

LIST OF ILLUSTRATIONS 



PAGE 



Distribution of Petroleum and Natural Gas Fields in the United States, 55 



Animal Production of Petroleum, 1S59 to 1910 56 



Distribution of Coal Fields in the United States 59 



Average Yearly Production of Coal in decades for the United States, 60 



Average Yearly Production of Coal in decades for Illinois '. 61 



Cedar Valley Limestone (1) 98 



Cedar Valley Limestone (2) 98 



Spring Basin 110 



Gulley cut through tufa deposit 110 



Map of Earthquake of January 2, 1912 112 



Grove of White Pine on Pine Creek 122 



Bluff overhanging Pine Creek 122 



Evaporation Power of Air in Depression in Oak-Hickory Forest 129 



Evaporation Power of Air in grazed and undisturbed forest 131 



Average Evaporating Power of Air 132 



Range of Soil IMoisture in Depression in Oak-Hickory Forest 134 



Range of Soil Moisture below Surface in Forest 135 



Range of Soil Moisture below Surface in Grazed Forest 136 



Evaporation and Soil Moisture 139 



Range of Soil Moisture in Cottonwood Dune 140 



Cottonwood with roots uncovered by wind 140 



Pool in Dune 142 



Dune Moving Across Calumet Lake 140 



The Formation of Dunes 142 



Diagram of the La Salle Anticline 90 



Diagram 92 



Cross Section for Northern Illinois from Rock Island to Joliet along 



the line of the Chicago and Rock Island Railroad 94 



