IT-HS Microfabric Evolution

First transient stage (0<g <2):
The volume proportions of yellow and magenta grains increase at the expense of the proportions of  bright blue and dark blue grains. This is attributed to subgrain rotation and glide induced vorticity,  both of which rotate the grains´ crystallography into orientations that are more favourable for intracrystalline gliding. Note the formation of a stable, oblique grain SPO at angles of about 60° with respect to the SZB.

Second transient stage (2<g<6):
The increase in areal proportion of  yellow grains is attributed to a combination of subgrain rotation and grain boundary migration recrystallization. The coalescence of yellow grains leads to the formation of  a microfabric comprising yellow and magenta domains. Along the SZB, few small fractures appear which grow subparallel to the incremental stretching direction.

Steady state (g>6):
The areal proportion of yellow and magenta grains is strain invariant on the sample scale. On the grain scale, however, a cyclical behavior of consumption and growth of individual grains. This behaviour is identical to that of steady state in the HT-LS experiments.

Analogy:
The microfabric is very similar to that to natural quartz mylonite deformed under greenschist facies conditions.