432 CHARLES EMERSON PEET 



While stratified materials appear to prevail in the capping of the 

 clay, a number of places are to be found where the material is not 

 stratified, and where it has the character of a compact till showing 

 indications, at the contact with the clay, of having been subjected to 

 a pressure which forced the clay and the till together. The contact 

 surface is irregular. (Fig. 4.) The clay surface rises and falls as much 

 as 2 feet in a distance of 10 feet, while the layers of clay show contor- 

 tion- in the upper part. In earlier observations compact lumps of 

 clay were noted in till-like material. Before it was firmly established 

 that till overlies the clay, the writer did not feel sure that in the 

 extraction of the clay for brick-making the lumps of clay had not 

 become artificially mixed with till. It seems reasonably certain now, 

 however, that the observed clay lumps in the till were not introduced 

 artificially. Underlying the clay stratified gravel and sand was 

 observed in some places with a topography which suggested buried 

 kames. In other places till was observed with some constituents 

 that are not present in th^ overlying till. Flowing springs and 

 flowing wells arising from this underlying gravel and sand indicate 

 that the water has access to these porous layers at higher levels. 



North Haverstraw. — The gravel plateau at North Haverstraw 

 very Hkely was once continuous with that described south of Cedar 

 Pond Brook. It has a general elevation of something less than 120 

 feet A. T. on its west side, and a large part of its total area is 100 feet 

 A. T. It descends abruptly 100 feet to the meadow along Cedar 

 Pond Brook on the south, and on the northwest it descends abruptly 

 to a plain at about 20 feet A. T. On the northeast the descent is 

 to a kame-like gravel knoll at about 50 feet A. T. On the east there 

 is a similar knoll. Each of these knolls is indicated by a black circle 

 at No. 17 in Fig. 9. On the southeast the descent is to a terrace-like 

 form at 40 feet, and farther south to a ridge of gravel of uncertain 

 origin at 60 feet A. T. 



The west and northwest sides of the plateau have a gently undula- 

 tory topography, and the surface of the plateau farther east has some 

 ridge-like irregularities that suggest the presence of the ice during 

 its deposition. 



Materials and structure: There are no good exposures in this 

 conspicuous plateau, although exposures occur in the lower gravel 



