14 The Bulletin 



The Xortli Carolina Department of Agriculture at Ealeigh is now 

 working out varieties of seed adapted to the various soil types and 

 also the fertilizer requirements for these different soils. Anyone can 

 secure valuable information along this line upon application to that 

 department. 



SOILS AND THEIR ORIGIN 



Carharrus County lies wholly within the Piedmont Plateau province, 

 and all of its soils with the exception of small strips of bottom-land, 

 have been formed through the processes of weathering from the under- 

 lying rocks, which may be seen at varying depths from the surface. 

 The important rock formations in the county are granite, gneisses, 

 diorites, gabbros, and slates. These rocks differ widely in their physical 

 and chemical composition, and the decay of these give soils of different 

 color, structure, texture, and varying greatly in the elements of plant 



food. 



The slate rocks, known as the "Carolina Slates," occur in a belt vary- 

 ing from 4 to 5 miles in width across the eastern boundary of the 

 county along the Stanly County line. These slates are fine-grained and 

 bluish to gray in color, but upon w-eathering and oxidizing, the colors 

 become brilliant, and shades of purple, blue, red, yellow, and gray are 

 common. They have hot weathered to as great depths as the granites, 

 and frequently the broken slate is reached within 3 feet of the surface, 

 and even outcrops are seen in short distances. The weathering of these 

 give rise to soils having a floury-smooth feel and silty texture and com- 

 monly called "lean" or poor soils. The light gray to whitish soils Avith 

 yellow friable subsoils belong to the Alamance series. This group con- 

 tains the silt loam, silt loam (shallow phase), and the slate loam. The 

 gray to red surface soils, with red silty clay subsoils, are classed as the 

 Georgeville. Only one type, the silt loam, was mapped. The red color 

 of the Georgeville soils is due to a larger amount of iron in the slate 

 rock or to a further stage of oxidation of iron than has taken place in the 

 Alamance. 



In the southwestern part of the county around Ilarrisburg and to the 

 north thereof, for several miles, occurs an area of diorite, diabase, or 

 gabbro rocks. These are dark colored, hard rocks, sometimes called 

 "nigger head rocks," which have decayed into brown to reddish brown 

 soils and have yellowish brown or ocherous-colored heavy plastic im- 

 pervious clay subsoils. Here the rotten rock is usually reached at from 

 2 to 3 feet. The soils have been classed into the Mecklenburg series, 

 and two types occur, the sandy loam and the clay loam. 



The remaining, or greater part of the county, is underlain by granites, 

 gneisses, and diorites, the latter occurring in small bodies throughout the 

 granite and gneisses. The granites and gneisses are composed of quartz, 

 feldspar, and mica. In their decay into soil the quartz is left as sand, 



