4 SOILS OF THE EASTERN UNITED STATES. 



within the field will usually tend toward a brown or a dark-gray 

 color. This difference in coloration of the same material arises 

 chiefly from slight differences in the amount of organic matter pres- 

 ent and represents variations in the condition of its decomposition. 

 Where drainage has been most complete and the soil has been most 

 perfectly aerated, there is a tendency toward the destruction of 

 organic matter in the loose, incoherent surface soil and a resultant 

 tendency toward the lighter gray or nearly white color. In the lower 

 lying areas, Avhere there is a greater amount of moisture and where 

 complete decomposition of organic matter is not the general rule, the 

 colors become gradually darker with increasing humidity in the sur- 

 face soil, until a brown, somewhat loamy covering is formed at the 

 surface of the soil, showing its gradation toward other swampy and 

 lower lying types. 



The subsoil to a depth of 36 inches or more is typically .a medium 

 to somewhat coarse, incoherent yellow sand. In small areas where 

 the Norfolk sand occurs in connection with other types the deeper sub- 

 soil is often modified in color from the usual pale yellow to orange, 

 red, or even mottled yellow and red. Such variations in the color 

 frequently occur where the Norfolk sand is found in small patches and 

 in close association with types of the other series. They usually 

 mark a thin development of the Norfolk sand associated with soils 

 of the Orangeburg or Sassafras series. Even in localities where the 

 Norfolk sand is typically developed to a considerable extent it is not 

 unusual to find near the margins of each of the areas of this type 

 locations where borings at the greater depths show sandy yellow clay, 

 or yellow friable clay, which characterize such types as the Norfolk 

 sandy loam and the Norfolk fine sandy loam. These constitute the 

 gradation into another type of the same series. 



A characteristic difference between the Norfolk sand and other 

 sandy soils of the Coastal Plain is a yellow subsoil to the complete 

 depth of 36 inches. In the case of the Sassafras and the Orange- 

 burg sand, respectively, the subsoil is either orange sand or orange? 

 loamy sand grading into red sandy clay. Thus the Norfolk sand is 

 easily distinguished from all other soils of similar texture within the 

 region in which it occurs. 



SURFACE FEATURES AND DRAINAGE. 



The surface topography of the Norfolk sand varie's to some degree 

 in the different areas within which it is found. In general the sur- 

 face is level to slightly undulating, with no steep slopes and no pro- 

 nounced stream channels or drainage ways within the area of the 

 type itself. It is so easily permeated by atmospheric water that no 

 large amount of erosion occurs, and consequently no pronounced topo- 

 graphic relief is formed. It is somewhat subject to movement by the 



