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

Abstract We present a series of analogue models inspired by the geology Zürcher Weinland region in Northern Alpine Foreland Basin Switzerland to explore influence rheological weak, i.e. (partially) ductile layers on 3D evolution tectonic deformation. Our model test impact varying weak layer thickness and rheology, as well different kinematics an underlying “basal fault”. Model analysis focuses deformation overburden and, uniquely, within itself. find that for low moderate basal fault displacements, above-mentioned parameters strongly degree coupling between overburden. Coupling decreases reducing strength layer, or increasing layer’s thickness. As result, displacement is less readily transferred through leading structural style By contrast, amount, rate, slip enhances leads more similar Moreover, dip-slip than strike-slip same magnitude. results compare fairly natural examples Basin, explaining various features. These comparisons suggest such Jurassic Opalinus Clay have exerted stronger control zone architecture commonly inferred, potentially resulting vertical segmentation variations style. Furthermore, novel addition internal marker intervals our reveals how complex viscous flow these can accommodate slip. demonstrate links kinematics, mechanics geometries, be used interpreting structures Foreland, other settings with faults driving system.