CLINTON-ALNA SYSTEM. 169 



thei'e is an interval of a mile or more without gravel, and then a discontin- 

 uous series of short and not very broad ridges, which extends from Alna Post- 

 Office (Head of the Tide) southward to Sheepscot Bridge, lying most of the 

 way along a valley situated west of the Sheepscot River. A short distance 

 north of Sheepscot Bridge the glacial river turned abruptly east and flowed 

 up and over a hill, and then descended into the valley of the Sheepscot 

 River, where the gravel becomes a little broader. Thence a series of low 

 mounds and short ridges is found near the river to a point about half a 

 mile south of Sheepscot Bridge, where the system ends at the shore of 

 Sheepscot Bay. Like many other systems, the mounds of gravel become 

 smaller toward the south. I explored the country in Newcastle and Edge- 

 comb lying south of where the system disappears. There are many old 

 beaches in the region, but no glacial gravels were found. 



At three places this large glacial river deposited deltas in the sea. 

 These are situated near the line between Alna and Whitefield, in the cen- 

 tral part of Windsor, and possibly another at Chadwicks Corner, in the 

 south part of China. Perhaps near the top of the hills in the southern part 

 of Clinton the system was above the sea, but in all the rest of its course it 

 lies in a country covered by the marine clays. No system in the central 

 part of the State contains so much gravel as this. 



Its length is 45 or more miles. 



ALBION BRANCH. 



A series of short ridges, separated by intervals of half a mile to more 

 than a mile, begins about 1^ miles northwest of Albion Village, and takes 

 a course south and west to join the main system aboiit a mile north of 

 China Village. Toward the north the gravel is but little water washed ; so 

 the series probably does not extend far in that direction. 



WINSLOW-WINDSOR BRANCH. 



A discontinuous series of short ridges begins about a mile south of the 

 Sebasticook River in Winslow and extends southward along the crest of 

 the hills bordering the valley of Outlet Stream on the east. It thence 

 extends southward past East Vassalboro and near the northeast angle of 

 Webber Pond; thence southeastward to the head of Threemile Pond; 

 thence across this pond and in nearly a straight line to a point about 2 

 miles north of Windsor Village, where it joins the main system. 



