TABLE OF CONTENTS 



CHAPTER I 



PAGES 



SOME GENERAL CONSIDERATIONS 1-12 



Composition of the soil, 1 Factors for plant growth, 

 2 Plant food elements, 3 Abundance of plant food 

 elements, 4 Soil-forming rocks, 5 Soil-forming min- 

 erals, 6 Relative abundance of minerals, 7 Organic 

 matter, 8 The soil and the plant, 9. 



CHAPTER II 

 SOIL-FORMING PROCESSES ....... 13-30 



Water, 10 Wind, 11 Ice, 12 Heat and cold, 13 



Frost, 14 Plants and animals, 15 Oxidation and 

 carbonation, 16 Deoxidation, 17 Hydratkm, 18 

 Solution, 19 A general statement of weathering, 20 

 Factors affecting weathering, 21 Law of mineral and 

 rock decay, 22 Special cases of weathering, 23 Prac- 

 tical relationships of weathering, 24. 



CHAPTER III 



GEOLOGICAL CLASSIFICATION OF SOILS . . . 31-45 

 Residual soils, 25 Distribution of residual soils, 26 



Cumulose soils, 27 Colluvial soils, 28 Alluvial 

 soils, 29 Distribution of alluvial soils, 30 Marine 

 soils, 31 Characteristics of marine soils, 32 Distri- 

 bution of marine soils, 33. 



CHAPTER IV 



'GEOLOGICAL CLASSIFICATION OF SOILS (Continued) . . 46-64 



The ice sheet, 34 The American ice sheet, 35 

 Cause of the ice age, 06 The extension of the ice sheet, 

 37 The ice as a soil builder, 38 Glacial till soils, 39 

 vii 



