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Northwest Africa 12726
Basic information Name: Northwest Africa 12726
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 12726
Observed fall: No
Year found: 2010
Country: (Northwest Africa)
Mass:help 606 g
Classification
  history:
Recommended:  LL4    [explanation]

This is 1 of 368 approved meteorites classified as LL4.   [show all]
Search for other: LL chondrites, LL chondrites (type 4-7), Ordinary chondrites, and Ordinary chondrites (type 4-7)
Comments: Approved 11 Jun 2019
Writeuphelp
Writeup from MB 108:

Northwest Africa 12726 (NWA 12726)

(Northwest Africa)

Purchased: 2010 Feb

Classification: Ordinary chondrite (LL4)

History: Purchased in Tucson by Bob Falls in February 2010. A piece was brought to Cascadia by Fred Olsen.

Physical characteristics: Sample has black, patchy remnant fusion crust and a weathering patina. Already cut faces have chondritic texture with abundant sulfide and metal and rust haloes.

Petrography: (M. Ream, M. Hutson, A. Ruzicka, Cascadia) In thin section, matrix is black and fine-grained, with well-defined chondrules. Minor clinoenstatite is present. A 2.5 mm × 2.3 mm clast is present, which is cut off on its long axis by the edge of the thin section. The clast has well-defined chondrules, matrix that is darker than the host, and contains abundant oriented troilite, including a ~0.17 mm thick vein. Pyroxenes in the clast are zoned in BSE images.

Geochemistry: Mineral compositions and geochemistry: Olivine and pyroxene grains in the host lithology are relatively equilibrated (Fa27.9±0.3, N=14; Fs21.6±2.8Wo1.0±0.5, N=33). Clast olivine (Fa28.0±0.4, N=9) is essentially identical with host olivine. Clast pyroxene (Fs21.7±7.7Wo1.9±1.1, N=11) has the same mean Fs content, but a much greater range of compositions than host pyroxene.

Classification: Ordinary chondrite (LL4) based on chemistry and texture.

Specimens: Cascadia holds 30.1 g in three pieces, a polished thin section, and a mounted butt. The main mass is held by Bob Falls (no address given).

Data from:
  MB108
  Table 0
  Line 0:
Place of purchase:Tucson AZ
Date:P 2010 Feb
Mass (g):606.4
Pieces:1
Class:LL4
Shock stage:S4
Weathering grade:W1
Fayalite (mol%):27.9±0.3 (host), 28.0±0.4 (clast)
Ferrosilite (mol%):21.6±2.8 (host), 21.7±7.7 (clast)
Wollastonite (mol%):1.0±0.5 (host), 1.9±1.1 (clast)
Classifier:M. Ream, M. Hutson, and A. Ruzicka, Cascadia
Type spec mass (g):30.1
Type spec location:Cascadia
Main mass:Bob Falls
Comments:Field number used by Fred Olsen BF 2010-2, Lab number CML0683.; submitted by A. Ruzicka
Institutions
   and collections
Cascadia: Cascadia Meteorite Laboratory, Portland State University, Department of Geology, Room 17 Cramer Hall, 1721 SW Broadway, Portland, OR 97201, United States; Website (institutional address; updated 28 Oct 2011)
Olsen: Unknown person (private address; updated 17 Apr 2009)
Catalogs:
References: Published in Meteoritical Bulletin, no. 108, in preparation (2019)
Find references in NASA ADS:
Find references in Google Scholar:
Geography: 
Coordinates:Unknown.

Statistics:
     This is 1 of 7320 approved meteorites from (Northwest Africa) (plus 1973 unapproved names)

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