TROY-BELFAST SYSTEM. 143 



gravel disappears is a cone of gravel and cobbles 80 feet high. The Brooks- 

 Belfast and Troy-Belfast systems are both so situated that this short glacial 

 river might connect with either of them, but I have not been able to trace 

 any connection with them. The clay in the valley of Martin Stream 

 overlies these gravels; hence the flow of this glacial stream dates previous 

 to the time when the terminal delta of the Corinna-Dixmont system was 

 deposited in a body of water then filling this valley. 



This short series does not have a wholly satisfactory beginning or end, 

 but I have not been able to trace any connections with other gravels. It 

 may at one time have been part of the Corinna-Dixmont system. 



The length is about 3 miles. 



TROY-BELFAST SYSTEM. 



This system appears to begin about one- half mile south of the road 

 from West Troy to Troy Post-Office (Troy Corner), as a low, north-aud- 

 south ridge, which shows numerous meanderings. It lies in a region of 

 rather low hills, forming a rolling plain lying north of the much higher hills 

 of southern Troy and of Thorndike. At the northern base of these high 

 hills this ridge is joined in the southern part of Troy by a rather level 

 gravel plain from the west. It is nearly one-fourth mile in length and per- 

 haps half as wide. This appears to be a delta, either of a lake wholly 

 glacial or of a lake confined between the ice on the north and the hills on 

 the south. The gravel system then crosses a low divide in a narrow pass 

 and follows the valley of Parsons or Halls Brook for 2 miles southwestward. 

 It then abandons this valley and follows a low pass into the valley of 

 Higgins's Stream. It follows this valley southward for several miles, passing 

 about one-half mile west of the Friends' Meeting House in Thorndike. It 

 leaves this valley not far from Thorndike Corner, and by a crooked route 

 penetrates the hilly region of eastern Knox and the northwestern part of 

 Brooks, crossing several pretty high hills. It then follows the valley 

 of Marsh Stream, parallel with the railroad, to a point about 1 mile west of 

 Brooks Village, when it turns southward along a low valley. It soon goes 

 up and over a hill 100 or more feet high and descends to Passagassawawkeag 

 Pond. From this point south its course lies in a rather level region in 

 Brooks and Waldo. In Waldo it expands into a rather level plain several 

 miles long and one-eighth of a mile or more in breadth. The material 



