138 THE PIEDMONT REGION, 



the rather remarkable extent and depth of the disintegration of these 

 rocks. It is not an uncommon occurrence that wells sunk through 

 granite to a depth of thirty or forty feet, require for their excavation no 

 other implement than a spade. Frequently so thorough is the decom- 

 position, that the sides of railroad cuts and of mines might be mistaken 

 for a heap of transplanted materials, did not the existence of seams and 

 quartz veins, which may be always traced on the fresh surfaces, make it 

 certain that the rock had rotted where it stood. The chief impediments 

 to culture are the masses of quartz rock, once forming these veins, but 

 now scattered broadcast over the surface, in consequence of the rotting 

 and denudation of the strata that contained them. This is especially the 

 case among the clay slates, and often the first indication which a traveller 

 has that he has entered the Piedmont region is the sight of fields and 

 woods covered with angular fragments of these white quartz rock. The 

 inclination of the rocks of this region allows drainage along their edges, 

 and even where the rock is near the surface, water seldom collects above 

 them to an injurious extent. 



Owing to the transportation and intermixture (often by the wind) of 

 the debris from the different rocks, the areas of the soils derived from 

 each can be characterized with much less distinctness than the areas 

 occupied by the underlying rocks themselves. Nevertheless three lead- 

 ing varieties of soil may be traced, with much clearness, viz. : the gran- 

 itic, the clay slate and the Trappean soils. 



I. The granitic soils occupy by far the largest area, as under this head 

 is comprised the soils whose substratum is granite and gneiss, and also 

 those resting on the hornblende, talc and mica slates. These soils are 

 characterized b}^ two distinct names : 1st. the gray sandy soils ; 2d. the 

 red cla}'^ soils. 



1st. The gray sandy soils occupy the ridges and levels, and have been 

 formed by the gradual separation of the silicious and argillaceous materials 

 found in the debris ol the decomposing rocks that underlie them. This 

 has been etfected by a process of lixiviation, during which the rain water 

 not running off", owing to the level nature of the land, sank directly into 

 the earth, carrying down with it the heavier and finer particles of the 

 clay through the interstices of the lighter and larger particles of sand. 

 This gives a light, loose, warm sandy loam, varying in depth from three 

 to eighteen inches, and fine or coarse, according to the grain of the rock, 

 from which they are derived. The subsoil is red or yellow clay. Such 

 soils are of easy culture, respond readily to the use of commercial ferti- 

 lizers, and are well adapted for cotton. For these reasons they are much 

 more highly esteemed now than formerly. The following analii^^ses of 

 them are taken from Tuomey's report ; 



