4-0 Quaternary Formations of Southern New Jersey. 



or 70 feet at Dividing Creek, a slope of 2 to 3 feet per mile. 

 This decline is slightly less than that to the southeast. 



The most notable irregularity of the formation, apart from 

 the irregularity of base at Barnsboro, appears in the 124-foot 

 hill south of west of Carmel, where the formation, as mapped, 

 occurs higher than in its surroundings. The relations in the 

 124-foot hill here are similar to those in the 176-foot hill at 

 Richwood, except that at the latter place the base of the forma- 

 tion is not higher in the hill than about it, while at Carmel it 

 is. It may be that the gravel about the 124-foot hill at Carmel, 

 mapped as Bridgeton, is really older. The irregularity of base, 

 however, even regarding the gravel and sand about the hill as 

 Bridgeton, is no greater than in some other places. 



The formation appears to have its maximum thickness in the 

 vicinity of Richwood, where erosion has been least; but its 

 greater thickness here does not necessarily mean greater thick- 

 ness originally. 



Exposures. — The Bridgeton is well exposed in the vicinity of 

 Aura (formerly Unionville), Harding, and Monroe. Still Run 

 (near Aura) has removed much of the formation, and the rem- 

 nants are thin, coarse gravel being common. It is probable 

 that the coarse material was in the base of the formation orig- 

 inally. 



There are gravel pits west of Monroeville, and exposures are 

 found along the stream north of the village. The stream bank 

 shows the base of the Bridgeton at an elevation of about no 

 to 115. The gravel in this region is rather loose for the Bridge- 

 ton, and contains some shale. 



A mile west of Monroeville, a pit shows 9 feet of Bridgeton, 

 the upper 2 feet being gravel, sand, and loam, and the lower 7 

 feet highly colored compact gravel with some sand. Large 

 pebbles and cobbles are rare, though present. Quartz and chert 

 make up the body of the gravel, but there are some pieces of 

 sandstone and a little shale. 



Half a mile south of Monroe Station the Bridgeton is only 

 3 to 5 feet thick, and overlies glass sand. A mile southwest of 

 the station there are several bowlders, one of "bull's head" type 

 i 1 / feet in diameter. 



