Identification of major sources controlling groundwater chemistry from a multilayered aquifer system
Year: 2010
Type: article
Abstract: The Maknassy basin is a typical example of an arid area in Central Tunisia. The geology of the area is mainly composed of Cretaceous calcareous formations. To identify the major process involved in controlling the groundwater chemistry, 53 groundwater samples for three different aquifer levels have been examined. The groundwater chemistry is dominated by SO4 (Na + Mg) and (Cl + SO4). The presence of (Ca + Mg) and (Na + K) with HCO3 indicates the domination of dolomitic rock weathering as the major source of cations. The plots for Na to Cl indicate a fine correlation and reflects their release from halite dissolution during groundwater transition. An ion exchange process is also activated in study area which is indicated by a shift to the right in a plot for Ca + Mg to SO4 + HCO3. The plot of Na – Cl to Ca + Mg – (HCO3 + SO4) confirms that Ca, Mg and Na concentrations in groundwater are derived from aquifer materials. Saturation indexes of groundwater samples indicate undersaturation for gypsum and anhydrite, and oversaturation for calcite, dolomite and aragonite confirming waterrock interactions by dissolution and dilution processes. In general, water chemistry is guided by weathering process, ion exchange and water-rock interaction during groundwater transition.
Institutions: Tunis University, Tunis El Manar University
Language: English
Subfield: Geochemistry and Petrology
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2007199936