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  • 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.
  • A surface of erosion or nondeposition that separates younger strata from older strata; most unconformites indicate intervals of time when former areas of the sea bottom were temporarily raised above sea level.
  • Nonlithified sediment that has no mineral cement or matrix binding its grains.