88 GLACIAL GRAVELS OF MAINE. 



the retreat of the ice northward, and the glacial stream which deposited it 

 was soon terminated by flowing into the sea. 



WILDERNESS REGION NORTH OF COLUMBIA, COLUMBIA FALLS, AND 



JONESBORO. 



We now approach a region very difficult to investigate. The gravel 

 deposits situated in it are vast, being equaled only by the great plains of 

 the southwestern part of the State. The western part of Washington County 

 and the eastern part of Hancock County are mostly wooded. There are 

 many swamps impassable in summer or penetrated with difficulty. There 

 are only four continuous east-and-west roads crossing the great region lying 

 south of the railroad from Mattawamkeag to Vanceboro. These roads I 

 have traversed, and have penetrated the wilderness in several other direc- 

 tions. In addition, I have derived much information from lumbermen and 

 explorers and from thi-ee experienced land surveyors — Mr. F. I. Campbell, of 

 Cherryfield; Mr. J. R. Buckman, of Columbia Falls, and Mr. H. R. Taylor, 

 of Machias. I am indebted to Mr. Taylor for quite an elaborate map of 

 this region. As a result of my observations and inquiries, it is hoped that 

 the map (PI. LI) contains all the larger systems of glacial gravel, but as to 

 the details of their courses much remains to be done. 



The sea at one time extended northward up the Machias Valley to the 

 Air Line road from Calais to Bangor, in Wesley, and probably a few miles 

 farther. Machias Bay was then a pretty broad body of water, in places 10 

 or more miles broad. This gave great force to the waves, and sea beaches 

 are found as far north as Wesley. The necessity of distinguishing these 

 beach gravels from the glacial gravels in this wooded country, where the 

 whole is often disguised by marine clays and the peats of swamps, compli- 

 cates considerably the problem of the drift of this valley. The till is very 

 heterogeneous in its composition, fragments of slates, schists, and granite 

 being rather indiscriminately mixed. The granite is partly derived from 

 local bosses of that rock which rise in the midst of the slates and schists, 

 but chiefly from the great area of granite Avhich extends from Orland to 

 Aurora and thence northeastward past the region of the great Schoodic 

 Lakes. Heaps and trains of granite bowlders abound. Many of the 

 granite stones of the till are so rounded by the glacial attrition that it often 

 requires close study to distinguish the till from a slightly water-washed 



