The uplift history of the Arabian Plateau as inferred from geomorphologic analysis of its northwestern edge

The Arabian Plateau (AP) is an Oligocene sub-horizontal regional planation surface, extending throughout the western half of the Arabian Peninsula. Its present elevation of about 1 km required a prominent uplift since the Late Eocene. In order to reconstruct the uplift history, we documented abundant abrasive and fluvial terraces that were left along and across the raised Judea Mountains (JM), which comprised the NW edge of the AP. Using the ages of those terraces and the differences in height between them, we found that the JM was uplifted in three major phases: a few hundred meters during the Late Eocene-Early Oligocene, similar to 500 m during the Early Miocene-early Middle Miocene, and similar to 350 m during the Late Pliocene. The two earliest uplift phases predate the formation of the Dead-Sea Transform (DST), which today separates the JM from the AP, meaning that these two phases affected the continuous rigid lithosphere extending southeastwards to the AP interiors. Moreover, restoration of the paleogeography predating the lateral offset along the DST eliminates the main height differences across it and suggests that the DST does not play a major role in the vertical position of its bordering plates, but rather forms a relatively narrow deformation strip within the AP. Those two early phases of uplift can be corroborated by previous thermochronology studies, which exhibit similar ages around the Red Sea but may reflect the uplift age of the entire region. The present sub-horizontal morphology of the AP is in contrast to the presumed original northeastward drainage and may suggest a subsequent long-wave moderate tilting to the SW. Three possible mechanisms were suggested for the uplift of the AP: a long wavelength flexure of the Arabian plate during early stages of the uplift, and lithospheric thinning or dynamic topography during later stages of the uplift. (C) 2016 Elsevier B.V. All rights reserved.