THE PORTERS LOAM AND PORTERS BLACK LOAM. 5 



bordering the Piedmont section to the east and the Great Valley 

 region to the west. Thus throughout the entire extent of the terri- 

 tory which the soils of the Porters series dominate, and where the 

 Porters loam and black loam have their greatest development, the 

 topography is that of the highest ridges and most notable mountain 

 peaks in the eastern portion of the United States. 



The Porters loam and black loam are found at all altitudes within 

 this mountainous region, rising gently over the bordering foothills, 

 occupying the rolling floors of the intermountain valleys, and form- 

 ing the dominant soils of the minor valleys and the coves which are 

 included between the principal ranges and which are enfolded within 

 the minor ridges and cross ridges of the mountain system. 



In general the Porters loam is most extensively developed in the 

 intermountain valleys and over the lower foothills, although it is 

 found also upon the flanks of the lower mountains and across the 

 crests of the smaller ridges. The Porters black loam, on the other 

 hand, occurs almost universally at some elevation, and is prevalent 

 upon the northern, northeastern, and northwestern slopes of the 

 higher mountains and within the more elevated coves having the same 

 exposure. It occupies practically all of the soil areas to be found 

 upon the flanks and the higher peaks of Mount Mitchell. 



These two soil types occupy practically all of the territory which 

 may become subject to agricultural occupation in this general region, 

 although not nearly all of the area, even of these two types, is topo- 

 graphically so situated that it may be brought under cultivation. 

 Only other subordinate types of the Porters series with some minor 

 local types constitute the remainder of the farm land of this mountain 

 section, while vast areas are too stony for cultivation or consist of 

 rocky ledges' and steep slopes totally unsuited to agricultural occu- 

 pation. Thus the Porters loam and the Porters black loam constitute 

 the principal agricultural soils of the south-central portion of the 

 more eastern Appalachian ranges. 



Owing to the elevated mountainous position of the Porters 

 loam and the Porters black loam, drainage is excellent throughout 

 practically all portions of both types. The slopes are considerable and 

 the heavy precipitation of the higher mountain regions gives rise 

 to the formation of many large mountain springs and of innumerable 

 smaller streams which coalesce to form the larger southeastern rivers 

 which have their sources in the Appalachian system and flow, thence, 

 both to the Atlantic Ocean and to the eastern tributaries of the 

 Mississippi River. 



The region is one of heavy to excessive rainfalls, due to its high alti- 

 tude and to the interception of moisture-laden air currents by the 

 mountain peaks and ranges. In consequence of the heavy rainfall 

 and the steep slopes of this section, erosion is apt to be excessive 



