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Northwest Africa 8545 | |||||||||||||||||||||||||||||
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Basic information | Name: Northwest Africa 8545 This is an OFFICIAL meteorite name. Abbreviation: NWA 8545 Observed fall: No Year found: 2013 Country: (Northwest Africa) Mass: ![]() | ||||||||||||||||||||||||||||
Classification history: |
This is 1 of 131 approved meteorites classified as Achondrite-ung. [show all] Search for other: Achondrites, Ungrouped achondrites | ||||||||||||||||||||||||||||
Comments: | Approved 18 Oct 2014 | ||||||||||||||||||||||||||||
Writeup![]() |
Writeup from MB 103:
Northwest Africa 8545 (NWA 8545) (Northwest Africa) Purchased: 2013 Classification: Ungrouped achondrite History: Purchased by Brahim Tahiri from a Moroccan hunter and sent to his partner Sean Tutorow for classification, April, 2013. Physical characteristics: Single stone. Exterior shows remnants of black fusion crust, saw cut reveals light orange-brown crystalline texture with scattered dark grains ~1 mm, moderately friable. Petrography: (C. Agee, UNM) Microprobe examination of a polished mount shows approximately 70% pyroxene and ~30% plagioclase. Pyroxenes all show exsolution lamellae, grains are 500-2000 μm, and have a striking appearance in that the grain boundaries are all very irregular with ~50 μm embayments and protrusions. Plagioclase is interstitial to pyroxene and poikioblastic with silica inclusions, some grains up to 1000 μm. Accessory troilite and Cr-Ti oxides. Geochemistry: (C. Agee and N. Muttik, UNM) Pigeonite Fs62.4±1.9Wo7.6±2.1, Fe/Mn=69±2, n=9; augite Fs39.9±5.4Wo34.0±6.3, Fe/Mn=67±5, n=8; olivine Fa84.2, Fe/Mn=89, n=1; plagioclase An85.3±2.6Ab14.2±2.5Or0.4±0.1, n=10. Oxygen isotopes (K. Ziegler, UNM) Oxygen isotope values of 3 acid-washed aliquots of bulk sample, 1.3, 1.3, 2.1 mg, gave δ17O = 0.004, 0.120, 0.013, δ18O = 2.966, 3.159, 2.297, Δ17O = -1.562, -1.548, -1.532 (linearized, all permil). Classification: Achondrite (ungrouped), probably paired with NWA 011 and NWA 2976. Specimens: 11.7 g including a probe mount on deposit at UNM, Sean Tutorow holds the main mass. | ||||||||||||||||||||||||||||
Data from: MB103 Table 0 Line 0: |
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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 12 Feb 2015) |
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Catalogs: |
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References: | Published in Meteoritical Bulletin, no. 103, MAPS 52, 1014, May 2017, http://onlinelibrary.wiley.com/doi/10.1111/maps.12888/full
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Geography: |
Statistics: This is 1 of 9116 approved meteorites from (Northwest Africa) (plus 1873 unapproved names) |