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Northwest Africa 2994
Basic information Name: Northwest Africa 2994
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 2994
Observed fall: No
Year found: 2007
Country: (Northwest Africa)
Mass:help 4.76 kg
Classification
  history:
Meteoritical Bulletin:  MB 93  (2008)  Chondrite-ung
Recommended:  Chondrite-ung    [explanation]

This is 1 of 24 approved meteorites classified as Chondrite-ung.   [show all]
Search for other: Ungrouped chondrites
Comments: Approved 14 Jan 2008
Revised 4 Aug 2008: final writeup
Writeuphelp
Writeup from MB 93:

Northwest Africa 2994

    Northwest Africa

    Find: 2007

    Chondrite (ungrouped)

History and physical characteristics: A 4756 g unbrecciated, complete stone was purchased in Morocco in July 2007. This greenish stone is desert-polished to a high degree with only patches of semi-polished black fusion crust. Large, dark green olivine and orthopyroxene porphyroblasts on the surface range in size from a few to 38 mm.  One centimeter-sized metal blob, together with minor metal enclaves of several millimeters, is also a prominent surface characteristic. Only minor iron oxide staining is present as a chemical weathering signature, and alteration veining is not evident.

Petrography (T. Bunch and J. Wittke, NAU; A. Irving, UWS): A remarkable, recrystallized stone with textures that range from porphyroblastic to poikiloblastic. Grain boundaries are irregular with few 120º triple junctions. Both olivine poikiloblasts (with orthopyroxene and opaque inclusions) and orthopyroxene poikiloblasts (with olivine inclusions) are common. Grain size, exclusive of porphyroblasts, is 0.1 to 1.6 mm in largest dimension. Scarce, highly modified relict chondrule fragments (2 per 1.6 mm2) are present and are evident only as patches of recrystallized barred olivine and felsic mesostasis (one example has an annular olivine ring). SEM-BSE integrated gray-scale modal analyses, in vol%: olivine = 45; orthopyroxene = 42; augite = 3; plagioclase = 3; FeS = 3; chromite = 2 and metal = 2 with a trace amount of merrillite.

Mineral compositions: Olivine (Fa37.3; FeO/MnO = 81-88), orthopyroxene (Fs29.5Wo3.1; FeO/MnO = 53-58), augite (Fs12.1Wo45.7), plagioclase (An53.3Or0.8; FeO = 0.38 wt%); chromite (cr# = 71; TiO2 = 1.91, MgO = [both 2.66 wt%]), kamacite (Ni = 6.0 wt%) and taenite (Ni = 25.6 wt%).

Oxygen isotopes: (D. Rumble, CIW) Replicate analyses of acid-washed material by laser fluorination gave, respectively: d17O= -0.007 ; +0.078; d18O = 3.331 ; 3.355, D17O = -1.6769 ; -1.687 (all ‰).

Classification: Chondrite (Ungrouped); S1, minor weathering.

Type specimen: A total of 23 g is on deposit at NAU. The main mass holder is anonymous.

 

Data from:
  MB93
  Table 2
  Line 11:
Place of purchase:Morocco
Date:July 2007
Mass (g):4756
Pieces:1
Class:Chon-ung
Type spec mass (g):23
Plots: O isotopes:  
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)
CIW: Carnegie Insitution Washington, Geophysical Laboratory, 5251 Broad Branch Rd., NW, Washington DC 20015, United States (institutional address)
Catalogs:
References: Published in Meteoritical Bulletin, no. 93, MAPS 43, 571-632 (2008)
Find references in NASA ADS:
Find references in Google Scholar:
Geography: 
Coordinates:Unknown.

Statistics:
     This is 1 of 6759 approved meteorites from (Northwest Africa) (plus 2047 unapproved names)

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