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| Northwest Africa 4724 | |||||||||||||
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| Basic information | Name: Northwest Africa 4724 This is an OFFICIAL meteorite name. Abbreviation: NWA 4724 Observed fall: No Year found: 2001 Country: Morocco Mass:  35 g | ||||||||||||
| Classification history: |
This is 1 of 79 approved meteorites classified as CK3. [show all] Search for other: Carbonaceous chondrites, Carbonaceous chondrites (type 3), CK chondrites, CK3 chondrites, and CV-CK clan chondrites | ||||||||||||
| Comments: |
Approved 6 Mar 2008 Revised 17 Dec 2008: corrected year; 2008-08-04 final writeup | ||||||||||||
| Writeup |
Writeup from MB 93:
Northwest Africa 4724 Morocco Find: January 2006 Carbonaceous chondrite (CK3) History: The sample was purchased in Erfoud, Morocco, in January 2006 by C. Giessler. Physical characteristics: One stone weighing 35 g; slightly brown colored; 80% covered with fusion crust. Petrography: (M. Bourot-Denise, MNHN) Obvious chondrules with most having a diameter in the range of 500- 1500 µm; the largest are porphyritic olivine chondrules (largest chondrule studied section is 5000 µm in size). A large (1.5 cm) spinel-rich CAI also occurs; there are also many smaller CAIs. Magnetite is abundant and is associated with sulfides (troilite + pyrrhotite + pentlandite) in large nodules in between chondrules, in small isolated grains between clinopyroxene and plagioclase laths in the crystalline matrix, and as very small grains interspersed in the matrix around CAIs and chondrules. Magnetite beads also occur inside porphyritic chondrules. BSE images show that most olivines in porphyritic chondrules are unequilibrated with an FeO-poor core. Low-Ca pyroxene in the outer part of these chondrules is equilibrated. Outside of chondrules, clinopyroxene is dominant with a variable composition. Terrestrial weathering seems to have little affected the minerals, but the sample studied is crossed by a few veinlets filled with calcite. Geochemistry: Chondrule olivine, Fa in the range 0.37- 25.53; recrystallized matrix olivine (Fa29.05-33.23, mean Fa30.85; CaO = 0.29, NiO = 0.22 [both in wt%]). Chondrule Low-Ca pyroxene (Fs21.8±1.3); outside chondrules, composition varies from pigeonite to augite to diopside. Plagioclase outside chondrules (An21.4-40.7). Magnetic susceptibility: (J. Gattacceca, CEREGE) log χ = 4.5 10-9 m3/kg. Classification: Carbonaceous chondrite (CK3; estimated subtype 3.8); minimal shock and moderate weathering. Type specimens: A total of 9.5 g of sample (1 sawn fragment) and two polished mounts on deposit at MNHN. Giessler holds the main mass. Submitted by: M. Bourot-Denise, MNHN. Writeup from MB 94: The correct find year is 2001. | ||||||||||||
| Data from: MB93 Table 2 Line 102: |
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| Institutions and collections |
CEREGE: CEREGE
BP 80
Avenue Philibert, Technopole de l'Arbois
13545 Aix-en-Provence Cedex 4
France, France (institutional address; updated 10 Jun 2023) MNHN: Museum National d'Histoire Naturelle, IMPMC-CP52, 57 rue Cuvier, 75005 Paris, France, France; Website (institutional address) |
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| Catalogs: |
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| References: | Published in Meteoritical Bulletin, no. 93, MAPS 43, 571-632 (2008) Published in Meteoritical Bulletin, no. 94, MAPS 43, 1551-1588 (2008)
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Geography:
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Statistics: This is 1 of 2012 approved meteorites from Morocco (plus 35 unapproved names) (plus 1 impact crater) | ||||||||||||