The Staffelegg Formation spans the entire Early Jurassic and thus represents a protracted period of deposition of nearly 30 million years. Three timelines picked within the Staffelegg Formation (199.5_Het_100, 192.9_Sin_200, 192.9_Sin_100; Fig. 4‑23) approximately follow lithostratigraphic boundaries (Top Schambelen Member, Top Beggingen Member and Top Frick Member). Within the very bituminous lower part of the Rietheim Member, the negative carbon-isotope excursion of the Toarcian Oceanic Anoxic Event is recognised (e.g. Fantasia et al. 2019). This global Toarcian Oceanic Anoxic Event, together with the C-isotope chemostratigraphy, allows a high-resolution correlation for the boreholes presented here (Wohlwend et al. 2024).