146 GLACIAL GRAVELS OF MAINE. 



Sebasticook River. Part, perhaps all, of these clays are marine, but the 

 estuarine, fluviatile, and lacustrine drift are all present in that region and 

 difficult to distinguish. On the slopes of rather low hills that border this 

 clay-covered plain on the south and east are several local kames. One of 

 these is situated in the southwestern part of Plymouth, at the southern end 

 of a hill bordered on each side by a low north-and-south valley. It ends 

 near the upper limit of the sedimentary clays. Two other deposits of 

 glacial gravel are found in the north-and-south valley of a small brook 

 flowing north into Carlton Stream. They are situated a short distance 

 north of Troy Center. Still another is found on the east side of a north- 

 and-south valley near Cooks Corner, about three-fourths of a mile Avest 

 of Troy Center. It is a short terrace, only a few rods long, about 40 feet 

 above the bottom of the valley and about midway up the slope. It has 

 been cut through by the road to a depth of several feet. On the south 

 side of the road the terrace is plainly stratified, the strata dipping down the 

 hill and transversely to the ridge. The different layers vary much in com- 

 position, some being fine sand, others coarse gravel and cobbles, slightly 

 polished and rounded. Near the surface the mass is pellmell in structure. 

 On the north side of the road, and only about 25 feet away, the Avhole 

 section exposed shows the pellmell structure. The separate pebbles and 

 cobbles are like those at the south side of the road in form, and the two 

 sections differ in structure only. Both have plainl)^ been water-assoi'ted 

 and the finer parts of the till have been washed away. It will be noted 

 that the pellmell layer at tlie south overlies the stratified portion. Appa- 

 rently a small kame was first deposited with a stratified structure, and 

 subsequently the advance of the ice pushed the sediments forward suffi- 

 ciently to mix up the several layers near the surface and destroy the 

 stratification. 



The hills extending from Palermo to Dixmont and Newburg rise 300 

 to 600 feet above the broad plain-like valleys of the Sebasticook and 

 Soudabscook, situated to the north of them. These hills would stop the 

 flow of ice southward during the final m.elti?^g of the great glacier long 

 before the ice had disappeared in the lowlands to the north. As the ice 

 gradually retreated northward, it would often happen that lakes would be 

 inclosed between the ice and the hills to the south of them. Within the 

 limited time these lakes were in existence no very large amount of sedi- 



