Influence of rheologically weak layers on fault architecture: insights from analogue models in the context of the Northern Alpine Foreland Basin

Swiss Journal of Geosciences

Table 5 Scaling parameters

	Model material	Nature^a
Material	Quartz sand	Overburden
Density (ρ_specific)	1560 kg/m³	2700 kg/m³
Internal peak friction angle	36.1°	ca. 40°
Cohesion	9 Pa	20 MPa (2 MPa^b)
Material	Kinetic sand	Opalinus Clay (strong end-member)
Density (ρ_specific)	1600 kg/m³	2400–2500 kg/m³
Internal peak friction angle	31°	ca. 30°
Cohesion	251 Pa	3 MPa
Material	Viscous mixture	Opalinus Clay (weak end-member)
Density (ρ_specific)	1600 kg/m³	2400–2500 kg/m³
Viscosity (η)	1.5 × 10⁵ Pa s	5 × 10¹⁷ Pa s

^aNatural values adopted from Giger and Marschall (2014), Roche et al. (2020), and Yarushina et al. (2021)
^bExperimentally measured cohesion values of natural rocks may be one or even two degrees of magnitude lower in natural situations due to initial heterogeneities, or weakening caused by preceding tectonic deformation (Von Hagke et al., 2019)