244 SURFACE GEOLOGY. 



railroad cuts into it, rising somewhat. At the excavation, the nature of 

 the material is well shown, consisting of smooth boulders, from pebbles 

 to boulders two and three feet in diameter. The bed of the river shows 

 similar detritus. The stream is so violent in high water that these boul- 

 ders are pushed downwards, and as the force of the current abates the 

 detritus accumulates by the sides. The amount brought down is so 

 great that it rises higher than the meadow, and thus we have a deposit 

 analogous to that of the levee near the mouth of the Mississippi. The 

 tributary stream causes this very coarse deposit to form a ridge reaching 

 nearly across the Saco valley, and at right angles to it. Hence it simu- 

 lates the terminal moraine of a glacier, and might easily be mistaken for 

 one, if the connection between its presence with the tributary were not 

 noticed. 



Below Sawyer's rock this coarse material exists in such amount that it 

 is difficult to decide whether it should be called a glacial or a river mo- 

 raine. The rubbish has accumulated in the eddy behind the ledge, and 

 can be called by either name. It must be 50 feet thick, and cover half a 

 square mile of surface. It seems to have been excavated at Stillings's 

 old hotel stand by Albany brook from the south, and the moraine be- 

 tween this stream and Upper Bartlett station is of large size. The rail- 

 road cuts through a similar bank on the north side of the Saco, about 

 opposite the mouth of Stony brook in Hart's Location. 



I have already mentioned a fev/ examples of stri^ on the ledges in the 

 valley of Saco river and its tributary. Duck pond, which are referable to a 

 local glacier. Through most of Bartlett the land is flat, as if all the rub- 

 bish that usually occurs in the form of terraces had been washed out. 

 The soil is sufficiently good to enable farmers to cultivate it extensively. 

 For a mile and a half along Burbank and Cow brooks, there is a ridge of 

 coarse material comparable with a lateral moraine. It is where detritus 

 would be naturally deposited, as the river begins to bend northwardly. 

 Where the Saco runs northerly to meet Rocky branch is another mo- 

 raine pile, at the angle formed by the meeting of these two streams. 

 Below this point the valley widens into the broad gravelly meadows of 

 Lower Bartlett and Conway, which have been previously described 

 (p. 143). Dr. Bemis points out at the base of Mt. Crawford a granite 

 block, as much as 12 feet in cubical dimensions, now in the middle of 



