A Note on "Concentric" Folding of Multilayered Rocks

The structural features of a "concentric" fold of a multilayered system consisting of alternating quartz-rich layers and mica-rich layers have been analysed in detail, with regard to the strain distribution and the nature of behaviour of rock material in all the layers involved in the system. On the basis of obtained data, the strain distribution and geometry of the "concentric" folds of multilayered rocks have been discussed, and a new kinematic and geometric model of "concentric" folding of multilayered rocks has been proposed. In order to understand physical conditions in which the "concentric" folding can occur in multilayered rocks, some schematic patterns of flexural folding of multilayered rocks odserved in nature have been also examined with reference to mutual relationships between them.