| MetSoc Home Publications Contacts |
|
||
|
||
| Northwest Africa 4875 | |||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Basic information | Name: Northwest Africa 4875 This is an OFFICIAL meteorite name. Abbreviation: NWA 4875 Observed fall: No Year found: 2007 Country: (Northwest Africa) Mass:  904 g | ||||||||||||||||||||
| Classification history: |
This is 1 of 89 approved meteorites classified as Lodranite. [show all] Search for other: Acapulcoite-lodranite family, Lodranites, and Primitive achondrites | ||||||||||||||||||||
| Comments: | Approved 17 Apr 2008 | ||||||||||||||||||||
| Writeup |
Writeup from MB 94:
Northwest Africa 4875 Northwest Africa Find: 2007 Achondrite (lodranite) History and physical characteristics: A 904 g dark brown stone was purchased by A. Aaronson in Morocco in July 2007. The irregular-shaped stone has no remnant fusion crust and has been desert-polished. Petrography: (T. Bunch and J. Wittke, NAU) This coarse-grained harzburgite-like specimen is brecciated and contains olivine and orthopyroxene grains of ~equal size (up to 5 mm in diameter). In addition, intact lithologic clasts contain minor interstitial clinopyroxene, kamacite, troilite, and pentlandite, no plagioclase was found. Olivine shows small (<0.02 mm), randomly oriented irregular- to ovoid-shaped inclusions of chromite and diopside. Some of these inclusions exhibit a symplectitic relationship with host olivine. Orthopyroxene has twin lamellae and tiny metal and sulfide inclusions oriented parallel to the (100) crystallographic plane. Oxidation of kamacite is extensive and imparts a dark stain throughout the sample. Shock level is S3. Mineral compositions: Olivine is Fa10.3 and FeO/MnO = 24; orthopyroxene is Fs9.6Wo1.4 and FeO/MnO = 14; clinopyroxene is Fs3.6Wo45.7 and contains 1.35 wt% Cr2O3. Chromite cr# is 84 and troilite contains 2.5 to 5.4 wt% Ni. Classification: Achondrite (lodranite), possibly paired with NWA 4478, but not with NWA 4833. Type specimen: A total of 21.2 g is on deposit at NAU. A. Aaronson holds the main mass. | ||||||||||||||||||||
| Data from: MB94 Table 2 Line 81: |
|
||||||||||||||||||||
| Institutions and collections |
NAU: Geology, Bldg 12
Knoles Dr
Northern Arizona University, Flagstaff, AZ 86011, United States; Website (institutional address; updated 12 Apr 2012) Aaronson: Sahara Overland Ltd., Harhora, Temara, 12000, Morocco (private address; updated 3 Jan 2010) |
||||||||||||||||||||
| Catalogs: |
| ||||||||||||||||||||
| References: | Published in Meteoritical Bulletin, no. 94, MAPS 43, 1551-1588 (2008)
| ||||||||||||||||||||
| Geography: |
Statistics: This is 1 of 8904 approved meteorites from (Northwest Africa) (plus 1871 unapproved names) | ||||||||||||||||||||