650 PROCEEDINGS OF THE BALTIMORE MEETING 



TABLE OF TERTIARY FORMATIONS 





Maryland 



Virginia North Carolina 



5 



Lafayette 



Lafayette 



Lafayette 







Waccamaw 



r 





Yorktown Yorktown and Duplin 



a 



St. Mary's 



St. Mary's St. Mary's 



2 1 



i 



Choptank 









Calvert 



Calvert 











Castle Hayne 



c 







Trent 



o 

 H 



Nanjemoy 



Nanjemoy 







Aquia 



Aquia 





Quaternary 



The Quaternary deposits overlie the older Coastal Plain formations as a sur- 

 ficial cover, and embrace a large part of the country from the Piedmont border 

 to the coastal margin. They represent the most recent phase of deposition, and 

 still preserve largely their original form. Physiographic criteria, therefore, 

 are of much importance in interpreting and correlating the deposits. 



PLEISTOCENE 



The Pleistocene deposits consist chiefly of a series of terraces, the earliest 

 found along the western border of the Coastal plain, encircling the margin of 

 the Piedmont plateau and the higher elevations of the Coastal plain, and ex- 

 tending up the estuaries and streams, where it finally merges into fluviatile 

 deposits. This oldest terrace, known as the Sunderland formation, can be 

 traced from the glacial deposits southward across Maryland and Virginia into 

 North Carolina. The Sunderland terrace, which has an elevation of 150 to 200 

 feet along its shoreward margin, declines gradually seaward and toward the 

 larger valleys, where it reaches to below 100 feet in height. Another terrace 

 is found in central and southern North Carolina between the Lafayette and 

 Sunderland. 



The next younger terrace, known as the Wicomico, encircles the preceding 

 terrace at a lower elevation, and forms a well marked belt along the eastward 

 margin of the latter, although extending up the river channels in some places 

 to the Piedmont border, where it also merges into fluvatile deposits. Its land- 

 ward margin has an elevation of 80 to 110 feet, from which point it declines 

 seaward and toward the larger stream valleys to 50 to 60 feet in elevation. Its 



