Northwest Africa 7203 meteorite (NWA 7203), Northwest Africa Meteorites
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| Non-native locality type: | Meteorite |
|---|---|
| Meteorite Type: | Angrite |
Quenched Angrite (achondrite)
Find, 2011; 107 g
The Northwest Africa 7203 meteorite is a small stone covered with a fusion crust. Ca-rich olivine and anorthitic plagioclase grains up to 1mm in size are in a fine-grained variolitic matrix with interstitial fassaite. Kirschsteinite olivine (up to 20 wt% CaO) is intergrown with fayalitic olivine. The variolitic textures are somewhat unusual in that the very fine-grained (≤10 mm) and medium-grained (~1mm) regions are approximately equal in area. Extensively zoning of both olivine and Al-Ti-rich clinopyroxene result in Mg-free end member compositions (e.g., fayalite and hedenbergite). Minor accessories include troilite and ulvöspinel. Thin shock veins (100 µm wide) indicate moderate shock.
NWA 7203 is one of 15 recovered angrite meteorites. Its mineral chemistry is similar to other quenched angrites, NWA 1297 and NWA 1670, but its textures are different — probably due to changes in cooling rates during crystallization.
Mineral List
7 valid minerals.
Meteorite/Rock Types Recorded
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Alphabetical List Tree DiagramThis page contains all mineral locality references listed on mindat.org. This does not claim to be a complete list. If you know of more minerals from this site, please register so you can add to our database. This locality information is for reference purposes only. You should never attempt to
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References
Ruzicka, A., Grossman, J. N. & Garvie, L. (2014) Meteoritical Bulletin, no. 100: Meteoritical & Planetary science 49: E1-E101. (Aug 2014) [Online supplement]
Mikouchi, T. & Bizzarro, M. (2012) Mineralogy and Petrology of NWA 7203: A New Quenched Angrite Similar to NWA 1296 and NWA 1670. Meteoritics and Planetary Science Supplement, id.5120. (Sept 2012).
Grady, M. M., Pratesi, G. & Moggi-Cecchi, V. (2015) Atlas of Meteorites. Cambridge University Press: Cambridge, United Kingdom. 373 pages.
Mikouchi, T. & Bizzarro, M. (2012) Mineralogy and Petrology of NWA 7203: A New Quenched Angrite Similar to NWA 1296 and NWA 1670. Meteoritics and Planetary Science Supplement, id.5120. (Sept 2012).
Grady, M. M., Pratesi, G. & Moggi-Cecchi, V. (2015) Atlas of Meteorites. Cambridge University Press: Cambridge, United Kingdom. 373 pages.
External Links
http:www.lpi.usra.edu/meteor/metbull.php?code=55296 -NWA7203@MetBullDatabase
http://www.lpi.usra.edu/meetings/metsoc2012/pdf/5120.pdf -Mikouchi & Bizzarro (2012)
http://www.lpi.usra.edu/meetings/metsoc2012/pdf/5120.pdf -Mikouchi & Bizzarro (2012)
