{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,1]],"date-time":"2026-05-01T22:42:57Z","timestamp":1777675377059,"version":"3.51.4"},"reference-count":78,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2023,1,5]],"date-time":"2023-01-05T00:00:00Z","timestamp":1672876800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"HEATSTORE\u2014Geothermica Era net","award":["European Project with Portuguese national funding from FRCT\u2014Fundo Regional da Ci\u00eancia e Tecnologia, Azores Government"],"award-info":[{"award-number":["European Project with Portuguese national funding from FRCT\u2014Fundo Regional da Ci\u00eancia e Tecnologia, Azores Government"]}]},{"name":"HEATSTORE\u2014Geothermica Era net","award":["(SFRH\/UI\/643\/2020)"],"award-info":[{"award-number":["(SFRH\/UI\/643\/2020)"]}]},{"name":"Funda\u00e7\u00e3o para a Ci\u00eancia e Tecnologia","award":["European Project with Portuguese national funding from FRCT\u2014Fundo Regional da Ci\u00eancia e Tecnologia, Azores Government"],"award-info":[{"award-number":["European Project with Portuguese national funding from FRCT\u2014Fundo Regional da Ci\u00eancia e Tecnologia, Azores Government"]}]},{"name":"Funda\u00e7\u00e3o para a Ci\u00eancia e Tecnologia","award":["(SFRH\/UI\/643\/2020)"],"award-info":[{"award-number":["(SFRH\/UI\/643\/2020)"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Water"],"abstract":"<jats:p>This study focused on 13 water samples collected from two of the main active volcanoes (Furnas and Fogo) at S\u00e3o Miguel, Azores. Based on the major element composition, the waters are classified into Na-HCO3 and Na-Cl types. While the concentrations of chloride seem to reflect the contribution of sea salt aerosols, the behavior of the main cationic species and Sr in the analyzed waters appear to have been largely controlled by the interaction between meteoric waters and the underlying bedrock. The temperature and input of CO2 from the secondary volcanic activity are enhancing the silicate leaching. The stable isotopic data show that these waters have a meteoric origin (\u03b418O = \u22122.03 to \u22124.29\u2030; \u03b42H = \u22127.6 to \u221217.4\u2030) and are influenced by a deep hydrothermal\/volcanic carbon source (\u03b413C = \u22124.36 to \u22127.04\u2030). The values of \u03b434S (0.13 to 12.76\u2030) reflects a juvenile sulfur source derived from the leaching of volcanic rocks. The Sr isotopic ratios show a slight difference between the values from Furnas (87Sr\/86Sr = 0.705235\u20130.705432) and Fogo (87Sr\/86Sr = 0.705509\u20130.707307) whereas the Furnas waters are less radiogenic. The Sr isotope also shows that the hydrochemical signatures of the groundwater was controlled by the rock leaching, and the samples Furnas reached water-rock isotopic equilibrium.<\/jats:p>","DOI":"10.3390\/w15020245","type":"journal-article","created":{"date-parts":[[2023,1,6]],"date-time":"2023-01-06T02:20:30Z","timestamp":1672971630000},"page":"245","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":11,"title":["Hydrogeochemistry and Strontium Isotopic Signatures of Mineral Waters from Furnas and Fogo Volcanoes (S\u00e3o Miguel, Azores)"],"prefix":"10.3390","volume":"15","author":[{"given":"Let\u00edcia","family":"Ferreira","sequence":"first","affiliation":[{"name":"IVAR\u2014Instituto de Investiga\u00e7\u00e3o em Vulcanologia e Avalia\u00e7\u00e3o de Riscos, Universidade dos A\u00e7ores, 9500-321 Ponta Delgada, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6475-3824","authenticated-orcid":false,"given":"Jos\u00e9 Virg\u00edlio","family":"Cruz","sequence":"additional","affiliation":[{"name":"IVAR\u2014Instituto de Investiga\u00e7\u00e3o em Vulcanologia e Avalia\u00e7\u00e3o de Riscos, Universidade dos A\u00e7ores, 9500-321 Ponta Delgada, Portugal"},{"name":"FCT\u2014Faculdade de Ci\u00eancias e Tecnologia, Universidade dos A\u00e7ores, 9500-321 Ponta Delgada, Portugal"}]},{"given":"Fatima","family":"Viveiros","sequence":"additional","affiliation":[{"name":"IVAR\u2014Instituto de Investiga\u00e7\u00e3o em Vulcanologia e