Isotopes and chemistry in ground water of Western Sudan and Eastern Chad (Geneina and Adré region)

Isotopes and chemical analyses in ground water indicate enrichment in stable isotopes in alluvium aquifer. They show a significant decrease in δ¹⁸0 and δ²H relation in Paleozoic sandstones, that means the stable isotopes are not submitted evaporation before the recharge. The tritium and the stable isotopes pointed out that the alluvium aquifer was recharged after 1953 and Paleozoic sandstones aquifer contains old water which was been recharged before that date.