Deformation and metamorphic reactions in polyphase rocks

 

Granodiorites

Deformation and metamorphic reactions

 

granodiorites / anorthosites

 

List of microstructures

 

 

 

 

93

 

Plagioclase grain from granodiorite weakly deformed at low to mid greenschist conditions; recrystallization involved change of composition.

94

 

Plagioclase grain from granodiorite moderately deformed at low to mid greenschist conditions, and mostly reacted to a mixture of albite and clinozoisite.

95

 

Mylonite derived from granodiorite at low to mid greenschist conditions; reaction plus deformation produced a weak fine-grained mixed phase matrix.

96

 

Granodiorite mylonite deformed at low to mid greeenschist conditions; pure quartz layers are stronger than mixed phase matrix.

97

 

Granodiorite mylonite (same as 96), plane polarized light.

98

 

Detail of granodiorite mylonite; pure quartz regions deformed by regime 3 dislocation creep; fine-grained mixed phase matrix deformed by grain boundary sliding - diffusion creep.