Avalia\u00e7\u00e3o de Riscos, Universidade dos A\u00e7ores, 9500-321 Ponta Delgada, Portugal"},{"name":"FCT\u2014Faculdade de Ci\u00eancias e Tecnologia, Universidade dos A\u00e7ores, 9500-321 Ponta Delgada, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2834-043X","authenticated-orcid":false,"given":"Nuno","family":"Dur\u00e3es","sequence":"additional","affiliation":[{"name":"GeoBioTec\u2014Geobioci\u00eancias, Geoengenharias e Geotecnologias, Departamento de Geoci\u00eancias, Universidade de Aveiro, 3810-193 Aveiro, Portugal"}]},{"given":"Rui","family":"Coutinho","sequence":"additional","affiliation":[{"name":"IVAR\u2014Instituto de Investiga\u00e7\u00e3o em Vulcanologia e Avalia\u00e7\u00e3o de Riscos, Universidade dos A\u00e7ores, 9500-321 Ponta Delgada, Portugal"},{"name":"FCT\u2014Faculdade de Ci\u00eancias e Tecnologia, Universidade dos A\u00e7ores, 9500-321 Ponta Delgada, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5793-1987","authenticated-orcid":false,"given":"C\u00e9sar","family":"Andrade","sequence":"additional","affiliation":[{"name":"IVAR\u2014Instituto de Investiga\u00e7\u00e3o em Vulcanologia e Avalia\u00e7\u00e3o de Riscos, Universidade dos A\u00e7ores, 9500-321 Ponta Delgada, Portugal"},{"name":"CIVISA\u2014Centro de Informa\u00e7\u00e3o e Vigil\u00e2ncia Sismovulc\u00e2nica dos A\u00e7ores, Universidade dos A\u00e7ores, 9500-321 Ponta Delgada, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4997-8264","authenticated-orcid":false,"given":"Jos\u00e9 Francisco","family":"Santos","sequence":"additional","affiliation":[{"name":"GeoBioTec\u2014Geobioci\u00eancias, Geoengenharias e Geotecnologias, Departamento de Geoci\u00eancias, Universidade de Aveiro, 3810-193 Aveiro, Portugal"}]},{"given":"Maria Helena","family":"Acciaioli","sequence":"additional","affiliation":[{"name":"GeoBioTec\u2014Geobioci\u00eancias, Geoengenharias e Geotecnologias, Departamento de Geoci\u00eancias, Universidade de Aveiro, 3810-193 Aveiro, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2023,1,5]]},"reference":[{"key":"ref_1","unstructured":"Faure, G., and Mensing, T.M. (2005). Isotopes, Principles and Applications, John Wiley & Sons. [3rd ed.]."},{"key":"ref_2","unstructured":"Faure, G. (1986). Principles of Isotope Geology, John Wiley & Sons. [2nd ed.]."},{"key":"ref_3","first-page":"29","article-title":"Sr isotopic signatures of Portuguese bottled mineral waters and their relationships with the geological setting","volume":"101","author":"Ribeiro","year":"2014","journal-title":"Comun. Geol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"574","DOI":"10.1016\/j.apgeochem.2008.12.011","article-title":"Sr isotopes in natural waters: Applications to source characterisation and water-rock interaction in contrasting landscapes","volume":"24","author":"Shand","year":"2009","journal-title":"Appl. Geochem."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1471","DOI":"10.1016\/j.apgeochem.2012.03.007","article-title":"Input of 87Sr\/86Sr ratios and Sr geochemical signatures to update knowledge on thermal and mineral waters flow paths in fractured rocks (N-Portugal)","volume":"27","author":"Marques","year":"2012","journal-title":"Appl. Geochem."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"197","DOI":"10.1016\/S0016-7061(97)00102-X","article-title":"Strontium isotopes as tracers of ecosystem processes: Theory and methods","volume":"82","author":"Capo","year":"1998","journal-title":"Geoderma"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"326","DOI":"10.1016\/j.apgeochem.2010.12.006","article-title":"The geographic distribution of strontium isotopes in Danish surface waters\u2014A base for provenance studies in archaeology, hydrology and agriculture","volume":"26","author":"Frei","year":"2011","journal-title":"Appl. Geochem."