Flowage and recrystallization in paleozoic quartzites

The lower limit of visible traces of penetrative movement in quartz‐rich rocks can be defined by studies of orientations and mutual relations of grains. Intensity of deformation in the central Appalachians decreases gradually from the crystalline Piedmont toward the north, northwest, and west perpendicular to the regional trend. The author has attempted to determine the limits of visible deformation geographically and stratigraphically.