Late Tertiary subsidence history of the southern Levant Margin, eastern Mediterranean Sea, and its implications to the understanding of the Messinian Event

Abstract

The late Tertiary subsidence history of the southern Levant continental margin, situated in the southeastern Mediterranean Sea, was quantitatively analyzed. Paleodepth reconstruction across the margin off Ashdod suggests the existence of a deep basin in pre‐Messinian time which resembles the present one. This implies that, the deposition of the evaporites in the study area during the Messinian desiccation of the Mediterranean Sea occurred in a deep basin. The path of the tectonic subsidence of the basement since early Tertiary is generally smooth as expected from the nature of the thermal subsidence. The unconformity beneath the Messinian indicates erosion of 50–200 m at the coastal plain. In the Pliocene, the tectonic subsidence in the coastal plain and shelf area diverts from the expected thermal path and increases from 250 m to 450 m, respectively. In the Quaternary the rate of tectonic subsidence nearly resumed the predicted thermal subsidence. Sedimentation and subsidence rates decrease but are still higher than those of the pre‐Messinian. We suggest that the evolution of the southern Levant margin is most probably influenced by three main causes: (1) the Messinian event in late Miocene, (2) the deposition of large volumes of Nile derived sediments since the Pliocene, and (3) the flexural response of the lithosphere to the load from the Nile delta and/or from the uplift of the Judea Mountains (the western shoulder of the Dead Sea Transform). We interpret the latter to be the cause of the anomalous subsidence of the southern Levant margin during the Pliocene.

Salt tectonics off northern Israel

“…The central sub-unit shows little or no stratification in contrast to the surrounding, evenly parallel stratified layers. This sequence thins to the north, west and east (Tibor et al, 1992). On HH01 it can be traced towards 108 km in the east and reduces to indiscernible thickness in the west.…”

“…5). For the basic stratigraphic interpretation the terminology of Tibor et al (1992) will be used, which is based on the work of Derin and Reiss Fig. 3.…”

“…After the Messinian Salinity Crisis the huge water masses and increased influx of Nile sediments caused a high subsidence rate in Pliocene as demonstrated by Tibor et al (1992) by back-stripping analysis.…”

The Levantine Basin—crustal structure and origin

“…The basin has undergone significant subsidence for more than 100 Ma (Mart, 1982;Tibor et al, 1992;Almagor, 1993;Vidal et al, 2000a), over 2 km since Pliocene (Mart, 1982) and is still subsiding (Tibor et al, 1992). The basement is buried under up to 14km of sediments (Ben-Avraham et al, 2002).…”

Early-to-mid Pleistocene Tectonic Transition Across the Eastern Mediterranean Influences the Course of Human History

“…3 in Gvirtzman et al, 2008). Several works (e.g., Tibor et al, 1992) attributed both subsidence of the Levant margin and the uplift of Sinai plate (mainly in the Samaria and Judea) to the Nile sedimentary load. Others argue that the margin subsidence commenced prior to the Pliocene and therefore only part of it is attributed to the Nile sedimentary load (Gvirtzman et al, 2008).…”