A large rock outcrop, with a rampart of till on its lee side, formed by erosion on the up-glacier side of the outcrop and deposition of debris in the low-pressure lee area. Glasser and Bennett (2004) Prog. Phys. Geog. 28, 1 define micro crag and tails as small tails of rock that are preferentially protected from glacial abrasion in the lee of resistant grains or mineral crystals on the surface of a rock.