AREAS OF DRUMLINS IN NORTH AMERICA. 19 



like those of the ensuing Champlain epoch, to which the drumlins and 

 marginal moraines chiefly belong. By the depression of the land and 

 consequent return of a temperate climate the ice was rapidly melted 

 away, with steeper frontal gradients, more powerful currents, and more 

 vigorous drift accumulation in the drumUn and moraine hills than during 

 the earlier and longer part of the Ice age, while the land had a high alti- 

 tude and severely cold climate. 



Greenland now in a considerable degree represents the time of growth 

 and maximum extent of the Pleistocene ice-sheets ; but Alaska, with its 

 generally receding gla»ciers, and most notably the Malaspina ice-sheet, 

 having a drift-covered and forest-bearing border, partially illustrates the 

 conditions of the Champlain epoch. 



North American Areas of Drumlins. 



Besides the frequent arrangement of the drumlin hills and ridges of 

 till in groups and somewhat definite belts, which are from a few miles to 

 10 or 20 miles wide, lying approximately parallel with the general course 

 of neighboring marginal moraines, while intervening belts or irregular 

 areas are destitute of drumlins, a still more noteworthy feature of their 

 geographic distribution is found in their occurring thus upon some ex- 

 tensive districts, while they are utterly wanting on larger portions of the 

 great glaciated areas of North America and Europe. 



Mr Robert Chalmers has observed numerous drumlins on the east side 

 of lake Utopia and between the Magaguadavic and Saint Croix rivers in 

 Charlotte, the most southwestern county of New Brunswick.* Under 

 the name " whalebacks," Mr G. F. Matthew describes these and other 

 drumlins in the southern part of this province on an area extending from 

 the Saint Croix about 90 miles east to Upham township.f 



Drumlins are reported in Maine by Professor George H. Stone, the 

 lenticular type prevailing in the western part of the state, while toward 

 the east they also take the form of long ridges. In size and numbers, 

 however, they are described as inferior to the drumlins of New Hamp- 

 shire, Massachusetts, and New York.J 



The earliest mapping of drumlins in this country was done by the 

 writer in 1878, under the direction of Professor C. H. Hitchcock, for the 

 Geological Survey of New Hampshire. § Nearly 700 drumlins were noted 

 in the southern half of this state, but throughout its northern half these 

 drift accumulations are absent or very rare. Some 130 drumlins in adja- 



*Geol. and Nat. Hist. Survey of Canada, Annual Report, new series, vol. iv, for 1888-89, p. 23 N. 

 tGeol. and Nat. Hist. Survey of Canada, Report of Progress for 1877-78, pp. 12-14 EE. 

 I Proc. Bos. Soe. Nat. Hist , vol. xx, 1880, p. 434. Proceedings of the Portland Society of Natural 

 History, March 11 and Nov. 21, 1881. 

 § Geology of N. H., atlas and vol. iii, 1878, pp. 285-3C9, with heliotype. 



