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Woodroffe Thrust mylonite zone, central Australia:
an example of amphibolite facies mylonitization.

Unlike the low-grade mylonitization, all mineral phases (i.e. quartz, plagioclase, K-feldspar and biotite) have been dynamically recrystallized into finer grains, resulting in very fine grained ultramylonite near the thrust. The mylonite zone is bounded by the pseudotachylite zone that is the largest pseudotachylite zone in the world.

Width of base: 5 mm.
Crossed polars. The protolith is "augen" orthogneiss, which has partly dynamically been recrystallized into smaller grains in spite of low strain.

Width of base: 5 mm.
Crossed polars. Coarse quartz grains are elongated and surrouned by new polygonal grains with intense undulose extinction.

Width of base: 5 mm.
Crossed polars. Quartz are completely recrystallized into smaller polygonal grains.

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Width of base: 5 mm.
Crossed polars. Recrystallized quartz grains are elongated subparallel to the foliation (horizontal). Feldspar grains are also dynamically recrystallized into finer grains, which grains sizes are finer than quartz grains.

Width of base: 5 mm.
Crossed polars. Ultramylonite. A few feldspar porphyroclasts occur in extremely fine grained matrix, where all mineral phases are mixed.

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Width of base: 5 mm.
Open polar. Pseudotachylite.

Width of base: 5mm.
Crossed polars. Pseudotachylite.

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