Milodowski, A.E., Tullborg, E.L., Buil, B., Gomez, P., Turrero, M.-J., Haszeldine, S., England, G., Gillespie, M.R., Torres, T., Ortiz, J., Zacharias, J., Silar, J., Chvatal, M., Strnad, L., Sebek, O., Bouch, J.E., Chenery, S.R.N., Chenery, C.A., Shepherd, T.J., Milodowski, A.E., Tullborg, E.L., Buil, B., Gomez, P., Turrero, M.-J., Haszeldine, S., England, G., Gillespie, M.R., Torres, T., Ortiz, J., Zacharias, J., Silar, J., Chvatal, M., Strnad, L., Sebek, O., Bouch, J.E., Chenery, S.R.N., Chenery, C.A., and Shepherd, T.J.
The role of Work Package (WP) 2 of the PADAMOT project – ‘Palaeohydrogeological Data Measurements’ - has been to study late-stage fracture mineral and water samples from groundwater systems in Spain, Sweden, United Kingdom and the Czech Republic, with the aim of understanding the recent palaeohydrogeological evolution of these groundwater systems. In particular, the project sought to develop and evaluate methods for obtaining information about past groundwater evolution during the Quaternary (about the last 2 million years) by examining how the late-stage mineralization might record mineralogical, petrographical and geochemical evidence of how the groundwater system may have responded to past geological and climatological changes. Fracture-flow groundwater systems at six European sites were studied: • Melechov Hill, in the Bohemian Massif of the Czech Republic: a shallow (0-100 m) dilute groundwater flow system within the near-surface weathering zone in fractured granitic rocks; • Cloud Hill, in the English Midlands: a (~100 m) shallow dilute groundwater flow system in fractured and dolomitized Carboniferous limestone; • Los Ratones, in southwest Spain: an intermediate depth (0-500 m) dilute groundwater flow system in fractured granitic rocks; • Laxemar, in southeast Sweden: a deep (0-1000 m) groundwater flow system in fractured granitic rocks. This is a complex groundwater system with potential recharge and flushing by glacial, marine, lacustrine and freshwater during the Quaternary; • Sellafield, northwest England: a deep (0-2000 m) groundwater flow system in fractured Ordovician low-grade metamorphosed volcaniclastic rocks and discontinuous Carboniferous Limestone, overlain by a Permo-Triassic sedimentary sequence with fracture and matrix porosity. This is a complex coastal groundwater system with deep hypersaline sedimentary basinal brines, and deep saline groundwaters in crystalline basement rocks, overlain by a shallow freshwater aquifer system. The site was g