Contribution of isotopic techniques to the knowledge of the aquiferous system of the great Sebkha of Oran

Abstract In the Great Sebkha Basin of Oran, water flows, both surface and subterranean, originate on slopes converge toward discharging area salt Lake Oran (≈ 80 m above sea level). Isotopic tracing 2 H, 18 O, 14 C, 13 C was carried out main aquifer formations to clarify phenomena evaporation, dissolution, mixing different bodies, their residence time in system. The data concern: Quaternary alluvial table periphery, limestone Miocene, Brédéah pumping station (whose waters are polluted by brackish intrusions), deepwater tabler Mio-Pliocene complex Plain Maflak, Pliocene Tameira, Thermal Complex Hammam Bou Hadjar. d O levels range from −9.61 + 4.8 ‰ V-SMOW at Oran. H contents −70 20. Minimum values characterize run off northern Tessala. dissolved total inorganic carbon (TDI) measured ranged −10.92 −3.9 vs PDB. activities divided between 51 PMC. highest activity (≈50 PMC) is samples taken Miocene limestones Djebel Murdjadjo.