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Northwest Africa 8534 | |||||||||||||||||||||||||||||
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Basic information | Name: Northwest Africa 8534 This is an OFFICIAL meteorite name. Abbreviation: NWA 8534 Observed fall: No Year found: 2014 Country: (Northwest Africa) Mass: ![]() | ||||||||||||||||||||||||||||
Classification history: |
This is 1 of 26 approved meteorites classified as CM1/2. [show all] Search for other: Carbonaceous chondrites, Carbonaceous chondrites (type 1), CM chondrites, and CM-CO clan chondrites | ||||||||||||||||||||||||||||
Comments: | Approved 16 Sep 2014 | ||||||||||||||||||||||||||||
Writeup![]() |
Writeup from MB 103:
Northwest Africa 8534 (NWA 8534) (Northwest Africa) Purchased: 2014 Jun 12 Classification: Carbonaceous chondrite (CM1/2) History: Purchased 12 June 2014 in Morocco. Physical characteristics: Many identically appearing small fragments, the largest being 2.6 g, with black, fresh fusion crust. Broken surface reveals black, uniform, very fine-grained texture, rare sub-mm CAIs, with no visible chondrules. Petrography: (C. Agee, UNM) Microprobe examination of a polished mount shows a matrix (80-90%) dominated by (Mg,Fe)-rich phyllosilicates, with scattered, small (~250 μm), mostly irregularly shaped chondrules, many of which contain secondary alteration phases. There is no mesostasis in any chondrule; they are all altered. This meteorite is transitional between CM1 and CM2. There is more fine-grained (80-90%, dominantly phyllosilicate) matrix than in CM2, but less than CM1. Calcium carbonate, (Ca,Mg)-carbonate, sulfides, and Fe-oxides are ubiquitous. Geochemistry: (C. Agee and N. Muttik, UNM) Ferroan olivine Fa25.3±23.9, Fe/Mn=78±39, Cr2O3=0.40±0.09 (wt%), n=4; forsterite Fa1.4±0.4, Fe/Mn=15±14, n=16; aluminous diopside Fs2.9±1.6Wo47.4±9.6, n=3. Oxygen isotopes (K. Ziegler, UNM): acid-washed material analyzed in 8 replicates by laser fluorination gave, respectively δ18O=10.694, 15.433, 9.721, 12.571, 12.343, 13.254, 12.798, 12.440; δ17O=3.496, 6.442, 2.651, 4.363, 4.207, 4.863, 4.722, 4.450; Δ17O= -2.150, -1.706, -2.481, -2.274,-2.310, -2.135, -2.035, -2.118 (all per mil). Classification: Carbonaceous chondrite (CM1/2), the petrologic type 1/2 is based on the relatively low abundance of chondrules and refractory inclusions, the high abundance of hydrous phases, and high volume percentage of matrix. It is also based on the mean value of eight oxygen isotope analyses that plots outside the field of CM2, at higher values δ17O=4.399±1.096 and δ18O=12.407±1.699 permil. Specimens: 12 g including a probe mount on deposit at UNM, Robert Cucchiara and Ruben Garcia hold 48 g. | ||||||||||||||||||||||||||||
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 9305 approved meteorites from (Northwest Africa) (plus 1873 unapproved names) |