Mistastin crater is a

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 ...

crater Crater may refer to: Landforms *Impact crater, a depression caused by two celestial bodies impacting each other, such as a meteorite hitting a planet *Explosion crater, a hole formed in the ground produced by an explosion near or below the surfac ...

Labrador , nickname = "The Big Land" , etymology = , subdivision_type = Country , subdivision_name = Canada , subdivision_type1 = Province , subdivision_name1 ...

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...

which contains the roughly circular Mistastin Lake. The

lake A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much large ...

is approximately in diameter, while the estimated diameter of the original crater is . The age of the crater is calculated to be 36.6 ± 2 million years (

Eocene The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene' ...

). The lake was first identified as a possible impact crater in 1968, after being viewed from space.

Location

Mistastin crater, aka Kamestastin, is located in northwestern inland Labrador, due west of Natuashish, near the Quebec border. It lies within the traditional hunting grounds of the Mushuau Innu First Nation. Although it is not within a declared reserve, it does require permission to visit.

Formation and geology

Mistastin crater was created 36 million years ago by a violent asteroid impact. The presence of

cubic zirconia Cubic zirconia (CZ) is the cubic crystalline form of zirconium dioxide (ZrO2). The synthesized material is hard and usually colorless, but may be made in a variety of different colors. It should not be confused with zircon, which is a zirconi ...

around the crater rim suggests that the impact generated temperatures in excess of 43% that of the

surface of the Sun The photosphere is a star's outer shell from which light is radiated. The term itself is derived from Ancient Greek roots, φῶς, φωτός/''phos, photos'' meaning "light" and σφαῖρα/''sphaira'' meaning "sphere", in reference to it ...

and the highest crustal temperatures known on produced global changes that lasted for decades after the impact. Mishta-minishtikᐡ, the lake's arcuate central island, is interpreted to be the central uplift of the complex crater structure. The target rocks were part of a

batholith A batholith () is a large mass of intrusive igneous rock (also called plutonic rock), larger than in area, that forms from cooled magma deep in Earth's crust. Batholiths are almost always made mostly of felsic or intermediate rock types, such ...

composed of

adamellite Quartz monzonite is an intrusive, felsic, igneous rock that has an approximately equal proportion of orthoclase and plagioclase feldspars. It is typically a light colored phaneritic (coarse-grained) to porphyritic granitic rock. The plagioclas ...

mangerite Mangerite is a plutonic intrusive igneous rock, that is essentially a hypersthene-bearing monzonite. It often occurs in association with norite, anorthosite, charnockite and rapakivi granite in Proterozoic metamorphic Metamorphic rocks ar ...

and lenses of

anorthosite Anorthosite () is a phaneritic, intrusive igneous rock characterized by its composition: mostly plagioclase feldspar (90–100%), with a minimal mafic component (0–10%). Pyroxene, ilmenite, magnetite, and olivine are the mafic minerals most c ...

. There are abundant shock metamorphic features exhibited in the rocks of the island.

Planar deformation features Planar deformation features, or PDFs, are optically recognizable microscopic features in grains of silicate minerals (usually quartz or feldspar), consisting of very narrow planes of glassy material arranged in parallel sets that have distinct orie ...

, diaplectic glass, melt rocks, and

shatter cone Shatter cones are rare geological features that are only known to form in the bedrock beneath meteorite impact craters or underground nuclear explosions. They are evidence that the rock has been subjected to a shock with pressures in the rang ...

s have been identified. Mistastin crater L1C T20UMG T20VMH A026091 20200620T152632

References

External links

Aerial Exploration of the Mistastin Structure
Impact craters of Canada Eocene impact craters Labrador Lakes of Newfoundland and Labrador Impact crater lakes {{Canada-geology-stub

Location

Formation and geology

See also

References

Further reading

External links