(Child’s Gazetteer of Jefferson County, N. Y. p. 23-28)

*Furnished by D. S. Marvin, of Watertown

It will be seen by an examination of the cut of the stratagraphical geology on another page that the strata of the rocks of various ages, from the azoic to the Hudson River, inclusive, are found in the county; but of course the cut cannot show the fact that the various layers above the archean all thin out before reaching the northern limits of the county. This fact is one that has much significance in a study of the effects of the ice age upon denudation. There are little or no evidences of intense glaciation previous to the tertiary period; it was not until the quartanary was ushered in that glaciation assumed its grand proportions here. The fact that gneissoidal and granitic rocks are the surface rocks in the northern portions of the county is evidence that the territory was among the earliest portions of the globe to rise above the waters of the primeval ocean without subsequent prolonged subsidence. There are many theories concerning the causes that have produced and ushered in the glacial period, among them the most plausible, changes of level of land surface. Visitors to all mountain lands observe snow and ice upon each considerable elevation, and perhaps it is sufficient in this connection to cite the fact that glaciation seems to have been one of the finishing processes of world making; fitting the surface and soil conditions for their capabilities to maintain and sustain the higher and more important forms of animal existences. The countries that are the most thickly inhabited are the ones that have been submitted to the most intense glaciation. The scenery of lake and forest, the formation of hills and valleys, have in most instances been sculptured and shaped by glaciation.

Professor Agassiz was the first to study the glaciation of the Alps; that of Greenland, Alaska, and other countries has since been studied by others. It has been found that exactly a similar wearing away and scoring of the rocks, the transportation of detritus, and other forms of ice action may be observed all over the north part of the continent, and this is now the accepted explanation of the same phenomena and conditions here. They can be accounted for in no other rational manner. It has been thought that there has been more than one period of glaciation, but a study of the local conditions seem to reveal but one period here. The section seems (sic) have been in the center and track of the most intense denudation. The movement of the ice lob seems to have begun upon the shores of the Atlantic, perhaps as far north as Greenland, and slowly crept southward year by years, always most intense upon and near the ocean, or other large bodies of water, and to have extended as far south as Central New Jersey, then following an irregular line northwestward to near the east end of Lake Erie, thence southwestward to Cincinnati, Ohio, thence northwestward to Central Iowa, and continuing via Bismark, Dakota, to an unknown distance over the Saskatchewan. There was at the same time another lobe moving from Alaska on the Pacific, extending as far south as Northern California, and another extending from North to Central Europe upon the Eastern continent. Ice seems a solid and rigid body, but is really a solid with some of the characteristics of a liquid.

These semi-solid movements have been most carefully studied and measured in Greenland. It has been found that ice moves over the continent wherever there is a slope of 40 feet to the mile; and in the Alps over a like slope the distance of 70 feet a day where there was an ice front of not more than a half mile. On steeper slopes and wider fronts the movement is several hundred feet a day. The power of ice to tear away and transport rock masses from one place to another seems to lie in the fact of congealation at night, and thawing during the day time. Ice expands in freezing. This is the force that loosens and rends the solid mountains. These detached masses, falling upon the ice, are carried to lower levels, or frozen fast to the bottom ice and carried onward with the mass, scoring and grinding the rocks over which they move with prodigious energy.

THICKNESS OF THE ICE

Glacialists estimate that the lobe of ice upon the shores of the Atlantic, in New England, was over 11,000 feet thick. There has been no careful estimate made for the thickness over Northern New York, but it must have been, from the territorial conditions, nearly, or quite, as thick here. The local circumdenudation that has taken place is quite as marked as that of most other localities. There are no high mountains within the region under consideration by which to measure the thickness. Dry Hill being the main low range within the county, this has certainly been covered by ice, for there is observed to be an abundance of bowlders and drumlins upon the highest summits. Between the cemetery and the hamlet of Burrville may be seen drumlins, lateral and medial moraines, also in the town of Rutland, and all over the northern, and western, and central portions of the county.

GLACIAL STREAMS.

