Characteristics of Saharan aquifers in the Tunisian outlets

The Tunisian chotts and the Gulf of Gabès serve as the outlet for the aquifers of the Continental Intercalary (CI) and Terminal Complex (CT) - known as the Saharan aquifers - which are shared by Algeria, Tunisia and Libya. In this region, the hydrogeochemical characteristics of the waters show significant variations compared to those of the recharge zones of the Algerian highlands and the Tunisian Dahar. This book focuses on the various mechanisms by which water acquires mineralisation during its transit from recharge zones to discharge zones, as well as the geothermal significance of the CI aquifer, evidenced by water temperatures exceeding 100 °C at depth (as estimated by geothermometers). Local connections between the Terminal Complex aquifer and the Plio-Quaternary surface aquifer have been demonstrated by an isotopic study, notably an isotopic signal in precipitation from the town of Nefta. This book also presents new data concerning the karstification of the buried limestones of the Jeffara aquifer and a pseudo-karst affecting gypsum deposits at and below the surface.