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Northwest Africa 7611
Basic information Name: Northwest Africa 7611
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 7611
Observed fall: No
Year found: 2012
Country: Morocco
Mass:help 916 g
Classification
  history:
Meteoritical Bulletin:  MB 102  (2013)  Lunar
Recommended:  Lunar    [explanation]

This is 1 of 81 approved meteorites classified as Lunar.   [show all]
Search for other: Lunar meteorites
Comments: Approved 1 Jan 2013
Writeuphelp
Writeup from MB 102:

Northwest Africa 7611 (NWA 7611)

Morocco

Found: May 2012

Classification: Lunar meteorite

History: Reportedly found near the Moroccan/Algerian border in May 2012. Purchased from a Moroccan meteorite dealer in 2012.

Physical characteristics: Single 916 g stone, no fusion crust, smooth exterior with numerous light- and dark-colored clasts, saw cuts reveal brecciated texture with white feldspar and green-brown pyroxene and olivine grains (up to 3 mm) set in a darker gray-green matrix; scattered gabbroic and dark clasts up to 1 cm.

Petrography: (C. Agee, UNM; A. Irving, UWS) Microprobe examination of a polished 7 × 2 cm sawn slice and a separate polished mount shows a fragmental breccia of plagioclase, pyroxene, and olivine grains in a wide range of grain sizes. A prominent ~1-cm pyroxene-plagioclase gabbroic clast was observed as well as several smaller gabbroic fragments. One small clast consists of intergrown hedenbergite+fayalite+silica (after pyroxferroite). The groundmass is variable with some domains showing a uniform fine-grained subophitic plagioclase-pyroxene texture, while other domains show densely packed mineral clasts ranging from 10-300 μm. There are several sharp boundaries between the various textural domains, with at least two compositionally distinct olivine populations, and a wide range of pyroxene compositions, indicating multiple lithologies of a mingled fragmental breccia. Accessory ilmenite, silica polymorph, minor zircon, troilite, Ti-bearing chromite, Ni-free iron metal and kamacite are present.

Geochemistry: (C. Agee and M. Spilde, UNM; A. Irving and S. Kuehner, UWS). Fayalitic olivine Fa90.6±5.7, Fe/Mn=90±4, n=15; forsteritic olivine Fa31.6±11.1, Fe/Mn=93±9, n=3; pyroxene Fs43.6±13.3Wo20.2±8.5, Fe/Mn=67±8, n=37; pyroxene in gabbroic clast Fs45.3±13.1 Wo15.4±5.3, Fe/Mn=69±7, n=12; plagioclase An93.5±1.5Ab6.0±1.4Or0.5±0.5, n=13. Bulk composition (R. Korotev, WUSL). INAA on 4 subsamples gave the following mean values: Na2O=0.405, CaO=14.8, FeO=11.27 (wt%); Sc=25.1, Cr=1692, Co=37.6, Ni=181, La=6.38, Nd=8.9, Sm=3.07, Eu=0.891, Lu=0.321, Hf=2.12, Ir=0.0044, Au=0.0036, Th=0.97, U=0.36 (ppm). Oxygen Isotopes, laser fluorination (K.Ziegler, UNM), 6 analyses on 3 acid-washed aliquots gave mean values δ17O=3.161±0.080, δ18O=5.931±0.031, Δ17O=0.030±0.075 (linearized, all permil).

Classification: Achondrite (lunar, mingled breccia), high bulk FeO and Sc, and fayalitic olivines suggest the presence of a mare basalt component.

Specimens: A total of 20 g is on deposit at UNM. The remainder is divided between Jay Piatek, Matt Morgan, Mike Hankey, and Haag; Jay Piatek holds the main mass.

Data from:
  MB102
  Table 0
  Line 0:
Place of purchase:Morocco
Date:May 2012
Mass (g):916
Pieces:1
Class:Lunar
Fayalite (mol%):90.6±5.7, 31.6±11.1
Ferrosilite (mol%):43.6±13.3
Wollastonite (mol%):20.2±8.5
Classifier:C. Agee
Type spec mass (g):20
Type spec location:UNM
Main mass:Jay Piatek
Comments:Submitted by C. Agee
Institutions
   and collections
UNM: Institute of Meteoritics MSC03 2050 University of New Mexico Albuquerque NM 87131-1126 USA, United States; Website (institutional address; updated 12 Feb 2015)
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)
Haag: Robert Haag, P.O. Box 27527, Tucson, AZ 85726, United States; Website (private address)
Catalogs:
References: Published in Meteoritical Bulletin, no. 102, MAPS 50, 1662, September 2015
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)
Volker Heinrich      
Geography:

Morocco
Coordinates:Unknown.

Statistics:
     This is 1 of 1312 approved meteorites from Morocco (plus 14 unapproved names) (plus 1 impact crater)

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