It was not until the closing scenes of the glacial period, when these great masses of ice were thawing and wasting away, the slow accumulations of many thousands of years, that the system of glacial rivers, seen all over the county, were formed. The more prominent ones came down from the direction of Carthage, trending southwestward, and emptying into Lake Ontario. What is known as Rutland Hollow, and the swamp in the towns of Rutland, Watertown, and Hounsfield, was one of these old glacial river beds, dividing just east of the city of Watertown. One branch flowed along its bed through the cemetery, the other through the fair ground, thus making the site of Watertown an island at that time. Where it crosses the present river, near the new engine works, deep striae may be seen in the heavy bedded birds-eye limestone. Later on, and nearer the close of glaciation, this channel in Rutland was filled or dammed with ice, and a lower one, the same as the one now occupied by the present river, formed. The old geologists, before glaciation was much studied, believed that the present river channel, from Watertown to Dexter, is later and denuded by causes now in action; but the better explanation seems to be that the present river bed is the old channel of preglacial erosion, temporarily dammed with ice during the glacial period, and that, upon the ice thawing, the present channel was again reoccupied. It is readily observed and apparent that while the ice sheet overlaid the whole country all previously existing streams became filled and dammed with ice, and new ones established, flowing southward, or, as in the case here, more to the westward.

The St. Lawrence was turned back upon itself; the waters of Lake Ontario forced to find an outlet into the Hudson through the channel of the Mohawk; then the channel of the Mohawk was dammed with ice, and the whole watershed reversed and turned westward into the Ohio and the Wabash. The old shores of Lake Ontario, 200 feet above their present level, may be seen in many places and upon different levels as the successive channels were closed and opened. The theory of a molten condition of the earth’s center obtains some confirmation from these old lake shores occupying elevations. They suggest that the vast masses of ice temporarily depressed the portions of the earth that they covered.

Local conditions to some extent determined the direction of the streams and rivers. The Adirondack Mountains, being a center of local glaciation, forced all outflows of water and ice in southwesterly direction. The glacial scratches, the sculpturing of the hills, and directions of the valleys show this.

The Potsdam sandstone, the strata of the birds-eye limestone, and that of the Hudson River group probably extended further north than at present; but over all the northern and western portions of the county the edges have been denuded and carried away. An examination of the sands that now lie upon the western slopes of the mountains shows them to have been made up from the calciferous and Potsdam sandstone mainly. The same red sands now fill the bottoms of the channels of the old glacial streams, and they overlie considerable stretches of the surface of the county. The “pine plains” above Great Bend, once densely covered with pine forest, is made up of this sand, so little intermixed with sediment and glacial clays, common over most other portions of the territory, that there is no fertility in the soil, it being almost pure sand.

The southeastern portions of the county seem not to have been so much disturbed by glaciation. The streams are usually old channels of erosion, and the general face of the country, though deeply scored in places, appears more like unglaciated regions. There was undoubtedly the same covering of ice there, but the land being higher, and a little outside of the center of glacial activities, the ice melted more slowly. There is a fine natural exposure of the edge of the Utica slate, where it thins out in the bed of Sandy Creek, a short distance from Whitesville, perhaps the only natural thinning out exposure left in the county readily found. It was this natural thinning out of the strata that presented the opportunity for the great displays of local dynamic energy; the ice, following the harder gneiss and granite, easily displaced the edges of the stratified rocks, until it met the heavy bedded birds-eye limestone in the central portions of the county. Genuine “hogs backs” are seen at Carthage upon the carved and worn beds of gneiss that form the county rock there.

Perch Lake and nearly all the other small lakes in the county are what are termed by glacialists kettle holes. They were formed by glacial detritus, being dropped at the lower ends of depressions, and there has not yet time intervened for their filling up, or the wearing down of their outlets. It is in these respects that the county has been benefitted by glaciation; but taking the county as a whole there may be doubts of any benefits arising out of former glaciation. In too many places the fine preglacial soils have either been covered up or removed to Central and Southern New York, Pennsylvania, and Ohio, too little time since intervening for the reformation of fertile soils by natural causes. Judging by the data we have in the wearing away of streams it is scarcely ten thousand years since glaciers were floating to Lake Ontario from the Adirondack region, past the site of the city of Watertown.

The heavy bedded clays in the central and western part of the county, underlaid by gravel and bowlders, are true glacial clays, deposited while the lake was at a higher level. In some beds there are intermixtures of blue clay. These have been derived from the denuded Utica slate and Lorraine shale.

Bowlders of gneiss, hornblende, granite, Labradorite, marble, mica schist, and other minerals from the Laurentian rocks of Canada, and the highlands of the Adirondack, some of them weighing an hundred tons, are common and indiscriminately distributed upon and below the surface in nearly all parts of the county.