The trunk channels of each system are 2 to 4 km wide and are incised 30 to 50 m into underlying strata; they have irregular longitudinal profiles and very low gradients within the Chesapeake Bay area. The youngest paleochannel is clearly of late Wisconsinan age, about 18 ka, and the intermediate one appears to be late Illinoian in age, or about 150 ka. The age of the oldest is in the range of about 200 to 400 ka. The three paleochannel systems imply a dynamic coastal-plain environment and at least two previous generations of the Chesapeake Bay. -from Authors