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Northwest Africa 7034
Basic information Name: Northwest Africa 7034
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 7034
Observed fall: No
Year found: 2011
Country: Morocco
Mass:help 320 g
Classification
  history:
Meteoritical Bulletin:  MB 100  (2011)  Achondrite-ung
Recommended:  Martian (basaltic breccia)    [explanation]

This is 1 of 6 approved meteorites classified as Martian (basaltic breccia).   [show all]
Search for other: Martian meteorites
Comments: Approved 24 Jan 2012
Revised 4 Jan 2013: Updated classification and info
Writeuphelp
Writeup from MB 100:

Northwest Africa 7034 (NWA 7034)

Morocco

Purchased: 2011

Classification: Ungrouped achondrite

History: Purchased by Jay Piatek from AHabibi in Morocco, 2011.

Physical characteristics: Single stone, shiny, black surface, saw cut reveals porphyritic breccia with numerous dark and light colored phenocrysts and clasts of variable size and texture, set in a dark groundmass, many reflective opaques visible.

Petrography: (C. Agee, UNM) Microprobe examination of two polished epoxy mounts show a porphyritic, brecciated texture with plagioclase and pyroxene phenocrysts to 5 mm, ubiquitous chlorapatite, ilmenite, magnetite, and trace K-feldspar. Fine-grained groundmass composed of plagioclase, pyroxene, oxides, and trace Fe-sulfides. Poikilitic pyroxene-plagioclase clasts and quench melt clasts present. No Fe-Ni metal observed.

Geochemistry: (C. Agee , N. Wilson, F. McCubbin, UNM) Plagioclase Ab52±6An45±7Or3±1, n=10, low-Ca pyroxene Fs31.6±6.7Wo3.1±0.8, Fe/Mn=37±3, n=23, pigeonite Fs35.5±3.5Wo8.0±3.3, Fe/Mn=34±1, n=8, augite Fs24.3±4.5Wo38.7±4.6, Fe/Mn=32±6, n=12, apatite with Cl=4.85±0.34 F=0.70±0.13 F+Cl=-O 1.38±0.06 (wt%) n=16, ilmenite with up to 5.3 wt% MgO, magnetite with up to 22.5 wt% Cr2O3, K-feldspar Or77Ab21An3. Oxygen isotopes (Z. Sharp, UNM): acid-washed material analyzed in replicate by laser fluorination gave, respectively δ18O=6.00, 5.79, 6.51, 6.32; δ17O=3.76, 3.52, 4.09, 3.89; Δ17O= +0.59, +0.46, +0.65, +0.55 (all per mil).

Classification: Achondrite ungrouped (basaltic breccia). Plagioclase and pyroxene compositions similar to basaltic shergottites, however the oxygen isotopic values are higher than the SNC fractionation array.

Specimens: 30 g including a probe mount on deposit at UNM, Jay Piatek holds the main mass.


Writeup from MB 101:

Northwest Africa 7034 (NWA 7034), updated information, based on Agee et al. (2013)


Revised classification: Martian, Basaltic Breccia


Updated petrography (C. Agee, UNM): Porphyritic basaltic monomict breccia, with a few euhedral phenocrysts up to several millimeters and many phenocryst fragments of dominant andesine, low-Ca pyroxene, pigeonite, and augite set in a very fine-grained, clastic to plumose, groundmass with abundant magnetite and maghemite; accessory sanidine, anorthoclase, Cl-rich apatite, ilmenite, rutile, chromite, pyrite, and goethite, identified by electron microprobe analyses on eight different sections at UNM. X-ray diffraction analyses conducted at UNM on a powdered sample and on a polished surface show that plagioclase feldspar is the most abundant phase (38.0±1.2%), followed by low-Ca pyroxene (25.4±8.1%), clinopyroxenes (18.2±4.0%), iron-oxides (9.7±1.3%), alkali feldspars (4.9±1.3%), and apatite (3.7±2.6%). The x-ray data also indicate a minor amount of iron-sulfide and chromite. The data are also consistent with magnetite and maghemite making up ~70% and ~30%, respectively, of the iron oxide detected.

Additional geochemical data. Rb-Sr age (V. Polyak, Y. Asmerom, N. Wilson, UNM): 2.089±0.081 Ga (2-σ).  REE: La=58 × CI, (La/Yb)=2.3.   Hydrogen isotopes (Z. Sharp, K. Ziegler, UNM): six whole-rock combustion measurements yielded a bulk water content of 6190±620 ppm. The mean δD value for the bulk combustion analyses was +46.3±8.6‰. The maximum δD values in two separate stepwise heating experiments were +319‰ and +327‰, reached at 804°C and 1014°C respectively.  Oxygen isotopes (Z. Sharp, K. Ziegler, UNM; M. Nunn, UCSD): 21 analyses of bulk NWA 7034 were carried out. The mean value obtained at UNM was Δ17O=0.58±0.05‰ n=13 for acid washed samples and Δ17O=0.60±0.02‰ n=6 for non-acid-washed samples; at UCSD the mean value was Δ17O=0.50±0.03‰ n=2 for vacuum pre-heated samples that were dewatered and decarbonated. The combined data give Δ17O=0.58±0.05‰ n=21.


Bibliography:
  • Agee C.B., Wilson N.V., McCubbin F.M., Ziegler K., Polyak V.J., Sharp Z.D., Asmerom Y., Nunn M.H., Shaheen R., Thiemens M.H., Steele A., Fogel M.L., Bowden R., Glamoclija M., Zhang Z., and Elardo S.M. (2013) Unique meteorite from Early Amazonian Mars: water-rich basaltic breccia Northwest Africa 7034. Science 1228858, Published online 3 January 2013 DOI:10.1126/science.1228858] (link)
Data from:
  MB100
  Table 0
  Line 0:
Place of purchase:Morocco
Date:P 2011
Mass (g):319.8
Pieces:1
Class:Achondrite-ung
Ferrosilite (mol%):31.6±6.7, 35.5±3.5, 24.3±4.5
Wollastonite (mol%):3.1±0.8, 8.0±3.3, 38.7±4.6
Classifier:C. Agee
Type spec mass (g):30
Type spec location:UNM
Main mass:Jay Piatek
Comments:Submitted by C. Agee
Plots: O isotopes:  
Institutions
   and collections
UNM: Institute of Meteoritics MSC03 2050 University of New Mexico Albuquerque NM 87131-1126 USA, United States; Website (institutional address; updated 26 Dec 2011)
AHabibi: Palms Hotel Club, Erfoud 52200, Morocco (private address; updated 3 Jan 2010)
UCSD: Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, United States (institutional address; updated 4 Jan 2013)
Catalogs:
References: Published in Meteoritical Bulletin, no. 100, MAPS 46, in preparation (2013)
Published in Meteoritical Bulletin, no. 101, MAPS 47, in preparation (2013)
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)
Chris Osborn   
Gregor H.   
Institute of Meteoritics UNM   
jdc-meteorite   
Randall Taylor               
Geography:

Morocco
Coordinates:Unknown.

Statistics:
     This is 1 of 936 approved meteorites from Morocco (plus 8 unapproved names)

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