caa a22 4500 445814829 CHVBK 20180317145223.0 cr unu---uuuuu 170323e20111101xx s 000 0 eng 10.1007/s10040-011-0766-6 doi (NATIONALLICENCE)springer-10.1007/s10040-011-0766-6 Delineating volcanic aquifer recharge areas using geochemical and isotopic tools [Elektronische Daten] [Brendan Mulligan, M. Ryan, Tomás Cámbara] Délimitation des aires d'alimentation d'un aquifère volcanique à l'aide d'outils géochimiques et isotopiques Relative recharge areas are evaluated using geochemical and isotopic tools, and inverse modeling. Geochemistry and water quality in springs discharging from a volcanic aquifer system in Guatemala are related to relative recharge area elevations and land use. Plagioclase feldspar and olivine react with volcanically derived CO2 to produce Ca-montmorillonite, chalcedony and goethite in the groundwater. Alkalinity, Mg, Ca, Na, and SiO2(aq) are produced, along with minor increases in Cl and SO4 concentrations. Variations in groundwater δD and δ18O values are attributed to recharge elevation and used in concert with geochemical evolution to distinguish local, intermediate, and regional flow systems. Springs with geochemically inferred short flow paths provided useful proxies to estimate an isotopic gradient for precipitation (−0.67 δ18O/100m). No correlation between spring discharge and relative flow-path length or interpreted recharge elevation was observed. The conceptual model was consistent with evidence of anthropogenic impacts (sewage and manure) in springs recharged in the lower watershed where livestock and humans reside. Spring sampling is a low-budget approach that can be used to develop a useful conceptual model of the relative scale of groundwater flow (and appropriate watershed protection areas), particularly in volcanic terrain where wells and boreholes are scarce. Springer-Verlag, 2011 Conceptual models nationallicence Guatemala nationallicence Inverse modeling nationallicence Stable isotopes nationallicence Volcanic aquifer nationallicence Mulligan Brendan Geoscience, University of Calgary, 2500 University Drive NW, T2N 1N4, Calgary, AB, Canada aut Ryan M. Geoscience, University of Calgary, 2500 University Drive NW, T2N 1N4, Calgary, AB, Canada aut Cámbara Tomás Facultad de Agronomía, Universidad de San Carlos de Guatemala, Ciudad Universitaria, Zona 12, 01012, Ciudad de Guatemala, Guatemala aut Hydrogeology Journal Springer-Verlag 19/7(2011-11-01), 1335-1347 1431-2174 19:7<1335 2011 19 10040 https://doi.org/10.1007/s10040-011-0766-6 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10040-011-0766-6 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Mulligan Brendan Geoscience, University of Calgary, 2500 University Drive NW, T2N 1N4, Calgary, AB, Canada aut NATIONALLICENCE 700 1- Ryan M. Geoscience, University of Calgary, 2500 University Drive NW, T2N 1N4, Calgary, AB, Canada aut NATIONALLICENCE 700 1- Cámbara Tomás Facultad de Agronomía, Universidad de San Carlos de Guatemala, Ciudad Universitaria, Zona 12, 01012, Ciudad de Guatemala, Guatemala aut NATIONALLICENCE 773 0- Hydrogeology Journal Springer-Verlag 19/7(2011-11-01), 1335-1347 1431-2174 19:7<1335 2011 19 10040 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer