BY E. C. ANDREWS. 831 



platforms may be still further reduced. Until such time the 

 weapons of the '' record " gale, by their very mass, act as a 

 decided protection to the shoreline, and energy is confined to 

 rearrangement of smaller-storm debris and smoothing over of 

 major irregularities of shoreline contour. 



Similar reasoning applies to the action of the great storm in 

 handling vast areas of sand, thus modifying the coastal profile. 

 In this case it is the mass of sand capable of being moved in a 

 given time which enables work thus to be done that is not wholly 

 destro3^ed by successive years of interstorm activity. 



ii. Glaclation. — The Glacial Period marked an ice-flood or a 

 series of ic3-floods, during which huge basins, spurless walls, 

 terraced floors, hanging-valleys and cirques were formed. The 

 disappearance of the Ice Age would signify a glacial drought. 

 By analogy with ordinary stream-action, ice-stagnation would 

 characterise such reduced glaciers. Along the old flood-worn 

 channels the gravitative thrusts of these shrunken glaciers would 

 be expended before the deeper portions (basins) of the channel 

 leases were reached. These drought ice-streams then would be 

 competent only to rearrange the old flcod debris, and to round 

 over the moraines. Hence arise : — 



(a) Stagnating glaciers such as occur in the Muir and Melas- 

 pina localities. 



(b) Pronounced overriding of moraines b}' glaciers. 



(c) The peculiar appearance of drumlin areas. 



(d) The obliteration of smaller ice-flood action by great ice- 

 floods, on the assumption of stable equilibrium for the local land- 

 mass during such glacial action. 



Again, since maximum stream-thrusts are, from gravitative 

 considerations, extremely localised and depend on channel- 

 slopes and convergences, so glacial corrasion, as regards deep 

 basin-formation and spur-cutting, is of rare occurrence. A 

 Niagara, a Victoria, a Yosemite, or a Yellowstone waterfall is 

 rare, and determined by some marked channel-grade discordance, 

 whereby great velocity is attainable. So also the flood-glaciation 

 of Yosemite, Alaska, Norway and other regions of similar great 



