Basins with interior drainage are of widespread occurrence on the New Jersey Coastal Plain. They are oval, irregular, shallow depressions, without rims or orientation, and occur on all lithologic formations. The presence of extensive frost-wedge fillings, involutions, festoons, and other frost structures indicate that the area was exposed to a colder climate than that of today. The origin of the basins is attributed to frost-thaw action and subsidence in the periglacial zone when the Continental Ice Sheet stood just north of the Coastal Plain in Pleistocene time and is likened to the subsidence thaw basins being formed in arctic regions today.