Anomalous vergence patterns on the rhoscolyn anticline, anglesey: Implications for structural analysis of refolded regions

Traditional methods of mapping folded regions rely heavily on vergence or minor structures (folds and intersecting foliations) to confine the position of major folds of the same generation. It is argued on theoretical grounds that in certain circumstances the vergence of early structures can become reversed by later deformation. Natural examples of this vergence reversal occur on the NW limb of the Rhoscolyn Anticline in Anglesey. Lack of awareness of the possibility of this phenomenon could lead to serious misinterpretation of data from less completely exposed folded regions.