Itqiy meteorite

The Itqiy meteorite is an enstatite-rich stony-iron meteorite. It is classified as an enstatite chondrite of the EH group that was nearly melted and is therefore very unusual for that group.[2][4] Other classifications have been proposed and are an ongoing scientific debate.

Itqiy meteorite
TypeChondrite (ongoing scientific debate)
ClassEnstatite chondrite (ongoing scientific debate)
GroupEH7-an (ongoing scientific debate)
Parent bodyNWA2526-Itqiy[1]
CompositionEnstatite (78 %), meteoric iron (22 %), sulfides.[2]
CountryWestern Sahara[3]
Coordinates26°35′27″N 12°57′8″W[3]
Observed fallYes[3]
Fall date1990[3]
Found date1990 + 2000-07[3]
TKW0.410 kilograms (0.90 lb)[3] + 4.310 kilograms (9.50 lb)[3]

History

Itqiy was initially attributed to a 1990 fireball in Western Sahara. One stone was recovered by a nomad, and a second stone was recovered in July 2000 by Marc, Luc, and Jim Labenne who were searching for meteorites in the same location.[3] The meteorite was analyzed in 2001.[5] Later work showed that the meteorite had fallen nearly 6,000 years ago and was not associated with any recent fireball. [6]

Mineralogy and petrology

Itqiy is a stony meteorite consisting of 78% enstatite and 22% meteoric iron. The meteoric iron is kamacite with 5.77% nickel. Small amounts of other minerals include troilite, Mg-Mn-Fe sulfides and Fe-Cr sulfides.[2][7]

Classification

The meteorite was described as an "ungrouped stony meteorite" in 2000, and reclassified as an "ungrouped enstatite meteorite" in 2001.[2][7] In 2006, Itqiy was classified as a member of the EH enstatite chondrites, with a petrologic type of 7, emphasizing that it was a strongly metamorphosed EH chondrite.[2]

Itqiy represents a rock that formed through partial melting of an EH chondrite. This process removed the more volatile minerals like plagioclase.[8] In 2010-1 it was proposed that Itqiy, QUE 94204, QUE 97289, QUE 97348, NWA 2526 and possibly Yamato 793225 form a new group from the same parent body that should be called "primitive enstatite achondrites".[8] [9]

gollark: Yes, however there are non-coal-generator things in existence.
gollark: Apiology?
gollark: You mostly care about how efficiently it deals with items, not RF, as RF is cheap.
gollark: Or other mathy solution, I mean.
gollark: You need to rigorously define "best" if you want an equation here.

See also

References
  1. Keil, Klaus (31 December 2009). "Enstatite achondrite meteorites (aubrites) and the histories of their asteroidal parent bodies". Chemie der Erde - Geochemistry. 70 (4): 295–317. Bibcode:2010ChEG...70..295K. doi:10.1016/j.chemer.2010.02.002.
  2. "Itqiy". Meteoritical Society.
  3. "Itqiy". Meteoritical Society. Retrieved 21 December 2012.
  4. "EH7-an". Meteoritical Society.
  5. Grossman, Jeffrey N.; Jutta Zipfel (2001). "The Meteoritical Bulletin, No. 85, 2001 September" (PDF). Meteoritics & Planetary Science. 36: A293–A322. Bibcode:2001M&PS...36..293G. doi:10.1111/j.1945-5100.2001.tb01542.x. Retrieved 21 December 2012.
  6. {{cite journal|last=Patzer|first=Andrea|author2=Dolores Hill|author3=William Boynton|author4=Luitgard Franke|author5=Ludolf Schultz|author6=Timothy Jull|author7=Lanny McHargue|author8=Ian Franchi|title=Itqiy: A study of noble gases and oxygen isotopes including its terrestrial age and a comparison with Zakłodzie|journal=Meteoritics & Planetary Science|date=2010|volume=37|pages=823–833|doi=10.1111/j.1945-5100.2002.tb00858.x |url=https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1945-5100.2002.tb00858.x%7Caccessdate=14 July 2020}
  7. Patzer, Andrea; Hill, Dolores H.; Boynton, William V. (1 November 2001). "Itqiy: A metal-rich enstatite meteorite with achondritic texture". Meteoritics & Planetary Science. 36 (11): 1495–1505. Bibcode:2001M&PS...36.1495P. doi:10.1111/j.1945-5100.2001.tb01841.x.
  8. Keil, Klaus (2010). "Enstatite achondrite meteorites (aubrites) and the histories of their asteroidal parent bodies". Chemie der Erde - Geochemistry. 70 (4): 295–317. Bibcode:2010ChEG...70..295K. doi:10.1016/j.chemer.2010.02.002.
  9. IZAWA, Matthew R. M.; FLEMMING, Roberta L.; BANERJEE, Neil R.; MATVEEV, Sergei (1 November 2011). "QUE 94204: A primitive enstatite achondrite produced by the partial melting of an E chondrite-like protolith". Meteoritics & Planetary Science. 46 (11): 1742–1753. Bibcode:2011M&PS...46.1742I. doi:10.1111/j.1945-5100.2011.01263.x.
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