1 66 CLAYS AND CLAY INDUSTRY. 



Subdivisions of the Raritan formation in Middlesex County. 



The Cliffwood lignitic sands and clays. 



No. 4. Sand — laminated quartz sand. 



The Amboy stoneware clay. 



No. 3 Sand — chiefly quartz. 



The South Amboy fire clay. 



No. 2 Sand — including beds of so-called "feldspar" and 

 "kaolin." 



The Woodbridge clays — fire, stoneware and brick clays. 



No. 1 Sand — in part, fire sand. 



The Raritan clays — fire, and terra-cotta clays. 



Locally, still more minute subdivisions can be recognized, but 

 the above are the only ones which can be successfully mapped. 



THE CLIFFWOOD UGNITIC SANDS AND ClyAYS. 



These beds, the upper portion of the Raritan, are nowhere 

 exposed in a continuous section, but are well shown, a) in, the 

 cliffs along the Raritan bay from the southeast side of Cheese- 

 quake creek to Prospect Grove, near Cliffwood; b) in the vari- 

 ous clay pits about Cliffwood, and c) in the cuts of the Long 

 Branch railroad, southeast of Cheesequake creek. Combining 

 these various exposures, as well as possible, we have the following 

 sequence of beds. 



At Prospect Grove 40 feet of white sand, with seams of black 

 lignite and thin beds of black clay (becoming thicker and more 

 numerous in base of section), are exposed immediately beneath 

 Clay Marl I. At tide level the top of a massive black clay is 

 shown. These beds contain many sandstone concretions which 

 have yielded numerous plant remains. 1 The lenses of clay in 

 the sand thicken and thin out variously, as shown in the bluff 

 along the shore. Apparently the basal portion of these alternat- 

 ing sands and clays are exposed in the higher beds at Geldhaus' 



1 Hollick, Arthur — The Cretaceous Clay Marl exposure at Cliffwood, N. J 

 Trans. N. Y. Acad. Sci., Vol. XXI, p. 124. 