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"65","DOI":"10.1016\/0022-1694(89)90007-3","article-title":"Weathering rates and 87Sr\/86Sr ratios: An isotopic approach","volume":"109","author":"Jacks","year":"1989","journal-title":"J. Hydrol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"89","DOI":"10.1016\/S0009-2541(96)00110-6","article-title":"A strontium isotopic study of mineral and surface waters from the C\u00e9zallier (Massif Central, France): Implications for mixing processes in areas of disseminated emergences of mineral waters","volume":"135","author":"Fouillac","year":"1997","journal-title":"Chem. Geol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1535","DOI":"10.1007\/s10040-007-0227-4","article-title":"Hydrogeochemical processes, mixing and isotope tracing in hard rock aquifers and surface waters from the Subarnarekha River Basin, (east Singhbhum District, Jharkhand State, India)","volume":"15","author":"Lemiere","year":"2007","journal-title":"Hydrogeol. J."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"99","DOI":"10.1016\/j.jhydrol.2004.08.031","article-title":"Strontium isotopes as tracers of groundwater-induced floods: The Somme case study (France)","volume":"305","year":"2005","journal-title":"J. Hydrol."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Wu, C., Wu, X., Mu, W., and Zhu, G. (2020). Using isotopes (H, O, and Sr) and major ions to identify hydrogeochemical characteristics of groundwater in the Hongjiannao Lake Basin, Northwest China. Water, 12.","DOI":"10.3390\/w12051467"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"106682","DOI":"10.1016\/j.jvolgeores.2019.106682","article-title":"Origin and fate of hydrothermal fluids at Piton des Neiges volcano (R\u00e9union Island): A geochemical and isotopic (O, H, C, Sr, Li, Cl) study of thermal springs","volume":"392","author":"Famin","year":"2020","journal-title":"J. Volcanol. Geotherm. Res."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"382","DOI":"10.1016\/j.jvolgeores.2005.09.001","article-title":"Hydrogeochemistry of thermal and mineral water springs of the Azores archipelago (Portugal)","volume":"151","author":"Cruz","year":"2006","journal-title":"J. Volcanol. Geotherm. Res."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"353","DOI":"10.1016\/j.jvolgeores.2009.12.001","article-title":"Mineral waters characterization in the Azores archipelago (Portugal)","volume":"190","author":"Cruz","year":"2010","journal-title":"J. Volcanol. Geotherm. Res."},{"key":"ref_16","first-page":"289","article-title":"Hydrogeology of S\u00e3o Miguel Island, Azores: A review","volume":"Volume 44","author":"Gaspar","year":"2015","journal-title":"Volcanic Geology of S\u00e3o Miguel Island (Azores Archipelago)"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"2749","DOI":"10.1007\/s12665-014-3157-1","article-title":"Mineral water occurrence and geochemistry in the Azores volcanic archipelago (Portugal): Insight from an extended database on water chemistry","volume":"73","author":"Freire","year":"2015","journal-title":"Environ. Earth Sci."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"43","DOI":"10.1016\/j.gca.2015.07.009","article-title":"Gas geochemistry of hydrothermal fluids of the S. Miguel and Terceira Islands, Azores","volume":"168","author":"Caliro","year":"2015","journal-title":"Geochim. Cosmochim. Acta"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"B12208","DOI":"10.1029\/2010JB007555","article-title":"Soil CO2 emissions at Furnas volcano, S\u00e3o Miguel Island, Azores archipelago: Volcano monitoring perspectives, geomorphologic studies, and land use planning application","volume":"115","author":"Viveiros","year":"2010","journal-title":"J. Geophys. Res. Solid Earth"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"106968","DOI":"10.1016\/j.jvolgeores.2020.106968","article-title":"Deep CO2 emitted at Furnas do Enxofre geothermal area (Terceira Island, Azores archipelago). An approach for determining CO2 sources and total emissions using carbon isotopic data","volume":"401","author":"Viveiros","year":"2020","journal-title":"J. Volcanol. Geotherm. Res."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"154","DOI":"10.1016\/j.scitotenv.2013.02.090","article-title":"Fluvial geochemistry in S\u00e3o Miguel Island (Azores, Portugal): Source and fluxes of inorganic solutes in an active volcanic environment","volume":"454","author":"Freire","year":"2013","journal-title":"Sci. Total Environ."