This thesis investigates the Quaternary evolution of the Geneva Basin (Switzerland and neighbouring France), aiming to improve subsurface models for groundwater management, geothermal energy, and infrastructure planning. It combines harmonised borehole data, high-resolution seismic imaging, facies analysis, and sediment provenance studies to reconstruct buried glacial landscapes and depositional systems.
To address inconsistencies in stratigraphic nomenclature and database structures that hinder cross-border geological correlation, borehole data from the French BRGM InfoTerre database were harmonised into U_SOLSTISS, aligned with Geneva’s SOLSTISS system. This unified geodatabase provided critical input for updating the Quaternary base/top Molasse surface model, supporting regional planning and projects such as CERN’s Future Circular Collider.
Integration of 180 km² of 3D seismic data, 2D profiles, and 4,378 borehole logs produced a detailed map of the Quaternary–Molasse interface. Imaging revealed four NE–SW trending tunnel valleys—Montbrillant–Aire-la-Ville, Gaillard–Plan‑les‑Ouates, Versoix–Avully, and Lancy–Avusy—incised up to 250 m into Molasse bedrock. Their undulatory thalweg morphology and fault-controlled segments indicate polyphase origins linked to subglacial erosion during successive advances and retreats of the Rhône and Arve glaciers.
A revised stratigraphic framework is introduced in this study to clarify the sequence of Quaternary deposits and improve the understanding of their depositional history. This approach refines valley infill interpretation by differentiating ice-proximal deposits from meltwater-driven sequences. The facies model captures variability across glacial complexes, including tills, glaciolacustrine deposits, and deltaic systems, illustrating the interplay of ice advance, meltwater erosion, and sedimentary infill across multiple glacial cycles.
Finally, a multi-proxy provenance approach (XRF, Nd isotopes, QEMSCAN mineralogy, U–Pb zircon dating) indicates dominant sediment sources from the Aar and Mont Blanc–Aiguilles Rouges massifs, with zircon age spectra spanning Ordovician to Permian and negative εNd values confirming felsic upper-crustal contributions.
