Itqiy meteorite

Itqiy meteorite
Type Chondrite (ongoing scientific debate)
Class Enstatite chondrite (ongoing scientific debate)
Group EH7-an (ongoing scientific debate)
Parent body NWA2526-Itqiy[1]
Composition Enstatite (78 %), meteoric iron (22 %), sulfides.[2]
Country Western Sahara[3]
Coordinates 26°35′27″N 12°57′8″W / 26.59083°N 12.95222°W / 26.59083; -12.95222Coordinates: 26°35′27″N 12°57′8″W / 26.59083°N 12.95222°W / 26.59083; -12.95222[3]
Observed fall Yes[3]
Fall date 1990[3]
Found date 1990 + 2000-07[3]
TKW 0.410 kilograms (0.90 lb)[3] + 4.310 kilograms (9.50 lb)[3]

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.

History

Itqiy fell during 1990 in Western Sahara and is named after a small hamlet.[3][5] One stone was recovered soon after by a nomad, a second stone was recovered in July 2000 by Marc, Luc, and Jim Labenne who were searching for meteorites in the same location.[3] It was first described in 2001.[6]

Mineralogy and petrology

Itqiy is a stony-iron 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 "Enstatite meteorite ungrouped" in 2001. It was reasoned that Itqiy represents a rock that formed through partial melting of an enstatite chondrite.[2][7] In 2006 Itqiy was classified as a member of the EH group, petrologic type 7, emphasizing the strong metamorphic overprint of the specimen.[2] In 2008 it was argued that Itqiy represents the residue of an enstatite chondrite that was partially molten about 20%, thereby removing the plagioclase.[8] In 2011 it was proposed that Itqiy, QUE 94204, QUE 97289, QUE 97348, NWA 2526 and possibly Yamato 793225 are part of a new group that should be called "primitive enstatite achondrites".[9]

Parent body

In 2010 it was proposed that NWA 2526 and Itqiy share the same parent body.[8]

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. doi:10.1016/j.chemer.2010.02.002.
  2. 1 2 3 4 5 "Itqiy". Meteoritical Society.
  3. 1 2 3 4 5 6 7 8 9 "Itqiy". Meteoritical Society. Retrieved 21 December 2012.
  4. ↑ "EH7-an". Meteoritical Society.
  5. ↑ "Meteorites Western Sahara 7". niger-meteorite-recon.de.
  6. ↑ Grossman, Jeffrey N.; Jutta Zipfel (2001). "The Meteoritical Bulletin, No. 85, 2001 September" (PDF). Meteoritics & Planetary Science. 36: A293–A322. doi:10.1111/j.1945-5100.2001.tb01542.x. Retrieved 21 December 2012.
  7. 1 2 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. doi:10.1111/j.1945-5100.2001.tb01841.x.
  8. 1 2 Keil, Klaus (2010). "Enstatite achondrite meteorites (aubrites) and the histories of their asteroidal parent bodies". Chemie der Erde - Geochemistry. 70 (4): 295–317. 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. doi:10.1111/j.1945-5100.2011.01263.x.
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