|AXIAL PROPAGATION IN FOLDS
The folds developing in a multilayerd complex not only propagate along the layers after the layers have begun to buckle but if the deformation is oblate, they also grow parallel to their hinges. Usually constraint on this in orogens give rise to folds or kink-bands that are steep or vertical. When this propagation takes place, the hinges of two contrasting spans may seem to join by least enery consumption giving the appearence as if the fold hinges are bifurcating. Dubey and Cobbold (1977) showed that in such a complex, the amplitude will be laregest at the place where fold first began to initiate at a point of perturbation or anomaly. The fold may open into a gentle one or a box fold either side of this point. They cited a example to support this from Bude, Cornwall. But surely many of the geologists do observe this feature even on the scale of a hand specimen.