Mylonite 1
Mylonite 1 : A cohesive, penetratively foliated (and usually lineated) faultrock (L-S tectonite) with at least one of the major mineral constituents (usually quartz) having undergone grain-size reduction through dynamic recrystallization accompanying crystal plastic flow. The mylonite series (protomylonite - mylonite - ultramylonite) reflects progressive reduction in grain size, generally under greenschist facies metamorphic conditions. See Sibson (2002, p. 458)