Slip lines and slip planes have been used to rationalize fault patterns in Earth's crust (Aydin, 1973; Cummings, 1976; and Tapponnier and Peltzer, 1982). Among the slip line analogies, the one proposed by Tapponnier et al. (1982) is perhaps the best known. By a rigid indenture, they produced two sets of slip surfaces (Figure 1A) which gradually evolved to a pattern that resembles the large scale fault systems in central Asia and southern China (Figure 1C) formed by the collision of the Indian plate with the Eurasian plate.

Figure 1. Photos as well as hand drawings of faults of three successive stages of an indentation experiment on unilaterally confined plasticine. C-1 shows similar pattern with that observed in Indochina and southern China, as labeled correspondingly in C-2. From Tapponnier et al. (1982).