Fig. 18
From: High-resolution mini-seismic methods applied in the Mont Terri rock laboratory (Switzerland)
Results from a seismic transmission experiment were used for an anisotropy study along the three facies types of the Opalinus Clay. a Derived vpz (z-component). The vpz-max. direction for each facies is interpreted to be the bedding-strike parallel orientation (sandy facies: vpz ≈ 3410 m/s, carbonate-rich sandy facies: vpz ≈ 3990 m/s and shaly facies: vpz ≈ 3010 m/s). For the shaly facies, the vpz distribution was disturbed, most probably by the Main Fault. b The ray coverage for emitter positions S09, S19 and S31. Three-component receivers R1–R50 were deployed in the access gallery and some niches. c–e Ensemble-normalised seismic sub-sections focusing on the first arrival phases for each facies of the Opalinus Clay