Investigating the complex hydrogeological settings in the northeastern slope of the West Bank to the Jordan Graben (Malih and Jeftlik)

Abstract

The northeastern part of the West Bank is located between brackish water sources in the Jordan Rift to the east, and the freshwater drainage from the mountain ridge, where the complex geological structure can facilitate a possible flow-path connecting different fresh and saline water bodies, saline sources, and the regional aquifers, which are the sources of their freshwater. Integrated stable and radioactive isotopic tools of tritium (3H), carbon (14C), carbon (δ13C), sulphur (δ34S) deuterium (δ2H) and oxygen (δ18O) were used to investigate the effect of complex geologic structure on the groundwater residence times, and respective potential sources, mixing, and recharge mechanisms. The low 14C values in the Malih and Marj Najeh area suggest mixing signatures between the old brine and the fresh water that conveyed from Cretaceous rocks and Eocene mountain aquifer in the west through the faults that intersect the water flow path to the north, toward the study area. The study differentiates between two salinity mechanisms, one that is coming from dissolution of saline sediments and salinized the triggered freshwater along with Faria flow path with high 14C pMC values and positive δ34Ssulphate and the second is the deep-seated pressurized CaCl2 brine, the upflow of which causes salinization of fresh groundwater bodies entering the system.