During the current reporting period, a new three-dimensional geological model of the Weschnitz and Ulfenbach catchments was developed in Leapfrog to provide an improved geological framework for integrated hydrological simulations in the GeoLaB area.

The model combines the reinterpretation of more than 600 borehole logs from the HLNUG database with geological maps, topographic information, and a structural framework incorporating the major fault systems of the Southern Odenwald. Based on the conceptualization of weathered crystalline aquifers, the subsurface was classified into five hydrogeological units: alluvial deposits, saprolite, sedimentary rocks, fractured rock, and bedrock. The resulting model extends to a depth of 600 m and captures the main geological structures and lithological heterogeneity of the study area.

The new geological model provides the basis for the next generation of ParFlow-CLM simulations, allowing the influence of subsurface heterogeneity on groundwater–surface water interactions and catchment-scale hydrological processes to be systematically investigated.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.