Figure 52

Naturally deformed feldspar aggregates

Figure caption

Naturally deformed feldspar rocks

regime 1 / regime 2 low deformation / regime 2 moderate-high deformation

52

Anorthosite strongly deformed and largely recrystallized at ~700°C and 900 MPa; regime 2 dislocation creep.

Example of strongly deformed and largely recrystallized anorthosite. Only a few porphyroclasts of plagioclase are left within a matrix of dynamically recrystallized grains. Some porphyroclasts are highly elongated, while others have lower aspect ratios. The difference in porphyroclast shapes is most likely due to the orientation of the easy slip system with respect to the shear plane and direction. Strongly elongated grains usually have their (010) planes at a small angle to the shear zone foliation and their [001] direction at a small angle to the stretching lineation. (010)[001] is one of the most important slip systems in plagioclase.

		Naturally deformed feldspar aggregates
		Figure caption

	Naturally deformed feldspar rocks	regime 1 / regime 2 low deformation / regime 2 moderate-high deformation


52		Anorthosite strongly deformed and largely recrystallized at ~700°C and 900 MPa; regime 2 dislocation creep. Example of strongly deformed and largely recrystallized anorthosite. Only a few porphyroclasts of plagioclase are left within a matrix of dynamically recrystallized grains. Some porphyroclasts are highly elongated, while others have lower aspect ratios. The difference in porphyroclast shapes is most likely due to the orientation of the easy slip system with respect to the shear plane and direction. Strongly elongated grains usually have their (010) planes at a small angle to the shear zone foliation and their [001] direction at a small angle to the stretching lineation. (010)[001] is one of the most important slip systems in plagioclase.