198 CLAYS AND CLAY INDUSTRY. 



worked. It is not possible to correlate these clays with any of 

 the beds in the Woodbridge area. 



In addition to the Dogtown clays, pits have been opened in the 

 Raritan formation at other points near Trenton, but they are no 

 longer worked. Clay occurs in the bluff along the Delaware river 

 south of Trenton and north of Crosswicks creek, particularly on 

 the property of Dr. C. C. Abbott and P. E. De Cou. Some of 

 this clay was at one time taken out by tunneling into the hillside, 

 some drifts being 200 feet long, but owing to the cost of timber- 

 ing it was abandoned. A black sandy clay, 6 to 7 feet thick, is 

 exposed beneath 10 or 15 feet of Pensauken gravel in a ravine 

 west of Yardville (107), but it has not been worked. 



BORDENTOWN. 



From Bordentown to' Kinkora the base of the Clay Marl I is 

 found at the top of the bluff along the river, and black lignitic 

 clays and interbedded sands of the Raritan formation form the 

 basal portion. Landslides and washes have very generally ob- 

 scured the section, but occasionally fresh faces are visible. About 

 one-half mile south of the Bordentown depot the following sec- 

 tion was reported by Drs, Cook and Smock. 1 



Section near the Bordentown Depot. 



( 1 ) Yellow sand and gravel, 8-10 ft. 



(2) Clay marl (greensand) , 5 ft. 



(3) Black, sandy clay full of pyrite and lignite, alter- 



nating with layers of white quartz sands, 35-40 ft. 



(4) White quartz sand at the level of the track (10 feet A. T.) 



At White Hill, at the north end of the forge building, they re- 

 ported the following 2 : 



Section near White Hill. 



( 1 ) Yellow earth and gravel, 8-10 ft. 



(2) Clay Marl, 6 ft. 



. (3) White sand containing red oxide of iron crusts, .... 12 ft. 



(4) Black, sandy clay alternating with thin layers of 



sand, 12 ft. 



(5) White sand from railroad track level to tide level,. . 10 ft. 



1 Cook & Smock, loc. cit. p. 239. 



2 Idem, p. 240. 



