In the BASTION project (“Influence of geological processes on the barrier properties of argillaceous rock formations”) the BGR is involved in carrying out research on the lithofacies composition, the structural conditions, and the repository-relevant properties of argillaceous rocks. This involves undertaking analysis on aspects including the influence of geological fault zones, and the influence of heterogeneities, on the barrier properties of argillaceous rock formations. The data acquired in this way is supplemented by investigations of natural analogues aiding in research towards a geological repository for the final disposal of heat-generating, high-level radioactive waste in argillaceous rocks. The main focus of the research activities is on multi-scale structural and mineralogical-geochemical investigations of intact and geologically deformed samples, the analysis of deformation and sealing processes, as well as studies on the impact of thermal processes.
The compositional and structural investigations of the rocks are accompanied by in-situ scale numerical simulations of coupled thermal, hydraulic and mechanical processes involved. The adequate representation of heterogeneous parameter distributions occurring at this scale in numerical models is a research topic in model development, which is essential in the project.
The results of the compositional, structural and numerical investigations acquired via the BASTION project so far enable the BGR to make an important contribution in the search for a geological repository site in argillaceous rock formations, and provides the basis for a comparative evaluation of argillaceous rock formations in northern and southern Germany and Switzerland.
Literature
Kneuker, T., Hammer, J., Shao, H., Schuster, K., Furche, M. & Zulauf, G. (2017): Microstructure and composition of brittle faults in claystones of the Mont Terri rock laboratory (Switzerland): New data from petrographic studies, geophysical borehole logging and permeability tests. Engineering Geology, 231: 139–156. DOI: 10.1016/j.enggeo.2017.10.016.
Kneuker, T., Blumenberg, M., Strauss, H., Dohrmann, R., Hammer, J. & Zulauf, G. (2020): Structure, kinematics and composition of fluid-controlled brittle faults and veins in Lower Cretaceous claystones (Lower Saxony Basin, Northern Germany): Constraints from petrographic studies, microfabrics, stable isotopes and biomarker analyses. Chemical Geology, 540: 119501. DOI: 10.1016/j.chemgeo.2020.119501.
Kneuker, T. & Furche, M. (2021): Capturing the structural and compositional variability of Opalinus Clay: Constraints from multidisciplinary investigations of Mont Terri drill cores (Switzerland). Environmental Earth Science, 80: 421. DOI: 10.1007/s12665-021-09708-1.
Kneuker, T., Dohrmann, R., Ufer, K. & Jaeggi, D. (2023): Compositional-structural characterization of the Opalinus Clay and Passwang Formation: New insights from Rietveld refinement (Mont Terri URL, Switzerland). Applied Clay Science, 242: 107017. DOI: 10.1016/j.clay.2023.107017.
Kneuker, T., Mann, T., Dohrmann, R., Ufer, K., Blumenberg, M., Erbacher, J., Bornemann, A., Schuck, B., Zimmerli, G. N. & Pollok, L. (2025). Compositional-structural properties of the Opalinus Clay in southern Germany: Combining facies-based studies and mineralogical analyses. Applied Clay Science, 279, 108032. DOI: 10.1016/j.clay.2025.108032.
Kumar, V., Kneuker, T. & Maßmann, J. (2020): Transferring geo-/mineralogical information to THM simulations of HLW storage in claystone formations. European Geosciences Union (EGU) General Assembly 2020, EGU2020-17898. DOI: 10.5194/egusphere-egu2020-17898.
Schuck, B. & Kneuker, T. (2021): Claystone formations in Germany: what we (don't) know about them and how we can change this. Safety of Nuclear Waste Disposal, 1: 47–48. DOI: 10.5194/sand-1-47-2021.