206 BULLETIN OF THE 



specified, the Penobscot flows over underlying granite, superlicial or 

 drift-covered. 



Mount Ktaadn, as we shall see, is composed wholly of granite, and its 

 relation to the Sourdnahunk Mountains, which extend from Ktaadn 

 westerly ten miles, is such that it and they must be regarded as parts of 

 one continuous range. It cannot be doubted, therefore, that a Ktaadn 

 "granite area" exists, having for its length that of this range, and 

 including on its southern side the channel of the Penobscot, at least so 

 far down as Sourdnahunk Falls, which are three miles above the month 

 of Aboljacarmegus Stream. These statements are confirmed by the few 

 observations upon this part of the river which the Geological Reports 

 record. 



The floor of the Great Basin of Ktaadn has an elevation of 2,900 feet 

 above the sea. As one goes outward from it by the present route to the 

 East Branch of the Penobscot, better styled the Mattagamon Pviver, he 

 skirts along the northern foot of the abrupt portion of the eastern moun- 

 tain. On leaving that, he quits the last trace of rock in situ, which 

 nowhere reappears in the descent of more than 2,400 feet made along the 

 twenty-three miles of way to the crossing of the Mattagamon at the 

 Hunt Place. There is abundant testimony that ledges do not come to 

 the surface on the old Keep Path, which diverges from the present route 

 at Ktaadn Lake and runs seven miles to the foot of the East Slide. 

 It is certain, then, that on the east side of Ktaadn granite has not 

 been discovered upon the gradual lower slopes of the mountain, which 

 make up nearly half of its whole height. It is certain, too, that just 

 beyond the western or Sourdnahunk end of the range, the granite dis- 

 appears beneath the surfl\ce. To the south of the Sourdnahunk Moun- 

 tains, as we have seen, granite without doubt makes up the river channel ; 

 but the aspect of the low country to the south warrants the supposition 

 that granite as a superficial rock extends in that direction not far beyond 

 the Penobscot. It seems, therefore, in the highest degree probable, that 

 the Ktaadn "granite area" includes little but the mountains them- 

 selves, and that, nowhere extending for out from the foot of the range, it 

 does not, in some parts, embrace even the lowest slopes. 



Mount Ktaadn. 



The low country south of Ktaadn has an average elevation of not 

 more than 550 feet above the sea. From it rises the mountain by mod- 

 erate gradations to less than half its altitude, or about 2,200 feet on 



