The Champlain Thrust is a 200-mile long
fault extending from southern
Quebec
Quebec ( ; )According to the Canadian government, ''Québec'' (with the acute accent) is the official name in Canadian French and ''Quebec'' (without the accent) is the province's official name in Canadian English is one of the thirtee ...
, down through western
Vermont
Vermont () is a state in the northeast New England region of the United States. Vermont is bordered by the states of Massachusetts to the south, New Hampshire to the east, and New York to the west, and the Canadian province of Quebec to ...
in the
Champlain Valley
The Champlain Valley is a region of the United States around Lake Champlain in Vermont and New York extending north slightly into Quebec, Canada. It is part of the St. Lawrence River drainage basin, drained northward by the Richelieu River into ...
, and into eastern
New York
New York most commonly refers to:
* New York City, the most populous city in the United States, located in the state of New York
* New York (state), a state in the northeastern United States
New York may also refer to:
Film and television
* '' ...
in the
Catskills
The Catskill Mountains, also known as the Catskills, are a physiographic province of the larger Appalachian Mountains, located in southeastern New York. As a cultural and geographic region, the Catskills are generally defined as those areas cl ...
/
Hudson Valley
The Hudson Valley (also known as the Hudson River Valley) comprises the valley of the Hudson River and its adjacent communities in the U.S. state of New York. The region stretches from the Capital District including Albany and Troy south to ...
. This east dipping
thrust fault
A thrust fault is a break in the Earth's crust, across which older rocks are pushed above younger rocks.
Thrust geometry and nomenclature
Reverse faults
A thrust fault is a type of reverse fault that has a dip of 45 degrees or less.
If ...
transports
Cambrian
The Cambrian Period ( ; sometimes symbolized C with bar, Ꞓ) was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the preceding Ediacaran Period 538.8 million ...
-
Ordovician
The Ordovician ( ) is a geologic period and System (geology), system, the second of six periods of the Paleozoic Era (geology), Era. The Ordovician spans 41.6 million years from the end of the Cambrian Period million years ago (Mya) to the start ...
passive margin shelf rocks westward by about and places them on top of
Middle Ordovician
The Ordovician ( ) is a geologic period and system, the second of six periods of the Paleozoic Era. The Ordovician spans 41.6 million years from the end of the Cambrian Period million years ago (Mya) to the start of the Silurian Period Mya.
The ...
rocks. The Middle Ordovician accretion of the one or more island arcs terranes drove the initial thrusting during the
Taconic Orogeny
The Taconic orogeny was a mountain building period that ended 440 million years ago and affected most of modern-day New England. A great mountain chain formed from eastern Canada down through what is now the Piedmont of the East coast of the Unit ...
, though reactivation of the fault may have occurred during the middle Devonian
Acadian Orogeny.
[Rolf Stanley, The Champlain thrust fault, Lone Rock Point, Burlington, Vermont., Geological Society of America Centennial Field Guide--Northeast Section, 1987] The Champlain Thrust marks the most westerly thrust of the Taconic Orogeny.
Prominent exposures
The thrust fault is exposed to the north of the city of
Burlington, Vermont
Burlington is the most populous city in the U.S. state of Vermont and the seat of Chittenden County. It is located south of the Canada–United States border and south of Montreal. As of the 2020 U.S. census, the population was 44,743. It ...
on the shores of
Lake Champlain
, native_name_lang =
, image = Champlainmap.svg
, caption = Lake Champlain-River Richelieu watershed
, image_bathymetry =
, caption_bathymetry =
, location = New York/Vermont in the United States; and Quebec in Canada
, coords =
, type =
, ...
at
Lone Rock Point
Lone Rock Point is a promontory north of Burlington, Vermont and on the eastern shore of Lake Champlain. It is publicly accessible via a trail network and sits on land owned by the Episcopal Diocese of Vermont.
The site is of geologic significance ...
. Here the
Lower Cambrian
The Cambrian Period ( ; sometimes symbolized Ꞓ) was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the preceding Ediacaran Period 538.8 million years ago (m ...
Dunham
Dolomite Dolomite may refer to:
*Dolomite (mineral), a carbonate mineral
*Dolomite (rock), also known as dolostone, a sedimentary carbonate rock
*Dolomite, Alabama, United States, an unincorporated community
*Dolomite, California, United States, an unincor ...
can be seen thrust on top of the Middle Ordovician Iberville shales.
References
External links
Vermont State Geologic Survey Website
Geology of Vermont
Structural geology
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