SOILS OF THE SASSAFRAS SERIES. 17 



Potomac River. 1 A. total area of 337,346 acres has been mapped in 

 these various surveys. It is probable that the entire geographic 

 range of the type has been outlined, but the total area of this soil is 

 undoubtedly considerably greater than the area already included 

 within the limits of the soil surveys. 



The surface soil of the Sassafras sand to an average depth of about 9 

 inches is a brown or reddish-brown, medium to coarse textured sand. 

 Frequently the surface color may grade into yellow or gray tints 

 and the texture is sometimes somewhat loamy, especially where a 

 considerable amount of organic matter exists in the surface soil. 

 The subsoil is most frequently a yellow or reddish-yellow sand, 

 usually rather incoherent just below the surface soil, but becoming 

 more loamy at a depth of 2 to 3 feet. Frequently the immediate sub- 

 soil is underlain at a depth of 3 feet by very coarse sand or by sand 

 and gravel mixed. The deeper subsoil is also frequently tinged with 

 red so as to become orange or brown in color. 



In some areas small amounts of fine gravel are mingled with both 

 the soil and subsoil, especially upon steep slopes, where erosion has 

 exposed underlying beds of coarser material. In a few localities 

 indurated, iron-cemented gravels give rise to plates and blocks of 

 "ironstone," which appear most numerously upon slopes or where 

 this soil type merely persists as a capping on partially eroded hills. 

 Typically the surface soil is a uniform, medium sand in which the 

 chief variations consist of more or less organic matter and in a 

 slightly variable amount of the finer-grained soil particles. 



The Sassafras sand is distinguishable from the Norfolk sand, with 

 which it is sometimes associated, through the generally gray appear- 

 ance of the surface soil and the yellow coloration of the subsoil of the 

 latter. 



The Sassafras sand occurs in quite a variety of topographic posi- 

 tions, but the greater part of the areas of the type thus far mapped 

 is found upon gently sloping terrace plains or upon the slightly 

 inclined surfaces of delta deposits. Within these areas there is 

 usually a small percentage of the type which occupies the sloping 

 sides of streamways or the marginal slopes of the deltas or terraces. 

 In some instances, also, erosion has left small areas of the Sassafras 

 sand as isolated cappings upon the higher hills. Areas of this 

 character are liable to be rougher and more sloping than the char- 

 acteristic occurrences of the type. The most extensive areas and 

 those of the highest agricultural value exist as gently sloping plains 

 and nearly level terrace areas. In such positions the level of the 

 ground water is frequently near the surface of the land. This is 

 the case along the southern shore of Long Island and along the low 



* In some of the earlier surveys no distinction was made between the sand and fine 

 sand, and both were mapped as Sassafras sand. 



63555°— Bull. 159—15 3 



