A parallel unconformity is also known as a ‘disconformity’, which is a type of unconformable contact. The term refers to rocks where the upper and lower layers have similar attitudes, but an obvious interruption in sedimentation has occurred. A parallel unconformity indicates that after the deposition of the lower strata, the crust of this area was uplifted evenly, causing an interruption of sedimentation and denudation. Later, the crust subsided again, and sedimentation resumed. However, the uplift and subsidence did not alter the bed attitude, so the attitudes of the strata remained consistent.