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″N12°57′8″W/ 26.59083°N 12.95222°W[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] |
TheItqiy meteoriteis an enstatite-richstony-iron meteorite.It is classified as anenstatite chondriteof theEH groupthat 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
[edit]Itqiy was initially attributed to a 1990 fireball inWestern 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
[edit]Itqiy is astony meteoriteconsisting of 78%enstatiteand 22%meteoric iron.The meteoric iron iskamacitewith 5.77%nickel.Small amounts of other minerals includetroilite,Mg-Mn-Fesulfidesand Fe-Cr sulfides.[2][7]
Classification
[edit]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 EHenstatite chondrites,with apetrologic 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 likeplagioclase.[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]
See also
[edit]References
[edit]- ^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.
- ^abcde"Itqiy".Meteoritical Society.
- ^abcdefgh"Itqiy".Meteoritical Society.Retrieved21 December2012.
- ^"EH7-an".Meteoritical Society.
- ^Grossman, Jeffrey N.; Jutta Zipfel (2001)."The Meteoritical Bulletin, No. 85, 2001 September"(PDF).Meteoritics & Planetary Science.36(S9): A293–A322.Bibcode:2001M&PS...36..293G.doi:10.1111/j.1945-5100.2001.tb01542.x.Retrieved21 December2012.
- ^Patzer, Andrea; Dolores Hill; William Boynton; Luitgard Franke; Ludolf Schultz; Timothy Jull; Lanny McHargue; Ian Franchi (2010)."Itqiy: A study of noble gases and oxygen isotopes including its terrestrial age and a comparison with Zakłodzie".Meteoritics & Planetary Science.37(6): 823–833.doi:10.1111/j.1945-5100.2002.tb00858.x.
- ^abPatzer, 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.
- ^abKeil, 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.
- ^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.