InTAPLES STANDISH SERIES. 241 



of which once formed a dam across the Long Pond (here very narrow) and 

 raised it probably 20 or more feet above its present leveL The outlet of 

 the pond has in process of time eroded the obstructing ridge and lowered 

 the level of Long and Brandy ponds. All of these ridges at the outlet of 

 Brandy Pond (Songo Lock) are composed of coarse gravel with cobbles 

 and bowlderets. The distinctively glacial origin of these coarse sediments 

 is an additional proof of the glacial origin of the sand terrace at Naples 

 Village, which is connected by a continuous deposit of sand and gravel 

 with these osars. The osar-plain at Naples is remarkable from the fact that 

 it is composed of such fine material at its north end. Whether the system 

 extends northward under Long Pond is uncertain. There are small deposits 

 of sand and rolled gravel reported on the shore of the pond and on islands 

 in that direction, but I now regard them as probably being beach gravels 

 of the lake. 



At Songo Lock, at the south end of Brandy Pond, there are a few 

 ridges that have a northeast-and-southwest direction. They are arranged 

 transversely across the valley, as the moraines of a local glacier would be, 

 but on the surface they are composed of rounded gravel, and I consider 

 them probably kames, perhaps deposited by a short tributary. 



South of Songo Lock an osar extends nearly continuously to the north- 

 ern shore of Sebago Lake at a point a short distance west of the mouth of 

 Songo River, which forms the mouth of Crooked River. The ridge ends 

 in a cliff of beach erosion about 35 feet high. Part of the way south of 

 Songo Lock the ridge is flanked by outlying hummocks and by a rather 

 level plain resembling an osar-plain in external form. 



The evidence is thus conclusive that a large glacial river flowed south 

 into the basin of Sebago Lake. Numerous credible witnesses report the 

 northwest bay of the lake as being from 250 to 400 feet deep. Glacial gravel 

 reappears at Sandy Beach, on the western shore of the lake, about 3 miles 

 from where it disappears at the noith end of the lake. A narrow plain of 

 glacial gravel extends southward for several miles along the western shore of 

 the lake, soon expanding into extensive plains in Standish. These plains are 

 rather level, yet show some basins and reticulations. The glacial river must 

 have flowed across the deep basin of the northwestern angle of the lake. 

 A tongue of these plains extends southeastward to the south end of the lake, 

 where it expands into a rounded plain more than a mile in diameter. Next 



MON xxxiv 16 



