The foliation in the rock is parallel to the lithological banding. This foliation (and the banding) is disrupted by small-scale folds - crenulations. Axial to these folds, a penetrative cleavage is developed - a crenulation cleavage. Note that this cleavage does not have a constant orientation: it may become deflected on passing from one lithological unit to another. This feature is called cleavage refraction.
Scale: coin is 26 mm in diameter
Grid reference: 955 255
This page is maintained by Roger Suthren
Last Modified: 23 October, 2008