Synopsis
Complex patterns, of folds with horizontal axes perpendicular to the foliation in gneiss, occur on vertical foliation surfaces. Similar complex patterns, of corresponding folds with vertically disposed axes, occur on horizontal surfaces. The vertical and horizontal surfaces represent cross-sections near to or within the steep limb of N.W.-S.E. monoclinal fold belts which cut rocks of a crystalline basement. Heterogeneous flow appears to have been operative in the formation of the complex folds. Local intensely developed small-scale folding along narrow N.W.-S.E. fold belts possibly resulted from their coincidence with pre-existing N.W.-S.E. master joints in the basement.
- © 1968 Scottish Journal of Geology