There is a significant variation across and along shear bands. In general, a shear band is composed of an inner zone or core made up of crushed grains surrounded by an outer zone which has only a tighter texture without much grain fracturing. This is depicted in a schematic diagram in Figure 1 from Aydin (1978). It is likely that along a band there are also lobes recording its incremental growth through a heterogeneous rock as pointed out by Torabi et al. (2015), which will be illustrated under 'Mechanisms and Mechanics of Shear Bands.'

Figure 1. A schematic diagram based on architecture of a shear band showing its components; inner zone or core and outer zone. From Aydin (1978).