Figure 15

Naturally deformed quartz-rich rocks

Figure caption

Naturally deformed quartz-rich rocks

undeformed / semibrittle & bulging recrystallization / subgrain rotation recrystallization / grain boundary migration recrystallization

15

Semi-brittle deformation of quartz vein, Eastern Tonale line.

Sample is from the cataclastic fault zone; deformation conditions are approximately 260°C, 200-300 MPa. Deformation is mainly by fracturing as evidenced by offsets along grain boundaries. Quartz grains show undulose and patchy extinction. Small scale serration of grain boundaries and very small recrystallized grains of the same size as the bulges indicate incipient dynamic recrystallization by bulging recrystallization. New grains form predominantly along fractures and at crack tips. (MS76-3)

		Naturally deformed quartz-rich rocks
		Figure caption

	Naturally deformed quartz-rich rocks	undeformed / semibrittle & bulging recrystallization / subgrain rotation recrystallization / grain boundary migration recrystallization


15		Semi-brittle deformation of quartz vein, Eastern Tonale line. Sample is from the cataclastic fault zone; deformation conditions are approximately 260°C, 200-300 MPa. Deformation is mainly by fracturing as evidenced by offsets along grain boundaries. Quartz grains show undulose and patchy extinction. Small scale serration of grain boundaries and very small recrystallized grains of the same size as the bulges indicate incipient dynamic recrystallization by bulging recrystallization. New grains form predominantly along fractures and at crack tips. (MS76-3)