Bridgeton Formation 1 — Local Details. 25 



less we may recognize certain beds, which, from their topographic 

 relations, we infer to be of Bridgeton age. These gravels, sands, 

 etc., were derived from local formations, and must have been 

 deposited under conditions which were somewhat different from 

 those of the present time. These conditions may have been 

 either climatic or topographic, or both. If, for instance, the 

 Bridgeton epoch was an epoch when the land was sinking, so 

 that the ocean encroached upon it, marine deposition must have 

 taken place in the lower ends of the valleys and along the coast. 



Local Details. 



The Glassboro Phase, 

 general occurrence. 



The largest areas of the Bridgeton formation occur in the 

 northeast-southwest belt between Berlin and Shiloh (a few miles 

 west of Bridgeton), along the divide between the drainage which 

 flows westward into the Delaware and that which flows to the 

 southern and southeastern coast. But even here the continuity 

 of the formation is interrupted by the headwater tributaries of 

 Great Egg Harbor and Maurice rivers, and of Timber and 

 Mantua creeks. A line drawn from Clementon southwest through 

 Mullica Hill, Harrisonville, Yorktown and Roadstown (5 miles 

 west of Bridgeton) would mark approximately the northwestern 

 limit of all considerable areas of the formation, though to the 

 northwest of this line small outliers cap some of the higher 

 hills which have been separated from the highland to the south- 

 east by erosion. 



The general relations of the Bridgeton formation will be 

 brought out in connection with a series of sections, mostly at 

 right angles to the strike of the formations of the Coastal 

 Plain. The order in which these sections will be described, is 

 from the south to the north. 



