![BarabooRangeWIS78](https://upload.wikimedia.org/wikipedia/commons/4/42/BarabooRangeWIS78.jpg)
The Baraboo Range is a
syncline located in
Columbia and
Sauk Counties,
Wisconsin
Wisconsin () is a state in the upper Midwestern United States. Wisconsin is the 25th-largest state by total area and the 20th-most populous. It is bordered by Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake M ...
. It consists of highly eroded
Precambrian metamorphic rock
Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock ( protolith) is subjected to temperatures greater than and, often, elevated pressure of or more, caus ...
. It is about long and varies from 5 to in width. The
Wisconsin River
The Wisconsin River is a tributary of the Mississippi River in the U.S. state of Wisconsin. At approximately 430 miles (692 km) long, it is the state's longest river. The river's name, first recorded in 1673 by Jacques Marquette as "Meskous ...
, previously traveling in a north to south direction, turns to the east just north of the range before making its turn to the west towards the
Upper Mississippi River
The Upper Mississippi River is the portion of the Mississippi River upstream of St. Louis, Missouri, United States, at the confluence of its main tributary, the Missouri River.
History
In terms of geologic and hydrographic history, the Upper ...
. The eastern end of the range was glaciated during the
Wisconsinian glaciation
The Wisconsin Glacial Episode, also called the Wisconsin glaciation, was the most recent glacial period of the North American ice sheet complex. This advance included the Cordilleran Ice Sheet, which nucleated in the northern North American Cord ...
, while the western half was not, and consequently, marks the eastern boundary of Wisconsin's
Driftless Area
The Driftless Area, a topographical and cultural region in the American Midwest, comprises southwestern Wisconsin, southeastern Minnesota, northeastern Iowa, and the extreme northwestern corner of Illinois.
Never covered by ice during the las ...
.
The city of
Baraboo
Baraboo is a city in the Midwest and the county seat of Sauk County, Wisconsin, United States. The largest city in the county, Baraboo is the principal city of the Baraboo Micropolitan Statistical Area. Its 2020 population was 12,556. It is situ ...
is in the center of the valley. The range was designated a
National Natural Landmark
The National Natural Landmarks (NNL) Program recognizes and encourages the conservation of outstanding examples of the natural history of the United States. It is the only national natural areas program that identifies and recognizes the best ...
in 1980.
Geology
The range is an example of a buried mountain range exposed through erosion, to once again undergo the forces of surface erosion. The rocks are as much as 1.5 billion years old,
[Hanson, G. F.]
''Geology of the Baraboo District, Wisconsin''
, The University of Wisconsin Extension, November 1970, Information Circular 14 among the oldest exposed rocks in North America, consisting mainly of gray to pink
Baraboo Quartzite
Baraboo Quartzite is a Precambrian geological formationHanson, G. F.''Geology of the Barabou District, Wisconsin'', The University of Wisconsin Extension, 1970, Information Circular 14 of quartzite, found in the region of Baraboo, Wisconsin. Whi ...
and red
rhyolite. The
Baraboo River divides the range in half, flowing through Upper Narrows Gorge near
Rock Springs and travels onto its confluence with the
Wisconsin River
The Wisconsin River is a tributary of the Mississippi River in the U.S. state of Wisconsin. At approximately 430 miles (692 km) long, it is the state's longest river. The river's name, first recorded in 1673 by Jacques Marquette as "Meskous ...
downstream from
Portage through the Lower Narrows. The Baraboos are composed of resistant
Precambrian quartzite
Quartzite is a hard, non- foliated metamorphic rock which was originally pure quartz sandstone.Essentials of Geology, 3rd Edition, Stephen Marshak, p 182 Sandstone is converted into quartzite through heating and pressure usually related to tec ...
(a
metamorphic rock
Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock ( protolith) is subjected to temperatures greater than and, often, elevated pressure of or more, caus ...
) which has formed an erosional remnant or
Monadnock, resulting in
topographic prominence
In topography, prominence (also referred to as autonomous height, relative height, and shoulder drop in US English, and drop or relative height in British English) measures the height of a mountain or hill's summit relative to the lowest contou ...
. The mountains may have formed as long ago as the late Precambrian. These formations were buried by
Paleozoic
The Paleozoic (or Palaeozoic) Era is the earliest of three geologic eras of the Phanerozoic Eon.
The name ''Paleozoic'' ( ;) was coined by the British geologist Adam Sedgwick in 1838
by combining the Greek words ''palaiĆ³s'' (, "old") and ' ...
sedimentary
Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation. Sedimentation is the collective name for processes that cause these particles ...
strata and are still being uncovered by the erosion of the softer, overlying rocks.
Devil's Lake, the centerpiece of
Devil's Lake State Park, was formed from
terminal moraine
A terminal moraine, also called end moraine, is a type of moraine that forms at the terminal (edge) of a glacier, marking its maximum advance. At this point, debris that has accumulated by plucking and abrasion, has been pushed by the front edge ...
s blocking access to its outlet, creating what is today an
endorheic lake
An endorheic lake (also called a sink lake or terminal lake) is a collection of water within an endorheic basin, or sink, with no evident outlet. Endorheic lakes are generally saline as a result of being unable to get rid of solutes left in the l ...
(i.e., a lake lacking a surface outlet to the world's oceans).
References
* Steven Dutch
Devil's Lake Retrieved July 27, 2007 (With map)
Retrieved July 27, 2007
Baraboo Range Protection Plan Sauk County, Retrieved July 27, 2007
Wisconsin Department of Natural Resources
The Wisconsin Department of Natural Resources (WDNR) is a government agency of the U.S. state of Wisconsin charged with conserving and managing Wisconsin's natural resources. The Wisconsin Natural Resources Board has the authority to set policy ...
, Retrieved July 27, 2007
* Keith Montgomery
The Baraboo Ranges and Devil's Lake Gorge: A Geologic Tour Retrieved April 30, 2019
External links
*
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Driftless Area
Landforms of Columbia County, Wisconsin
Landforms of Sauk County, Wisconsin
Geology of Wisconsin
Inselbergs of North America
Mountain ranges of Wisconsin
National Natural Landmarks in Wisconsin