10 



NORTH-CAROLINA GEOLOGICAL SURVEY. 



is also another peculiar soil which skirts the northern counties, 

 Granville, Person, Caswell and Rockirigham. It is adapted 

 to the growth of fine tobacco. It is a light gray soil. 



The soils, however, which form the subject of this report, 

 occupy the eastern counties of the State, and may all be re- 

 garded as marine products with one exception, the vegetable 

 eoils, which occupy the swamps and pocosins of the extreme 

 eastern part of the State. The others which have been re- 

 ferred to are derived immediately from the rocks upon which 

 they rest, and have been formed by atmospheric agencies. 



The vegetable soils, on the other hand, were formed by the 

 growth of vegetables which have long since ceased to live, 

 and have undergone disintegration in a greater or less degree ; 

 some are coarse and fibrous, others exist as a close compact 

 mass of vegetable matter, perfectly disorganized and in the 

 best condition possible for cultivation. The mass remains in 

 situ, frequently homogeneous, and may be cut into blocks 

 and dried like brick. 



I have applied to these vegetable accumulations the usual 

 term soil, for the reason that they are cultivated and frequent- 

 ly productive. Others probably come more properly under 

 the common name peat, as the mixed earthy matter is too 

 small to be cultivated without the addition of earthy matter, 

 and have remained in situ, and undisturbed since their seeds 

 took root. 



The peculiarity of this vegetable soil then consists in ita 

 composition, and the interest which is especially attached to 

 it arises from the small amount of earthy matter which it 

 contains. It gives us, therefore, an opportunity to determine 

 the smallest amount of earthy matter compatible with re- 

 munerating crops. It is also proved by observation that all 

 crops require earthy matter, it may be comparatively small, 

 but if the inorganic matter is reduced to a certain small per- 

 centage, the crop fails, although it is placed, in one sense, in 

 a magazine of food. The determination of the smallest per- 

 centage of inorganic matter which is compatible with a good 

 crop, is practically important. Large tracts of land in North 

 Carolina consist of organic matter, with too little soil to permit 



