Jointing History of the Palo Duro Basin

Joints are fractures or partings in a rock that exhibit no displacement (Bates and Jackson, 1980, p. 334). Two styles of joints are systematic joints and nonsystematic joints (Hodgson, 1961). Systematic joints occur in sets. Joints composing each set are subparallel and are commonly orthogonal to the upper and lower surfaces of the rock units in which they are present. Nonsystematic joints display no preferred orientation and truncate against systematic joints.