Encyclopædia Britannica, Ninth Edition/Vermont

VERMONT, one of the New England States of the American Union, lies between 42° 44' and 45° 0' 43" N. lat. and 71° 38' and 73° 25' W. long. It is bounded on the N. by the Canadian province of Quebec, on the E. by New Hampshire, from which it is separated by the Connecticut river, on the S. by Massachusetts, and on the W. by New York, from which it is separated for more than 100 miles by Lake Champlain. The Canadian boundary is 90 miles long; but from this the width of Vermont continually grows less towards the southern border, where it is 41 miles. The length is 158 miles. The boundary between Vermont and New York passes through the western side of Lake Champlain, so that three-fourths of the lake and most of its islands belong to the former. The area of the State is 10,212 square miles.

The surface is greatly diversified, so that the scenery is everywhere attractive and often grand. The Green Mountains, following a south-westerly trend, divide the State into nearly equal portions. Near Canada there are two ranges, the western being the larger; but near the forty-fourth parallel they unite and continue through western New England as a single range. The highest mountain is Mansfield (4430 feet), and there are five others over 4000 feet and twelve over 3500 feet. Except upon the loftiest summits, the whole range is densely covered with forests of spruce (Abies nigra), mingled with which are other ever green and deciduous trees. Many of the streams flowing west unite to form five rivers which enter Lake Champlain. Eleven smaller rivers flow into the Connecticut, which drains about one-third of the area of Vermont. Three streams run north and enter Lake Memphremagog, about one-fifth of which is within the State, and two flow south to join the Hudson river. Most of the larger streams pass through wide, fertile valleys. Small lakes and ponds are abundant.

The rocks of Vermont are largely metamorphic. Their age has long been disputed among geologists; it appears now, however, to be clearly established that most of them are Palæozoic, although there are a few small areas which may prove to be Archæan. Along Lake Champlain there are many outcrops of unaltered fossiliferous strata, which, from the Lower Cambrian through the Hudson River or Cincinnati formations, lie in a regular conformable series, and upon these rest Quaternary deposits. The strata have a northerly strike and a dip 5°-90° E. They form frequent headlands and cliffs upon the shore of Lake Champlain, where they can be most easily studied. The Cambrian beds, nowhere more than a few miles broad, extend from Canada southwards for about 90 miles, having a total thickness of probably not less than 10,000 feet. They consist of limestone, sandstone, shale, slate, quartzite, and

The limestone is often arenaceous and dolomitic, sometimes magnesian. There are great masses of reddish, silicious limestone, the Red Sandrock of geologists, which, often destitute of fossils, contains here and there species of Ptychoparia, Olenellus, Orthisina, Obolus, Salterella, &amp;c. Included in these beds are thick layers of a beautifully mottled red and white dolomite, the &ldquo;Winooski marble,&rdquo; long used for architectural purposes. Similar fossils occur in the &ldquo;Georgia shales&rdquo; and elsewhere. Above the Cambrian are small patches of Calciferous and Quebec, then larger areas of Chazy, Trenton, Utica, and Hudson River. In the Chazy and Trenton there are extensive quarries upon Isle la Motte, and these formations are finely exhibited in many localities near the lake. The rocks are mostly limestones and shales of a black or dark grey colour, and frequently afford Silurian fossils in great abundance. Within a few miles of Lake Champlain the sedimentary rocks are replaced by schists, quartzites, and other metamorphic rocks, which continue beyond the mountains to Connecticut river. In the southern part of Vermont there are Lower Helderberg strata, and in the northern, about Lake Memphremagog, Upper Helderberg. These occupy but limited areas and are unconformable with the underlying rocks. Rev. A. Wing determined the age of the great marble beds of Rutland county to be mostly, if not wholly, of the Chazy epoch. He then extended his observations to the rocks of the Green Mountain mass; and by means of the results thus gained, as well as by his own long-continued independent researches, Prof. J. D. Dana seems to have substantially settled the age of the rocks which compose the mountains as Lower Silurian, and shown that the uplift ending in the range took place after the close of the Hudson River and before the Helderberg period. In the Champlain valley the rocks are traversed by dykes of trap and porphyry, which in some instances have spread over the strata. In the Utica and Hudson River shales there is most beautiful veining: innumerable seams of white calcite, from the finest line to several inches in width, cross and recross the black strata in every direction. In a narrow strip from Canada to Bennington there are Tertiary beds, which are well seen at Brandon. In this formation there are great masses of lignite, containing fossil fruits, also bog iron, manganese, kaolin, and variously and often brightly coloured clays. The entire surface of Vermont shows the effects of glaciation. Some of the Silurian ledges are striated and polished most beautifully. Drift, boulders, sands, clays occur everywhere; every stream is bordered by terraces; remains of mammoth, mastodon, beluga, are found in the drift deposits, as well as Mya, Saxicava, Mytilus, and other marine Mollusca. Sea-beaches over 2000 feet and terraces over 1000 feet above the present sea-level testify to movements of the surface. From the early Cambrian to the late Quaternary epoch Lake Champlain was an arm of the sea, and for a portion of this time it was connected with the ocean at each end, so that a current flowed from what is now New York Bay to St Lawrence Gulf, converting New England into an island.