Isotopic analyses and hydrochemistry of the thermal springs along the eastern side of the Jordan Dead Sea—Wadi Araba Rift Valley

The isotopic composition of the present precipitation as well as the groundwaters of Jordan is found to lie between the eastern Mediterranean and the meteoric water lines. Whereas the isotopic compositions of precipitation and groundwater from north and central Jordan plot between both lines, those of southern Jordan cluster closer to the meteoric water line. The deep sandstone aquifer complex in central Jordan receives water from the overlying Tertiary—Upper Cretaceous units as well as from the sandstones of southern Jordan. Both contributions mix in the eastern part of central Jordan, flow from there in a westerly direction and discharge on the slopes above the Dead Sea. At the interface of fresh groundwater and Dead Sea water, mixing between the latter two waters takes place under a normal geothermal gradient. The water is then discharged as thermal water with an isotopic composition following the equation: δD = 3.97 δ 18O − 16.9 (%)