244 GLACIAL GRAVELS OF MAINE. 



the eastern part of Gorham and in Scarboro may have been deposited 

 by the glacial streams that formed the plain at the foot of Sebago Lake, 

 but more probably, if those gravels have any connections, they will be 

 found in the direction of Windham. 



SEBAGO SERIES. 



A well-defined but somewhat discontinuous series of g'lacial gravels 

 extends for several miles along the valley of Northwest River in Sebago, 

 and joins the Naples-Standish series at East Sebago. In the northwestern 

 part of their course these gravels take the form of short ridg'es, but for 

 several miles above East Sebago they take the form of a broad osar of 

 fine gravel and sand, now much eroded. This series is probably dl^e to an 

 overflow from the direction of Grreat Hancock Pond, as will be described 

 in connection with the following series. Further description of the plains 

 extending from East Sebago into Standish and Baldwin will also be 

 given later. 



BRIDGTON-BALDWIN SERIES. 



This important series appears to begin in Sweden as a small ridge of 

 subangular gravel and cobbles situated in the valley of a small stream 

 which flows southward into Highland Lake. The ridge is on the side of a 

 steep hill 20 or more feet above the stream, and there is no corresponding 

 ridge or terrace on the opposite side of the valley. It must therefore be 

 glacial gravel. Several Islands in Highland Lake (Crotched Pond) show 

 water-washed gravel, probably glacial. A short distance from the south 

 end of the lake one of these islands is covered with gravel which is quite 

 certainly glacial, while a large and broad osar ridge comes out of the 

 water at the south end of the lake, forming in part the barrier which 

 dammed back the waters of the lake. It thus appears probable that a 

 single glacial river flowed from Sweden southward across the basin of 

 this lake. 



A series of low ridges and hummocks extends from the lake "south- 

 ward through Bridgton Village, and then for about 10 miles the series fol- 

 lows the very low valley along which is constructed the Bridgton and 

 Saco River Railroad. Excavations in Bridgton A^llage show pretty well- 

 rounded, glacial gravel overlying till, and a gradual transition between 

 them. In several places this series takes the form of an osar-ridge of coarse 



