Sources of the Constituents of Minnesota Soils. 



395 



I. Peaty Soil — characteristic of the bottom lands of eastern 

 Wisconsin. 



II. Prairie Loam — south central Wisconsin. 



III. Siliceous red clay, Ashland. This is fairly representa- 

 tive of an extensive stretch of country in eastern Minnesota. 



IV. Loamy soil, Douglas county, Wisconsin, characteristic 

 of the higher ridges and rolling areas of eastern Minnesota. 



V. Sandy soil from the barrens of Douglas county, identical 

 in general characters with the sandy tracts of eastern central Min- 

 nesota. 



I 



II 



III I IV I V 



57.601 80.36 94.08 



Silica Si02 



Alumina AIO2 



Ferric oxide F2O3 



Manganic oxide MnsOij 



Lime CaO 



Magnesia MgO 



Soda Na^O 



Potash K2O 



Phosphoric acid P2O: . 

 Carbonic acid CO2 . . . . 



Sulphuric SOu 



Water H2O 



Organic matter 



Totals 



64.49 

 4.80 



5.74 

 0.13 

 1.60 

 0.79 

 0.51 

 0.14 

 0.12 

 0.25 

 0.08 



79-59 

 4.17 

 8.16 

 18 

 30 

 04 

 49 

 10 

 0.06 

 0.52 

 0.03 



25-851 

 4. II 



2.90 

 0.90 



0.68 

 0.40 



4-6; 



21.40 

 100.00 



100.00 



2.57 

 100.00 



0.70 



3.15 

 9.60 



98.78 



0.74 

 1. 00 



0.64 

 0.12 



O.b: 



0.37 

 0.80 



98.40. 



Soils classified. — Powell classifies soils in the following 

 manner : 



I. Endogenous, — those derived from the common rocks, 

 and remaining in place. These vary greatly according to the 

 rocks from which they are derived; but broadly stated we have 

 three classes : 



1. Sandstone soils; 



2. Limestone soils ; 



3. Granitic soils. 



II. Exogenous soils, — those derived from other surfaces 

 than that of the common rock peculiar to the district in which 

 they occur. Of these soils there are many sub-divisions, but so 

 far as represented in Minnesota, they are, — 



1. Alluvial soils, formed from depositions on flat plains by 

 running waters ; 



2. Lacustrine soils, formed from depositions in lakes; 



3. Drift soils, formed from depositions by glacial agencies. 

 This classification can be considered only in a general way 



since the entire state, save a small area in the southeastern corner 



