4 SOILS OF THE EASTERN UNITED STATES. 



of all other series through the fact that it is derived from the crystal- 

 line rocks, chiefly granites, gneisses, and mica schists, and through 

 the fact of the yellowish-red or deep-red color of the subsoil. In 

 this latter respect it resembles the soils of the Cecil series, which 

 are confined to the lower, Piedmont region, lying at the eastern 

 foot of the mountains. It is separable from the soils of the latter 

 series chiefly through its more rolling and mountainous surface 

 features and through its occurrence at considerably higher altitudes. 

 The surface soil of the Porters black loam is a rich, dark loam 

 having an average depth of about 15 inches, but ranging in depth 

 from 5 or 6 inches to a maximum of 2 or 3 feet. It is not infre- 

 quently, mixed with rounded and angular fragments of rock varying 

 in size from a few inches to several feet in diameter. The im- 

 mediate subsoil is usually a brown or reddish-brown loam which 

 grades downward into a heavy red clay at greater depths, as is 

 the case with the Porters loam. The surface soil of the Porters 

 black loam consists of the partly decayed organic remains of a heavy 

 vegetative growth mingled with the broken fragments and the finer 

 earth formed through the decay in place of the gneisses, granites, 

 and other eruptive rocks at the higher altitudes in the eastern 

 Appalachian ranges and particularly in the north sloping coves to 

 be found between the ridges in this mountainous country. It is 

 easily distinguishable from all other members of the Porters series 

 through the deep, dark-colored surface soil, rich in organic matter, 

 while, like the Porters loam and the other members of the same 

 series, it is the only mountain soil possessing a dark-red subsoil. 



SURFACE FEATURES AND DRAINAGE. 



Both the Porters loam and the Porters black loam are distinctively 

 mountain soils occurring at all elevations in the eastern ranges of the 

 Appalachian Mountains from an altitude of 850 or 900 feet in the 

 foothills to altitudes of 3,000 and 4/)00 feet in the main ridges and 

 even attaining to an altitude of 6,700 feet above tide at the top of 

 Mount Mitchell in North Carolina. The country throughout which 

 these two types prevail is marked by extreme ruggedness. Some of 

 the mountain slopes are so steep as to render their cultivation un- 

 profitable, or in many places even impossible. On the higher plateau 

 portion marking the crests of the main ridges in western North Caro- 

 lina are superimposed many cross-chains of mountains, the most 

 notable of these being the Newfound Mountains and the Black Moun- 

 tains. In the Blue Ridge section of western Virginia the altitudes 

 rise nearly 4,000 feet above tidewater and the mountain country is 

 characterized by a smooth broad-topped ridge which is flanked on 

 either slope by spurs and sharp knobs which descend to the foothills, 



