

SOILS OF SOUTHERN NEW JERSEY AND THEIR USES. 47 
. SOILS. 
The underlying formations which constitute the basal structure 
of the Swedesboro area consist of distinct layers belonging to the 
marl formations which extend across the State from the Raritan 
Bay to the Delaware River. In the immediate vicinity of Swedes- 
boro these beds consist of a lower layer of dark-colored, nonglau- 
conitic clay, only exposed at the surface in a limited area; of a some- 
what glauconitic sand, which underlies the upland along both sides 
~ of the Woodbury pike; and of a distinctly glauconitic, or marl sand 
which occurs along the slopes to Raccoon Creek and also along the 
slopes from the high ridge to the upper rolling terrace. The marly 
material from this formation gives rise to the soils of the Collington 
series either where it outcrops directly at the surface or where the 
same material has been mixed to any considerable extent with the 
later terrace materials. 
The soil-forming materials of the area are derived chiefly from 
later river or estuarine deposits which cover the older formations 
to varying depths, usually ranging from a few inches to an extreme 
depth of 5 to 15 feet. 
The greater part of the soils of the Swedesboro area, including 
nearly all of the rolling upland of the higher terrace level, has been 
formed from these later deposits, while the soils of the lower terrace 
are more recent and have been formed from materials derived from 
all of the older formations. 
Thirteen distinct soils were mapped in ‘the detailed soil and crop 
map of the Swedesboro area. These fall into four main groups. 
The most extensive and agriculturally the most important soils be- 
long to the Sassafras series, represented by six different types. The 
Collington series is represented by two types and a phase of one of 
them. The Colts Neck series has two soils in the area, while the 
Portsmouth series is represented by only one. In addition there are 
accessory areas of Rough, broken land, chiefly in forest, and of 
Tidal marsh, used for the growing of hay and for pastures. 
Sassafras coarse sandy loam.—The surface soil of the Sassafras 
coarse sandy loam, to an average depth of about 10 inches, consists 
of a coarse, loamy sand of a brown to yellowish-brown color. There 
is frequently a scattering of fine gravel over the surface. It does 
not interfere with cultivation. The subsoil to a depth of 30 to 32 
inches is a somewhat more coherent, loamy sand containing some 
fine gravel. At about 30 inches in depth the subsoil becomes de- 
cidedly more coherent and a sticky sandy loam subsoil is encountered. 
The surface of the type is either gently sloping or nearly level, 
although slight depressions exist within its area. Drainage is com- 
