GLACIATION IN OHIO 



Introduction 184 



Margin of the ice sheet 



How this ice was formed 



How glacier ice moves 



The work done by glaciers - 190 



Erosion by glaciers 190 



Contrast between glaciated and unglaciated regions 



Tools of glacier ice 



Evidences of erosion 

 Deposition by glaciers 194 



Simplest condition of glacial accumulations 



More complex conditions of a continental ice sheet 



Terminal moraines, retreatal moraines, morainic loops 



Glacial deposits in valleys 



Outwash plains 



Eskers 



Valleys leading away from the ice 



Lake deposits 

 Effects of glacial action . . .' 199 



When relief is increased 



When relief is decreased 



Glacial topography 



Drainage changes 

 Cause of glacial period 202 



Former high altitude of continent 



Change in position of the earth's poles 



Change in eccentricity of the earth's orbit 



Variation in content of the earth's atmosphere 

 Complexity of the Pleistocene glacial period 206 



Pleistocene stages 

 Other glacial periods 207 



Evidences of earlier periods 



Proterozoic glaciation 



Cambrian glaciation 



Permian glaciation 



Conclusions 

 The glacial deposits of Ohio 212 



Glacial lobes in Ohio 



Ice lobe margins 

 Ice front lakes 214 



Lake Maumee 



Lake Whittlesey 



Lake Warren 



183 



