VIII CONTENTS. 



Chaptee v. — Classiflcation and genesis — Continued. Page- 

 The till— Continued. 



Ground moraine , 277 



Drumlins 280- 



Relation to marine gravels 282 



BowVler fields and trains 284 



Was there more than one glaciation of Maine? 284 



Glacial sediments 291 



Relation of water to the glacier 291 



Sizes of the glacial rivers of Maine 292 



Zones of the Maine ice-sheet 294 



Englacial streams 296 



Directions of subglacial and englacial streams under existing glaciers 297 



Internal temperatures of ice-sheets 302 



Basal waters of ice-sheets - 30.5- 



Basa 1 furrows as stream tunnels 308 



Genesis and maintenance of subglacial and englacial channels 310' 



Forms of glacial channels 316 



Extraordinary enlargements of the glacial river channels 317 



Directions of glacial rivers compared with the flow of the ice 319 



Relations of glacial rivers to relief forms of the land 321 



Sedimentation in places favorable or unfavorable to the formation of crevasses 323 



Glacial rivers of Maine : Summary 324 



Glacial potholes 324 



Formation of kames and osars , 330 



Bowlders of the glacial gravels 333 



Remarks on the glaciation of the Rocky Mountains 338 



La Plata Mountains 338 



Las Animas Valley 340 



Upper Rio Grande Valley 343 



Valley of the San Miguel River 343 



Valley of the Uncompahgre River 344 



Upper Arkansas Valley 345 



Pikes Peak Range 348 



South Park 349 



Roaring Fork 349 



Rock Creek 350' 



Estes Park - 350 



Valley of the Salmon River, Idaho 351 



Moraines 352 



Glacial gravels 353 



Summary 354 



General summary of the Rocky Mountain region 354 



Glaciers of Alaska 355 



Overwash aprons 356 



Osar streams and osars 356 



Chapter VI. — Classification of the glacial sediments of Maine 359 



Preliminary remarks 359' 



Names 359 



Glacial gravels as modified by the sea 360 



Short isolated osars or eskers 361 



Hillside osars or eskers 364 



Isolated kames or short eskers ending in marine deltas 368 



Isolated osar-mounds or massi ves not ending in marine deltas proper 369 



Glacial marine deltas 371 



