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Northwest Africa 12818 | |||||||||||||||||||||||||||||||||||
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Basic information | Name: Northwest Africa 12818 This is an OFFICIAL meteorite name. Abbreviation: NWA 12818 Observed fall: No Year found: 2018 Country: (Northwest Africa) Mass: 241 g | ||||||||||||||||||||||||||||||||||
Classification history: |
This is 1 of 13 approved meteorites classified as LL3-5. [show all] Search for other: LL chondrites, LL chondrites (type 3), Ordinary chondrites, and Ordinary chondrites (type 3) | ||||||||||||||||||||||||||||||||||
Comments: | Approved 3 Sep 2019 | ||||||||||||||||||||||||||||||||||
Writeup |
Writeup from MB 108:
Northwest Africa 12818 (NWA 12818) (Northwest Africa) Purchased: 2018 Classification: Ordinary chondrite (LL3-5) History: Marc Jost purchased from a Moroccan dealer at the 2018 Ensisheim meteorite show. Physical characteristics: The 241g sample has a brown weathered exterior with an irregular shape and a weathered fusion crust. The cut face shows the interior is a breccia composed of clasts of equilibrated lithologies set within a host of flattened chondrules that define a foliation. Petrography: Description and Classification (A. Love, App) Sample is a breccia composed of sparse, angular-rounded clasts of recrystallized equilibrated chondrite set within a host of densely-packed, unequilibrated chondrules and fragments (avg. dia. 917 μm, N=58) with fine-grained rims and rare matrix lumps. Geochemistry: (A. Love, App) Host: Olivine Fa18.6±11.1 (Fa0.5-37.6), Fe/Mn=53.5±17.0, mean Cr2O3 in ferroan olivine=0.1±0.1 (0.0-0.4), PMD=51% N=16; low Ca pyroxene Fs12.3±7.4Wo0.8±0.8 (Fs1.4-29.5Wo0.2-3.5), PMD=47%, N=14. Clast 1: Olivine Fa28.2±2.5 (Fa22.9-30.1), Fe/Mn=55.0, N=6; low Ca pyroxene Fs25.1±0.1Wo1.7±0.4, N=3. Clast 2: Olivine Fa30.4±0.2, Fe/Mn=56.5, N=6; low Ca Pyroxene Fs25.2±0.2Wo1.4±0.5, N=3. Classification: Ordinary Chondrite (LL3, 5C-S3, W3) Based on chondrule size and magnetic susceptibility and mineral compositions, this sample is an LL ordinary chondrite. Based on textures and mineral compositions, this sample is an LL3-5 breccia. Host is ≥3.2 based on PMD of Ol and Opx, CL observations indicate ≥3.3 following Huss et al. (2006), and mean and standard deviation of Cr2O3 in ferroan Ol ≥3.2. Specimens: Marc Jost (SJS) holds the main mass. 2 slices weighing 33.2 g and a polished mount and thin section and mount are on deposit at App. | ||||||||||||||||||||||||||||||||||
Bibliography: |
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Data from: MB108 Table 0 Line 0: |
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Institutions and collections |
App: Department of Geology, 572 Rivers St., Appalachian State University, Boone, NC 28608, United States (institutional address; updated 7 Mar 2013) SJS: Space Jewels Switzerland, 2555 Brügg, Switzerland (private address; updated 3 Jan 2010) |
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Catalogs: |
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References: | Published in Meteoritical Bulletin, no. 108 (2020) Meteorit. Planet. Sci. 55, 1146-1150
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Geography: |
Statistics: This is 1 of 9589 approved meteorites from (Northwest Africa) (plus 1869 unapproved names) | ||||||||||||||||||||||||||||||||||
Also see: |
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Revision history: |
This lists important revisions made to data for this record.
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