Pensauken Formation — Local, Details. 103 



various, but the more striking contrasts come from the fact that 

 some parts are much more cemented than others. 



The vicinity of Blackwood in post-Bridgeton time, was de- 

 veloped to a fairly definite plain in which valleys 20 to 60 feet 

 deep were cut. This was the topography when the deposition 

 of the Pensauken formation began. Much of the so-called Pen- 

 saukcn on this plain may have been stream deposits made as the 

 plain developed. Such deposits were followed by the deposition 

 resulting from the filling- of the Delaware. 



Between Coopers and Rancocas creeks. — Between the lower 

 ends of these creeks,' there are two belts of Pensauken remnants, 

 the one near the Delaware and the other a few miles farther 

 back. In the belt nearer the river, the patches occur near Fish 

 House (Beidemans-Bethel-Merchantville), southeast of Morris, 

 about Cinnaminson (east of Palmyra), and smaller. ones at and 

 near New Albany, Fairview, Pavonia and Delair. At the highest, 

 the surface of the formation in these patches reaches an elevation 

 of 100 feet, as at Merchantville, while its base ranges in altitude 

 from about 60 feet, down nearly to sea level. At Fish House, 

 indeed, it probably goes down to sea level, under younger beds. 

 The general relations of the Pensauken in this latitude are 

 shown in Figs. 45, 46 and 47 (p. 136). 



The patches of the second belt occur north of EHisburg and 

 southwest of Moorestown, between the north and south branches 

 of Pensauken Creek, at Moorestown, and thence north to Swedes 

 Run, and northeast nearly to Rancocas Creek. The elevation of 

 the surfaces of these remnants is about the same as that of the 

 patches to the west, but their bases are not so low, rarely below 

 50 feet. The altitude of the Swedesboro Plain here was about 

 70 feet, a level which extended well up to the Delaware. 



These two series of remnants are so related to each other and 

 to drainage lines as to show that they were once continuous, 

 and that their isolation is the result of stream erosion. The 

 smaller streams, such as Pompeston Creek and Swedes Run, have 

 not dissected the area to the extent the larger streams have. 



The material of the formation nearer the Delaware is more 

 gravelly, that of the remnants farther from the stream more 



