CYCLES OF EROSION IN PENNSYLVANIA 559 
and Schooley peneplains with an indefinite thin margin is indicative 
of subaerial eresion. ‘The contact of the Honeybrook and Schooley 
peneplains, on the Reading quadrangle, on the other hand, suggests 
_ Fic. 24.—Late Brandywine peneplain in the Reading quadrangle. The pene- 
plain at an altitude of 400 feet, as seen from the hillside south of Oley Furnace, looking 
south toward Friedensburg. 
- a 
Fic. 25——Honeybrook and Late Brandywine peneplains in the Reading and 
Boyertown quadrangles. The surface of the upland in the distance at an altitude of 
800 feet represents the Honeybrook peneplain, and the level land in the middle distance 
at altitudes ranging from 400 to 440 feet, the Late Brandywine peneplain, as seen from 
a point one-fourth miles southwest of Oley Furnace, looking south 45° east toward 
Shenkel Hill. 
a sea cliff. In the case of the Harrisburg and Early Brandywine 
peneplains definite proof of subaerial or marine origin has not 
been found. 
