Résumé
This study was conducted to determine the main hydrogeochemical processes controlling the mineralization in the Angads groundwater in North-East Morocco. To achieve this, hydrogeochemical compositions combined with multiple stable and radioactive isotopes (18O, 2H, 3H, and 14C) were analyzed in groundwater. Statistical analysis showed that average ion concentrations in groundwater were in the following order: Na+ > Ca2+ > Mg2+ > K+ > NH4+ for cations, and Cl− > HCO3− > SO42− > NO3− for anions. The aquifer is mainly composed of Ca-Mg-Cl type waters, which account for over 70 % of the samples. The results show that water mineralization is mainly due to the dissolution of evaporites, as well as the influence of ion exchange, and probably a part of evaporative enrichment. The 2H vs 18O diagram revealed that aquifer recharge is more depleted isotopically than the local rainfall, pointing to a recharge in high elevation mountains to the south/south-east of the zone, and that all points are influenced by evaporation before or during infiltration. The levels of 3H indicate that all samples show a limited recent water component mixed with an older component dated back to 2233 BP according to 14C measurements.
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•Integrated isotope and hydrogeochemical analysis reveals Ca-Mg-Cl dominance.•Groundwater mineralization through evaporite dissolution and reverse exchange.•Recharge originates from high-elevation mountains, not local rainfall.•Dual groundwater sources: recent infiltration and ancient lateral input.•Multivariate statistics-geospatial tools validate hydrochemical evolution-salinization mechanisms.