The Oligo-Miocene deepwater system of the Levant Basin

- 45 -hundred meters deep, where the Oligocene clastics overlie upper Eocene strata (Fig. 24c and 25 andBuchbinder et al., 2005).In the Hanaha-1 borehole the Oligocene incision cuts about 968 m (the thickness of the entireOligocene fill), breaching a NE-SW trending Syrian Arc fold structure (Figs. 5 and 24), thusindicating that the water depth during the Early Oligocene exceeded 1,000 m. In comparison, arange of 1,600 m water depth was estimated for the Afiq Canyon (Druckman et al., 1995) in theEarly Oligocene.A Late Tortonian incision was interpreted in the Hannah-1 borehole, based on the dating of thechannel fill underlying the Messinian evaporites (Fig. 24a). No stratigraphic gap was found betweenthe evaporites and the underlying section of the channel fill. Both were assigned the MessinianNN11a nannofossil zone (Micro-Strat, 2003). A major stratigraphic gap was found between theLate Tortonian, at the base of the channel, and the Early Langhian (early Middle Miocene)underlying section (Fig. 25). The Late Tortonian incision carved up to 965 m meters (thecumulative thickness of the Late Tortonian and Messinian canyon fill) (Fig. 24a,b).Based on the above observation it is concluded that the N marker (base evaporates) is, in fact,merely a velocity contrast between evaporites and low velocity sediments, and does not reflect anunconformity surface. The relief into which the Messinian evaporites were deposited was carved inLate Tortonian time.Near the coastline, in the Ashdod-1 borehole, the Late Tortonian canyon is about 700 m deep andalso overlies unconformably Langhian clastics similarly to the Hannah-1 borehole. It is filled by 50m of Messinian carbonate reefal debris overlain by a 150 m thick evaporitic section, which in turn isoverlain by a thick Pliocene section of ~ 1,740 m (Buchbinder et al., 2005) (Figs. 18, 21, 24 and25).The reduced evaporitic section and the significantly thicker Pliocene section overlying it (Fig. 24c)indicate the removal of part of the evaporites due to a ~ 800 m fall of the Messinian sea level(Druckman et al., 1995; Cartwright and Jackson, 2007) and thus signifies the post-evaporite incisionevent. This event is better pronounced in the Afiq Canyon, where the evaporites are overlain bylacustrine clastic sediment, reflecting the Lago Mare circum Mediterranean event.