CLAYS OF CRETACEOUS FORMATION. 167 



clay bank (223), at the south bank of the Cliff wood. Brick Com- 

 pany (220), and at Gaston's pits (221). The massive black 

 clay at sea level at Prospect Grove is probably the same as that 

 at Furman's bank (222), at Gaston's., and at the more northerly 

 exposures of the Cliffwood Brick Company. The thickness of 

 this clay bed is not known, but it is probably at least 15-20 feet. 

 One-fourth mile northwest of the Cliffwood Brick Company's 

 bank there is a deep cut along- the railroad, which shows 



Weathered clay, 6 feet 



Sand and clay, 14 feet 



Clay with very much lignite, 10 feet 



Beneath the lignite is a massive black clay, seen, at the level of 

 the track, which apparently extends down to tide level (20 feet) 

 and borders the meadow east of Cheesequake creek. The weath- 

 ered clay in the railroad cut is probably the basal portion of the 

 more massive black clay dug in the Cliffwood Brick Company's 

 banks. If so, the entire thickness of the lignitic sands and clays 

 east of the Cheesequake meadows is about 104 feet. This cor- 

 responds closely with an estimate of the thickness (113 feet) 

 a) based upon the dip of the base of the Clay Marls, 35 feet per 

 mile, and b) on the distance from the appearance of the lowest 

 bed bordering 1 the Cheesequake meadows at the railroad cut to 

 the Clay Marls near Cliffwood station. 



The lignite bed exposed in the railroad cut has been struck 

 at numerous points in this vicinity, and many years ago consid- 

 erable exploring and mining work was done, particularly on the 

 farm of George C. Thomas, 1 in the hope of opening a workable 

 bed of coal. The material contains considerable pyrite ("sul- 

 phur"), which causes a disagreeable odor in burning, and it is 

 always mixed with considerable quantities of sand and clay, so 

 that these efforts were unsuccessful. A good specimen of it, 

 analyzed some years ago in the laboratory of the Geological Sur- 

 vey, yielded 



Gases, 50.2% 



Coke, 34-6% 



Ash, 15-2% 



1 Report on Clay Deposits of New Jersey, 1878, p. 74. 



