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Northwest Africa 4523
Basic information Name: Northwest Africa 4523
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 4523
Observed fall: No
Year found: 2001
Country: (Northwest Africa)
Mass:help 174 g
Meteoritical Bulletin:  MB 92  (2007)  Eucrite-basaltic
Recommended:  Eucrite    [explanation]

This is 1 of 598 approved meteorites (plus 1 unapproved name) classified as Eucrite.   [show all]
Search for other: Achondrites, Eucrites, and HED achondrites
Comments: Approved 21 May 2007
Writeup from MB 92:

Northwest Africa 4523

Al Nif, Morocco

Find: April 2001

Achondrite (eucrite, basaltic)

History: Carine and Bruno Fectay purchased the rock in Al Nif, Morocco in April 2001.

Physical characteristicsThe very fresh stone weights 174 g and is nearly covered with fusion crust. The interior of the stone is light gray in color and displays a brecciated texture with dark clasts ranging from a few mm to about 1.5 cm.

Petrography: (J.A. Barrat and M. Bohn, IUEM; A. Yamaguchi, NIPR) Two types of clasts are found in a fine-grained recrystallized matrix: medium-grained ophitic/subophitic and fine-grained clasts. Medium-grained clasts (~1-2 mm) display a subophitic texture, and are composed of plagioclase, pyroxene (pigeonitic core and augitic rim), silica, ilmenite, chromite, and recrystallized mesostasis. Fine-grained clasts consist of pyroxene phenocrysts (~150 µm in diameter) in a fine-grained groundmass that consists of plagioclase, pigeonite, augite, silica, ilmenite, troilite, and K-feldspar.

Geochemistry: (J.A. Barrat, M. Benoit, J. Cotton, IUEM and A.Yamaguchi, NIPR). Mineral phases in clasts and matrix have idenital composition; pyroxenes (Mg35.9Ca4.7Fe59.4 to En30.2Wo43.3Fs26.5; FeO/MnO=34 [n=265]) and plagioclase (An90-71). Bulk composition: FeOtotal/MgO= 2.84 (ICP-AES) close to typical main group eucrites but exhibits the highest concentrations in K2O = 0.15 wt% measured in eucrites. Moreover, it is richer in TiO2 =1.35 wt% (ICP-MS) and incompatible trace elements relative to Stannern. Its REE element pattern is flat (Lan/Ybn = 1.29) and displays a marked negative Eu anomaly (Eu/Eu* = 0.62). Bulk oxygen isotopic: (R.C. Greenwood, I.A. Franchi, OU) composition is δ17O= 1.757 ± 0.004, δ18O= 3.791 ± 0.013, Δ17O= -0.230 ± 0.003 (all ‰).

Classification: Achondrite (eucrite, basaltic) and lies on the Stannern trend.

Type specimens: A total of 21 g of sample and one thick section are on deposit at IUEM. Fectay holds the main mass.

Data from:
  Table 2
  Line 86:
Place of purchase:Al Nif, Morocco
Mass (g):174
Type spec mass (g):21
Plots: O isotopes:  
   and collections
IUEM: Institut Universitaire Européen de la Mer, Université de Bretagne Occidentale, place Nicolas Copernic, F-29280 Plouzané Cedex, France (institutional address; updated 15 Sep 2017)
NIPR: Antarctic Meteorite Research Center, National Institute of Polar Research, 10-3 Midori-cho, Tachikawa, Tokyo 190-8518, Japan; Website (institutional address; updated 9 Dec 2013)
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)
References: Published in Meteoritical Bulletin, no. 92, MAPS 42, 1647-1694 (2007)
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     This is 1 of 9699 approved meteorites from (Northwest Africa) (plus 1854 unapproved names)

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