MARYLAND GEOLOGICAL SURVEY 57 



the low land of the typical Coastal Plain and on the west" of it are the 



rolling uplands." 



Calvert County contains only one type of Coastal Plain topography, 



which is the Western Shore type. Its former level surface has 

 been so extensively dissected, however, by the streams which run east 



into Chesapeake Bay and west into the Patuxent Eiver that the country 

 now possesses the character of a rolling upland, such as is customary to 

 associate with the eastern margin of the Piedmont Plateau. The sur- 

 face, although resembling a dissected plain, is in reality made up of 

 three distinct systems of terraces, which lie above one another like steps 

 in a flight of stairs. The oldest, which is topographically highest, occu- 

 pies the center and the other terraces are grouped about it in concentric 

 arrangement in order of their age. 



The oldest terrace, having been subjected to erosion longer than the 

 others, is more dissected and its surface, which was originally level, has 

 now been modified so as to present a gently rolling aspect. The next 

 younger terrace, although it also has suffered from erosion has not yet 

 reached the advanced stage of the oldest, wlnlc the terrace which is 

 topographically lowest and therefore the youngest of the three has suf- 

 fered least of all by erosion and, in fact, has been subjected to the work 

 of streams for so short a time that its surface for the most part retains 

 its originally level and unbroken character. 



Each of these terraces is separated from the one just below by a well- 

 defined scarp-line similar in appearance to the sea-cliff which separates 

 the lowest terrace from the modern beach. In approaching the main 

 divide of Calvert County from the shore of the Patuxent Eiver, one 

 travels for some distance over an unbroken flat, which constitutes the 

 lowest and youngest terrace. The surface of this plain gradually rises 

 toward the interior. At its inner margin, which is about 45 feet in 

 height, it is terminated by an abrupt scarp of 10 to 20 feet, which leads 

 up to the surface of the middle terrace. This also is a flat, lying higher 

 than the former and extensively eroded by the headwaters of streams 

 which rise within it. This middle flat in its turn gently rises toward the 



interior until at a height of about 75 or 80 feet it is terminated by a 

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