Hydrogeology of the Nurra Region, Sardinia (Italy): basement-cover influences on groundwater occurrence and hydrogeochemistry

摘要: The Nurra district in the Island of Sardinia (Italy) has a Palaeozoic basement and covers, consisting Mesozoic carbonates, Cenozoic pyroclastic rocks Quaternary, mainly clastic, sediments. faulting folding affecting covers predominantly control geomorphology. morphology southern part is controlled by Tertiary volcanic activity that generated stack flows. Geological structures lithology exert main on recharge groundwater circulation, as well its availability quality. watershed divides do not fit divide; latter conditioned open folds faults. folded carbonate sequences contain appreciable amounts groundwater, particularly where structural lows are synclines normal regional flow been defined. investigated shows relatively high TDS chloride concentrations which, along with other hydrogeochemical evidence, rules out sea-water intrusion cause salinity. sulphate can be related to deep hydrothermal circuits Triassic evaporites, respectively. source water chemistry modified various geochemical processes due groundwater–rock interaction, including ion exchange minerals clays, incongruent solution dolomite, reduction.