SYSTEMATIC ANALYSES OF THE LARGE-SCALE TOPOGRAPHY AND STRUCTURE ACROSS THE DEAD-SEA RIFT

The Dead Sea Rift (DSR) is one of the deepest continental depressions on the Earth's surface and is the best example of a continental rift l ying along a transform plate boundary (the Dead Sea Transform). We sys tematically analyze the large-scale topography, structure, and morphol ogy across the central part of the DSR between Lake Kinneret and the G ulf of flat and show a distinct asymmetrical topographic pattern acros s the rift axis. The topography analysis uses a Digital Terrain Model (DTM) of Israel and adjacent areas to plot a series of 64 profiles per pendicular to the rift axis. The profiles show that the eastern side i s topographically higher than the western side and that its overall sh ape resembles an uplifted shoulder; the lower western side resembles a n arch. This analysis also reveals along-strike variations in the topo graphy that allow us to subdivide the central DSR into five segments o f similar topography. The large-scale structure across the DSR is inve stigated by a series of 10 geological cross sections drawn perpendicul ar to the rift axis along the five segments. On the basis of the strat igraphic record and the geological history of the region, we identify a regional marker (Top Eocene Sequence) to trace the rift-related stru cture. This marker shows that the structure parallels the topographic asymmetry across the rift axis: the rift's eastern margin is uplifted toward the axis, whereas the rift's western margin is downflexed towar d the axis and defines a wide asymmetrical monocline. Our analyses ind icate that (1) the large-scale asymmetry across the DSR reflects a wid e half-graben structure (30-60 km wide), (2) the rift's eastern margin reflects broad regional uplift along the rift, and (3) the western si de arching is a subsidary structure that follows the main rift structu re.