Said of strata that do not succeed the underlying rocks in immediate order of age or in parallel position. A general term applied to any strata deposited directly upon older rocks after an interruption in sedimentation, with or without any deformation and/or erosion of the older rocks.
An interrupted sequence of beds or strata.
Said of strata or stratification exhibiting the relation of unconformity to the older underlying rocks; not succeeding the underlying rocks in immediate order or age or not fitting together with them as parts of a continuous whole. In the strict sense, the term is applied to younger strata that do not "conform" in position or that do not have the same dip and strike as those of the immediate underlying rocks.
The term is applied to younger rocks which are deposited after a time hiatus on top of older rocks. Often refers to younger rocks which have a different dip and strike as underlying rocks (angular unconformity)