196 CLAYS AND CLAY INDUSTRY. 



grade fire clay — were found in digging a well. There is here no 

 overburden. A considerable thickness of white clay (14 feet) 

 was also' reported from' a well at Franklin Park station, 4 miles 

 southwest of New Brunswick, but the overburden of gravel is 

 here considerable. 



The Raritan Formation Southwest oe the Woodbridge- 

 South River District. 



From the Woodbridge-South River area, represented on Plate 

 XI, the Raritan formation extends across the State to the Dela- 

 ware river between Trenton and Bordentown, but over most of 

 this area it is somewhat deeply buried by the Pensauken gravel. 

 Nevertheless, at a few localities plastic clays have been noted and 

 borings at other points have demonstrated the extension of the 

 clays in this direction. 



The occurrence of clay just above the red shale along the val- 

 ley of Lawrence brook has been mentioned in the previous section, 

 as well as its occurrence in a thick bed on the Buckalew farm 

 (263) and on the Van Deventer property (264). This clay is 

 at the base of the Raritan formation in the Raritan potter's and 

 ■fire-clay bed. Two miles west of south of Monmouth Junction a 

 dark-gray clay is exposed in the bottom, of a cut along the Trenton 

 and New Brunswick trolley at an elevation of 95 feet. The over- 

 burden is very slight and the clay is favorably located as regards 

 shipment. Clay has also been found by boring along the Mill- 

 stone river midway between Hightstown and Princeton Junction, 

 but it is not exposed at the surface and the overburden of gravel 

 is heavy. Still farther southwest sandy clays are reported to 

 occur along the Pennsylvania railroad (a) a mile southwest of 

 Princeton Junction (b), near the Clarksville road, and (c) near 

 Lawrence station, but verv little is known of them. 1 



TEN-MIEE RUN. 



An isolated area of the Raritan formation is found on the hills 

 north of Monmouth Junction and near Ten-Mile Run. The Rar- 



1 Cook & Smock, loc. cit. p. 233. 



