SOILS OF THE EASTERN UNITED STATES AND THEIR USE VI. 



THE CECIL CLAY. 



GEOGRAPHICAL DISTRIBUTION. 



Typical areas of the Cecil clay have been mapped by the soil survey 

 from eastern Pennsylvania southward through the Piedmont section 

 to central Alabama. Occurrences of the type have been encountered 

 in the soil-survey work in 32 different areas located in 7 States and 

 comprising an aggregate of 2,490,627 acres. The extent of develop- 

 ment of the Cecil clay is only less than that of the Cecil sandy loam, 

 and the former type has even a more widespread distribution than the 

 latter. From the areas thus far encountered in the soil-survey work 

 it is safe to estimate that nearly one-third of the total extent of the 

 Piedmont Plateau soil province is occupied by the Cecil clay. It thus 

 constitutes one of the most important soil types in the region, and 

 because of its inherent properties it constitutes one of the most valu- 

 able soil assets of that portion of the United States. 



CHARACTERISTICS OF THE SOIL AND SUBSOIL. 



The surface soil of the Cecil clay to an average depth of about 6 

 inches consists either of a heavy reddish-brown loam or of a heavy 

 red clay loam. In the fields which have been subject to the best 

 forms of tillage the heavy reddish-brown loam may have a depth of 

 8 to 10 inches, while in regions where erosion has continually removed 

 the surface soil materials the heavy red clay loam either occupies the 

 surface or is covered only by 3 or 4 inches of the more friable soil 

 material. In all cases the subsoil from a depth of 6 or 8 inches to a 

 depth of many feet consists of a tenacious heavy red clay. In the 

 majority of the areas which have been surveyed there will be found 

 scattered over the surface and through both soil and subsoil angular 

 fragments of quartz, or " white flint," as it is locally known, amount- 

 ing in some instances to 20 or 30 per cent of the entire soil mass. Not 

 infrequently also un weathered portions of the parent rock are still 

 present in the form of rounded bowlders, usually deeply iron stained 

 and segregated in those portions of the area where erosion has most 

 nearly kept pace with the weathering of the rock. It is a distinguish- 

 ing characteristic of the surface soil of the Cecil clay that it granu- 

 lates readily when plowed in the proper moisture condition, and thus 



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