4^ 



CHARLES EMERSON PEET 



valley wall, and the smoother and lower edge toward the Hudson/ 

 The inner and higher edge is sometimes marked by distinct kames or 

 by moraine. The structure is delta-like. The layers usually dip at 

 high angles toward the Hudson, and the coarse gravels and sands 

 grade rapidly down the dip of the layers into fine laminated clay. 

 (See Fig. 5, A and B, and Fig. 6.) In the clay and over the clay 

 there are sometimes masses of till. (Fig. 4.) In the till there are 

 sometimes masses of clay. Over the clay there often is coarse 

 gravel with a subdued undulatory topography, and the contact of the 



Fig. 4. — Showing till both above and below the clay at Haverstraw. 



gravel and clay is of such a nature as to indicate that the gravel has 

 been forcibly pressed against the clay surface. This phase of the 

 gravel plateaus is the characteristic phase of the Appalachian Valley 

 division of the Hudson Valley, and is usually associated with a wide 

 clay plain. . These two classes may be referred to as high-level ter- 

 races. On the whole, they increase in altitude from south to north, 

 but not at a uniform rate or continuously. They indicate a water 



' Some of the smoother plateaus may properly be called subaqueous overwash 

 plains. See R. D. Salisbury and Henry B. Kummel, Annual Report oj State Geolo- 

 gist of New Jersey, 1893, pp. 266-68; and R. D. Salisbury, Glacial Geology of New 

 Jersey, pp. 130-33. 



