Crenulation
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In a geological context, crenulation or crenulation cleavage is a fabric formed in metamorphic rocks such as phyllite, schist and some gneiss by two or more stress directions causing the formation of
Example of a large-scale crenulation forming kink-folds, Nathans Mine, Glengarry Basin, W.A., showing the superposition of F5 foliation on earlier F3-F4 foliation. A mechanical pencil is seen for scale comparison.
Schist
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Schist is a medium-grained metamorphic rock generally derived from fine-grained sedimentary rock, like shale. It shows pronounced schistosity. This means that the rock is composed of mineral grains ea
A schist showing characteristic scaly schistose texture caused by platy micas
Microscopic view of garnet-mica-schist in thin section under polarized light with a large garnet crystal (black) in a matrix of quartz and feldspar (white and gray grains) and parallel strands of mica (red, purple and brown).
View of cut garnet-mica-schist
Manhattan schist from southeastern New York State