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Northwest Africa 5782 | |||||||||||||||||||||||||
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Basic information | Name: Northwest Africa 5782 This is an OFFICIAL meteorite name. Abbreviation: NWA 5782 Observed fall: No Year found: unknown Country: Morocco Mass: ![]() | ||||||||||||||||||||||||
Classification history: |
This is 1 of 11 approved meteorites classified as Acapulcoite/lodranite. [show all] Search for other: Acapulcoite-lodranite family, Primitive achondrites | ||||||||||||||||||||||||
Comments: | Approved 17 Dec 2009 | ||||||||||||||||||||||||
Writeup![]() |
Writeup from MB 97:
Northwest Africa 5782 Morocco Found: Purchased: September 2008 Classification: Achondrite (acapulcoite/lodranite) History and physical characteristics: Purchased by Blaine Reed at the Denver Mineral Show. Two pieces with a total mass of 130 g were found in a batch of meteorites. The stones experienced moderate terrestrial weathering, but some fusion crust is still visible. Petrography: (T. Bunch and J. Wittke, NAU; A. Irving, UWS; P. Sipiera, PSF): A polymict breccia of subrounded to subangular clasts (exhibiting some preferred orientation) set in a cataclastic matrix with minor glass and secondary Fe hydroxide veinlets (Fig. 3). The most abundant clasts (45 vol%) are recrystallized acapulcoites with polygonal texture (mean grain size is 0.225 mm). Coarser grained, protogranular to polygonal textured clasts (25 vol%) are various types of lodranites (mean grain size is 0.745). The matrix (30 vol%) contains debris from both types of lithology, and additionally rare, small xenolithic fragments of augite with exsolution lamellae of Ca-poor pyroxene. Mineral compositions and geochemistry: Acapulcoites Olivine Fa8.7–13.3 (FeO⁄MnO = 17–27); low-Ca pyroxene Fs9.0–4.1, Wo2.1–3.0; clinopyroxene Fs4.8–7.5, Wo45.7–47.9. Lodranites Olivine Fa8.6–13.7 (FeO⁄MnO = 16–18); low-Ca pyroxene Fs12.7–13.7, Wo2.8; clinopyroxene Fs4.6, Wo46.7 (Al2O3 1.10 wt%, Cr2O3 1.83 wt%, TiO2 0.63 wt%). Xenolithic fragment clinopyroxene Fs19.5, Wo42.8 (FeO⁄MnO = 24); orthopyroxene Fs40.7Wo4.1 (FeO⁄MnO = 32). Oxygen isotopes (D. Rumble, CIW): acid-washed material analyzed in duplicate by laser fluorination gave, respectively δ17O = 0.53, 0.66; δ18O = 3.24, 3.03; Δ17O = -1.172, -0.936 per mil. Classification: Achondrite (acapulcoite, anomalous). This specimen is unusual among acapulcoites in that it is a breccia and contains a significant component of lodranite clasts. Specimens: A total of 20.8 g of material and one polished thin section are on deposit at FMNH in the PSF collection; another thin section is on deposit at NAU. The main mass is held by B. Reed. | ||||||||||||||||||||||||
Data from: MB97 Table 1 Line 261: |
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Plots: | O isotopes: | ||||||||||||||||||||||||
Institutions and collections |
FMNH: Department of Geology
The Field Museum of Natural History
1400 South Lake Shore Drive
Chicago, IL 60605-2496, USA, United States; Website (institutional address; updated 16 Nov 2011) NAU: Geology, Bldg 12 Knoles Dr Northern Arizona University, Flagstaff, AZ 86011, United States; Website (institutional address; updated 12 Apr 2012) PSF: Planetary Studies Foundation,10 Winterwood Lane, Unit B, Galena, Illinois 61036-9283, United States; Website (institutional address; updated 1 Dec 2011) UWS: University of Washington, Department of Earth and Space Sciences, 70 Johnson Hall, Seattle, WA 98195, United States (institutional address; updated 15 Jan 2012) CIW: Carnegie Insitution Washington, Geophysical Laboratory, 5251 Broad Branch Rd., NW, Washington DC 20015, United States (institutional address) Reed: Blaine Reed, P.O. Box 1141, Delta, CO 81416, United States; Website (private address) |
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Catalogs: |
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References: | Published in Meteoritical Bulletin, no. 97, MAPS 45, 449-493 (2010)
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Geography:![]() |
Statistics: This is 1 of 1973 approved meteorites from Morocco (plus 37 unapproved names) (plus 1 impact crater) |