72 GLACIAL GEAVBLS OF MAINE. 



DYER PLANTATION SYSTEM. 



An osar from 20 to 40 feet high extends from near the mouth of Big 

 Simsquish Stream southward nearly parallel with the St. Croix River for 

 about 3 miles, in Dyer Plantation, Washington County. It then takes 

 the form of somewhat discontinuous low bars and terraces, which perhaps 

 are a poorly defined osar-plain. ' This extends past the enlargement of the 

 St. Croix River known as Loon Bay to the mouth of the Canoose Stream, 

 where the system crosses into New Brunswick and sends out two tongues 

 of sand and gravel for about 6 miles southeastward, one on each side of 

 Basswood Ridge. I saw, in 1879, only a portion of these plains. They 

 appeared to be rather level on the top, with the exception of a few two- 

 sided ridges here and there rising above the rest of the plain. They present 

 the external features of a delta-plain, either marine or deposited in a glacial 

 lake. 



For several miles above the mouth of Little Simsquish Stream 1 could 

 find no glacial gravel on the west side of the St. Croix, but could see across 

 the river on the Canadian side considerable gravel of some kind in the form 

 of terraces. For about 1 mile above the mouth of Scotts Brook the gravel 

 near the St. Croix was very nearly in shape that of tillstones. This makes 

 it highly probable that the Vanceboro system does not continue in the St. 

 Croix Valley below the mouth of Trout Brook so as to connect with the 

 Dyer system. I could find no trace of this glacial river to the north or 

 west of the mouth of Big Simsquish Stream, unless a small plain covered 

 by a thin sheet of sand may have been deposited by it. This plain is over- 

 grown with pines, and is situated not far from Scotts Brook, about halfway 

 from Lambert Lake to the mouth of that stream. The country is a dense 

 wilderness, and one might pass very near a large osar and not see it. 



The osar in Dyer contains many rounded bowlderets and some bowl- 

 ders. In many places the lateral slopes are very steep. According to 

 Anson/ the elevation of the head of Canoose Rips is 211 feet; that of the 

 foot of Rocky Rips, near the north end of the Dyer osar, as here described, 

 is 227 feet. The plains of the Canoose Valley and those near Basswood 

 Ridge are thus shown to be not far above the highest of the beaches. 



1 The Water Power of Maine, by Walter Wells, p. 115, Augusta, 1869. 