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"104","DOI":"10.1016\/j.jvolgeores.2017.03.020","article-title":"Characterization and origin of hydrothermal waters at S\u00e3o Miguel (Azores) inferred by chemical and isotopic composition","volume":"346","author":"Woitischek","year":"2017","journal-title":"J. Volcanol. Geotherm. Res."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"151","DOI":"10.1016\/S0377-0273(99)00073-6","article-title":"Chemistry of waters from Furnas volcano, S\u00e3o Miguel, Azores: Fluxes of volcanic carbon dioxide and leached material","volume":"92","author":"Cruz","year":"1999","journal-title":"J. Volcanol. Geotherm. Res."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"4386","DOI":"10.1002\/hyp.7042","article-title":"Chemical and isotopic assessment in volcanic thermal waters: Cases of Ischia (Italy) and S\u00e3o Miguel (Azores, Portugal)","volume":"22","author":"Morell","year":"2008","journal-title":"Hydrol. Process."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"177","DOI":"10.1016\/S0009-2541(98)00028-X","article-title":"Riverine erosion rates on S\u00e3o Miguel volcanic island, Azores archipelago","volume":"148","author":"Louvat","year":"1998","journal-title":"Chem. Geol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"69","DOI":"10.1016\/j.ejrh.2017.04.003","article-title":"Groundwater salinization in Graciosa and Pico islands (Azores archipelago, Portugal): Processes and impacts","volume":"12","author":"Cruz","year":"2017","journal-title":"J. Hydrol. Reg. Stud."},{"key":"ref_27","first-page":"595","article-title":"Notas sobre a Geologia do Arquip\u00e9lago dos A\u00e7ores","volume":"Volume 2","author":"Dias","year":"2013","journal-title":"Geologia de Portugal"},{"key":"ref_28","first-page":"1","article-title":"Volcanic Geology of S\u00e3o Miguel Island (Azores Archipelago): Introduction","volume":"Volume 44","author":"Gaspar","year":"2015","journal-title":"Volcanic Geology of S\u00e3o Miguel Island (Azores Archipelago)"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"28","DOI":"10.1038\/280028a0","article-title":"143Nd\/144Nd and 87Sr\/86Sr ratios from the Azores and their significance in LIL-element enriched mantle","volume":"280","author":"Hawkesworth","year":"1979","journal-title":"Nature"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"186","DOI":"10.1016\/j.epsl.2007.04.038","article-title":"The peculiar geochemical signatures of S\u00e3o Miguel (Azores) lavas: Metasomatised or recycled mantle sources?","volume":"259","author":"Beier","year":"2007","journal-title":"Earth Planet. Sci. Lett."},{"key":"ref_31","first-page":"85","article-title":"Conditions for mafic magma storage beneath fissure zones at oceanic islands. The case of S\u00e3o Miguel Island (Azores archipelago)","volume":"Volume 422","author":"Zanon","year":"2015","journal-title":"Chemical, Physical and Temporal Evolution of Magmatic Systems"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"49","DOI":"10.1016\/S0009-2541(97)00041-7","article-title":"Th-Sr-Nb-Pb isotope and trace element evidence for the origin of the S\u00e3o Miguel, Azores, enriched mantle source","volume":"140","author":"Widom","year":"1997","journal-title":"Chem. Geol."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"42","DOI":"10.1007\/s00410-016-1235-y","article-title":"Temporal evolution of a post-caldera, mildly peralkaline magmatic system: Furnas volcano, S\u00e3o Miguel, Azores","volume":"171","author":"Jeffery","year":"2016","journal-title":"Contrib. Mineral. Petrol."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"219","DOI":"10.1016\/j.gca.2006.07.043","article-title":"The origin of enriched mantle beneath S\u00e3o Miguel, Azores","volume":"71","author":"Elliott","year":"2007","journal-title":"Geochim. Cosmochim. Acta"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"145","DOI":"10.1016\/S0009-2541(97)00031-4","article-title":"U-Th isotope disequilibria and ocean island basalt generation in the Azores","volume":"139","author":"Turner","year":"1997","journal-title":"Chem. Geol."