38 GLACIAL GRAVELS OF MAINE. 



systems receive branches which converge toward the south, like the tribu- 

 taries of ordinary rivers flowing- in that direction. This sort is especially 

 noticeable in the eastern part of the State. (2) Delta branches. Systems 

 often divide into two or more branches diverging toward the south, like rivers 

 at their deltas. The most remarkable examples of this class of divergent 

 branches are found in the southwestern part of the State. When both 

 kinds of branches are found in the same system, the tributaries are toward 

 the northern end of the system and the delta branches toward the southern. 

 Assuming that the glacial gravels were deposited by glacial streams, we 

 see that these streams in many respects conform to the habits of ordinary 

 surface streams, though their causes and environment were different. 



Meanderings. — Tlie map sliows that tlie longer systems follow tortuous 

 courses. Many of these deflections were taken because of the surface 

 features of the land, such as the positions of the high hills and low passes. 

 There are also many short zigzags which plainly resemble the meandering 

 of streams, yet they are found in level regions where there are no surface 

 features to cause them. Apparently many of the minor curves and mean- 

 derings of the glacial rivers were caused by conditions of the ice which 

 did not depend on the land surface beneath the glacier. 



Directions of their courses. — Tlie averagc dircction of the gravel systems is a 

 little east of south, varying all the way from southwest to south and east, 

 and in a few cases for a short distance even a little north of east. While 

 there is often a tendency to follow the lines of glaciation, yet there are 

 many notable exceptions. Thus, in eastern Maine there is a remarkable 

 convergence of several gravel systems toward Jonesboro and ColumlDia 

 Falls. There is a convergence of the glacial scratches toward the same 

 points, but it is not so great as that of the gravels. The convergence of 

 the gravel systems and that of the scratches are nearly uniform toward 

 Belfast Bay. Most of the discontinuous systems are nearly parallel with 

 the scratches. At Danforth Village the glacial river abandoned a low pass 

 and took a higher one more nearly parallel with the glaciation. On the 

 other hand, there is but little convergence of scratches toward Penobscot 

 Bay; yet several long glacial rivers which were widely separated at their 

 northern ends, united to form a single river a few miles north of the bay. 

 The Holden-Bucksport and the South Albion-China systems both take a 

 southwest course on account of hiffh ranges of hills. At North Waterford 



