200 GLACIAL GRAVELS OF MAINE. 



common and probably has a connnon origin. If so, a glacial river once 

 flowed through the upper Sandy River Valley to near Farmington Falls, 

 and thence southward, and was a part of the Chesterville-Leeds system. 

 It deposited a somewhat discontinuous osar-plain along this route. Subse- 

 quently, as the ice melted, a great quantity of frontal matter was poured 

 out into the open Sandy River Valley in front of the retreating glacier. 

 The floods now more or less washed away and reclassified the previously 

 deposited glacial gravels, and flanked and covered them with later sedi- 

 ments. The finer matter, being carried southward, formed the great sed- 

 imentary plain that borders the Sandy River from near Farmington to its 

 mouth, and also furnished the sediment for the overflows through Mercer 

 and Norridgewock to the Kennebec River, also that through Chesterville 

 to the Androscoggin, and thereby helped to form the broad clay-and-sand 

 plains of Chesterville, Jay, East Livermore, Leeds, Greene, etc. In other 

 words, these great clay plains situated above 230 feet are frontal plains, com- 

 posed of the glacial mud poured out from the diminished glaciers which 

 yet lingered in some of the larger valleys in this region and covered nearly 

 all the country situated 20 to 30 miles to the north. This was the chief 

 orio-in of the mud, no matter at what elevation the sea stood at this 

 distance from the coast. At the place of deposition this fine sediment now 

 forms a part of the valley sediments.^ 



FREEPORT SYSTEM. 



This is a short system appearing to begin in Brunswick near the 

 southern brow of a broad hill of granite, a short distance southeast of 

 South Durham. For about a mile it is a nearly continuous ridge with a 

 meandering course and obscure stratification. The gravel here is but little 

 waterworn and has a morainal aspect. Going southward, we find the stones 

 more rounded and the series becomes discontinuous, consisting of short 

 ridges one-half mile or less in length and separated by intervals of varying 

 length up to 2 miles. One ridge of the series is found in Freeport Village, 

 near the railroad station. The size of the ridges and hummocks of the 

 series decreases toward the south. The last of the series seems to be a small 

 bed of gravel situated about a mile southwest of Freeport Village. Except 



' The sea may liave reached to Farmington, and these great plains be in large part fluviatile 

 marine deltas. This I now (1893) consider probable. 



