Tectonic and volcanic controls on hydrothermal silicification in marginal zones of the Ohře Rift

Near-contact silicification along intrusive/volcanic bodies and large-volume silicification beneath sealing horizons are the two types of hydrothermal alteration with newly formed SiO2 in coarse clastics of the fill of the Ohře Rift graben (Oligocene to Miocene), its floor and its shoulder blocks (Late Cretaceous). Their association with other types of young minerelization like ferruginization, fluoritization and barization will be taken as a circumstance permitting to trace the development of mineralizing fluids (chemistry, temperature, pH) through time. The function of faults, fracture zones and intrusive/volcanic bodies as elements of convective fluid transport will be particularly established. The respective hydraulic model will be constructed for marginal zones of the Ohře Rift and compared with fluid circulation patterns on other rift basins in the world.