Folding with thermal-mechanical feedback: Discussion

A recent paper in this Journal by Bruce Hobbs, Klaus Regenauer-Lieb and Alison Ord [Hobbs, B., Regenauer-Lieb, K., Ord, A., 2008. Folding with thermal-mechanical feedback. Journal of Structural Geology 30, 1572-1592] presents an alternative theory to the traditional Biot-Ramberg theory for folding of viscous rocks that involves non-equilibrium thermodynamics and thermal-mechanical feedback. The authors convey a strong message throughout their paper that the folds produced by this theoretical and numerical modelling are geologically realistic and provide a better explanation for many natural folds than the traditional theory. They promise the same approach for boudinage, and present this folding paper as part of a "unified framework for rock deformation processes" Readers of the Journal of Structural Geology might be led to conclude that this paper provides a good alternative model for folding of rocks. Our discussion will disagree, on four counts.