Open main menu

Page:Popular Science Monthly Volume 2.djvu/681

This page has been validated.
661
RIVER AND LAKE TERRACES.
RIVER AND LAKE TERRACES.

TRAVELLERS along the river-valleys of New England, and in other sections of our Northern States, will observe that the banks in many places rise by a series of terraces, which at a distance resemble the steps of an amphitheatre. Carved with singular uniformity upon the slopes, they are everywhere a striking and beautiful feature of these most picturesque and beautiful landscapes. In the valleys of the Connecticut, Merrimac, St. Lawrence, Kennebec, Hudson, and innumerable other streams, these levels have been utilized as sites for villages, country-seats, forest, and cultivation.

Northampton, Brattleboro, and Springfield, are built on terraces; and part of the charming village of North Conway, at the gate of the White Mountains, stands upon a similar level. Dartmouth College is upon an elevated terrace.

Terraces occur on both sides of the Niagara River, and on the east side four levels are described, the highest being 38 feet above the top of the American Fall. They occur also on the Hudson Highlands at Cornwall 180 feet, and at Cozzens 130 feet above tide-level. The Catskill Mountains are fringed with terraces almost to their summits; and on the east side of the Hudson, at Albany, eight distinct levels are passed on the line of the Boston and Albany Railway before reaching the summit station.

On Hoosac Mountain is a terrace 1,813 feet above the level of the sea, and near it an ancient beach 200 feet higher. They occur at Quebec, 500 feet; at Montreal, 400 feet; and, on the Genesee River, 1,410 feet above the ocean-level.

But terraces abound on lake-margins with the same distinctness as on the banks of rivers. Prof. Agassiz counted fifteen on the shore of Lake Superior, and the writer counted six, beautifully defined, at Portage Lake. Visitors at Watkins Glen may notice terraces sculptured on the amphitheatre of hills at the head of Seneca Lake, whose geological history is contemporary with that of the great gorge, the object of their visit. In Northern Utah lake-terraces are found, according to Hayden, nearly a mile above the ocean, and on islands in Barrow's Straits they occur at 1,000 feet elevation.

On some of the great Western prairies terraces extend like vast coast-lines bounding the plain.

Nor are they confined to North America. They have been noticed on the slopes of the Ural and Altai Mountains, around the Dead Sea, on the banks of the river Jordan, on the mountain-sides in the Great Sahara, and on the banks of the Nile above the first cataract.

The ocean, too, has its terraces. Darwin observed that, around Patagonia, the ocean had eaten deep into the rocky coast "a series of