Fig. 9

a Base Tertiary horizon structural map by (Interoil 2010) (bold lines) with traces of interpreted seismic profiles (dotted lines) and location of deep boreholes used for calibration (tagged circles). b Seismic transect FR.N8105 across the FL (see trace of line in a); five stratigraphic limits were interpreted and interpolated in structural map horizons: bMz base Mesozoic, tMs top Muschelkalk, tLi top Lias, bMa base Malm, bTe base Tertiary (Interoil 2010). c 3D fault plane model of Fribourg region with interpolated base Mesozoic and base Tertiary horizons. The spatial distribution of well constrained master event hypocenters of the Fribourg micro-earthquake dataset is shown and correlates well with the Fendringen and St. Sylvester structures (FS and StS, respectively in a). Due to the absence of seismic survey in Fribourg agglomeration, no subsurface tectonic features that could be linked to the Fribourg Cluster are interpreted at that location