Q GLACIAL GEAVELS OF MAINE. 



of surface. In the absence of topographical maps these surface features 

 can be described only approximately. A fact of great significance in an 

 investigation of the drift of Maine is the presence of numerous ranges of 

 hills rising 200 to 1,000 feet above the country to the north of them, and — 

 a fact still more significant — they usually were more or less transverse to 

 the direction of glacial flow. Part of these have the general northeast 

 Appalachian direction, others lie nearly east and west. During the time 

 of maximum thickness of the ice the glacier flowed up and over these 

 hills, but during the final melting these ranges stopped the flow of the 

 ice in many cases and confined it to the valleys lying north of them. 

 The behavior of the glacial rivers with respect to these transverse 

 hills is of great assistance in determining the character of the rivers and 

 their laws. 



Much information regarding the kames, eskers, and osars of Maine was 

 collected during the geological surveys of Maine made by Dr. Jackson and 

 Professor Hitchcock. I have also received assistance from hundreds in 

 various parts of the State, but it has hardly been practicable to make the 

 proper acknowledgments in detail in cases where the information gained 

 from others was subsequently superseded hj my own field work. 



NATURE OF THE ROCKS OF MAINE. 



A small area of sandstone is found in Perry and adjoining towns in 

 the southeastern part of the State. With this exception the coast region is 

 covered by granite, gneiss, mica, and other coarse-grained schists, with 

 small areas of syenite, diorite, and other crystalline rocks. In the central 

 part of the State, nearly parallel with the coast, is a long belt of slates and 

 other fine-grained schists. Still farther north is a parallel belt of fossilif- 

 erous rocks — sandstones, conglomerates, and limestones. Numerous knobs 

 and ridges of granite rise in the midst of the other rocks. The contrast 

 between these various rocks is great, both chemically and mineralogically, 

 and this makes it possible to readily compare the areas of different rocks 

 one with another with respect to the composition both of the till and of the 

 glacial sediments. Most of these rocks are tough and compact in structure 

 and contain free quartz; they are therefore hard to abrade. Except in a 

 few places the nature of the rock is favorable to the production of a great 

 number of stones and bowlders. The great abundance of gravel in the 



