127586 20241125101155.0 doi 10.1016/j.jhydrol.2023.129818 sideral 134614 ART-2023-134614 eng Gimeno, Maria J. Universidad de Zaragoza (orcid)0000-0001-5645-9150 Hydrogeochemical characterisation of the groundwater in the crystalline basement of Forsmark, the selected area for the geological nuclear repositories in Sweden 2023 Access copy available to the general public Unrestricted Numerous groundwater analyses from the crystalline bedrock in the Forsmark area have been performed between 2002 and 2019, together with thorough geological, geophysical, and hydrogeological studies, within the site investigations carried out by the Swedish Nuclear Fuel and Waste Management Company. The groundwater samples have been taken from boreholes down to ≈ 1000 m and the analysis include major- and trace-elements, stable and radiogenic isotopes, gases and microbes. The chemical and isotopic composition of these groundwaters evidences the presence of non-marine brackish to saline groundwaters with very long residence times (many hundreds of thousands of years) and a series of complex mixing events resulting from the recharge of different waters over time: glacial meltwaters, probably from different glaciations of which the latest culminated some 20,000 years ago, and marine waters from the Baltic starting some 7000 years ago. Later, meteoric water and present Baltic Sea water have recharged in different parts of the upper 100 m. These mixing events have also triggered chemical and microbial reactions that have conditioned some of the important groundwater parameters and, together with the structural complexity of the area, they have promoted a heterogeneous distribution of groundwater compositions in the bedrock. Due to these evident differences in chemistry, residence time and origin of the groundwater, several groundwater types were defined in order to facilitate the visualisation and communication. The differentiation (linked to the paleohydrological history of the area) was based on Cl concentration, Cl/Mg ratio (marine component), and δ18O value (glacial component). The work presented in this paper increases the understanding of the groundwater evolution in fractured and compartmentalised aquifers where mixing processes are the most important mechanisms. The model proposed to characterise the present groundwater system of the Forsmark area will also help to predict the future hydrogeochemical behaviour of the groundwater system after the construction of the repositories for the nuclear wastes. info:eu-repo/semantics/openAccess by-nc-nd http://creativecommons.org/licenses/by-nc-nd/3.0/es/ 5.9 2023 ENGINEERING, CIVIL 14 / 182 = 0.077 2023 Q1 T1 WATER RESOURCES 8 / 128 = 0.062 2023 Q1 T1 GEOSCIENCES, MULTIDISCIPLINARY 19 / 254 = 0.075 2023 Q1 T1 1.764 2023 Water Science and Technology 2023 Q1 11.0 2023 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Tullborg, Eva-Lena Nilsson, Ann-Chatrin Auqué, Luis F. Universidad de Zaragoza (orcid)0000-0003-1463-1682 Nilsson, Lino 2000 685 Universidad de Zaragoza Dpto. Ciencias de la Tierra Área Petrología y Geoquímica 624 (2023), 129818 [21 pp.] J. hydrol. Journal of Hydrology 0022-1694 12745236 http://zaguan.unizar.es/record/127586/files/texto_completo.pdf Versión publicada 2411534 http://zaguan.unizar.es/record/127586/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:127586 articulos driver 2024-11-22-12:09:02 ARTICLE