One opens a map of the colonies, say at the time of the French and Indian war, and looks for Vermont, and looks without finding. The space wedged in between Lake Champlain and the Connecticut river is plotted and named as a part of New York.
It is interesting to a Vermonter to trace the development of the mapping of the State; how this blank space became filled in. The bare outline of the State first appears. The Connecticut on the east affords a definite border; so Canada on the north and Massachusetts on the south. The Champlain forms a fairly good boundary part of the way on the west but farther to the south the line is a wandering one, varying and uncertain. Later this west line becomes fixed on the maps and is henceforward rigid. Lines indicating river courses come in and an array of angles showing the position of the mountain spine of the State. Then heavy straight and broken lines parcel out the State into counties and finer lines show the divisions into towns. Circles and dots drop in to show the situation of the larger and smaller villages Possibly an attempt will be made to show the propertional height and contour of the land, giving thus the topography of the State.
And the map is said to be complete; in a way it is. But under the green of forests and of shrubs and of herbage, there lies another Vermont out of common sight, yet the substance and strength of the Green Mountain State. This underground Vermont has been charted to some extent and its general features drawn. But it will not be even fairly well known until the measuring line of the special surveyor has been laid in care upon its many and varied rocks; their position, thickness and extent, their metes and bounds determined: and as well, the character and contents of these rocks by long-continued and careful study made evident.
Facts and observations concerning the geology of Vermont have been contributed by many persons, but careful and systematic work has been done by comparatively few men. Some of these, volunteers in the field, have worked because of their love for this work, and have found their reward in the results of their labors. Others just as ardent in study have had behind them appropriations, meager appropriations, from the funds of the State. it is from the labor of the latter, those aided by the State, that a systematic knowledge of the rocks of the State has chiefly come. The early leaders in Vermont geological study have had a varying and scattered band of followers, yet each individual, diligent and careful, has helped to lighten some dark corner, so in a way contributing to the illuminating of the whole.
The names of men doing special service the field of Vermont geology come quickly to mind. Standing at the head of the pioneers, is without doubt that of the Rev. Zadock Thompson. His History of Vermont, Natural, Civil, and Statistical, published at Burlington in 1842, is a treasury of knowledge from which writers of later periods have drawn supplies. Nearly a score of years before publication, this active and successful student of the Natural History of the State had busied himself in the accumulation of his material.
This professor of Natural History in the University of Vermont, this preacher, this man of vast and varied knowledge, has probably influenced science more in Vermont than any other person the State has produced. A pioneer, he run lines for himself and others into new fields. Physiographic geology was especially advanced by him. He could do well his own personal work, and beyond this he had the power of pressing into his service the best scientific ability of the whole country, thus accomplishing a vast amount of work which his own engagements would not permit him to do.
The decade near I830-1840 was one of great general interest in geology. By means of lectures, discussions, and explorations, the subject was brought to the attention of the people. Under legislative authority, geological surveys in various states were organized and entered upon. The example of the State of New York, particularly was of great influence. As early as 1836, the matter of a State geological survey was brought to the attention of the legislature of Vermont. The following year, 1837, such a survey was the subject of a favorable report by the Chairman of the Committee on Education. But it was not until 1834 that the legislature authorized a State geological survey, and set aside the sum of two thousand dollars annually for the term of three years.
The Governor, William Slade, appointed as State Geologist Charles B. Adams, at that time, professor of Natural History in Middlebury College, a man of great scientific acquirements. He associated with himself as chief assistants the Rev. Zadock Thompson and the Rev. S. B. Hall. Other assistants, paid and volunteer, joined the force. Many towns of the State were visited, and to a greater or less extent explored. Over twelve thousand specimens of rocks, fossils and minerals, were collected, which later were to form suites to be distributed to the literary and medical educational institutions of the State; the most complete collection, however, to be deposited at Montpelier.
A preliminary map was constructed, a portion of the specimens collected were labeled, and distributed, reports of progress were annually put into print; the grand results were to be gathered and presented in a final report.
But sad, such final report never came from the hand of the principal of the survey. The legislature of the State, at a time of strange financial economy, failed to make an appropriation for completing the work. Prof. Adams had accepted a position outside of the State, and not long after he died. The undistributed specimens, charts, sections, and field notes, were in trays and boxes and these later were committed to the care of the State Librarian at Montpelier.
