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| Northwest Africa 13249 | |||||||||||||||||||||||||||||||
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| Basic information | Name: Northwest Africa 13249 This is an OFFICIAL meteorite name. Abbreviation: NWA 13249 Observed fall: No Year found: 2019 Country: Libya Mass:  4.7 kg | ||||||||||||||||||||||||||||||
| Classification history: |
This is 1 of 27 approved meteorites classified as C2-ung. [show all] Search for other: Carbonaceous chondrites, Carbonaceous chondrites (type 2), and Ungrouped chondrites | ||||||||||||||||||||||||||||||
| Comments: | Approved 11 Nov 2020 | ||||||||||||||||||||||||||||||
| Writeup |
Writeup from MB 109:
Northwest Africa 13249 (NWA 13249) Libya Purchased: March 2019 Classification: Carbonaceous chondrite (C2, ungrouped) History: Reportedly found 400 km south of Gadamis in the Libya-Algeria border region. Purchased at the market in Gadamis in 2019. Physical characteristics: Thirty matching stones, fresh fusion crust covers the exterior. Contraction cracks on the surface filled with desert soil are present. Saw cuts reveal numerous small chondrules set in a very dark colored abundant matrix. Friable. Scattered CAIs observed thoughout. Petrography: (C. Agee, UNM) Microprobe examination shows scattered chondrules, many of which are irregular in shape. There are approximately equal numbers of type I and type II chondrules. Apparent mean chondrule diameter 230±230 μm, n=33. Fine-grained matrix makes up about 70% of this meteorite. Cronstedtite was detected in the matrix. Aluminous diopside and Cr-rich spinel present. Fusion crust is approximately 200 μm thick. Geochemistry: (C. Agee, UNM) All chondrule olivine Fa24.4±21.6, Fe/Mn=63±44, Cr2O3=0.33±0.15 wt%, n=20; ferroan chondrule olivine Fa40.1±11.5, Fe/Mn=97±12, Cr2O3=0.32±0.11 wt%, n=12; low-Ca pyroxene Fs12.0±13.7Wo1.6±1.0, n=5. Oxygen isotopes (K. Ziegler, UNM): 3 acid-washed fragments analyzed by laser fluorination gave δ18O= -4.759, -6.292, -1.716; δ17O= -8.654, -10.479, -5.673; Δ17O= -6.141, -7.157, -4.767 (linearized, all per mil, TFL slope=0.528). Classification: Carbonaceous chondrite C2 ungrouped. Type 2 based on the presence of cronstedtite in the matrix. Ungrouped based on the oxygen isotopes plotting near the CO3 field with small chondrules, but the meteorite is petrologic type 2 with abundant matrix. This is not a CM2 or CO3, possibly similar to NWA 5958. Specimens: 20.1 g on deposit at UNM, DPitt holds the main mass. | ||||||||||||||||||||||||||||||
| Data from: MB109 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) DPitt: Darryl Pitt, 225 West 83rd Street, New York, NY 10024, United States; Website (private address) |
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| Catalogs: |
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| References: | Published in Meteoritical Bulletin, no. 109, in preparation (2020)
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| Photos: |
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Geography:
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Statistics: This is 1 of 1553 approved meteorites from Libya (plus 24 unapproved names) (plus 2 impact craters) | ||||||||||||||||||||||||||||||
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| Revision history: |
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