Bridgeton Formation — Local Details. 49 



Exposures. — Good sections have been seen in the railway cut 

 at the sanitarium near Hammonton, where the distinctive fea- 

 tures of the formation are well shown, and in the railway cut 

 at Folsom, 3 miles southwest of Hammonton. At the last 

 locality, the foreign constituents (shale, schist, etc.) are espe- 

 cially abundant, and in large pieces (Fig". 9). 



Exposures are common east and south of Hammonton in 

 gravel pits and road cuts. Many of the cuts are in the Cohansey 

 sand beneath the Bridgeton, rather than in the Bridgeton itself. 

 In some of the pits, only the upper part of the Bridgeton is 

 exposed, because this part is more gravelly than that below, and 

 more compact by reason of its content of loam. 



At Elwood the exposures show the same features with a 

 coarse layer at the bottom at many places. A good exposure was 

 seen iy 2 miles northeast of Elwood, on the road to Batsto, in 

 the 121-foot hill. Here 5^2 feet of compact gravel of quartz 

 and chert overlay 2 J / 2 feet of loamy gravel. 



About Egg Harbor City and farther east, the separation 

 of the Bridgeton formation from the Pensauken becomes un- 

 certain, for the gravel and sand concerned sink tx> low levels and 

 are well exposed in but few places. 



In the vicinity of Pomona and Pleasantville, there are large 

 areas of gravel with greater thickness, which are perhaps Bridg'e- 

 ton. There are good exposures in road-gravel pits 1 and 2 

 miles southeast of Pomona Junction, and also on the P. and R. 

 R. R., a mile north of Pleasantville, and near Farmington Sta- 

 tion. The exposures between Pomona and Pleasantville show 

 5 to 10 feet of Bridgeton material. In its general character it 

 is typical of the formation, except that shale and crystalline 

 material are wanting. The abundance of soft cherts is one of 

 the features which suggest its Bridgeton, rather than Pen- 

 sauken age. This chert must have been hard when deposited, 

 and the decay is subsequent. The upper part of the formation 

 here has more gravel and loam than the lower part, and less 

 sand. The stratification is much more distinct and more regu- 

 lar in the lower part than in the upper. This point, alone con- 

 sidered, suggests a marine, rather than a fluviatile origin. 



4 QUAT 



