Lac à l'Eau Claire Ouest
   HOME

TheInfoList



OR:

The Lac Wiyâshâkimî (the official name, in
French French (french: français(e), link=no) may refer to: * Something of, from, or related to France ** French language, which originated in France, and its various dialects and accents ** French people, a nation and ethnic group identified with Franc ...
, formerly Lac à l'Eau Claire, a calque of the lake's name, Wiyâšâkamî, in Northern East
Cree The Cree ( cr, néhinaw, script=Latn, , etc.; french: link=no, Cri) are a Indigenous peoples of the Americas, North American Indigenous people. They live primarily in Canada, where they form one of the country's largest First Nations in Canada ...
, changed form of ''wâšâkamî'' or ''wâšekamî'' in more southerly Cree dialects), also called the Clearwater Lakes in English and Allait Qasigialingat by the Inuit, are a pair of annular lakes on the
Canadian Shield The Canadian Shield (french: Bouclier canadien ), also called the Laurentian Plateau, is a geologic shield, a large area of exposed Precambrian igneous and high-grade metamorphic rocks. It forms the North American Craton (or Laurentia), the anc ...
in Quebec, Canada, near
Hudson Bay Hudson Bay ( crj, text=ᐐᓂᐯᒄ, translit=Wînipekw; crl, text=ᐐᓂᐹᒄ, translit=Wînipâkw; iu, text=ᑲᖏᖅᓱᐊᓗᒃ ᐃᓗᐊ, translit=Kangiqsualuk ilua or iu, text=ᑕᓯᐅᔭᕐᔪᐊᖅ, translit=Tasiujarjuaq; french: b ...
. The lakes are actually a single body of water with a sprinkling of islands forming a "dotted line" between the eastern and western parts. Its name in Cree is due to the clear water it holds. There are actually 25 lakes with names that mean "Clearwater Lake" in the province (26 if the ''Petit lac à l'Eau Claire'' — the Small Clearwater Lake — is included). Collectively, this body of water is the largest, northernmost and the second-largest natural lake in Quebec after Lake Mistassini. In 1896, the explorer and geologist
Albert Peter Low Albert Peter Low (May 24, 1861 – October 9, 1942) was a Canadian geologist, explorer and athlete. His explorations of 1893–1895 were important in declaring Canada's sovereignty over the Arctic, and eventually defining the border between Quebec ...
, a member of the Geological Survey of Canada, provided a probable explanation for the lakes' descriptive Cree name by highlighting the extraordinary clarity and depth of their icy waters.


Impact craters

The Clearwater Lakes occupy the near-circular depressions of two eroded impact craters ( astroblemes).Robertson, P.B. & Grieve, R.A.F. 1975 Impact structures in Canada: Their recognition and characteristics. Journal of the Royal Astronomical Society of Canada, v. 69, pp. 1-21. The eastern and western craters are and in diameter, respectively. Both craters were previously believed to have the same age, 290 ± 20 million years ( Permian period), promoting the long-held idea that they formed simultaneously. According to this doublet impact crater theory initially proposed by Michael R. Dence and colleagues in 1965, the impactors may have been gravitationally bound as a binary asteroid, a suggestion also made by Thomas Wm. Hamilton in a 1978 letter to '' Sky & Telescope'' magazine in support of the then-controversial theory that asteroids may possess moons (such as, for example, asteroid
243 Ida Ida, minor planet designation 243 Ida, is an asteroid in the Koronis family of the asteroid belt. It was discovered on 29 September 1884 by Austrian astronomer Johann Palisa at Vienna Observatory and named after a nymph from Greek mythology. ...
with its satellite Dactyl). Clearwater East and Clearwater West are both complex craters with distinct central peaks. These peaks are caused by the gravitational collapse of crater walls and subsequent rebound of the compressed crater floor. Lake water and sediments cover the central peak of Clearwater East, but bathymetric surveys of the lake floor and core drilling confirm the presence of a peak in its center.


Ordovician

However, repeated 40Ar/39Ar dating of impact melt rocks from both impact craters suggests that Clearwater East has an age of approximately 460–470 million years, corresponding to the Middle Ordovician time period.


Permian

Clearwater West was formed 286.2 ± 2.6 million years ago, in the
Early Permian 01 or '01 may refer to: * The year 2001, or any year ending with 01 * The month of January * 1 (number) Music * '01 (Richard Müller album), 01'' (Richard Müller album), 2001 * 01 (Son of Dave album), ''01'' (Son of Dave album), 2000 * 01 (Urban ...
.Bottomley, R.J., York, D., and Grieve, R.A.F. 1990. 40Argon-39Argon dating of impact craters. Proc. 20th Lunar Planet. Sci. Conf., LPI, Houston, pp. 421–431.Schmieder, M., Schwarz, W. H., Trieloff, M., Tohver, E., Buchner, E., Hopp, J. & Osinski, G. R. 2014
New 40Ar/39Ar dating of the Clearwater Lake impact structures (Québec, Canada) – Not the binary asteroid impact it seems?
Geochim. Cosmochim. Acta (in press).
Both Clearwater impact structures also carry different geophysical ( natural remanent magnetization) signatures and different geochemical fingerprints of the impacting
meteorite A meteorite is a solid piece of debris from an object, such as a comet, asteroid, or meteoroid, that originates in outer space and survives its passage through the atmosphere to reach the surface of a planet or Natural satellite, moon. When the ...
in the
impact melt Impact may refer to: * Impact (mechanics), a high force or shock (mechanics) over a short time period * Impact, Texas, a town in Taylor County, Texas, US Science and technology * Impact crater, a meteor crater caused by an impact event * Impac ...
of each crater.Palme, H., Janssens, M.-J., Takahashi, H., Anders, E. and Hertogen, J. 1978. Meteoritic material at five large impact craters. Geochim. Cosmochim. Acta 42, 313–323.


Micro climate

Because of its size, Lac à l'Eau Claire can affect the local climate, as attested to by the distribution of plant species. Although the lake's shorelines are populated mainly by
boreal Boreal may refer to: Climatology and geography *Boreal (age), the first climatic phase of the Blytt-Sernander sequence of northern Europe, during the Holocene epoch *Boreal climate, a climate characterized by long winters and short, cool to mild ...
species, the flora of the central islands in the western basin of the lake is characteristically arctic, making the islands an arctic enclave.


National park

A vast area surrounding the lakes, Richmond Gulf (''Lac Guillaume-Delisle''), and Iberville Lake (''Lac D'Iberville'') are part of the
Tursujuq National Park Tursujuq National Park is a Provincial Park of Quebec, Canada. Its creation was announced by the Province of Quebec on December 14, 2012, and officially established on July 18, 2013. Located on the east side of Hudson Bay near the Inuit village o ...
, Quebec's largest national park, opened in 2012.Ministère du Développement durable, de l'Environnement et des Parcs, ''Provisional Master Plan Parc national des Lacs-Guillaume-Delisle-et-à-l'Eau-Claire'', Quebec, 2008,
Online version
)


See also

*
Nastapoka arc The Nastapoka arc is a distinctively arcuate segment of the coastline of the southeastern shore of Hudson Bay in Quebec, Canada, that extends from the most northerly of the Hopewell Islands to Long Island near the junction with James Bay. It is ...
, an embayment of Hudson Bay 140 km to the west, discredited as an impact crater


Notes


References


External links


Aerial Exploration of the Clearwater West StructureAerial Exploration of the Clearwater East Structure
{{Impact cratering on Earth Impact craters of Quebec Lakes of Nord-du-Québec Ordovician impact craters Permian impact craters Impact crater lakes