Hydrochemistry, Geothermy, and Thermal Origin of Three Springs in the Eastern Rif, Morocco

Abstract

This geochemical and geothermal study focuses on three thermal springs located in the northeastern region of Morocco. The objective is to better understand the geochemical processes influencing the composition of these source waters in relation to deep geothermal systems, in order to determine geothermometers. In this research used the chemical elements (SO42-, Cl-, HCO3-, Ca2+, Mg2+, Na+, K+, Li, and SiO2) present in the surface thermal waters to determine their chemical facies and estimate the temperature of deep reservoirs using geothermometers (Silica, Na-K, Na-Li, and Na-K-Ca) and the Giggenbach diagram. The geology of the eastern Rif region is complex, including tectonic formations such as faults and fractures, which facilitate the circulation of groundwater at great depths within the geological structures. The ionic concentrations of the waters from the three thermal springs, influenced by local geochemical processes, allowed for the determination of their distinct chemical facies: a Cl-SO4-Mg facies for the Ain El Haouamed spring, a HCO3-Mg facies for the Ain Hamra spring, and a Cl-Na-SO4 facies for the Ain Mkbrta spring. Geothermal studies classified these waters as immature. Finally, the comparison with other regional springs, whose source reservoirs are well defined, suggests that these waters originate from a deep reservoir with geothermal reservoir temperatures ranging from 41,56 to 323,24 °C.