| Summary: | This report summarizes the results of the studies carried out for the achievement ofthe objectives described at page 14 of 40 of the DoW, i.e.: the description of thegeometric characteristics of the structural conduits and traps where geothermalfluids are channeled and stored, by studying exhumed geothermal systems to becompared to the active ones (Task 3.1). We studied also the geochemical features ofthe paleofluids (Task 3.1) The main target of WP3 is to provide information on the geological processes andprocesses controlling the relationships between the geological structures and fluidflow. To follow this, we have applied the classical approach of structural geology andgeochemistry of paleofluids and of hydrothermal minerals.The field structural study produced new geological maps and highlighted thekinematics and geometry of the shear and extensional fractures, as later ondescribed. The geochemical studies focused on the boundary conditions (P-T andgeochemical properties) of reservoirs of high-temperature magmatic geothermalsystems in both study areas, the exhumed Elba Island (Italy), for the continentalcrusta, and Geitafell (Iceland) for the oceanic crust. The geochemical studydeveloped through: 1) rock sampling for laboratory analyses in key-areas comprisinga selections of core-samples from bore-holes drilled in the Geitafell area and 2)mineralogical and petrographic studies and laboratory analyses of fluid inclusions,isotopes and mineral-chemistry on selected samples. Fluid inclusions, isotopes andminerals represent, in fact, unique geological archives to reconstruct the to derivethe pressure-temperature and geochemistry-time evolution of luid circulations infossil high-temperature magmatic-hydrothermal systems, to obtain information onwater-rock interaction between host rock and fluids and to characterize the fluidsource(s) that flowed in the fossil systems. The study had benefitted of the scientific and fruitful integration between the Italianand Islandic teams both during the field and laboratory ...
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