274 GLACIAL GRAVELS OF MAINE. 



Waldoboro moraine. The phenomenon of crag and tail is very common 

 in those ^jarts, but I have discovered no lateral or medial moraines proper 

 in any of the larger valleys, and I have crossed them all. The liills are 

 not precipitous nor very steep, at least they do not prove so to the Maine 

 farmer who has much of their surface under cultivation. These conditions 

 make it improbable that any considerable amount of moraiual matter got 

 upon the ice by sliding' froni the hilltops at the time the hills were bare and 

 glaciers still filled the valleys. 



The argument, then, stands thus: The moraine is not composed of pre- 

 viously^ deposited till plowed up and pushed before it by the snout of the 

 g-lacier. Neither can it contain much if any matter precipitated upon the 

 ice from above. It is a fair inference that the moraine consists chiefly or 

 wholl}' of matter which had previously got up into the lower part of the 

 ice from below. A part of it may have been on the surface of the ice at 

 the time the moraine was being- formed, but if so it was because it had been 

 laid bare by the melting- of the ice above it. The composition of the 

 moraine proves that debris of all degrees of fineness, from the finest clay 

 and dust up to the largest bowlders, were contained in the lower part of the 

 ice. True, the moraine at the excavations near Winslows Mills is some- 

 what more sandy than the average upper till of the locality, but this can be 

 easily accounted for if we assume that it was deposited in the sea at the 

 front of the ice, or became somewhat water washed by the terminal melting. 

 Onl}^ a few of the stones of the moraine are distinctly scratched, in which 

 respect they are like the stones of the upper part of the till. In n word, 

 the material is the same as found in the upper portion of the till of that 

 region. The structural difterence consists in the fact that we have here 

 piled in a single ridge material which during- a gradual recession of the ice 

 fi'ont would be scattered as a sheet over a zone a half mile, more or less, in 

 breadth. 



MORAINES OF ANDROSCOG-GIN GLACIEB. 



The basal character of the drift is also seen at the terminal moraine of 

 the local Androscoggin glacier. This glacier formed terminal moraines 

 near the line between New Hampshire and Maine. PI. XXV, B, shows 

 the moraine on the north side of the river rising on the slopes of Hark Hill. 

 If it carried surface moraines, the glacier ought to have deposited contem- 

 poraneously with this moraine a lateral moraine comparable with it in size. 



