THE STRUCTURAL AND GEOMORPHIC EVOLUTION OF THE DEAD SEA RIFT

Abstract

The two methods of projected profiles and reconstructed stream profiles are applied in a geomorphic study of the region on both sides of the Dead Sea Rift. This supplements an earlier study of the tectonics. There are three recognizable surfaces at high levels. The earliest is cut partly in Eocene marine sediments. On both the Arabia and the Sinai–Palestine blocks the third surface has been well preserved and extends far into central Arabia. Warping, tilting and local uplift which affected these early erosion surfaces are related to the first phase of horizontal movement on the wrench-faults of the Rift. Along some sectors tendency to oblique overthrusting and underthrusting caused the downwarping or upwarping of the margins of the blocks ; along others the margins separated and there was an absence of distortion. There followed a period of quiescence, and base-level changed negatively and then remained stationary on more than seven occasions. The last major still-stand was interrupted by a second phase of horizontal movement on the Rift faults, which is continuing. Except for the outpouring of the plateau basalts of the Hauran of southern Syria, volcanism in the region was confined almost entirely to the Arabia block south of Amman. It was characterized by short-lived and occasionally violent eruptions. It began shortly after the initial warping of the early surfaces.