12 Quaternary Formations of Southern New Jersey, 



Descriptive Summary. 



The Bridgeton is a thin formation, composed chiefly of coarse 

 sand and gravel. But at one place and another it contains sand 

 which is not coarse, loam, and even clay. At the other extreme 

 there are bowlders of considerable size, but they are few and 

 appear to have been chiefly limited, at the outset, to the base of 

 the formation. Owing to the fragmentary condition of the 

 formation, resulting from its extensive erosion, occasional bowl- 

 ders are the only part which remains in some places, and they 

 appear at the surface not infrequently where streams have cut 

 through the formation, removing all its finer parts. 



The formation has two phases which are so unlike that they 

 are best described separately. They will be called the Glassboro 

 phase and the Woodmansie phase. The former is the better 

 known, and the more distinctive. 



GLASSBORO PHASE. 



Distribution. — This phase of the formation has its distinctive 

 development in the southwestern part of the State. Its largest 

 continuous surface areas are on the upland which extends south- 

 west from Berlin, and overlooks the lowland bordering the Dela- 

 ware. Northwest of the escarpment which borders the high 

 land back from the Delaware, there are many outliers of the 

 formation on the crests of hills and divides. Remnants of this 

 phase are found south and west of a line drawn from Berlin 

 down the Mullica River to the Atlantic coast. 



Composition. — This phase of the formation consists primarily 

 of gravel and sand, arkose in many places. It contains occa- 

 sional bowlders, and, exceptionally, seams and lenses of clay. 

 The gravel and sand are dug extensively for road material, and 

 characteristic exposures may be seen in pits at numerous points 

 about Berlin, Atco, Williamstown, Glassboro, Pitman Grove 

 and Cohansey on the upland, and in many of the outliers north- 

 west of the main area, as at Houghton's Hill southwest of 



