222 PHYSIOGRAPHY AXD GEOLOGY OF THE COASTAL PLAIN PROVINCE. 



Recent stage. — The land probabl}^ did not remain stationary with 

 respect to the sea level long before another downward movement was 

 inaugurated. This last submergence is probably still in progress. Before 

 this subsidence occurred probably most of the important rivers, like the 

 Potomac, Eappahannock, and James, were streams of varying importance 

 lying above tide and emptying into the diminished Chesapeake Bay. 

 Whether this downward movement will continue much longer cannot of 

 of course be decided but there is evidence in many places throughout the 

 Coastal Plain to show that this movement has been in progress within very 

 recent time and in all probability still continues. Many square miles that 

 had been land before this subsidence commenced are now beneath the 

 waters of the Chesapeake Bay and its estuaries and are receiving deposits 

 of mud and sand from the adjoining land. 



