SOILS OF SOUTHERN NEW JERSEY AND THEIR USES. 47 



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 cla}^, 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 CoUington 

 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 rnain groups. 

 The most extensive and agriculturally the most important soils be- 

 long to the Sassafras sepes, represented by six different types. The 

 CoUington 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- 



