442 R. S. TARR — GLA.CIATION OF MOUNT KTAADN, MAINE 



cier. This close resemblance suggested to me that the walls of the South 

 and North basins were just recovering from the blanket of snow which 

 is the immediate successor of the dying valle} T glacier. 



A second and more definite class of evidence of valley glaciers is the 

 moraine deposit. This is very much more clearly shown in the North 

 than in the South basin, because of the absence of trees in the former. 

 The entire basin away from the inclosing walls is occupied by a distinct 

 hummocky moraine (see plate 35), with kettles, in at least two of which 

 there are ponds. This moraine is strewn with bonlders, nearly all of 

 which are of the Ktaadn granite, the number of foreign fragments being 

 exceedingly limited. The resemblance between this moraine and that 

 of Dogtown Common, Cape Ann, Massachusetts* is very striking. 



There is also a well defined lateral moraine upon the southern side, 

 where it stands as a bench against the granite wall of the basin, above 

 which the bare rock of the mountain is clearly seen. This lateral mo- 

 raine merges into what appears to be a medial moraine, extending into 

 the forest and joining with a lateral moraine from the South basin. The 

 denseness of the stunted tree growth at this place, and the difficulty of 

 travel through it made it impossible. to determine the nature of this 

 ridge with certainty ; but its position and form suggest a medial moraine, 

 and its association with other evidences of valley glaciers was such as 

 to make this determination almost certain. Upon the north side of the 

 North basin the lateral moraine is not well defined within the basin 

 proper, although a distinct ridge is traceable from near the mouth of the 

 basin out into the forest. Although very high, almost too high for such 

 a moraine, this does not appear to be a rock ridge, nor is it in line with 

 the undoubted rock ridges of the basin. I should not wish to pronounce 

 it positively a lateral moraine, though I fail to see any other explana- 

 tion for it. 



In the South basin the tree-cover prevented the clear recognition of 

 moraines in a part of the basin ; but enough could be seen to prove that 

 it has an irregular, hummocky floor, largely composed of boulders of 

 Ktaadn granite. 



Near the basin entrance, just below the Basin pond, which is in one 

 of the kettles, there is a " dry pond," in which the evidence of moraine 

 form is clearly shown (plate 36). The low hills inclosing this dry pond 

 are rugged, and, so far as the surface shows, composed almost entirel} 7 of 

 boulders (see plate 37), so that traveling over it is exceedingly difficult, 

 some of the boulders attaining a very large size. The "dry pond " is a 

 kettle in the midst of these boulder-covered hills, and that its bed is 



♦ See Shaler : Ninth Annual Report V. S. Geol. Survey, p. 546 ; Tarr : Amer. .lour. Sei., vol. cxliii, 

 1892, p. 141. 



