Aug. 13, 1917 



Origin of Alkali 



337 



Table I. — Soluble mils in Cretaceous sandstone 

 [Results expressed as pounds per 2,000,000 of material] 



Field No. 



260A. 



73- •• 

 80... 

 292. . 

 81... 

 279.. 

 88... 

 290. . 

 242. . 

 244- • 

 245- • 

 241.. 



Average . . 



Location of sample. 



Thompson, Utah 



Grand Junction, Colo 



do 



Vernal, Utah 



Grand Junction, Colo , 



Vernal, Utah 



Green River, Utah . . 



Vernal, Utah 



Superior, Wyo 



do 



do 



do 



Cretaceous. 



Calcium 



(Ca). 



1,042 

 48, 120 



3) 074 



160 



802 



I, 202 



1,470 



I, 042 



802 



1,058 



I, 604 



802 



5>098 



Mag- 

 nesimn 



(Mg). 



■ySo 

 38, 880 



2,257 

 768 



1,384 

 769 

 276 

 629 



943 



1,835 

 1,694 

 2,237 



4,329 



Carbonic 



add 



(CO3). 



1,040 

 880 



333 

 480 



383 

 600 



350 

 640 

 640 

 I, 480 

 I, 200 

 720 



729 



Sulphuric 

 acid 

 (SO3). 



461 

 106, 744 



31.710 

 I, 216 

 5,980 

 1,514 

 4,829 



2,503 



I, 136 



19,360 



1,218 



494 



14, 764 



Chlorin 

 (CI). 



Trace. 



2,552 



1,300 



Trace. 



2, 127 

 Trace. 

 Do. 

 Do. 

 Do. 

 1,701 

 567 

 567 



170 



All the samples of Cretaceous sandstone contain appreciable quantities 

 of soluble salts and are especially rich in sulphates with appreciable 

 quantities of carbonic acid and chlorin, and, as already reported, they 

 all contain nitric nitrogen. From the analytical data reported above, the 

 ' probable chemical combination may be calculated in any manner desired. 

 Some such calculations have been made in the manner suggested by the 

 Association of Official Agricultural Chemists. 



On this basis of calculation, with the average results reported above, 

 all the carbonates, sulphates, chlorids, and nitrates present in the Cre- 

 taceous sandstone consist of calcium and magnesium compounds. 

 There remains also a slight excess of magnesium after these acid ions are 

 satisfied, which undoubtedly represents that united with the phosphoric 

 and silicic acids. These soluble salts undoubtedly exist in the rock in the 

 crystalline form with water of crystallization; but the amount of this 

 water of crystallization was not determined, the results being simply 

 calculated to the anhydrous basis. There is present in these sandstones, 

 therefore, 983 pounds of calcium bicarbonate [Ca(HC03)], 16,469 pounds 

 of calcium sulphate, 3,922 pounds of magnesium sulphate, 985 pounds of 

 magnesium chlorid, and 1,961 pounds of magnesium nitrate — that is, 

 over 1. 2 1 per cent of the sandstone consist of these soluble salts. The 

 leaching of such rock by the irrigation and ground water must result in 

 a concentration of these salts where the seepage or ground water ap- 

 proaches the surface. The concentration of such soluble salts of calcium 

 and magnesium will bring about double decomposition with the formation 

 of soluble salts of sodium, such as the chlorid and sulphate. However, 

 it must be remembered that the sandstone and shale may and do become 

 mixed in the soil formation, in some areas. The soil derived entirely 

 from the sandstone, however, should not contain such an excess of soluble 

 salts of a harmful nature as to be destructive to crop growth. There 

 may be and undoubtedly are other reasons why the alkali problem is not 



