*''J7.V 27*3 SHOXGALO GREENSAND. 105 



also in cuts between that place and Roekport, contains a con- 

 siderable percentage of greensand grain?, sufficient to render it 

 highly efficacious as a manure. 



In the two small cuts N. of the deep one exhibiting gray and brown clay 

 (*|183 rf.), several different materials are exhibited ; partly coarse sand, forming 

 a soft sandstone, containing impressions of sea-shells, partly clay — all deeply 

 tinged with iron. The greensand grains are apparent throughout the mass, but 

 most so in the sandy portion, and may be readily observed, especially when the 

 mass is crushed and washed with water. 



The grains are generally about the size of small bird-shot, but 

 flattened, and of a dark green, in part also of a yellowish-green 

 tint. Thi value of the muss a* a manure, is precisely in proportion 

 to the umovnt of these green grains which it may con/urn. 



An analysis of the soft sandstone in the most southerly of the small cuts 

 gave the following result : 



SHONGALO GKEENSAND. 



nd, and insoluble Silica 36.707 



ible (in NaO, CO 2 ) Silica 18.298 



Potash 1.604 



Soda 0.045 



Lime 0.166 



Magnesia 1.630 



Peroxide of Iron, with little Alumina 34.377 



Phosphoric Acid trace. 



Carbonic Acid 0.129 



Water 7.012 



99.948 



^75. Potash and soh are the ingredients which render this material 



of value as a manure, and as such, it would probably be suited more especially 

 to small grain — oats and wheat, and to corn. It will be found beneficial, 

 however, to almost any crop, and the only precaution which it might be necessary 

 to observe in its use, would be to avoid applying it to land badly drained, where 

 the large amount of iron which this material contains might prove injurious in 

 wet seasons; and for the same reason, it is not well suited to being composted 

 with farmyard manure, but ought to be spread on the land either by itself, or 

 mixed with other mineral manures only. The quantity to be used will vary 

 greatly with the amount of greensand grains present. In the mass analyzed, 

 they constitute about one-third by bulk, and of such, dressings of 70 to 100 

 bushels per acre would no doubt produce an effect lasting for several years ; 

 while mass still richer, such as occurs occasionally, might even be used in the 

 drill. No overdressing need be feared, so long as the soil to which it is applied 

 is well drained. The admixture of some lime, or calcareous marl, would serve 

 to heighten the effect greatly, and would be likely to prevent, to a considerable 

 extent, injury which might otherwise happen in ill drained land. 



The material may be found, no doubt, in other hills in the neighborhood of 

 Shongalo ; when near the surface, it may be recognized by the dark orange, or 

 rust color which it imparts to the surface material, while the common surface 

 loam of the country is of rather a pale yellow tint. The same may be said of N. 

 E. Holmes, where, between Vaiden and Piockport Station, the ferruginous 

 greensand appears in the cuts of the railroad. 



276. The same material exists in N. Attala, not only in the 

 " Red Hills" toeraselves, whose soil appears to be formed, to a large 



