Thermodynamics of folding in the middle to lower crust

We show that dissipative processes involving thermal-mechanical coupling produce fold systems with characteristics observed in the middle to lower crust. These comprise folds in layers with little strength contrast, scale invariance, no strict periodicity, small wavelength/thickness ratios, nonconcentric fold shapes, and axial plane crenulations. This contrasts with classical folding theory that emphasizes large mechanical contrasts between a weak matrix and strong embedded layers leading to periodic concentric fold systems with no formal link to axial plane structures.

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