Migmatitic garnet-biotite gneiss in the east-central portion of the Zona Transversal Domain Borborema Province in northeastern of Brazil. In our point of view, the rock was affected by at least two phases of folding with axes subparallel. The first phase developed isoclinal folds that are responsible for bending the migmatitic banding generated in other oldest event of unknown genesis. The second phase of folding produced asymmetrical closed to tight folds with disharmonious character and steep axial surface that dips to SSE. The interference between the two phases of folding provided interference patterns of type 3 on a mesoscopic scale. The character of disharmonic folds generated in the second stage is coupled to irregular granitic garnet-leucosome and provides a curious swan-shape, as shown in the image.
PhotoID341
Migmatitic garnet-biotite gneiss in the east-central portion of the Zona Transversal Domain Borborema Province in northeastern of Brazil. In our point of view, the rock was affected by at least two phases of folding with axes subparallel. The first phase developed isoclinal folds that are responsible for bending the migmatitic banding generated in other oldest event of unknown genesis. The second phase of folding produced asymmetrical closed to tight folds with disharmonious character and steep axial surface that dips to SSE. The interference between the two phases of folding provided interference patterns of type 3 on a mesoscopic scale. The character of disharmonic folds generated in the second stage is coupled to irregular granitic garnet-leucosome and provides a curious swan-shape, as shown in the image.
PhotoID341
Photograph: Alan Miranda