Figure 4. Unfolding direction sensitivity analysis. (a) Map outline of the present-day Top Muschelkalk surface with the range of unfolding directions used to determine the most appropriate unfolding direction. (b) Plot of the percentage area change due to unfolding versus unfolding direction from North. The pin surface was oriented E-W. (c) Plot of the percentage area change due to unfolding versus unfolding direction from North. The pin surface was oriented orthogonally to the unfolding plane orientation. Note that this plot is almost identical to Figure 4b with the implication that the unfolding strain is insensitive to the pin surface orientation.