CAMBEIDGE-HARMONT GRAVELS. 159 



unless the plain in Cambridge and Harmony, soon to be described, was 

 formed by a remnant of this glacial river which still continued to flow 

 after the ice in the main Sebasticook Valley had disappeared but while the 

 ice still lingered north of Moose Pond 



The length of the system is 45 miles. 



CAMBBTDGE-HAEMONT GRAVELS. 



A series of low sand-and-gravel ridges, or narrow plains, extends from 

 near Main Stream in Cambridge northward past Cambridge Village and 

 then for 2 or 3 miles into the southwestern part of Parkman. The stones 

 are barely rounded on the angles, and in general the gravel is fine. On the 

 south the series spreads out into a sand plain in the Main Stream Vallej^. 

 This plain appears to have been deposited in the valley after the ice had 

 there melted, though still remaining northward; yet the sand ma}^ have 

 been laid down in a glacial lake. The currents which assorted these sedi- 

 ments were rather gentle, and probably the formation dates from a verj^ late 

 portion of the Glacial period. 



Another ridge is found near the line between Harmony and Cambridge, 

 ending in the south near the northern shore of a large pond above Main 

 Stream Village. Toward the south the material becomes fine, consisting of 

 sedimentary clay overlying fine sand. 



A short gravel deposit is found near Main Stream about a half mile 

 south of Main Stream Village. 



A gravel plain, probably glacial, is found in the south part of Har- 

 mony, in the valley of a small stream. It resembles an osar-plain. It is 

 possible that this extends northward past Harmony Village. I have note 

 of sand and clay in the valley of the Sebasticook above Harmony, and they 

 may be of glacial origin in part. 



Probabl}^ a large area in Cambridge, Parkman, Wellington, and Har- 

 mony was at one time di-ained of its glacial waters by the large glacial river 

 which flowed from Moose Pond south past Hartland. But if so, the proof is 

 not easily derived from the distribution of the gravels. The gravels in 

 this region seem to date from a late period, when the ice had retreated 

 north of Moose Pond, and the glacial streams wei'e in fact soon discharged 

 beyond the ice front into the open valleys. 



