EN
This geochemical study aims to resolve genesis of precipitation spots on the walls on the Nydeggbrücke in Bern, Switzerland. The bridge is composed of Jurassic limestone and dolomites and coated on both sides with Miocene flysch sandstone. As a result of infiltration of aqueous solutions derived directly from the road embankment into the sandstone, sulfate encrustation on the walls of sandstone has been formed.The study of these precipitates using optical and electron microscopy clearly shows dominant sulfate phases are gypsum (calcium sulfate), mirabilite (sodium hydrated sulfate) and polyhalite (potassium, calcium and magnesium sulfate). Impurities of Ni, Cu, Zn and Pb was encountered by ICP-MS analysis. Identified polymetallic mineralization is associated with the infrastructure of the bridge and the accumulation of pollution from vehicular traffic. This is also confirmed by sulfur and oxygen stable isotope analyses of sulfates.