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Northwest Africa 4757 | |||||||||||||
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Basic information | Name: Northwest Africa 4757 This is an OFFICIAL meteorite name. Abbreviation: NWA 4757 Observed fall: No Year found: 2004 Country: Morocco Mass: 5 g | ||||||||||||
Classification history: |
This is 1 of 636 approved meteorites classified as CM2. [show all] Search for other: Carbonaceous chondrites, Carbonaceous chondrites (type 2), CM chondrites, and CM-CO clan chondrites | ||||||||||||
Comments: |
Approved 6 Mar 2008 Revised 4 Aug 2008: final writeup | ||||||||||||
Writeup |
Writeup from MB 93:
Northwest Africa 4757 Morocco Find: October 2004 Carbonaceous chondrite (CM) History: An anonymous buyer purchased the stone in Munich, Germany, in October 2004. Physical characteristics: The single piece weighing 5 g is black and covered with black fusion crust. Petrography: (M. A. Ivanova, Vernad.) The meteorite consists of fine-grained phyllosilicate matrix material, relict chondrules, sometimes with haloes, and relict aggregates embedded in altered matrix. All silicates from the objects in the meteorite are altered and replaced by phyllosilicate. Only one tiny grain of olivine was found in the matrix. The minor phases are ilmenite, chromite, sulfides, kamacite, taenite, tetrataenite, phosphates, Ca,Mg carbonates. Abundant phyllosilicates in the matrix are mostly serpentine. Geochemistry: Mineralogy: olivine (Fa10; Fe/Mn=52, CaO = 0.06; MnO = 0.19 [both wt%]). Bulk composition (wt%): Al2O3 = 2.3, TiO2 = 0.09, FeO = 32.0, MgO = 22.7, MnO = 0.34, CaO = 2.4, Na2O = 0.26, K2O = 0.15, S = 5.3. Oxygen isotopic compositions: (I. A Franchi and R. C. Greenwood, OU, by laser fluorination): δ17O = 12.84; δ18O = 23.83; Δ17O = 0.45 (all ‰). Classification: Carbonaceous chondrite (CM); minor weathering. Type specimens: A total of 1 g sample and one thin section are on deposit at Vernad. An anonymous buyer holds the main mass. | ||||||||||||
Data from: MB93 Table 2 Line 108: |
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Plots: | O isotopes: | ||||||||||||
Institutions and collections |
OU: Planetary and Space Sciences
Department of Physical Sciences
The Open University
Walton Hall
Milton Keynes
MK7 6AA
United Kingdom, United Kingdom (institutional address; updated 8 Dec 2011) Vernad: Vernadsky Institute of Geochemistry and Analytical Chemistry, Russia (institutional address; updated 21 Feb 2016) |
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Catalogs: |
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References: | Published in Meteoritical Bulletin, no. 93, MAPS 43, 571-632 (2008)
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Geography: |
Statistics: This is 1 of 2082 approved meteorites from Morocco (plus 31 unapproved names) (plus 1 impact crater) | ||||||||||||
Also see: |
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Revision history: |
This lists important revisions made to data for this record.
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