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Northwest Africa 4819
Basic information Name: Northwest Africa 4819
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 4819
Observed fall: No
Year found: 2007
Country: (Northwest Africa)
Mass:help 234 g
Classification
  history:
Meteoritical Bulletin:  MB 93  (2008)  Lunar
Recommended:  Lunar    [explanation]

This is 1 of 89 approved meteorites classified as Lunar.   [show all]
Search for other: Lunar meteorites
Comments: Approved 14 Jan 2008
Revised 4 Aug 2008: final writeup
Writeuphelp
Writeup from MB 93:

Northwest Africa 4819

Northwest Africa

Find: 2007

Achondrite (lunar, feldspathic breccia)

History and Physical characteristics: A single 234 g crusted stone was purchased in Rissani, Morocco in 2007. The crust is fresh with dark gray to black crusted areas and vermillion to light brown in abraded to weathered areas; some areas show melt bubbles and flow. A network of thin fractures is filled with weathering products.

Petrography: (T. Bunch and J. Wittke, NAU; A. Irving, UWS) This stone is very dark, well indurated, and is fine-grained with few clasts that exceed one mm in diameter. No evidence of flow orientation was observed. NWA 4819 is a regolith breccia and has two unusual characteristics for a lunar sample: (1) a relatively large amount of homogeneously distributed fine-grained metallic nickel-iron (2 wt%) and troilite (1.5 wt%) and (2) a large population of pyroxene fragments. Most lithic clasts follow the ferroan anorthositic trend and include anorthosites, fine-grained anorthositic norites, gabbros, and troctolites, in addition to shock melt clast, K-rich glass, and spherules. No intact basaltic clasts were observed and all clasts are crushed to some extent.

Mineral compositions and Geochemistry: Host orthopyroxene (Fs48.9-67.5Wo2.2-4.3; FeO/MnO = 56), exsolution lamellae (Fs24.4-41.4Wo12.3-32.9; FeO/MnO = 60). Anorthositic norite: orthopyroxene (Fs35.4Wo4.3) and plagioclase (An96.5). Anorthositic troctolite olivine (Fa28.1; FeO/MnO = 105), pigeonite (Fs26.9Wo5.9; FeO/MnO = 54), plagioclase (An97) and chromite (cr# = 80). Kamacite (mean Ni = 6.2, Co = 0.77 (both wt%) and taenite (Ni = 8.2- 23.6 wt%). Bulk composition: (R. Korotev, WUSL): FeO = 7.0% wt%, Ni = 290 ppm, Sm = 3.4 ppm, Th = 1.5 ppm, Ir = 12 ppb.

Classification: Achondrite (lunar, feldspathic breccia).

Type specimens: A total of 20.3 g is on deposit at NAU. The main mass holder is anonymous.

Submitted by: T. Bunch, NAU.

Data from:
  MB93
  Table 2
  Line 122:
Place of purchase:Rissani, Morocco
Date:2007
Class:Lunar
Institutions
   and collections
NAU: Geology, Bldg 12 Knoles Dr Northern Arizona University, Flagstaff, AZ 86011, United States; Website (institutional address; updated 12 Apr 2012)
UWS: University of Washington, Department of Earth and Space Sciences, 70 Johnson Hall, Seattle, WA 98195, United States (institutional address; updated 15 Jan 2012)
WUSL: Washington Univ., One Brookings Drive, St. Louis, MO 63130, United States (institutional address; updated 17 Oct 2011)
Catalogs:
References: Published in Meteoritical Bulletin, no. 93, MAPS 43, 571-632 (2008)
Find references in NASA ADS:
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Photos:
CreditPhotos
Photos uploaded by members of the Encyclopedia of Meteorites.
    (Caution, these are of unknown reliability)
Doug R   
Geography: 
Coordinates:Unknown.

Statistics:
     This is 1 of 7385 approved meteorites from (Northwest Africa) (plus 1955 unapproved names)

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