Post-Messinian evolution of the Southeastern Levant Basin based on two-dimensional stratigraphic simulation

Abstract

The evolution of the southeastern Levant Basin following the Messinian salinity crisis was interpreted, using observations derived from seismic sections and well data, and from output of a two-dimensional forward stratigraphic simulation program (SEDPAK). The working assumption was that the thick evaporitic Messinian sequence was generated in a shallow-water, albeit a topographically deep basin. The sea-level dropped at least 800 m below its present level and may have been as low as 1300 m, the latter value representing the reconstructed depth of the top Messinian in the deep part of the basin. The top of the evaporitic sequence in that part of the basin was virtually horizontal at the end of the Messinian crisis and thus may be used as a regional datum. Subsidence rates measured for the shelf and coastal plain of Israel indicate a reduction of these rates for the Pleistocene when compared to the Pliocene. During the Pleistocene subsidence rates for the base slope increased and dictated the modern physiography of the margin. Earlier, in the Middle to Late Pliocene, small-scale salt movements occurred in the deep basin, producing the fragmented and irregular shape of the “M” horizon (the seismic event marking the top of the evaporitic sequence) and deforming the overlying Pliocene section. The simulated rate of sediment supply indicates a constant increase over time for the Pliocene and the Pleistocene, probably in response to an increased influx of Nile-derived, along-shelf sediment transport.