ANDKOSCOGGIN LAKES PORTLAND SYSTEM, 227 



ice walls, so broad as to approach the character of a glacial lake. In the 

 valley of Range Stream, not far north of Poland Post-Office, the osar-plain 

 broadens somewhat, and becomes finer toward the north and east, passing 

 from gravel into sand, and finally into a clay plain, which extends north- 

 eastward and at Mechanic Falls joins the broad plain of clay covering 

 the Little Androscoggin Valley. Here, then, is a delta-plain Vv^here the 

 glacial river at one time flowed into the broad body of water which 

 occupied the valley of the Little Androscoggin after the ice had melted 

 to this point but still remained at Oxford. 



Approaching Poland Post-Office, the gravel becomes coarser for about 

 2 miles along the north side of the Lower Range Pond. Here are great 

 numbers of very round cobbles, bowlderets, and some bowlders. Then 

 the gravel becomes finer toward the southeast, and in the valley of the 

 Worthley Brook consists of a rather thin plain of sand, which has been 

 much eroded by the stream. 



A series of hills borders on the south the valleys of the Audi-oscoggin 

 and Little Androscoggin from Brunswick to Oxford. Four low passes 

 penetrate these hills. One leads from Dtu-ham south through Pownal, 

 one past Danville Junction, a third lies south from Oxford along- Thompson 

 Pond, and the fom'th is in the eastern part of Poland, leading along the 

 eastern base of the high granitic hills on which the Poland Spring Hotel 

 and the Shaker Village are situated. The osar-plain turns south along 

 the valley of Worthley Brook and penetrates the last-named pass. It is 

 here composed of rather fine drift, and is somewhat interrupted in the 

 jaws of the pass. Soon after entering New Gloucester the system expands 

 into plains from 1 to 3 miles wide, which extend southwai-d nearly to 

 Gray Village. The western portion of this large plain shows a rolling 

 surface and much coarse matter (cobbles, bowlderets, and bowlders). 

 Toward the east and south the surface is more level (except where there 

 are sand dunes) and the material is finer, passing at last into fine sand. 

 In the midst of the sedimentary plain are several hills covered with till. 



It will be seen that the eastern portions of the great plain of New 

 Gloucester and Gray present the characters of a delta. Their relations to 

 the marine clays are significant. Two bays of the sea once united at these 

 plains. A line of marine clays extends up the valley of the Presumpscot 

 River to Windham, and thence northeastward iip the broad A^alley of Pleasant 



