Slickensides

Chambers's Encyclopaedia, Volume 9: Bound to Swansea, p. 508

Slickensides are the smooth, polished, or striated, and generally glazed surfaces of joints and faults (see DISLOCATION) in rocks, produced by the friction of the two surfaces during the movement of the rock. The surface of slickensides is often coated with a deposition of calcite, hematite, chalcidony, or the like.

Source scan(s): p. 0521