sentences:  The sand dune of Roanoke became disconnected from the mainland by water, and inlets in the Outer Banks turned fresh water sounds (lagoons) into brackish ecosystems.From approximately the years 460 AD to 800 AD the Mount Pleasant Culture had a village on the Tillett Site in southern Roanoke Island within the modern day Wanchese township.After the year 800 AD the village was occupied by the Colington Culture, the Colington Culture was the predecessor to the Roanoke Tribe who were encountered by the 1584 English Expedition.