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Northwest Africa 7907 | |||||||||||||||||||||||||||
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Basic information | Name: Northwest Africa 7907 This is an OFFICIAL meteorite name. Abbreviation: NWA 7907 Observed fall: No Year found: 2013 Country: (Northwest Africa) Mass: 29.9 g | ||||||||||||||||||||||||||
Classification history: |
This is 1 of 18 approved meteorites classified as Martian (polymict breccia). [show all] Search for other: Martian meteorites | ||||||||||||||||||||||||||
Comments: |
Approved 19 Jun 2013 Revised 16 Nov 2018: Updated class; see NWA 7034) | ||||||||||||||||||||||||||
Writeup |
Writeup from MB 102:
Northwest Africa 7907 (NWA 7907) (Northwest Africa) Purchased: Jan 2013 Classification: Martian meteorite (basaltic breccia) History: Purchased in January 2013 by Marc Jost in Morocco Physical characteristics: Black 29.94 g stone with remnants of fusion crust. Light-colored clasts and spheroidal objects in a brecciated matrix. Petrography: (B. Hofmann NMBE; N. Greber, Bern) Breccia of angular mineral grains (to 4 mm), lithic clasts and spheroidal objects (2-5 mm diameter) in fine-grained matrix. Minerals observed are pyroxenes, plagioclase, alkali feldspar, magnetite, chlorapatite, ilmenite, pyrite, maghemite, and goethite. Geochemistry: Orthopyroxene (Fs21-55Wo2-5, FeO/MnO = 26-55; n = 16), pigeonite (Fs33-47Wo7-18, FeO/MnO = 34-52; n = 6), augite (Fs16-26Wo37-45, FeO/MnO = 28-36; n = 3), plagioclase (An29-52Or1.6-4.5; n = 14), alkali feldspar (An4.8Or53; n = 1). Bulk analysis (XRF, n=21) shows Fe/Mn (wt) = 44.7, Ca/Si = 0.22, Mg/Si = 0.20, Ni = 550 ppm, Cr = 1680 ppm. Oxygen isotopes: (R. Greenwood, OU) gave δ18O = 6.27, δ17O = 3.89, Δ17O = 0.60 (all per mil). Classification: Martian (basaltic breccia). Closely resembles NWA 7034 and pairings and is very likely paired with these stones. Specimens: 8.20 g and one polished thin section at NMBE. Remaining material is held by Marc Jost. | ||||||||||||||||||||||||||
Data from: MB102 Table 0 Line 0: |
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Plots: | O isotopes: | ||||||||||||||||||||||||||
Institutions and collections |
NMBE: Natural History Museum Bern
Bernastrasse 15
CH-3005 Bern
Switzerland, Switzerland; Website (institutional address; updated 2 Mar 2012) OU: Planetary and Space Sciences Department of Physical Sciences The Open University Walton Hall Milton Keynes MK7 6AA United Kingdom, United Kingdom (institutional address; updated 8 Dec 2011) Bern: University of Bern, University of Bern, Hochschulstrasse 4, CH-3012 Bern, Switzerland (institutional address) |
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Catalogs: |
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References: | Published in Meteoritical Bulletin, no. 102, MAPS 50, 1662, September 2015
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Geography: |
Statistics: This is 1 of 9933 approved meteorites from (Northwest Africa) (plus 1837 unapproved names) |