The model domain has a depth of 5000 m below ground level. The mountain surface is assigned an elevation of 200 m, whereas the valley is set at sea level. The matrix permeability is set to 1E-15 m², while the fracture permeability is set to 1E-10 m². Two fracture apertures, 0.1 m and 0.01 m, are considered. For the hydraulic boundary conditions, the top boundary is prescribed as constant atmospheric pressure, while the initial pressure within the domain is depth dependent. For the thermal boundary conditions, the top temperature is assumed to vary with elevation. Specifically, the valley temperature is set to 10 °C and decreases with elevation at a lapse rate of 0.03 °C/m; consequently, the mountain-top temperature is 4 °C. The temperature differences between the fractured models and the unfractured reference model are shown in Figure A. The results indicate that the model with the larger fracture aperture develops more pronounced high-temperature zones around the fracture, accompanied by stronger hydraulic transport along the fracture pathway.

This quarters main focus is to select and measure further core samples in order to gain more petrological data for the understanding of the subsurface. More core samples are taken and destructive measurements were carried out, i.e. XRD and EMP. Thin sections analyse allow to identify modal rock forming primary minerals as well as alteration. XRD enables to determine the type of mineral forming the rock and mineral abundances can be obtained via a quantitative interpretation. MSCL (Multi Sensor Core Logging) measurements were interpreted, thermal properties measured and reactive flow-through experiments will start soon. The first geomechanical experiments were conducted as well. Structural modelling is progressing by implementing further information from literature and obtained via the data generated from measurements.

During Q2/2026, RWTH further developed the GeoDT structural modelling workflow. The focus was on transforming heterogeneous geological data – including lithological units, topography, model boundaries and faults – into consistent voxel-based models suitable for numerical simulation. New methods for clipping, merging and boundary extraction improved the geometrical consistency and robustness of the resulting model outputs.

In parallel, the GemPy-based node editor was expanded into a modular visual workflow environment. Users can now combine, reuse and monitor individual modelling and processing steps, from importing geological data and generating structural models to preparing simulation-ready voxel grids and boundary meshes.