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"1375","DOI":"10.1093\/petrology\/egl014","article-title":"Magma evolution of the Sete Cidades Volcano, S\u00e3o Miguel, Azores","volume":"47","author":"Beier","year":"2006","journal-title":"J. Petrol."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"281","DOI":"10.1038\/252281a0","article-title":"Deep drilling in an activite geothermal area in the Azores","volume":"252","author":"Muecke","year":"1974","journal-title":"Nature"},{"key":"ref_38","first-page":"105","article-title":"Eruptive History of Fogo Volcano, S\u00e3o Miguel, Azores","volume":"Volume 44","author":"Gaspar","year":"2015","journal-title":"Volcanic Geology of S\u00e3o Miguel Island (Azores Archipelago)"},{"key":"ref_39","unstructured":"Wallenstein, N. (1999). Estudo da Hist\u00f3ria Recente e do Comportamento Eruptivo do Vulc\u00e3o do Fogo (S.; Miguel, A\u00e7ores). [Ph.D. Thesis, Universidade dos A\u00e7ores]. (In Portuguese)."},{"key":"ref_40","first-page":"65","article-title":"Volcano-Tectonic Structures of S\u00e3o Miguel Island, Azores","volume":"Volume 44","author":"Gaspar","year":"2015","journal-title":"Volcanic Geology of S\u00e3o Miguel Island (Azores Archipelago)"},{"key":"ref_41","unstructured":"Santos, J.F., Acciaioli, M.H., Fran\u00e7a, Z., Nunes, J.C., Pinto, M.S., and Forjaz, V.H. (2005, January 11\u201316). Contribui\u00e7\u00e3o para o estudo das Varia\u00e7\u00f5es Litogeoqu\u00edmicas do Vulc\u00e3o do Fogo (ilha de S.; Miguel, A\u00e7ores). Proceedings of theActas da XIV Semana de Geoqu\u0131mica e do VIII Congresso de Geoqu\u0131mica de Pa\u0131ses de L\u0131ngua Portuguesa, Aveiro, Universidade de Aveiro, Aveiro, Portugal."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"723","DOI":"10.1093\/petrology\/egg104","article-title":"The role of open-system processes in the development of silicic magma chambers: A chemical and isotopic investigation of the Fogo A trachyte deposit, S\u00e3o Miguel, Azores","volume":"45","author":"Snyder","year":"2004","journal-title":"J. Petrol."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"102519","DOI":"10.1016\/j.geothermics.2022.102519","article-title":"The contribution of hydrothermal mineral alteration analysis and gas geothermometry for understanding high-temperatura geothermal fields. The case of Ribeira Grande geothermal field, Azores","volume":"105","author":"Pereira","year":"2022","journal-title":"Geothermics"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/S0377-0273(99)00064-5","article-title":"Volcanic geology of Furnas volcano, S\u00e3o Miguel, Azores","volume":"92","author":"Guest","year":"1999","journal-title":"J. Volcanol. Geotherm. Res."},{"key":"ref_45","first-page":"125","article-title":"The volcanic History of Furnas Volcano, S\u00e3o Miguel, Azores","volume":"Volume 44","author":"Gaspar","year":"2015","journal-title":"Volcanic Geology of S\u00e3o Miguel Island (Azores Archipelago)"},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"602","DOI":"10.1007\/BF00301211","article-title":"Volcanic geology and eruption frequency, S\u00e3o Miguel, Azores","volume":"52","author":"Moore","year":"1990","journal-title":"Bull. Volcanol."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"117","DOI":"10.1016\/0377-0273(95)00033-X","article-title":"An historic subplinianrphreatomagmatic eruption: The 1630 AD eruption of Furnas volcano, Azores","volume":"69","author":"Cole","year":"1995","journal-title":"J. Volcanol. Geotherm. Res."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"51","DOI":"10.1016\/j.jvolgeores.2016.02.005","article-title":"Estimation of the CO2 flux from Furnas volcanic Lake (S\u00e3o Miguel, Azores)","volume":"315","author":"Andrade","year":"2016","journal-title":"J. Geotherm. Res."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"445","DOI":"10.1016\/S0883-2927(03)00135-5","article-title":"Major ion chemistry of groundwater from perched-water bodies of the Azores (Portugal) volcanic archipelago","volume":"19","author":"Cruz","year":"2004","journal-title":"Appl. Geochem."