“Folds are perhaps the most common tectonic structure developed in deformed rocks” (from Ramsay & Huber 1987) and folds occur in rocks from the millimeter to the lithospheric scale. Understanding the mechanics of folding is therefore essential for understanding tectonic processes in compressional settings. We study folding with analytical and numerical solutions with particular interests in the large-strain, high-amplitude evolution of folds in two (Figure 1 and 2) and three (Figure 3) dimensions.

Figure 1: Quartz vein in shale forming a typical single-layer fold. This feature is the result of a mechanical instability which occurs when mechanically stronger layers (here the quartz vein) are shortened within a mechanically weaker medium (here the shale).



Figure 2: 2D Numerical finite simulation of ductile single-layer folding showing the distribution of strain rates during folding (red = high strain rate, blue = low strain rate).


Figure 3: 3D Numerical simulation of multilayer folding to study fold interference patterns.