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Northwest Africa 4507 | |||||||||||||
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Basic information | Name: Northwest Africa 4507 This is an OFFICIAL meteorite name. Abbreviation: NWA 4507 Observed fall: No Year found: 2006 Country: Morocco Mass: 85 g | ||||||||||||
Classification history: |
This is 1 of 676 approved meteorites classified as Ureilite. [show all] Search for other: Achondrites, Ureilites | ||||||||||||
Comments: | Approved 24 Jul 2007 | ||||||||||||
Writeup |
Writeup from MB 92:
Northwest Africa 4507 Morocco Find: 2005 Achondrite (ureilite) History: Purchased in 2006 at the Tucson Gem and Mineral Show. Physical characteristics: Total mass, 85.0 g, a deformed parallelepiped piece with smaller top surface, 68x24x24 mm in size, external color is dark brown and no fusion crust is apparent. Petrography: (H. Takeda, Chiba).The sample consists of olivine (up to 2.3x1.7 mm in size) and pyroxene. One PTS shows a typical ureilite texture with carbonaceous veins, in which Fe-metal and sulfide are present. Approximately one third of mafic silicates are pigeonite. A part of carbonaceous veins intrudes into an olivine crystal as a plate. Olivine crystals have minor cracks, but shock effect is minor. Some pigeonite grains show a twin texture. Mineral compositions: Olivine Fo79-82 (core) and >Fo90 (rims).Major pyroxenes have pigeonite compositions (Fs19Wo10). A large olivine crystal contains a small ellipsoidal inclusion of pigeonite, 0.26x0.20 mm, with small regions of high-Ca (Fs14Wo35) and low-Ca (Fs17.3Wo4.8). Pyroxenes enclosed in thick rims of the small ellipsoidal inclusion of pigeonite within the olivine grain; another ellipsoidal inclusion (0.16x0.09 mm) has low-Ca pyroxene composition (Fs18.5Wo4.6). Microscopic observations and Raman analyses (T. Nakamuta, KyuU) show tiny diamond crystals occurring in blade-shaped graphite crystals. Classification: Achondrite (ureilite); minimum weathering, minimum shock. Type specimen: A total of 17.22 g of sample and one thin section are on deposit at NSMT. Hori holds the main mass. | ||||||||||||
Data from: MB92 Table 2 Line 83: |
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Institutions and collections |
KyuU: Department of Earth and Planetary Science, Kyushu University Hakozaki, Higashi-ku, Fukuoka-shi 812- 8581, Japan (institutional address) Chiba: Chiba Institute of Technology, Tsudanuma, Narashino, Chiba 275-0016, Japan (institutional address) Hori: Unknown person (private address; updated 17 Apr 2009) NSMT: National Museum of Nature and Science, 4-1-1 Amakubo, Tsukuba, Ibaraki 305-0005, JAPAN, Japan; Website (institutional address; updated 16 Jun 2014) |
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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 2163 approved meteorites from Morocco (plus 32 unapproved names) (plus 1 impact crater) |