130 CLAYS AND CLAY INDUSTRY. 



horizons rather than equally distributed. They vary greatly in 

 size and shape, some cylindrical forms being 6 inches in length. 



The clays at higher levels are usually less distinctly laminated 

 and generally contain a few glacial pebbles. Locally, as at Mor- 

 ristown, they grade upward into stony till. 



Other localities. — Clay apparently of Glacial age has also been 

 observed at a few other localities. It was formerly dug for 

 "brick along Clove brook near Sussex (Deckertown), not far 

 from Fuller's mill. 



At Somerville a red clay occurs at Ross' brickyard, where it 

 is used for common brick. It contains many bits of waterworn 

 red shale and some yellow quartz pebbles, which are more com- 

 mon in the upper layer. The body of the clay is composed of the 

 finest material derived from the disintegration of the red shale. 

 It is clearly a slack water deposit, and the readiest, but not neces- 

 sarily the only, explanation, is that it was formed during the 

 Glacial period, when the Raritan valley was temporarily dammed 

 by sand and gravel discharged into it from the north near Bound 

 Brook. 1 



CAPE MAY CLAYS. 2 



Origin. — Around much of the coast there is an ill-defined ter- 

 race 30 to 50 feet above tide. In some places it seems to have 

 been cut by the waves in older formations. In other localities it 

 has been built by them of debris gathered where their work was 

 destructive. Terraces, corresponding in elevation to these wave- 

 cut and wave-built forms, extend up the streams, and, except 

 near the sea, are the result of stream action. Traced up the 

 Delaware bay, these river terraces, although often poorly denned, 

 pass into that formed of the glacial gravels brought down the 

 Delaware river from the melting glacier farther north. Corre- 

 sponding stream terraces occur along the tributaries of the Dela- 

 ware river below Trenton, just as they do along the valleys lead- 

 ing to the Atlantic coast. The fact seems well established that 



^nn. Rep. State Geologist of N. J., 1892., p. 123. 



2 See N. J. Geol. Surv., Vol. V, Report on Glacial Geology, for a fuller dis- 

 cussion of the Cape May formation. 



