Development of intragranular-fracturing in feldspar during mylonitization: an example from the Kashio shear zone along the Median Tectonic Line, central Honshu, Japan.

Michibayashi and Masuda (1993, Journal of Structural Geology, 15, 1421-1432)
Michibayashi (1996, Journal of Structural Geology, 18, 17-25)

Width of base:15 mm
Figure 2a of Michibayashi (1996, Jour. Struct. Geol.).
Fractures in an 'augen' K-feldspar porphyroclast. The fracture at the centre of this grain contains dynamically recrystallized quartz infill. A number of the cleavage-parallel fractures are present plus a fracture along a twin boundary. Crossed polars.　

Width of base: 5.5 mm.
Figure 3a of Michibayashi (1996, Jour. Struct. Geol.).
Intragranular fracture through a plagioclase porphyroclast. The quartz infill has been dynamically recrystallized to some extent. Syntaxial growth of plagioclase occurs along the walls. One small fracture is almost completely sealed by syntaxial growth of plagioclase. Crossed polars.

Width of base: 3 mm
Figure 2b of Michibayashi (1996, Jour. Struct. Geol.).
The intragranular fracture in a K-feldspar porphyroclast occurs near the middle of the grain. This grain is partly surrounded by myrmekite. The gaps are filled with quartz and fluorite. Crossed polars.

Post-mylonitic Intergranular tensile microfractures preserved in a mylonitized Ryoke granite: an example from the Kashio shear zone along the Median Tectonic Line, central Honshu, Japan.

Michibayashi (1996, Journal of the Geological Society of Japan, 102, 190-198)

width of base: 5 mm
Figure 6a of Michibayashi (1996, Jour. Geol. Soc. Japan).
Intergranular fractures overprint mylonitic microstructures, indicating that they occurred after the mylonitization. Quartz-chlorite veinlets in a plagioclase porphyroclast, and numerous numbers of fluid inclusion planes in the dynamically recrystallized quartz matrix. Open polar.