Joint Orientation and Lithology

Numerous joint surface exposed in quarry wall in the Lockatong Formation, Newark basin, PA. Note that the joint orientation is different in the bed located one-quarter of the distance down from the top of the credit than in the surrounding strata. The joint surface on this special bed is relatively planar over most of the bed but consists of en echelon border fractures near the top and bottom of the bed. Photo credt: Roy W. Schlische.