Dynamic Recrystallization of a Quartz Porphyroclast

Abstract

Dynamic recrystallization occurs to minimize strain energy via either grain boundary migration or subgrain rotation^1,2. Both result in similar microstructures, but whereas in the former new grains have their crystallographic orientation controlled by neighbouring grains, in the latter new grains are derived from the parent grain. We have used the scanning electron microscope (SEM) electron channelling (EC) technique^3-7 and the program CHANNEL⁸ to distinguish the contribution of these processes in a 50% recrystallized quartz porphyroclast (Crinan Grits, Dalradian, SW Highlands, Scotland; 370-400℃)^9,10. This grain exhibits a core region of subgrains and a mantle region of neoblast grains (Fig. 1).