554 F, BASCOM 
Aquia Greensands (Tertiary), which lie far out on the Coastal 
Plain. 
The Early Brandywine, the youngest and most widely preserved 
of the five peneplains, is found on Ordovician shale at the 500-foot 
level, northeast of Harrisburg. It contains at this altitude in the 
Fic. 17.—Early Brandywine peneplain in the Boyertown quadrangle. The 
peneplain corresponding with the surface of the upland in the distance at an altitude 
of 560 feet is seen from a point one-half mile west of Eschbach, looking south 45° east. 
Fic. 18.—Early Brandywine peneplain in the Reading quadrangle. The pene- 
plain at an altitude of 500 feet is represented by the surface of the upland in the 
distance, as seen from a point on the Sunderland level one-half mile northwest of 
Maiden Creek, looking south 65° west toward Leesport. 
valley of the Delaware at the Water Gap and in the Schuylkill and 
Potomac valleys (Antietam quadrangle). It ranges from 400 to 
450 feet in the Piedmont upland of Pennsylvania where, as is to 
be expected, because it is the most recently formed peneplain, it 
is the most pronounced upland level (see Figs. 15-18). 
