CHAPTER IX. 



TERMINAL MORAINES. 



Since the word moraine originally designates a consider- 

 able accumulation of glacial debris, it has been found impos- 

 sible to apply the term to the marginal deposits along the 

 whole boundary ; for, as was stated in the chapter treating 

 of the subject, the glacial margin in the Mississippi Valley is 

 not marked by such accumulations as characterize it east of 

 the Alleghanies. The glacial deposits south of New England 

 are, however, truly phenomenal in their extent, and can with 

 perfect propriety be called terminal moraines. Why glacial 

 debris should have accumulated to such an extent along that 

 line it is impossible to tell with certainty ; but, recurring to 

 the principles already presented, it would seem, not only that 

 such an extensive terminal moraine indicates an abundance 

 of easily disintegrated rock to the north offering itself for 

 transportation in the line of the glacial movement, but that 

 it also indicates that the ice-front remained for a long time 

 stationary in the latitude of New York between Nantucket 

 and the Delaware River. How much the proximity of the 

 ocean may have had to do with the maintenance of this sta- 

 tionary ice-front we may never fully determine ; but, both 

 by its natural effect in eroding the advancing ice-column, 

 and thus limiting its movement, and by its tendency to pro- 

 vide moisture to the clouds which furnished the glacier of 

 that whole region with its fresh supply of snow, the neigh- 

 boring waters of the Atlantic would seem to be an adequate 

 cause for the phenomenon. At any rate, in the hills of Cape 

 Cod, of Nantucket, of Martha's Vineyard, of the Elizabeth 



