NOKTH-CAKOLINA GEOLOGICAL SURVEY. 



Organic matter, 92.70 



Sand, 6.02 



Lime, 0.02 



Phosphate of lime, alumina and iron, 0.90 



Potash, 0.20 



Soda, 0.06 



Magnesia, trace. 



The silex in this case is a whi^te marine sand which becomes 

 visible after rains, or after a year or two of cultivation. It 

 is too coarse to furnish the necessary amount of soluble silica 

 for a succession of crops. When the vegetable matter is re- 

 moved, it remains as a white sand still, and is blown into 

 ridges. 



11. The condition of the vegetable matters, as in the 

 case of the other elements, is quite variable. Sometimes it 

 is very fine, and is thoroughly incorporated with them ; in 

 other instances it is coarse, or in the condition of fibres. In 

 the former state the sand is not so readily exposed ; in the 

 latter it is always visible, and is indicative of a poor condi- 

 tion, or of its unsuitableness for cultivation. It has not been 

 exposed long enough to change it to the condition required 

 for crops of the most valuable kind. 



A still more remarkable case of excess of vegetable matter 

 composes a tract in Carteret county, and is known as the 

 open ground prairie. This tract, or that portion of it lying 

 within a certain zone of rich and productive land, contains a 

 growth of sphagnum or moss, together with other vegetables 

 intermixed, with which there is only a minute quantity of 

 earth. I obtained it from a depth of 18 inches, and it gave 

 only 3 per cent, of inorganic matter, and this was mostly the 

 ash of the vegetable fibre. This case furnishes an example 

 of an unproductive soil, so far as the grains are concerned. 

 The outer rim of the open grounds is an excellent soil. 



Much has been said respecting the open ground prairie, and 

 enquiries are now frequently made respecting the character 

 of this tract ; and whether it is susceptible of a profitable 

 cultivation. As the soil is now constituted, a kernel of corn 

 planted in it would germinate and grow well apparently until 



