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Northwest Africa 4215
Basic information Name: Northwest Africa 4215
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 4215
Observed fall: No
Year found: 2002
Country: (Northwest Africa)
Mass:help 46.4 g
Meteoritical Bulletin:  MB 90  (2006)  Diogenite-unbr
Recommended:  Diogenite    [explanation]

This is 1 of 459 approved meteorites classified as Diogenite.   [show all]
Search for other: Achondrites, Diogenites, and HED achondrites
Comments: Approved 9 Sep 2006
Writeup from MB 90:

Northwest Africa 4215

Mhamid, Morocco

Find: April 2002

Achondrite (diogenite, unbrecciated)

History: This single stone was bought by Bruno Fectay and Carine Bidaut in Mhamid, Morocco, in April 2002.

Physical Characteristics: A single brown stone weighing 46.4 g and displaying limited patches of fusion crust.

Petrography: (J. A. Barrat, M. Bohn, UBO -IUEM; P. Beck, Ph. Gillet, ENSL) The sample displays a well-preserved cumulative texture, consisting of zoned xenomorphic orthopyroxene grains on the order of 500 µm in size, with a few large chromite crystals (<5 vol%, up to 3 mm). Accessory olivine and scarce diopside grains occur within the groundmass, usually around the chromite crystals. Minor phases are cristobalite (determined by Raman spectrometry), troilite, and metal. This meteorite is weathered and its fractures are filled by calcite, limonite, and gypsum typical of hot desert alteration.

Geochemistry: (J. A. Barrat, M. Bohn, J. Cotten, UBO-IUEM; R. Greenwood, I. Franchi, OU) Orthopyroxenes (En76.2Wo1.1Fs22.7 to En68.6Wo5.5Fs25.9); olivines (Fo76 to Fo71); chromites (Mg# = 14.3–44.0, Cr# = 42.2–86.5) are chemically zoned (EMP). The bulk composition of this stone has been determined for major and trace elements (ICP-AES, ICP-MS). Its FeO, CaO abundances and most of the trace element concentrations (Sr, Ba, Pb, and REE among others) are high and indicate a significant contribution of the secondary minerals (limonite+calcite). In order to remove the terrestrial contribution, a subsample has been leached with hot HCl. The residue, made essentially of orthopyroxene and chromite, is similar in major and trace element abundances to diogenites as shown by the shape of its REE pattern and by its high Al/Ga ratio. Oxygen isotopic: (R. Greenwood, I. Franchi, OU) Were determined on a fraction of the leached powder, δ17O = 1.431 ± 0.102, δ18O = 3.203 ± 0.205 relative to V-SMOW, and ∆17O = −0.248 ± 0.005 (all ‰).

Classification: Achondrite (diogenite, unbrecciated).

Specimens: A total of 10 g type specimen and two polished thick sections are on deposit at ENSL. Bruno Fectay and Carine Bidaut of La Mémoire de la Terre hold the main mass.

Data from:
  Table 2
  Line 338:
Place of purchase:Mhamid, Morocco
Date:Apr 2002
Mass (g):46.4
Classifier:omitted by accident
Type spec mass (g):10
Plots: O isotopes:  
   and collections
ENSL: Ecole Normale Supérieure de Lyon, Laboratoire de Sciences de la Terre, 46 allée d'Italie 69364 Lyon Cedex, France (institutional address; updated 27 Feb 2011)
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)
Fectay: Bruno Fectay and Carine Bidaut, La Memoire de la Terre SARL, 39800 Aumont, France; Website (private address)
UBO: Institut Universitaire Européen de la Mer, Université de Bretagne Occidentale, place Nicolas Copernic, F-29280 Plouzané Cedex, France (institutional address; updated 15 Sep 2017)
References: Published in Meteoritical Bulletin, no. 90, MAPS 41, 1383-1418 (2006)
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     This is 1 of 7688 approved meteorites from (Northwest Africa) (plus 1972 unapproved names)

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