Description: A continental inland basin extended in northern Israel and the southwest Golan Heights during the Neogene. Sedimentation of carbonates, marls, and evaporites was accompanied by massive basalt flows and by minor marine ingressions. The latter were recognized in restricted areas of the eastern Lower Galilee and the Kinnerot basin, herein termed together as the SE Galilee basin. This study aims to establish a detailed chronostratigraphic framework for ~5 m.y. of sedimentation between the top of the latest middle Miocene Lower Basalt unit and the base of the earliest Pliocene Cover Basalt unit in the SE Galilee basin, where stratigraphic exposure and lithologic variability are maximized. Data from five outcrop sections, two boreholes, and 27 40 Ar/ 39 Ar plateau ages of volcanic rocks were used. The upper Lower Basalt was eroded from tectonically uplifted blocks. Erosion products mixed with pyroclasts were deposited in structural lows between ca. 12 and 10 Ma, forming the Umm Sabune Formation. A gradual lithological transition to the overlying well-bedded lacustrine/lagoonal Bira Formation occurred between ca. 11 and 10 Ma. The transition to the overlying freshwater Gesher Formation occurred at ca. 7 Ma, around the Tortonian-Messinian boundary; hence, the gypsum beds at this transition predated the Messinian salinity crisis. The Cover Basalt flows started between 5.1 and 4.6 Ma at different locations, contemporaneously with the deposition of the upper part of the Gesher Formation and the Fejjas Tuff unit. A newly discovered unit of conglomerates and paleosols is considered to be the continental equivalent of Messinian salinity crisis evaporite deposition. This chronostratigraphic framework provides a basis for comparison with other similar late Neogene continental basins in the Levant and for the recognition on land of the Tortonian-Messinian boundary and the impact of the Messinian salinity crisis around the Mediterranean.

Description: Thick sequences of salt (halite) have been recovered in a 456-m-long core drilled at the deepest floor of the Dead Sea by the Dead Sea Deep Drilling Project and extending ~200 k.y. back in time. The salt sequences were precipitated in the ancient lake that occupied the Dead Sea Basin during the last three interglacials during intervals of extreme aridity in the lake’s watershed. The salt layers alternate with "mud" layers that indicate wetter periods in the watershed, when floods transported fine detritus matter to the lake. The salt sources include brine discharge and freshwater runoff that dissolved halite units. Dissolved salts accumulated in the lake during glacials and relatively wet periods when the lake expanded, and precipitated during interglacials when the lake levels dropped. This study establishes for the first time the evaporite facies and sedimentological features of the deep Dead Sea brine during interglacial periods, by using the modern precipitation of halite in the Dead Sea as an analogue for past halite depositional periods as recorded in the drill core. The halite intervals provide a record of facies characterizing a deep-water evaporitic environment. The halite layers consist mainly of two types of crystals: small cumulate crystals containing halite rafts, which indicate precipitation from the surface brine of the lake (epilimnion), and bottom-growth (usually large) halite crystals that precipitated on the lake floor (hypolimnion). The layers of small halite crystals formed during drier periods as compared to the bottom-growth crystals. The bottom-growth halite crystals contain variable quantities of detritus and show mild dissolution structures at the contact between the mud and the halite crystals. These two main types of halite, in combination with "muds" and gypsum, comprise seven categories of salt facies that reflect the hydrological conditions (dry-to-wet), and that display a cyclic (decadal to millennial) pattern along the sampled core intervals. Frequent alternation of these two salt crystal types suggests seasonal changes, whereby the small cumulate crystals were formed during the summer, and the bottom-growth crystals were formed during the winter, when the surface temperatures of the lake were low, and the surface water was less saline and less likely to be saturated with respect to halite. Comparison of the last interglacial halite with the modern halite facies, together with the absence of significant dissolution features within the halite and the cyclic nature of the facies, indicates that the lake was continuously deep (〉100 m) during the last 200 k.y.

Description: Pore fluids extracted from a 456 m sediment core, recovered within the framework of a multinational and International Continental Scientific Drilling Program (ICDP) co-sponsored effort at the bottom of the terminal Dead Sea, recorded the chemical variations in the deep lake over the past 220 k.y. Mg 2+ and Br – were shown to be conservative in the pore fluids, increasing in concentration during interglacial periods, diluting during glacials, and providing excellent proxies for deep lake net water balance changes. Furthermore, the Na/Cl ratio recorded the process of halite precipitation and dissolution induced by these hydrological changes. Mg 2+ and Br – records follow a glacial-interglacial pattern, such as observed in atmospheric CO 2 concentrations and global sea-surface temperatures, albeit with a phase offset. At the end of the last interglacial (ca. 116 ka), there is a delay in onset of dilution of the deep lake, most likely due to the limnological transition from holomictic to meromictic conditions. The increase in deep lake concentrations at Last Glacial Termination I is delayed as a result of freshwater input into the deep lake during the cooler Younger Dryas period. There is a persistent relationship between precipitation in the watershed and North Atlantic sea-surface temperatures, similar to conditions observed over the past instrumental record. Deviations from the long-term trends occurred during interglacial periods, Marine Isotope Stages MIS 5e and MIS 1, when the deep Dead Sea was significantly diluted, and coincided with Mediterranean sapropel layers S5 and S1.