46 BULLETIN 677, U. S. DEPARTMENT OF AGRICULTURE. 
ievels along the Raccoon Creek drainage in the extreme southeastern 
corner of the detailed survey. 
Rising above any of these elevations, a high ridge of land extends 
almost from the margin of the Raccoon Creek swamps, northeasterly 
across the area to its extreme northeastern corner. The summit of 
this ridge is clearly indicated upon the soil map by the areas oc- 
cupied by the Colts Neck gravelly sandy loam. From this summit 
the land surface slopes rather steeply down to the upper levels of 
the higher terrace. 
It is probable that the extreme summit of One higher ridge repre- 
sents remnants of an older formation which has elsewhere been re- 
moved by long-continued erosion. The slopes are undoubtedly 
formed from soil wash from this higher and partly destroyed forma- 
tion, mingled with a considerable amount of material which has been 
brought to its present condition through the weathering of underly- 
ing marl formations. Such areas are particularly in evidence in the 
southeastern third of the area, where considerable tracts ef both the 
Collington fine sandy loam and the Colts Neck loamy sand are found. 
These two types owe their origin and characteristics to the influence 
of the underlying marl formations, representing chiefiy different 
degrees of weathering to which the original materials have been 
subjected. Where the marls are still comparatively fresh they retain 
much of their original greenish color. Where they have been more 
thoroughly weathered they have assumed a decidedly reddish tinge, 
which serves to differentiate the resulting soils as members of the 
Colts Neck series. 
The greater part of the drainage of the area is accomplished 
through the medium of several smail streams. Those found in the 
eastern and southern parts of the area are tributary to Raccoon 
Creek. Their courses are relatively short and their gradients are 
steep. At their lower ends they have cut deep gorgelike channels 
through the lower terrace. At their upper ends they usually head 
in slight gullies or in springy areas within the upland. The streams 
of the remainder of the area flow almost directly to the Delaware 
River. They also head in springy areas in the upland. The land 
along their courses through the area mapped in detail is somewhat 
swampy. Their banks are low but steep. | 
Drainage is effective over all of the upland, and the run-off is so 
rapid upon the steeper slopes that heavy rains are likely to do some 
damage through erosion of soil from the fields. 
This is particularly the case along the flanks of the ridge crossing 
the southeastern corner of the area. 

