Rock produced in zones of tectonic dislocation, e.g. fault and shear zones. Mechanical crushing and grinding or cataclasis produces a rock that has a foliation which is often crude but which is sometimes very well developed, and that has a much finer grain size than its precursor. Mylonite is well laminated and often hard and splintery. The name literally means ‘milled rock’ from the Greek mylon, a grinding mill. See dynamic metamorphism.
Subjects: Earth Sciences and Geography.