Figure 1.

Deep understanding of crustal deformation relies on three approaches: field measurements of deformation, physics-based predictions of deformation, and direct documentation of deformational processes within laboratory experiments. To illustrate the power of the tectonics three-legged stool, we show results from a fully integrated study on the development of sheath folds in simple shear. (A) Sheath fold from Cap de Creus, Spain. (B) Photo from a physical experiment investigating the impact of layer viscosity contrast on the fold formation (Reber et al., 2013). (C) Cross section from an analytical model investigating the effect of total shear strain (Reber et al., 2012).