Chemical and isotopic (δ18O‰, δ2H‰, δ13C‰, 222Rn) multi-tracing for groundwater conceptual model of carbonate aquifer (Gran Sasso INFN underground laboratory – central Italy)

摘要: Summary A hydrochemical and isotope study was conducted on the drainage waters of an underground laboratory, located inside Gran Sasso massif (central Italy). The expected to improve conceptual model groundwater circulation at base over 1000-thick unsaturated zone in partitioned karst aquifer. This lithostratigraphically tectonically complex aquifer is typical Africa–Europe thrust-and-fold collision belt Mediterranean area. In this case, investigations water–rock interactions during recharge aquifers, overlaid by a thick zone, have been made thanks strategic location laboratories, core huge carbonate Knowledge local basic hydrogeological setting starting point for detailed hydrogeochemical isotopic study, which carried out scale fine laboratories. interaction processes were investigated both spatially temporal sequences, analysing laboratories multitracing techniques, including major ions δ18O‰, δ2H‰ δ13C‰ stable isotopes. Use 222Rn provides information transit time Processes proved be rocks, with clear influence vertical movement water chemical–physical parameters through zone. Conversely, saturated these dominantly affected geological–structural conditions. dual flow velocity proposed, directly related geological-structural setting. decay enables calculate effective around 10 m/day fracture network, sequence less permeable dolomites underlying limestone. Lag between chemical changes testifies about 35 m/day fast recent active extensional faults.