90 Quaternary Formations of Southern New Jersey. 



(Pliocene?) sand beds. In addition to these finer materials, 

 there are some larg-e bowlders of quartzite from the Kirkwood 

 (Miocene), for though most of the Kirkwood sand is not 

 cemented, it appears to have been cemented to quartzite in a few 

 places, and these portions have given rise to bowlders. The 

 "Lime Sand" of the Cretaceous also has given rise to bowlders in 

 some places. 



This non-arkose phase of the Pensauken is thin for the most 

 part, and its remnants scattered. It is doubtful if it ever 

 covered the whole of the area within which it is found, and much 

 of that which once existed has been removed. If these deposits 

 be fluvial, they were made along the water courses of the time, 

 and large areas were perhaps never covered by them. If this 

 view is correct, some of the old stream courses have since become 

 divides. Since glacial waters did not affect the streams con- 

 cerned in the deposition of this phase of the formation, the 

 deposits were much less considerable than in the main Raritan 

 Bay-Trenton valley. Furthermore, the streams involved were all 

 small, as compared with those which contributed to the main 

 area of the Pensauken formation, and they did not come from 

 areas of such great altitude. 



Differentiation of the formation, especially on the southeast 

 slope, is difficult, for deposition by streams has taken place in 

 later time, and these later deposits (Cape May formation) rise 

 upstream, and in many places reach levels which make them 

 inseparable, topographically, from the deposits of the Pensauken 

 epoch. In constitution, too, the gravels of the two ages are 

 essentially the same. The most persistent differences are (i) the 

 apparent greater age of the Pensauken, as contrasted with the 

 Cape May. This is shown by more cementation, more incrusting 

 of grains and pebbles with iron oxide, more oxidation of 

 glauconitic grains, more decay of chert, etc.; and (2) topo- 

 graphic position, for much of the Pensauken occupies divides, 

 while most of the Cape May formation is in the form of terraces, 

 or on lowlands near the shore. 