The completion of the survey with a broadening of its scope, by including Botany and Zoology, was, by legislative action late in 1853, committed to Prof. Thompson. His title was now State Naturalist. A sum of one thousand dollars annually was set aside for three years for the purpose. The principal of the survey was directed by the act, to do work for which five thousand dollars would have been a small remuneration.
Professor Thompson entered upon his duties with an adeyuate appreciation of the greatness of the work committed to him. Stimulated by the valuable reports coming to him from surveys of other states, he proposed an admirable scheme for the publication of the Natural History of Vermont. He carefully prepared a full table of topics to be treated, and the three volume report, was to include a volume each, on Geology, Botany, and Zoology.
This proposed completion of the survey, begun with so much promise, came to a regretful ending. The health of Prof. Thompson failed and it was a dying lamentation that he could not be permitted to live to finish the work to which he was appointed, and on whidz his heart was set.
After the decease of Professor Thompson, in 1856, Judge Augustus Young was appointed State Naturalist. He appointed as assistant Mr. Albert D. Hager. This assistant, as far as possible, carried into effect the plans of Prof. Thompson in the arrangement of the collected geological specimens. These were placed in cases at the State House at Montpelier. A report on the history of the survey, a valuable one, came from the hand of the State Naturalist, but none other. Death made his term of offce short.
Then came a sharp disaster in the eventful history of the Vermont geological survey. The State House, in which the geological specimens were exhibited, was burned; the work of Adams and his successors went down in ashes.
Still the purpose of completing the survey was not abandoned. President Edward Hitchcock of Amherst College, who had won an admirable name in the survey of his own State, Massachusetts, was called in. He was to be principal in what from previous losses was essentially a new survey.
With a scanty appropriation of four thousand dollars, President Hitchcock and his assistants, Albert D. Hager, Edward Hitchcock, Jr., and Charles H. Hitchcock, on explorations, made measurements and collected specimens through the seasons of 1857, 1858 and 1859. Thirteen sections of the rocks of the State on lines running east and west were made, thousands of specimens were collected along these lines, and later placed in the State House. Many observations of surface geology were made, and valuable facts collected. The various formations of the rocks were discussed, and a geological map of the State was prepared. The results, greater than could have been expected from the inadequate appropriations, were embodied in a report, and by the authority of the legislature these appeared in 186I in two fine quarto volumes, the Report of the Geology of Vermont.
A small annual appropriation has been made by the State for the care and enlargement of the State cabinet, and for the payment of the salary of a State Geologist. So additions have been made to Hitchcock's collections by the State Geologists, notably by Dr. H. A. Cutting, Prof. G. W. Perry, and Prof. G. H. Perkins.
A legislative act in 1896 enlarged the duties of the State Geologist and set apart an additional sum for his work. Two valuable reports made to the Governor of the State, one in I898 on the Marble, Slate and Granite Industries of Vermont, and a second in Igoo on the Mineral Resources of Vermont, have come from the hand of Prof. Perkins.
The problem of the geology of Vermont is confessedly a difficult one. The legislators, who have voted small sums from time to time, have had no adequate idea of the amount of careful investigation necessary to solve the problem. President Hitchcock in his report spoke of the rocks of Vermont as the most difficult with which he had ever attempted to grapple, and of the geological survey as a gigantic work for the little time given him. He regarded his survey as incomplete and claimed only to have laid a foundation for future super-structure. So Vermont has remained a field for farther geological investigations.
For the years past such work has been left mostly to volunteer students. Unique among these investigators has been the Rev. Augustus Wing, who with many of the surroundings and characteristics of Prof. Thompson, took up geological research. The relative age of the rocks in the western part of the State was a question of great interest to him. It became almost a passion with hint to find out the truth. He explored, he observed, he collected; and abated not his self-imposed labor until the facts were revealed. The Vermont report had classed many varying deposits as Eolian Limestone. The limestones so placed, Mr. Wing showed to be made up of rocks of different periods. He also constructed a map showing both their relationships and the general geology of the district he had studied. His discoveries made an era in Vermont Geology.
Thus Prof. James D. Dana of Yale, in the American Journal of Science, May, 1877, writes: "Mr. Wing, by the use of his spare time and amid the duties of teaching, accomplished vastly more for the elucidation of the age of the Vermont rocks than had been done by the Vermont Geological Survey *** Mr. Wing's discoveries shed light not on these rocks alone, but on the general geology of New England and Eastern North America." Praise great for a quiet worker, but not too great for the ten years of loving toil.
