THE 



POPULAR S C IENOB 



MONTHLY 



MARCH, 1906 



THE PHYSIOGRAPHY OF THE ADIROXDACKS 



By Professor JAMES FURMAN KEMP, 



COLUMBIA UNIVERSITY 



Introduction. — The state of New York is shaped like a shoe, with 

 its toe pointing due west and a long spur extending from the heel to 

 the east. In the upper part of the shoe where the ankle of the wearer 

 would be placed, is the Adirondack region, containing 10,000 square 

 miles of very sparsely inhabited mountain, plateau and forest. It 

 embraces the highest summits in the state, and at the same time the 

 highest in eastern North America, except the White Mountains of New 

 Hampshire and the Blue Ridge of North Carolina. Were it not for 

 these two, even though the Appalachian region is decidedly and impress- 

 ively mountainous, the Adirondacks would remain the loftiest summits 

 in the east ; and the equal of Mt. Marcy, called Tahawus or the ' Cloud- 

 splitter ' by the Indians, would not appear on the hither side of the 

 Black Hills of South Dakota or the remoter Rocky Mountains. 



Geological Formations Present. — The Adirondack region in its geol- 

 ogy presents an important and interesting series of Precambrian rocks. 

 Roughly speaking, nearly the whole area consists of gneisses, but the 

 metamorphic rocks can be separated into a great series of sedimentary 

 gneisses, quartzites and coarsely crystalline limestones, on the one hand, 

 and, on the other, into a second great series of eruptive syenites, 

 granites and rocks of the gabbro family. Except for the limestones, 

 all these rocks are hard and resistant, their weak points of attack being 

 in a small degree their sehistosity, and in a greater degree their joints 

 and faults. 



On all sides the Precambrian rocks are mantled with the Paleozoics, 

 the oldest of which is the Potsdam sandstone of the Upper Cambrian, 

 a hard quartzite, gray, pink and pale yellow in color. The latest mem- 

 ber of the Paleozoics having any association with the old crystallines 



