50 PHYSIOGRAPHY AND GEOLOGY OF THE COASTAL PLAIN PROVINCE. 



The same description applies to the surface of this terrace as to that 

 of the Lafayette, namely, that in the interior where it has not been greatly 

 affected by erosion, it still retains its original level, featureless character, 

 but along the borders where it has been attacked by the headwaters of 

 streams it has been transformed into a rolling country. 



The Sunderland terrace reaches an altitude of about 200 to 250 feet 

 above sea level where it abuts against the Lafayette terrace. From that 

 line the surface slopes toward tlie larger streams as well as seaward, some- 

 times at the rate of several feet to the mile, at other times at the rate of 

 only a few inches to the mile. In general, it may be stated that the greater 

 portion of the Coastal Plain area of Virginia lying between 100 and 200 

 feet above sea level belongs to the Sunderland terrace. Could the Coastal 

 Plain of Virginia be depressed 200 feet permitting the waters of the sea 

 to cover the entire region below that elevation, the shore-line would more or 

 less definitely define the present landward margin of the Sunderland 

 terrace. Could the region then be uplifted 100 feet the resulting shore-line 

 would approximately mark the eastward limit of the terrace. 



Wironiicf/ icrrare. — Bordering the Sunderland terrace at a lower level 

 is the Wicomico terrace. It bears the same relationship to the Sunderland 

 terrace that the latter does to the Lafayette terrace in that it wraps about 

 it as a border, extends up the larger stream valleys, and is .separated from it 

 by a well-defined line of low cliffs, especially in the northern portion of the 

 State. In the eastern portion of the State from Northumberland County 

 to Nansemond County it forms most of the flat-topped stream divides, while 

 it is continued westward along the larger streams to the head of tide. The 

 Wicomico terrace has suffered from erosion although less than the two older 

 terraces but like them it no longer forms a continuous plain. In some 

 places where streams have not yet cut the terrace it has a very flat surface, 

 but elsewhere considerable portions have been entirely removed or cut up 

 into a rolling country. The Wicomico terrace at its landward margin wliere 

 it is in contact with the Sunderland has a nearly constant altitude of from 

 80 to 90 feet. From that line it slopes gradually eastward and to the 

 larger valleys ending at the escarpment which represents the sliore margin 

 of the next lower or Talbot terrace. 



Talbot ierrace. — The lowest of the subaerial terraces is the Talbot. 

 Like the other members of the series, it wraps about the preceding terrace 

 like a border, penetrates it in re-entrants and is separated from the Wicomico 

 terrace by a scarp line. This scarp line is very conspicuous in many parts of 

 the region, sometimes with a height of 20 or more feet, at other times with 