Other students have entered the field of Vermont Geology which still offers so many opportunities for original investigation, and their work has helped to make plainer some of the obscure portions of geological history.
Members of the United States Geological Survey also have been working at problems within the State; particularly have they interested themselves in the age of the slate and marble deposits.
So the difficult questions of Vermont Geology are one by one being answered.
And the results of all these investigations as to the geology of Vermontl It may not be easy to tell in a few lines all that has been made out. Too many points are yet obscure.
Beginning back a little. By those who have carefully studied physical geography, it is said there is water enough on the globe to cover the round solid earth a mile deep. So the world would be as a drop of dew hanging in space. But the solid earth is not a smooth round ball; wrinkles on its surface have pushed some portions high above the water, while profound depths find place in the ocean bed.
Let one push his fingers over several folds of cloth laid upon one another. Wrinkles perpendicular to the motion of the fingers will run before them. Looking at the continents of the globe such folds or wrinkles appear near the borders, for the most part, running north and south.
So the wrinkled earth and so Vermont has been standing in the water and out of the water. An elevation forms the back bone of the State; other worn wrinkles as the Adirondacks, and the White Mountains, flank the Vermont elevation.
We may well believe that upon these uplifts the forces of air, frost, rain, waves, have been at work, disintegrating, transporting, sorting, distributing the pebbles, sand and clay in the near by sea. Plants and animals would here live, and dying leave their hard parts to increase the mass. In quiet seas, corals, and lime bearing animals, would contribute so much of cast off material as to form limestone beds. Out of such strata of pebbles, sand, clay, limestone, simple or mixed, were the rocks of Vermont chiefly made.
To determine the order, position, thickness and distribution of these rocks would seem a very easy work. The newer rocks ought to lie directly upon the older beneath, the fossils different in the different formations, should give a quick indication of their relative age.
And yet how many events have intervened since the early deposits were made!
What upliftings, thrustings, fractures, displacements, metamorphisms! Heat, pressure, water, have been doing their work; the lines of the original deposition have not usually wholly disappeared, but often the fossils have, and the rock has become a crystalline one. A limestone rock is here full of fossils, farther away the fossils have faded, and farther still, the rock is changed to a marble.
The age of rocks is chiefly recorded by their fossil contents. Metamorphosed strata give little clue to the time of their deposition.
We may assume that beneath the known rocks there is a basal mass, that has never been seen. Upon this are known rocks bearing evidence of stratification, yet without observed fossils. These old time rocks, geologists have come to call Archean. Of such are the tops of the Green Mountains.
And as the age of the schists, gneisses, soapstones, and crystalline limestones, metamorphosed rocks,of the eastern part of the State has not been made out, they for the present are included in the Archean. The granites of the State are so like rocks that have been melted and cooled, it is still difficult to determine whether they are really eruptive rock, or that after deposition in water, heat has obliterated all traces of their origin.
These too for the present may be included in the Archean.
West of the Green Mountain range metamorphism is less marked; the beds of rock are less disturbed. It is from these that the history of Vermont Geology must be read.
The first rock within the State to register the time mark, is the much changed gray sandstone that in ridges flank the western slope of the Green Mountains. At intervals these ridges are notched by the breaking away of the formation; streams of water may go down, lines of travel may go up through these notches.
The sandstones here as elsewhere were apparently old time sea beaches.
There is a strange uplift of rock, half way between the mountains and Lake Champlain: seen now chiefly as a line of knobs extending from Bridport to Burlington and north. Snake Mountain, Buck Mountain, and Lone Rock Point, still indicate the profound fractures and over thrusting these rocks at an early time underwent. In the tremendous strain to which they were subjected, the rocks were folded and in this folding the older sand rock was pushed up and over the newer rocks. This sandrock could not endure the sharp folding, it snapped, and its broken strata now form the wall-like western face of these elevations. The rounded hills and the red boulders strewn over country east and south show something- of the enormous wasting that has been going on since the elevation.
This rock early known as Red Sandrock is thought to be of the same age as the gray sandstone of the mountains. It is much varied in structure and composition. At Burlington, very compact and red in color, it is a noted building stone. Farther north it seems to have taken into its composition both lime and magnesia and becomes a beautiful variegated stone which when sawn has been known under the old name of Winooski Marble. Farther to the north, in the town of Georgia, slate of apparently the same age occurs, which holds in its layers strange and noted forms of earlier trilobites.