184 GLACIAL GRAVELS OF MAINE. 



well-developed beach in this region. It is therefore evident that the deep 

 sheet of clay northwest of Angusta represents eroded till in only a small 

 proportion, but was chiefly composed of the mud brought into the sea by 

 the glacial river at the delta of Augusta and Belgrade above described. 



NORTH POND BRANCH. 



A north-and-south ridge of glacial gravel crosses North Pond in the 

 northeast part of Rome. It nearly divides the pond into two parts. Its 

 connections are unexplored. Probably it is a branch of the Belgrade sys- 

 tem, 3^et it mav urove to be a local deposit. 



MERCER-BELGRADE BRANCH. 



An irregular mound of glacial gravel 80 feet high and one-eighth of a 

 mile in diameter is found not far south of Mercer Village, at the northeast 

 base of Hampshire Hill. A neaidy north-and-south valley in Mercer, 

 Eome, and Belgrade extends for several miles along the eastern base of 

 this high hill, and in this valley two streams take their rise, one flowing 

 north to Mercer Village, the other south and west into Belgrade Great 

 Pond. A well-defined gravel series extends along this valley, now takmg 

 the form of terraces near the base of the hill and now appearing as a two- 

 sided ridge in the midst of the valley. The ridges are 10 to 20 feet in 

 height — nowhere so high as the large hummock at the north end of the 

 series. The series does not expand into a delta-plain near Belgrade Great 

 Pond, into which it runs from the north, making it probable this was a 

 tributary of the Belgrade system. At the southwest angle of this pond 

 a short gravel ridge, which is in a line with the Mercer-Belgrade series, is 

 found, about half a mile west of the main system, which maj be a part 

 of the Mercer series. 



The valley along this gravel series is deeply covered by sedimentary 

 sand and clay, which on the north is continuous with the broad alluvial 

 plain of the Sandy River Valley, and on the south there is a line of similar 

 clays along the outlet of Belgrade Great Pond all the way in its circuitous 

 route to Messalonskee Pond, near Belgrade station. There seems to have 

 been an overflow of the great Sandy River estuary this way, and previous 

 to the melting of the ice there may have been some border clay deposited 

 along the flanks of the gravel ridges. This makes the problem of the clays 

 of this valley rather complex. 



