Naturally deformed quartz-rich rocks
Figure caption
undeformed / semibrittle & bulging recrystallization / subgrain rotation recrystallization / grain boundary migration recrystallization
20
Detail of mica-poor Heavitree quartzite, showing recrystallization by progressive subgrain misorientation.
Detail of photo #19. Original grains contain subgrains that grade into recrystallized grains toward their margins or in linear zones that may have originated as fractures or deformation bands. The similarity in shape and size of low-angle subgrains and high-angle recrystallized grains suggests that progressive rotation was the dominant process of dynamic recrystallization (dislocation creep regime 2). (703 A)