1 62 Quaternary Formations of Southern New Jersey. 



the land stood somewhat higher than now, relative to sea level, 

 during some part of this interval, for in some places valleys were 

 cut down a little below sea level. The great duration of the 

 period is indicated by the great width of the valleys cut by larger 

 streams in and through the Pensauken formation. 



deposition oe the cape may gravel. 



Date. — After this period of erosion there followed an 

 epoch when deposition again became important. Deposits 

 were made both in the valleys and on the low lands about the 

 coast up to levels of 40 or 50 feet at least. The date of this 

 epoch of deposition can be fixed more definitely than that of 

 some of the preceding events, for it was coincident with the last 

 glacial epoch, when a continental ice sheet covered the northern 

 part of the State, its edge occupying a sinuous line from Perth 

 Amboy to Belvidere, passing through or near Plainfield, Summit, 

 Madison, Morristown, Denville, Dover,- Budds Lake, Towns- 

 bury, and Buttzville. At this time, a large volume of ice water 

 flowed down through the Delaware Valley, and carried glacial 

 debris in abundance to Trenton, and in lesser amount to Cam- 

 den and possibly below. It is the association of this glacially 

 derived material in the Delaware Valley with materials not so 

 derived in the lower Delaware, that fixes the age of this last 

 important stage of deposition in southern New Jersey; for in 

 the lower Delaware, the contemporaneity of the deposits made 

 by glacial waters issuing from the ice at Belvidere, with de- 

 posits about the coast at levels up to 40 or 50 feet, is clear. 



The deposits of this epoch affected not only the coastal lands 

 and the low lands of the main valleys, but they were made in 

 essentially all the valleys of the southern part of the State, even 

 those parts which were far from the coast and at elevations far 

 above sea level. 



Cause. — During this epoch of deposition, the southern part of 

 the State seems to have stood a few feet (30 to 50) lower than 

 now. This was doubtless one cause of deposition, but not the 

 only one. If all parts of a stream's basin were lowered by the 



