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| Northwest Africa 4523 | |||||||||||||
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| 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:  174 g | ||||||||||||
| Classification history: |
This is 1 of 571 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 |
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: MB92 Table 2 Line 86: |
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| Plots: | O isotopes: | ||||||||||||
| Institutions 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) |
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| Catalogs: |
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| References: | Published in Meteoritical Bulletin, no. 92, MAPS 42, 1647-1694 (2007)
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| Geography: |
Statistics: This is 1 of 9013 approved meteorites from (Northwest Africa) (plus 1869 unapproved names) | ||||||||||||