[1]Most of the information for this section was graciously supplied by
Clara E. Follette, Librarian and Museum Director, Vermont Historical
Society, Montpelier, Vermont, in a letter to the author dated April
26, 1961.
[2]“The governors (and other gentlemen) appear to have included Sir
Henry Moore, Governor of New York, General Carleton, Governor of
Quebec, Brig. General Philip Schuyler (and Adolphus Benzel, map
maker). The activities of these persons on the lake at that time
were evidently concerned with making observations, primarily to
determine boundaries.”
[3]Seely, H. M., 1910, Preliminary Report of the Geology of Addison
County; Vermont State Geologist, 7th Biennial Report, p. 257-315.
[4]Concretions consist of concentrations of certain chemical elements
and compounds into regular or irregular masses. Many times the
center of a concretion consists of a definite nucleus such as a
grain of sand or shell fragment. For a general idea of the size and
shape of the concretions seen along the Button Bay State Park beach
see Fig. 3 and cover picture.
[5]These clays were deposited from marine waters which flooded the
Champlain Valley after the final retreat of the glaciers which
completely covered New England during the “Great Ice Age” or
Pleistocene Epoch. The Pleistocene Epoch began approximately one
million years ago and if the age of the Earth is considered to be
five billion (5,000 million) years, then, the clays do record recent
geologic history.
[6]As the weight of the ice was removed from the Hudson Valley region
the earth’s crust, in way of adjustment to this removal of weight,
slowly began to rise. Some geologists doubt whether the removal of
ice weight alone can account for the crustal rise and propose other
internal forces as partly or wholly responsible. The fact remains
that the earth’s crust did rise in this area.
[7]As the ice retreated, a succession of lakes formed in the Champlain
Valley. Each lake had a level waterline during its history and
certain lakeshore features formed, as they do in any present-day
lake, with respect to each past level water-line. For example,
ridges of sand and gravel were heaped along the shoreline by lake
waves. Wave-cut and wave-built flat areas or terraces were formed
along the margins of lakes or along the sides of islands within a
lake. Streams entering a lake built deltas by depositing materials
it had carried down from the surrounding highlands.
[8]Elevation is measured in feet above the mean sea level of today, with
mean sea level being zero feet.
[9]A most impressive view can be gained from any one of the several
lookout points at the summit level of Mt. Philo. Looking to the
west, toward Lake Champlain, and south in the direction of Vergennes
and Button Bay State Park, a three dimensional view of an old lake
(Lake Vermont) can be seen. In this view the present Lake Champlain
Lowlands represent the old lake bottom and the numerous hills rising
above this Lowland were once islands or near-islands which dotted
the surface of the lake. It takes very little imagination to place
yourself on the “island of Mt. Philo” and to visualize a boat tied
to a dock just below the rocky cliffs on which you stand. A trip to
Mt. Philo with its spectacular view of the Champlain Lowlands (see
Fig. 6) is recommended.
[10]One word of caution, the Park authorities may import sand from other
areas of Vermont to improve the swimming facilities along the beach.
In this case, the abundant sand on the beach will not constitute the
“natural beach composition” for Button Bay State Park.
[11]The blue color is due to the presence of ferrous iron (bivalent
iron) together with iron compounds in which iron has its higher
chemical valence (ferric iron). This ferrous iron demands a
chemically reducing environment for its formation and indicates that
the clays were deposited in a shallow sea or that they remained for
some time beneath a stable water-table. They contained a fair
quantity of decaying organic material.
[12]The brown color is due to the presence of the ferric hydroxide,
goethite (HFeO₂).
[13]This fossil whale is scientifically known as _Delphinapterus
vermontanus_ (_Thompson_).
[14]The pelecypods found are scientifically known as _Macoma
groenlandica_ and _Saxicava rugosa_.
[15]The size limits of sand lie between 2mm in diameter (largest) and
¹/₁₆mm in diameter (smallest). Two millimeters (mm) equals
approximately ²/₂₅ inches. Fine sand would fall between ¼mm and ⅛mm
in diameter.
[16]Convolute beds show their layers thrown into a series of folds (some
quite irregular) which result from the pressing weight of overlying
sediments on highly plastic layers beneath. Some feel that these
folds were the result of actual flowage of the layers in the
direction of their tilt, and others credit the distorted bedding to
the pressing weight of large boulders. These dragged across the
layers while still frozen to overriding glacial ice.
[17]The author noted both _Macoma groenlandica_ and _Saxicava rugosa_
(see Fig. 10 and Plate 1, Sketches 3 and 4).
[18]Fossils are the preserved evidence of past life (animal or plant) as
found in rocks or sediments, for example, the clams found in the
clays. They may be direct evidence, such as the actual shells or
mineralogically replaced shells of long-dead animals; or indirect
evidence, such as the tracks or trails of animals now preserved in
rocks.
[19]Geologic time is divided into four Eras which are designated from
oldest to youngest: Precambrian, Paleozoic, Mesozoic, and Cenozoic.
Each of these Eras is divided into geologic Periods of time. The
Ordovician Period is next to the oldest Period of the Paleozoic Era.
This Period began some 420 million years ago, and ended
approximately 360 million years ago.
[20]Present Arthropods include the insects, spiders and crabs.
Arthropods, which are invertebrate animals (without backbones), are
characterized by jointed legs, chitinous outer covering and
segmented body parts. Trilobites were very numerous in the early
Paleozoic seas, but became extinct before the end of that Era.
[21]The folding and the faulting of the Ordovician rocks took place
sometime between the closing phases of the Ordovician Period and the
beginning of late Silurian time (between 360 and 330 million years
ago). Usually these earth movements are ascribed to the Taconic
Disturbance which took place at the end of the Ordovician Period.
[22]A walk along the beach in the direction of Button Island or “sickle
point” (west and then south from the northern boundary of the Park)
traverses the following geologic formations: the Glens Falls
limestone which can be seen on Ship Point (actually an island off
the northern end of the Park); the Orwell limestone, seen on Button
Island; the Valcour formation which makes up “sickle point”; and the
Crown Point limestone which is found on the Basin Harbor-side of
“sickle point.” These rock units belong to the Chazyan Stage (Crown
Point limestone and Valcour formation) and the next younger
Mohawkian Stage (Orwell and Glens Falls limestones) of the Middle
Ordovician Champlainian Series.