CONTENTS 9 



PAGE 



Mountain Glaciers 143 



Formation. Cirques. Origin of Cirques. Development of Cirques. Fate 

 of Cirques. Ablation. 



Surface of Mountain Glaciers 147 



Irregularities Due to Tension. Irregularities Due to Streams and Ice Tables. 



Movement of Glaciers 150 



Rate of Movement. Differential Movement of Glaciers. Factors In- 

 fluencing the Rate of Movement. Lower Limit of Glaciers. 



Transportation of Mountain Glaciers 154 



Surface Moraines. Subglacial Material. Englacial Material. 



Erosion by Mountain Glaciers 157 



Plucking and Abrasion. Effect on the Material Carried. Factors In- 

 fluencing the Rate of Erosion. 



Deposits of Mountain Glaciers 159 



Terminal Moraines. Submarginal Moraines. Ground Moraine. The 

 Work of Glacial Streams. 



Landscape Modified by Glacial Action 163 



Characteristics of Glaciated Valleys. Mature Glaciated Valleys. De- 

 struction of Features of Glaciated Valleys. Fiords. 



Piedmont Glaciers 167 



Continental Ice Sheets 168 



Greenland. The Antarctic Continent. 



Ancient Glaciation 171 



Deposition 171 



Bowlders. Unstratified Drift. Moraines. Terminal Moraines. Moraines 

 of the Last Great Ice Sheet in North America. Ground Moraine. 

 Drumlins. Stratified Drift. Outwash Plains. Terraces. Deltas. 

 Eskers. Kames. Relation between Stratified and Unstratified Drift. 



Erosion by Continental Glaciers 182 



Effect on the Underlying Rock. Modification in the Shape of the Hills. 

 Effect of Glaciation on Drainage. Lakes and Ponds. Rivers. 



Icebergs „ 188 



Formation of Icebergs. Size and Work of Icebergs. 



Glacial Movement 189 



Viscosity Theory. Expansion and Contraction. Regelation. Melting and 

 Pressure. Growth of Granules. 



CHAPTER VI 

 THE OCEAN AND ITS WORK 



General Character of the Ocean 194 



Topography of the Ocean Floor. Irregularities of the Ocean Floor. Com- 

 position of Ocean Water. Temperature of the Ocean. Distribution 

 of Marine Life. Age of the Ocean. 



