24 Quaternary Formations of Southern New Jersey. 



stop the overspread of gravel and sand to the southeast, the 

 valleys down the southeast slope should have shown the effect 

 of this altitude; but such effects have not been recognized. It 

 would seem, therefore, either that the region about Berlin must 

 have been lower then than now, relatively, or elevated since. 

 While fluvio-glacial waters were depositing sand and gravel along 

 the lines of their flow, other sands and gravels must have been 

 accumulating in the valleys which did not carry glacial waters. 

 In valleys tributary to the Delaware there must have been 

 deposits of sediment brought down from higher parts of the 

 Coastal Plain, while the Delaware Valley itself was being rilled 

 up with fluvio-glacial debris. If the southern part of the State 

 was then lower than now, floating ice may have had a share in 

 the remarkable deposits referred to the Bridgeton formation, 

 such as those about Folsom, Hammonton, Tuckahoe, etc., where 

 the large blocks of soft red shale and sandstone appear to be so 

 anomalous as to make the presence of floating ice seem necessary. 

 Possibly the southern part of the State was low enough during 

 some stage of the epoch, to convert the area of the present 

 lowland between Raritan Bay and Trenton into a sound; but of 

 such submergence specific evidence is wanting. 



The Woodmansie Phase. — While the deposition of the Glass- 

 boro phase of the formation was in progress, other deposits 

 were being made by the streams which were not so situated as 

 to receive glacial drainage. 



Theoretically, the deposits made in the valleys of streams 

 flowing to the southeast from the divide northeast of Berlin, at 

 the time sedimentation by fluvio-glacial waters was in progress 

 in the main Delaware Valley, constitute the second (the Wood- 

 mansie) phase of the Bridgeton formation, which is confined to 

 the area southeast of the Amboy-Bordentown Valley, and north 

 of Mullica River. Practically, the deposits of this time in this 

 area are difficult of identification. They possess none of the 

 distinctive features of constitution which are relied on for 

 identification of the Bridgeton formation farther south and 

 west, and their topographic positions become less and less dis- 

 tinctive as sea level and the coast line are approached. Neverthe- 



