Enhancing copper predictions at the base of Zechstein with 4D modelling

3D restoration can help to better understand the history of geological formations, to identify fossil mineralizing fluid pathways, to establish the physical and chemical processes involved in ore formations and to predict the locations of potential economic mineral resources. In the case of sediment-hosted ore deposits, the unfolding and unfaulting techniques allow to visualize the impact of tectonic events during the mineralization stages and their role in the final ore-distribution. We applied a 3D restoration procedure on the German and Polish Kupferschiefer, pointing out the role played by the Late Cretaceous-Early Paleocene uplifting which affected Central Europe. On both sides of the Fore-Sudetic block, the fluids trapped beneath the Zechstein formations reached over-pressurized conditions due to the inverse up-lift phase, provoking the hydro-fracturing and the re-opening of previous discontinuities. This set of hydro-fractures was necessary in the Cu re-mobilization and later during its precipitation as enriched Cu (Cu-Fe) sulfides. A hydro-fracturing index accounting for the stress and the geomechanical constraints in the ore-series was estimated and seems to correlate with the presence of Cu-sulfides within the Kupferschiefer.