Joint (Bates, R. L. & Jackson J. A., 1980).
A surface of fracture or parting in a rock, without displacement.
A planar fracture, crack, or parting in a rock, without shear displacement. The surface is usually is decorated with a plumose structure i.e., a ridge like tracing in a plume like pattern, usually oriented parallel to the upper and lower surfaces of the containing rock unit. Often occurs with parallels joints to form part of a joint set.
Joint Set (Bates, R. L. & Jackson J. A., 1980).
A group of more or less parallel joints.
Joint System (Bates, R. L. & Jackson J. A., 1980).
Two or more joint sets that intersect. They may be of the same age or of different ages.
The Jurassic and Triassic periods combined.
