‐middle Pliocene time producing E‐W normal faults, and minor N‐S elongation. The second and third stress regimes show local distribution and developed as a consequence of the bent geometry of the transform vis‐a‐vis the plate‐slip vector. Finite element and photoelastic models predict the development of local stress fields and elongation of the plate margin parallel and subparallel to the transform plate boundary. The strain of the plate margin in northern Israel and southern Lebanon indicate remarkable elongation parallel to the Dead Sea transform by a factor of 1.5–2.1 since the Miocene. This process of intraplate deformation and the consequent strain is unique to the parts of the plate margin which are adjacent to the bent segment of the transform.