ABSTRACT
The field images are here sorted in order from brittle (Figs. 18.2-18.4), to transitional between brittle and ductile (Figs. 18.5-18.7), to ductile (Figs. 18.8-18.10). Figure 18.11 shows a boudin that is almost round, having been distantly separated from neighboring boudins, and having lost its boudin necks. Figure 18.12 shows how mullions can develop on a cleavage surface, as the result of boudinaged layers below that surface. Figures 18.13 and 18.14 show asymmetric boudins that developed during shear. Finally, Figure 18.15 shows a subtle boudin as a reminder that nature tends to cover many geologic features, making them more difficult to spot. Think of it as a practice example, to help readers train their eyes to extract patterns from beneath the obscuring cover.
