Structural analysis of the Monghyr area, India
1, 2

Structural analysis of the Monghyr area indicates the existence of two superposed deformations in the rocks. The first deformation produced folds (B folds on primary S1 surfaces) trending NNE-SSW and axial plane cleavage S2. The second deformation gave rise to SE-ward plunging cross folds on the western limb of the major B fold and an antiformal flexural bend on the eastern limb with associated S3 cleavage. The evolution of the overall structure is discussed in the light of the geometrical relationship between various mesoscopic structural features and the quartz microfabric. It is revealed that, although the megafabric was developed as a consequence of the superposition of two monoclinic strains (B ? B' tectonite), deformation in the rocks took place essentially as a result of flexural slip during both stages. The presence of thick competent beds of quartzites and attendant low grade regional metamorphism (disfavouring the production of a coarse-grained fabric in the rocks) prevented the development of deformation by shear during the later stages.