436 CHARLES EMERSON FEET 



Croton. — On the east side of the river at Croton Point, and Croton 

 Landing, deposits of similar import occur, but not identical in detail, 

 with those on the west side of the river. Lack of space forbids detailed 

 description. 



Oscawanna — Crugers — Peekskill. — Clays and gravels: The clays 

 and gravels in the city of Peekskill and south to Oscawanna show 

 phenomena which in some features are similar to, and in other 

 features are unlike, those at Haverstraw and Croton. They are 

 evidently deposits made later than the last-mentioned deposits. 

 Their relations, however, to any marked and definite position of the 

 ice-edge are not so well shown. The approximate area of these 

 deposits is shown in Fig. 9 between Nos. 23 and 25. 



The deposits in this region are notable for their irregularity in 

 level. The clay surface varies from an elevation approaching 100 

 feet A. T. to tide-level. It is in most cases covered with sand, or 

 gravel, and in a broad statement it may be said that the finer materials 

 predominate at the south, while at the north the materials overlying 

 the clay include both fine materials and coarse gravels with bowlders 

 up to five feet in diameter. In one or two instances till has been 

 found overlying the clay in this region. 



The structure of the stratified materials overlying the clay even 

 at high levels does not generally show the high angle of dip so common 

 in the high-level gravels at Haverstraw and Croton. 



The high-level terrace has an elevation of 100-120 feet A. T. 

 Parts of it, however, reach lower levels — 60-80 feet A. T., and per- 

 haps less. It is somewhat difficult to discriminate between what may 

 properly be called high-level terrace and what may properly be called 

 low-level terrace. Terraces at low levels exist at 60, 40, 30, and 

 10-20 feet A. T. In general, these terraces are covered by gravel 

 and sand. The gravel is sometimes very coarse, containing bowlders 

 as large as five feet in diameter. The relations to the clay are not 

 always distinguishable. It is not an uncommon relation, however, 

 to find these low-level gravels much lower in level than clay in the 

 immediate vicinity. It is questionable, however, if in all cases this 

 relation has been brought about by the erosion of the higher-level 

 deposits. It is conceivable that some of the low-level deposits are 

 original deposits by the ice water, which simply failed to build up at 



