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Northwest Africa 7870 | |||||||||||||||||||||||||||||||
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Basic information | Name: Northwest Africa 7870 This is an OFFICIAL meteorite name. Abbreviation: NWA 7870 Observed fall: No Year found: 2004 Country: (Northwest Africa) Mass: ![]() | ||||||||||||||||||||||||||||||
Classification history: |
This is 1 of 2051 approved meteorites (plus 4 unapproved names) classified as L4. [show all] Search for other: L chondrites, L chondrites (type 4-7), Ordinary chondrites, and Ordinary chondrites (type 4-7) | ||||||||||||||||||||||||||||||
Comments: | Approved 9 May 2013 | ||||||||||||||||||||||||||||||
Writeup![]() |
Writeup from MB 102:
Northwest Africa 7870 (NWA 7870) (Northwest Africa) Purchased: Feb 2004 Classification: Ordinary chondrite (L4) History: The rock was obtained by Edwin Thompson from a Moroccan trader at the Tucson Gem and Mineral Show and a portion was donated to Cascadia in February 2004. Physical characteristics: The rock has a grey and pitted/bumpy exterior, and appears grey in cut faces. Petrography: (K. Armstrong and A. Ruzicka, Cascadia) The specimen shows chondritic texture with readily discernible chondrules (mean diameter = 0.5 ± 0.3 mm) and matrix that appears translucent in transmitted light. The abundance of metal and troilite as determined by pixel counting in reflected light images is 3.1±0.1 and 3.5±0.7 area%, respectively. Geochemistry: Olivine Fa25.3±1.2 Fe/Mn=47.4±6.5 (N=36) and low-Ca pyroxene Wo1.6±0.2 Fs16.2±6.4 Fe/Mn = 25.3±6.9 (N=25). Classification: Mineral chemistry, chondrule sizes, and metal abundance are most consistent with an L4 chondrite. Specimens: 14.6 g in two pieces and a polished thin section are on deposit at Cascadia; Thompson holds the main mass. | ||||||||||||||||||||||||||||||
Data from: MB102 Table 0 Line 0: |
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Institutions and collections |
Cascadia: Cascadia Meteorite Laboratory, Portland State University, Department of Geology, Room 17 Cramer Hall, 1721 SW Broadway, Portland, OR 97201, United States; Website (institutional address; updated 28 Oct 2011) Thompson: Edwin Thompson, 5150 Dawn St., Lake Oswego, OR 97035, United States (private address) |
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Catalogs: |
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References: | Published in Meteoritical Bulletin, no. 102, MAPS 50, 1662, September 2015
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Geography: |
Statistics: This is 1 of 9429 approved meteorites from (Northwest Africa) (plus 1876 unapproved names) |