Page:Popular Science Monthly Volume 68.djvu/199

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THE

POPULAR SCIENCE

MONTHLY


MARCH, 1906




THE PHYSIOGRAPHY OF THE ADIRONDACKS

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 impressively 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 geology 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 schistosity, 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 member of the Paleozoics having any association with the old crystallines