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Northwest Africa 11781
Basic information Name: Northwest Africa 11781
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 11781
Observed fall: No
Year found: 2017
Country: (Northwest Africa)
Mass:help 15.5 g
Meteoritical Bulletin:  MB 107  (2018)  CM2
Recommended:  CM2    [explanation]

This is 1 of 541 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 20 Jul 2018
Writeup from MB 107:

Northwest Africa 11781 (NWA 11781)

(Northwest Africa)

Purchased: 2017 Aug 09

Classification: Carbonaceous chondrite (CM2)

History: The meteorite was purchased from a meteorite dealer in Moscow, Russia.

Petrography: (S. V. Berzin and K. A. Dugushkina, RAS-UB) Chondrule ~20%, refractory inclusion (CAIs, AOAs, Forsterite rich objects) ~3-5% and fine-grained matrix. Most chondrules are porphyritic. Average chondrule size is 0.3 mm. Chondrule mesostasis is rare. The matrix contains phyllosilicates and calcite. CAIs are small (0.05-0.3 mm in size) and very fine grained. The dominant minerals of CAIs are spinel, Ca-pyroxene, hibonite, with accessory perovskite. Some CAIs have forsterite rims. AOAs mainly has spinel-diopside inclusion. Forsterite rich objects have low-Ca pyroxene rims. Refractory forsterite is zoned. Unshocked, low grade of terrestrial weathering (metal partially oxidized).

Geochemistry: Element composition by ICP-MS (ppm): Li 6.05, Sc 2.93, Ti 427, V 55.9, Cr 2307, Mn 1365, Co 236, Ni 2597, Cu 86.0, Zn 129, Ga 6.82, Ge 8.91, As 2.69, Se 4.82, Rb 0.952, Sr 190, Y 1.87, Zr 5.54, Nb 0.431, Mo 1.33, Ag 0.197, Cd 0.151, Sn 1.180, Sb 0.146, Te 0.949, Cs 0.038, Ba 283, La 0.545, Ce 1.33, Pr 0.194, Nd 0.963, Sm 0.281, Eu 0.104, Gd 0.458, Tb 0.061, Dy 0.409, Ho 0.088, Er 0.267, Tm 0.040, Yb 0.264, Lu 0.041, Hf 0.209, Ta 0.365, W 0.151, Tl 0.053, Pb 7.36, Bi 0.024, Th 0.100, U 0.481.

Classification: CM2 Carbonaceous chondrite

Data from:
  Table 0
  Line 0:
Place of purchase:Moscow (Russia)
Date:P 2017 Aug 09
Mass (g):15.5
Weathering grade:low
Classifier:S. V. Berzin and K. A. Dugushkina, RAS-UB
Type spec mass (g):3.9
Type spec location:UrFU
Main mass:A.N. Zavaritsky, RAS-UB
Comments:Submitted by Stepan Vasilevich Berzin
   and collections
TM: Geoscience Museum, Transvaal Museum, P. O. Box 413, Pretoria 0001, South Africa (institutional address; updated 3 Mar 2011)
UrFU: Ural Federal University, 620002, 19 Mira street, Ekaterinburg, Russia (institutional address; updated 14 Jan 2015)
RAS-UB: Zavaritsky Institute of Geology and Geochemistry Russian Academy of Sciences, Ural Branch 15 Akademika Vonsovskogo str., Ekaterinburg, 620016, Russia (institutional address; updated 19 Apr 2018)
References: Published in Meteoritical Bulletin, no. 107, MAPS 55, 460-462
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     This is 1 of 7377 approved meteorites from (Northwest Africa) (plus 1955 unapproved names)

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