Fold geometry: a basis for their kinematical analysis

Analysis of kinematical folding mechanisms requires extensive geometrical information to be obtained from the folds. This analysis can be made attempting to find theoretical folds that fit natural or experimental folds by the use of the point transformation equations for the basic mechanisms. Examples of folds theoretically modelled by tangential longitudinal strain and flexural flow are shown, as well as an example of analysis of kinematical mechanisms in a natural fold. All these examples make it clear how geometry can be the basis for the strain and kinematical analysis of folds.