Sources of Salinization of Groundwater in the Lower Yarmouk Gorge, East of the River Jordan

In the Lower Yarmouk Gorge the chemical composition of regional, fresh to brackish, mostly thermal groundwater reveal a zonation in respect to salinization and geochemical evolution, which is seemingly controlled by the Lower Yarmouk fault (LYF) but does not strictly follow the morphological Yarmouk Gorge. South of LYF the artesian Mukeihbeh well field produces in its central segment groundwaters of almost pure basaltic-rock type with low contribution (<0.3 vol-%) of Tertiary brine, hosted in deep Cretaceous and Jurassic formations. Further distal, the contribution of limestone water increases originating from the Ajloun Mts. North of the LYF, the Mezar wells, the springs of Hammat Gader and Ain Himma produce dominantly limestone water, which contains 0.14-3 vol-% of the Tertiary brine and possess hence variable salinity. The total dissolved equivalents of solutes gained by water/rock interaction (WRI) and mixing with brine, TDE(WRI+brine), amounts to 10-70 % in the region comprising the Mukheibeh field, Ain Himma and Mezar 3 well, to 55-70 % in the springs of Hammat Gader, and to 80-90 % in wells Mezar 1 and 2. The type of salinization indicates that the Lower Yarmouk fault seemingly acts as the divide between the Ajloun and the Golan Heigths dominated groundwater.