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"127","DOI":"10.1016\/j.scitotenv.2015.03.057","article-title":"Natural background groundwater composition in the Azores archipelago (Portugal): A hydrogeochemical study and threshold value determination","volume":"520","author":"Cruz","year":"2015","journal-title":"Sci. Total Environ."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"162","DOI":"10.1016\/j.apgeochem.2012.11.009","article-title":"Groundwater composition and pollution due to agricultural pratices at Sete Cidades volcano (Azores, Portugal)","volume":"29","author":"Cruz","year":"2013","journal-title":"Appl. Geochem."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"343","DOI":"10.1007\/s00254-003-0769-2","article-title":"Groundwater and volcanoes: Examples from the Azores archipelago","volume":"44","author":"Cruz","year":"2003","journal-title":"Environ. Geol."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"177","DOI":"10.1007\/s100400000106","article-title":"Hydrogeologic framework of the Pico Island (Azores, Portugal)","volume":"9","author":"Cruz","year":"2001","journal-title":"Hydrogeol. J."},{"key":"ref_54","first-page":"257","article-title":"Hydrogeochemical Characterization of Mineral Waters in S\u00e3o Miguel Island, Azores","volume":"Volume 44","author":"Gaspar","year":"2015","journal-title":"Volcanic Geology of S\u00e3o Miguel Island (Azores Archipelago)"},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"55","DOI":"10.2307\/210739","article-title":"An approach toward a national classification of climate","volume":"38","author":"Thornthwaite","year":"1948","journal-title":"Geogr. Rev."},{"key":"ref_56","first-page":"275","article-title":"Esbo\u00e7o pedol\u00f3gico da ilha de S. Miguel (A\u00e7ores)","volume":"37","author":"Ricardo","year":"1977","journal-title":"An. Inst. Super. Agron."},{"key":"ref_57","first-page":"173","article-title":"Monitoring of the groundwater chemical status in the Azores archipelago (Portugal) in the context of the EU water framework directive","volume":"61","author":"Cruz","year":"2010","journal-title":"Sci. Total Environ."},{"key":"ref_58","unstructured":"DROTRH-INAG (2022, November 14). Plano Regional da \u00c1gua-Relat\u00f3rio T\u00e9cnico, Available online: https:\/\/www.google.com\/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwju9ZDKuK_8AhVGtVYBHflEDVkQFnoECBkQAQ&url=https%3A%2F%2Fservicos-sraa.azores.gov.pt%2Fgrastore%2FDRA%2FQSIGA%2FPP_DocumentoApoio.pdf&usg=AOvVaw22BHEM-kkz1K7wwgvAS4ci."},{"key":"ref_59","unstructured":"Cruz, J.V. (2022, November 14). Ensaio Sobre a \u00c1gua Subterr\u00e2nea nos A\u00e7ores. Hist\u00f3ria, Ocorr\u00eancia e Eualidade. SRA, Ponta Delgada, Available online: https:\/\/www.google.com\/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwjmn5Spt6_8AhU8s1YBHctVAlgQFnoECAgQAQ&url=http%3A%2F%2Fwww.ivar.azores.gov.pt%2Fpublicacoes%2FPaginas%2Fcms_908_CRUZ-J-V-2004-Ensaio-sobre-a-agua-subterranea-nos-Acores-Historia-ocorrencia-e-qualidade-Ed-Secretaria-Regional-do.aspx&usg=AOvVaw1zfHmlRlK5w206nxIKy1q4."},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"230","DOI":"10.1111\/j.1745-6584.1993.tb01815.x","article-title":"Classification of transmissivity magnitude and variation","volume":"31","year":"1993","journal-title":"Ground Water"},{"key":"ref_61","unstructured":"APHA-AWWA-WPCF (1985). Standard Methods for the Examination of Water and Wastewater, American Public Health Association."},{"key":"ref_62","unstructured":"Clark, I.D., and Fritz, P. (1997). Environmental Isotopes in Hydrology, Lewis Publishers."},{"key":"ref_63","unstructured":"IAEA (2017). Sampling Procedures for Isotope Hydrology, Water Resources Programe."},{"key":"ref_64","doi-asserted-by":"crossref","first-page":"291","DOI":"10.1016\/S0377-0273(01)00268-2","article-title":"Tracing and quantifying magmatic carbon discharge in cold groundwaters: Lessons learned from Mammoth Mountain, USA","volume":"114","author":"Evans","year":"2002","journal-title":"J. Volcanol. Geotherm. Res."