82 THE PHYSIOGRAPHY OF PRINCE GEORGE S COUNTY 



mergence, which carried part of the land beneath the sea and again 

 drowned the lower courses of the streams. 



The Talbot Stage.- — The Talbot deposition did not take place over 

 so extensive an area as was covered by that of the Wicomico. It 

 was confined to the old valleys and to the low stream divides, where 

 the advancing waves destroyed the Wicomico deposits. The sea 

 cliffs were pushed back as long as the waves advanced, and now 

 stand as an escarpment that marks the boundaries of the Talbot sea 

 and estuaries. This is the Talbot-Wicomico escarpment, previously 

 described. At some places in the old stream channels the deposits 

 were so thick that the streams in the succeeding period of elevation 

 and erosion found it easier to excavate new courses than to follow the 

 old ones. Generally, however, the streams reoccupied their former 

 channels and renewed the corrasive work which had been interrupted 

 by the Talbot submergence. As a result of this erosion the Talbot 

 plain is now in many places rather uneven, yet it is more regular 

 than the remnants of the Lafayette, Sunderland, and Wicomico 

 plains, which have been subjected to denudation for a much longer 

 period. 



The Recent Stage. — The land probably did not long remain 

 stationary with respect to sea level before another downward move- 

 ment began. This last subsidence is probably still in progress. 

 Before it began the Patuxent and Potomac rivers, instead of being- 

 estuaries, were undoubtedly streams of varying importance lying 

 above tide and emptying into a diminished Chesapeake Bay. 

 Whether this movement will continue much longer can not, of course, 

 be determined, but with respect to Delaware River there is sufficient 

 evidence to show that it has been in progress within very recent time 

 and undoubtedly still continues. Many square miles that had been 

 land before this subsidence commenced are now beneath the waters 

 of Chesapeake Bay and its estuaries, and are receiving deposits of 

 mud and sand from the adjoining land. 



