116 GLACIAL GEAVBLS OF MAINE. 



the Mattamiscontis Valley. I provisionally include this short osar among 

 the tributary branches of the Katahclin system. 



MILINOKET LAKE-HOWLAND BRANCH. ■ 



This, perhaps, ought to be considered as the main branch of the 

 Katahdin system. 



A series of gravel ridges is reported by J. W. Sewall, C. E., of Old- 

 town, as beginning near the West Branch of the Penobscot River at the 

 mouth of Katahdin Stream and extending eastward along the valley of 

 Aybol Stream for several miles. My information is conflicting and rather 

 indefinite as to the region from the head of Aybol Stream eastward to Mili- 

 noket Lake. On a down slope the glacial stream must have continued its 

 flow through that region, but if it left any gravels in its channel they seem 

 to have been scanty and discontinuous, just as happens on most steep down 

 slopes in the State, and not to have attracted the attention of my informants. 

 South of Milinoket Lake a neaidy continuous osar extends along the valley 

 of Milinoket Stream to the West Branch of the Penobscot River, at the 

 east end of the enlargement of the river known as Shad Pond. At this 

 j)oint the ridge contains numerous highly rounded pebbles and cobbles, 

 showing that it must extend for a long distance northward. It is not a large 

 ridge, and numerous hummocks rise above the rest of the low ridge. The 

 course of the osar lies obliquely across Shad Pond for about a mile, as is 

 proved by islands of gravel rising above the water. It soon leaves the 

 valley of the Penobscot and follows the Nollesemic Stream past the lake of 

 that name, and then, penetrating a low pass, it extends southward near the 

 Seboois River for many miles. The ridg-e is well developed almost all the 

 way. Near the Piscataquis River it does not show above the marine sedi- 

 ments and valley drift, and it has been either washed away or covered out 

 of sight by the clays, or the gravel may never have been deposited in this 

 part of the channel of the glacial river. This glacial river certainly crossed 

 the Piscataquis Valley, for the gravel ridge begins again a short distance 

 south of that river and continues southward through Edinburg and Argyle 

 as a low ridge rising only 10 to 30 feet above the marine clays. It then 

 turns southeastward, crosses the Penobscot River at Olamon Island, and 

 soon spreads out into broad, rather level, plains as it ajDproaches Greenfield. 



This glacial stream is pretty long, but, judging from the amount of sedi- 



