1:38 K. S. TARR — GLACIATION OF MOUNT CTAADN, MAINE 



But even without considering these latter causes for angularity of high 

 peaks, one does not need to marvel that an elevated mountain ridge, 

 narrow and projecting above the timber line, should have heen rendered 

 rugged by the rapid erosion which is in progress on lofty mountain tops. 



From the observations that have heen brought forward by different 

 observers, there appears no escape from the conclusion that an ice-sheet 

 moving from the north overtopped the highest peaks of the Adirondack-. 

 the loftiest mountains among the Green mountains, mount Washington, 

 mount Ktaadn, and all the lower mountains of northern New England. 

 Here is a perfect cordon of mountain peaks, a barrier to the on-moving 

 ice-sheet, but nevertheless overcome by it ; and it appears certain that 

 the facts which the Canadian geologists have brought forward must he 

 explained in some other way than by the elimination of the continental 

 glacier. I believe that its explanation is at hand, having been suggested 

 by Hitchcock, although little attention seems to have heen paid to the 

 suggestion.* 



Previous Announcements of Valley Glaciers 



A number of observers have presented evidence of former valley gla- 

 ciers among the mountains of New England, especially in the early days 

 of the study of glacial geology, though of late years very little work has 

 been done in that direction. Doubtless some of these early observations 

 were based on the confusion of deposits from the main ice sheet with 

 those from supposed valley glaciers; but other observations certainly 

 represent accurate correlation of glacial deposits with valley glaciers. 

 Among the suggestions of local glaciers in New England one of the very 

 earliest was that of Edward Hitch cock.f Professor C. H. Hitchcock J has 

 published further proof of ancient glaciers in Maine and Vermont. 

 In later publications § Professor C. H. Hitchcock has again and again 

 presented evidence of local glaciers in New England, and in his latest 

 paper, || in which he has once more called attention to the evidence of 

 glaciation in the Green mountains and the mountains of New Hampshire 

 and of Maine, he suggests the possibility of the contemporaneity of local 

 glaciers, from several large centers, with the " Champlain " depression 

 of the land in the Saint Lawrence valley. The work of Hitchcock in 



* Bnll. Geol. Soc. Am., vol. 7, 1896, pp. 3, 4. 



f Smithsonian Contributions, vol. ix, 1856, art. iii. p. L36. 



J Proc. A r. Assoc. Adv. Sci., vol. xiii, 1859, pp. 329-335. 



g Geology of New Hampshire, vol. i, 1874, pp. 539-544; same, vol. iii, 1878, pp. 181-340 ; Proe. Amer. 

 Assoc. Adv. Sci., vol. xxiv, part ii, 1875, pp. 92-96; Bull. Geol. Soc Am., vol. 7, 1896, pp. 3, 4; Pre- 

 liminary Report on the Natural History ami Geplogy of Maine (Sixth Ann. Kept. Maine Board of 

 Agriculture, 1861), p. 393. 



|| Bull. Geol, Soc. Am., vol. 7, 18%, pp. ;s, 4. 



