Distribution of Moraines. 185 



below the snow-line removes the ice and leaves the rocks. In 

 this manner the stones previously concealed in the neve are con- 

 centrated at the surface, and finally form sheets of debris many 

 miles in extent. So far as my observations go, there is nothing 

 to indicate that stones are brought to the surface by any other 

 means than the one here suggested. Upward currents in the ice 

 that would bring stones to the surface have been postulated by 

 certain writers, but nothing sustaining such an hypothesis has 

 been found in Alaska. 



The moraines on the lower extremities of the Alpine glaciers 

 may frequently be separated into individual ridges, which in 

 many instances would furnish instructive studies ; but in no case 

 has the history of these accumulations been worked out in detail. 



With the appearance of moraines at the surface come a great 

 variety of phenomena due to unequal melting. Ridges of ice 

 sheathed with debris, glacial tables, sand cones, etc., everywhere 

 attract the attention ; but these features are very similar on all 

 glaciers where the summer's waste exceeds the winter's increase, 

 and have been many times described. 



The general distribution of the moraines of the lower portion 

 of the Alpine glaciers of the St. Elias region merits attention. 

 The moraines themselves exhibit features not yet observed in 

 other regions. From Disenchantment bay westward to the 

 Seward glacier the lower portions of the ice-streams are covered 

 and concealed by sheets of debris. About their margins the 

 debris fields support luxuriant vegetation, and not infrequently 

 are so densely clothed with flowers that a tint is given to their 

 rugged surfaces. On the extreme outer margins of the moraines 

 there are sometimes thickets and forests so dense as to be almost 

 impenetrable. The best example of forest-covered moraines 

 resting on living glaciers, however, is found along the borders of 

 the Malaspina ice-field. 



Piedmont Glaciers. 



This type is represented in the region explored by the Malas- 

 pina glacier. This is a plateau of ice having an area of between 

 500 and 600 square miles, and a surface elevation in the central 

 part of between 1,500 and 1,600 feet. It is fed by the Agassiz, 

 Seward, Marvine, and Hayclen glaciers, and is of such volume that 



