Two models are currently applied to large-scale mountain building resulting from compressional tectonics. One maintains that the processes in the construction of fold- and-thrust mountain belts are continuous and are everywhere at failure (the critical wedge hypothesis). The other is that these processes are discrete and discontinuous, more in keeping with actual structural observations. This work will attempt to reconcile these hypotheses by a finite element analysis that incorporates both structural and thermal parameters, to systematically explore different thrusting scenarios and to test the modeled consequences against relevant observations. Results are expected to add to understanding of the process of mountain building.