Naturally deformed quartzo-feldspathic rocks
Figure caption
weak deformation (Mulwaree) / strong deformation (Mulwaree) / mylonites (Redbank) / ultramylonites (Redbank)
83
Gradation from mylonite to ultramylonite (UM) in aplite deformed at greenschist conditions; the UM matrix shows fine-scale phase mixing.
Contact between a mylonite and an ultramylonite in quartzo-feldspathic rock, from the Redbank shear zone. The ultramylonite matrix is very fine grained and composed of mixed quartz, mica, and K-feldspar with a large albitic content. The relatively high mica content may be original but may also be due to the breakdown of K-feldspar. (599 A)