title: Spatial distribution of electrical conductivity and stable isotopes in groundwater in large catchments: a geostatistical approach in the Quequén Grande River catchment, Argentina.
abstract: Stable isotopes and electrical conductivity in groundwater were used as natural tracers to adjust the hydrogeological conceptual model in one of the largest catchments within the inter-mountainous Pampa plain, Argentina. Geostatistical tools were used to define the model that best fitted the spatial distribution of each tracer, and information was obtained in areas where there was a lack of data. The conventional isotopic analysis allowed the identification of three groundwater groups with different isotopic fingerprints. One group containing 56% of the total groundwater samples suggested a well-mixed system and soil infiltration precipitation as the main recharge source to the aquifer. The other two groups included samples with depleted (25.5%) and enriched (18.5%) isotopic compositions, respectively. The combination of δ(18)O, δ(2)H and electrical conductivities maps suggested ascending regional flows and water transfer from the Quequén Grande River catchment to the Moro creek. The spatial interpretation of these tracers modified the conceptual hydrogeological model of the Quequén Grande River.
authors.affiliation: a Instituto de Geología de Costas y del Cuaternario, Universidad Nacional de Mar del Plata, FCEyN , Mar del Plata , Argentina.
authors.forename: Orlando Mauricio
authors.initials: OM
authors.lastname: Quiroz Londoño
authors.forename: Daniel Emilio
authors.initials: DE
authors.lastname: Martínez
authors.forename: Hector Enrique
authors.initials: HE
authors.lastname: Massone
authors.forename: Libardo Antonio
authors.initials: LA
authors.lastname: Londoño Ciro
authors.forename: Cristina
authors.initials: C
authors.lastname: Dapeña
mesh_terms: D001118:Argentina; D003903:Deuterium / Q000032:analysis*; D004553:Electric Conductivity; D004784:Environmental Monitoring; D060587:Groundwater / Q000737:chemistry*; D008962:Models, Theoretical; D010103:Oxygen Isotopes / Q000032:analysis
chemical_list: D010103:Oxygen Isotopes; D003903:Deuterium
keywords: Pampa plain; electrical conductivity; geostatistics; groundwater; hydrogen-2; isotope hydrology; oxygen-18