Pensauken Formation — Description. . 89 



areas southeast oe the main beet. 



Southeast of the main belt of the formation, there are many 

 areas of gravel and sand, some large and many small, which are, 

 perhaps, to be correlated with the Pensauken formation. The 

 areas in question are partly to the north and west of the main 

 divide of southern New Jersey, and partly to the southeast, on 

 the Atlantic slope. In general, these parts of the Pensauken 

 formation, if such they are, lie on divides and hills, though not 

 on the highest divides and hills along the crest of the watershed. 

 Their altitude is greatest as this divide is approached, whether 

 from the north and west, or from the south and east. Near this 

 divide, their altitude is somewhat greater than that of the Pen- 

 sauken formation in the Raritan Bay-Trenton belt. From this 

 divide the altitude of these areas declines with the streams in 

 both directions, so that the altitudes have a wide range, from 200 

 feet or so at a maximum, down to 60 feet or less at the south- 

 east, far from the main divide of the southern part of the State. 

 Many of the patches. of gravel in this area are so arranged as 

 to suggest that the material was deposited by streams flowing 

 parallel to those of the present time. Some of the patches, on 

 the other hand, show no such association with the courses of 

 existing streams. 



In essentially all cases — perhaps in all — the materials of these 

 areas came from underlying and adjacent formations. At the 

 northwest and west, the Cretaceous formations contributed much. 

 This is true in most places north and west of the main divide. 

 On the Atlantic slope, on the other hand, the streams, as a rule, 

 had no access to Cretaceous formations, and the Tertiary and 

 earlier Quaternary formations were the immediate sources of 

 the material regarded as probably Pensauken. The sand is not 

 arkose, and the gravel consists of quartz, chert, etc., from the 

 Bridgeton and Beacon Hill formations, and of ironstone, derived 

 from the cemented parts of the older formations of the region. 

 Where the Cretaceous formation contributed, glauconite is pres- 

 ent commonly. Sand definitely recognized as from the Miocene, 

 is found in many places. So also is sand from the Cohansey 



