First transient stage (0<g<1.5):
Blue and violet grains disappear whereas the volume proportions of
yellow and magenta grains increase. We attribute this behavior to continuous
reorientation of the grains´ crystallography into orientations that
are favourable for intracrystalline gliding (i.e., easy glide orientations).
Note the formation of a stable, oblique grain SPO at angles of about
60° with respect to the SZB.
Second transient stage (1.5<g<6):
Grain boundary migration recrystallization is the predominant grain
scale mechanism. The area proportion of the yellow grains, for example,
increases significantly at the expense of the area proportion of
magenta grains. This behavior leads to a strongly domainal microfabric
consisting of yellow and magenta domains.
Steady state (g>6):
The area proportion of yellow and magenta grains is strain invariant
on the sample scale. On the grain scale, however, one can observe cyclical
consumption and growth of individual grains (e.g., see magenta grains in
the lower left hand corner).
Analogy:
This steady state microfabric in norcamphor is very similar to that
of natural quartz mylonites deformed under upper greenschist to amphibolite
facies conditions (see Fig. 12 in Herwegh & Handy, 1996)