Deformed chert, Warrawoona Syncline. Dynamic recrystallization has resulted in coarsening of quartz grain size in chert. The foliation is defined by the alternation of recrystallized chert and transposed and recrystallized quartz veins showing the largest grain sizes. White mica pins the quartz boundaries, and in the layers of large quartz grain size, micas are contained within individual quartz grains. These microstructural relations suggest grain boundary migration. (Sample 606 A, chert, Pilbara, Western Australia) (3.2 mm)