The Oligo-Miocene deepwater system of the Levant Basin

- 40 -The Beer Sheva-Afiq Canyon located 50 km southeast of the present coastline is filled, in the BeerSheva area, with the upper Miocene sandy marlstone of the Bet Eshel and Sheva formations,exposed in outcrops in the town of Beer Sheva (Buchbinder and Zilberman, 1997). Near thecoastline the canyon is filled with 400 m of conglomerates, sandstones and marls of undeterminedage overlying Early Middle Miocene marls. This undefined section is overlain by Messinianevaporites and their replacement products (biochemical limestones) (Fig. 22) (Druckman et al.,1995).The Gad-1 and Nir-1 boreholes, located about 20 km offshore, penetrated a 500 m thick sections ofsandstones interlayered with conglomerate and shale of undetermined age (Fig. 22), overlayingmarls and conglomerates of Oligocene to Early Miocene age (Buchbinder et al., 2006).The age of the incision of this phase, in the Afiq-Beer Sheva Canyon, could not be firmlyestablished because of the nature of the mixed and disordered foraminiferal assemblages. However,the lack of any break in the canyon’s fill between the underlying undated section and the Messinianevaporates and the firmly dated upper Tortonian incision event in the Ashdod Canyon, led us topropose a similar age for this incision in the Afiq Canyon.The latest Miocene (top Messinian evaporites) incision event (Fig. 19) is best evidenced in the AfiqCanyon near the coastline. Over there, a relief of about 800 m is carved below the canyon's rim, intothe Messinian evaporites (Beeri gypsum) and the Mavqiim anhydrite. This relief is filled with 90 mof sandstone and conglomerates of the continental Afiq Formation and 600 m of the marinePliocene Yafo Formation (Druckman et al., 1995). The Afiq Formation yields eurohaline ostracodeswhich were interpreted to correspond to the Lago Mare deposits, known throughout theMediterranean (Delrieu, et al., 1993). The reduced evaporitic section and the significantly thickerPliocene section overlying it (Figs. 21 and 23c) indicate the removal of part of the evaporites due toa ~ 800 m fall of the Messinian sea level by the end of the Messinian salinity crisis (Druckman etal., 1995; Cartwright and Jackson, 2007).Unlike the two other major incisions discussed above, and which were interpreted to have beencarved by submarine mass-flow processes, the latest Miocene (top Messinian evaporates) incision isinterpreted to had been taking place under subaerial conditions. A fluvial drainage was thusresponsible for the incision and dilution of the terminal Messinian brines to eurohaline degree