},{"key":"ref_65","unstructured":"Hem, J.D. Study and Interpretation of the Chemical Characteristics of Natural Water, Water-Supply Paper 2254."},{"key":"ref_66","doi-asserted-by":"crossref","first-page":"216","DOI":"10.1016\/j.ejrh.2016.12.087","article-title":"Groundwater dependent pools in seasonal and permanent streams in the Clare Valley of South Australia","volume":"9","author":"Bestland","year":"2017","journal-title":"J. Hydrol. Reg. Stud."},{"key":"ref_67","unstructured":"Kelly, W.R., Panno, S.V., and Hackley, K.C. (2012). The Sources, Distribution and Trends of Chloride in the Waters of Illinois, Illinois State Water Survey. Bulletin Illinois State Water Survey B-74."},{"key":"ref_68","doi-asserted-by":"crossref","unstructured":"Berner, E.K., and Berner, R.A. (2012). Global Environment: Water, Air, and Geochemical Cycles, Princeton University Press. [2nd ed.].","DOI":"10.1515\/9781400842766"},{"key":"ref_69","unstructured":"Tomo, I. (1983). Hidrolog\u00eda Subterr\u00e2nea, Edici\u00f3nes \u00d3mega, S.A.. [2nd ed.]."},{"key":"ref_70","unstructured":"IAEA, Water Resource Programme (2014). Measurements of the Isotopic Composition of Meteoric Water of S\u00e3o Miguel, Azores from 1962 till 2009, Water Resources Programe."},{"key":"ref_71","doi-asserted-by":"crossref","first-page":"85","DOI":"10.1016\/S0012-821X(00)00357-5","article-title":"Diamond genesis, mantle fractionations and mantle nitrogen content: A study of \u03b413C\u2013N concentrations in diamonds","volume":"185","author":"Cartigny","year":"2001","journal-title":"Earth Planet. Sci. Lett."},{"key":"ref_72","doi-asserted-by":"crossref","unstructured":"Clark, T. (2015). Groundwater Geochemistry and Isotopes, Taylor & Francis Group.","DOI":"10.1201\/b18347"},{"key":"ref_73","first-page":"609","article-title":"Palaeolimnology","volume":"Volume 1","author":"Reynolds","year":"2004","journal-title":"The Lakes Handbook, Limnology and Limnetic Ecology"},{"key":"ref_74","doi-asserted-by":"crossref","first-page":"169","DOI":"10.1016\/S0377-0273(99)00074-8","article-title":"Chemistry and isotopic composition of fumarole discharges of Furnas caldera","volume":"92","author":"Ferreira","year":"1999","journal-title":"J. Volcanol. Geotherm. Res."},{"key":"ref_75","doi-asserted-by":"crossref","first-page":"106835","DOI":"10.1016\/j.gexplo.2021.106835","article-title":"Global carbon dioxide output of volcanic lakes in the Azores archipelago, Portugal","volume":"229","author":"Andrade","year":"2021","journal-title":"J. Geochem. Explor."},{"key":"ref_76","first-page":"319","article-title":"Stable Isotopic Applications in Hydrological Studies","volume":"Volume 9","author":"Drever","year":"2015","journal-title":"Surface and Groundwater, Weathering, and Soils"},{"key":"ref_77","doi-asserted-by":"crossref","first-page":"179","DOI":"10.1080\/10256010701550773","article-title":"Chemical and strontium isotope characterization of rainwater in France: Influence of sources and hydrogeochemical implications","volume":"3","author":"Negrel","year":"2007","journal-title":"Isot. Environ. Health Stud."},{"key":"ref_78","doi-asserted-by":"crossref","first-page":"7","DOI":"10.1016\/j.jvolgeores.2007.06.006","article-title":"Sr isotope diversity of hot spring and volcanic lake waters from Zao volcano, Japan","volume":"166","author":"Ishikawa","year":"2007","journal-title":"J. Volcanol. Geotherm. Res."}],"container-title":["Water"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2073-4441\/15\/2\/245\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T18:00:41Z","timestamp":1760119241000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2073-4441\/15\/2\/245"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,1,5]]},"references-count":78,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2023,1]]}},"alternative-id":["w15020245"],"URL":"https:\/\/doi.org\/10.3390\/w15020245","relation":{},"ISSN":["2073-4441"],"issn-type":[{"value":"2073-4441","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,1,5]]}}}