424 



CHARLES EMERSON PEET 



level to which the hilltops reach east of the Hudson.^ Below the 

 level of this upland to the west of the Palisade Ridge there is a low- 

 land. Below the surface of this lowland 100-150 feet there are 



Fig. 6. — Photograph showing gradation of gravel and sand down the dip of the 

 layers into clay, in the part of the Newburg delta north of the Quassaic. The work- 

 man's shovel marks the point where one of the layers of gravel and sand at the left 

 changes into clay. 



valleys^ in which there are deposits of gravel, sand, and clay, pres- 

 ently to be described. In the valleys in the southern part of this 



^New York City Folio, U. S. Geological Survey; Geography by R. E. Dodge and 

 Bailey Willis, p. I. 



'Physical Geography of New Jersey, R. D. Salisbury, p. 141. 



