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Lunar Meteorite: Northwest Africa (NWA) 3163, 4483, and 4881 (paired stones)Mauritania or Algeria |
   NWA 3163 (photos courtesy of Greg Hupé)  Sawn slice of NWA 3163 (photo by Randy Korotev)  Slices of NWA 4881, with exterior (left) (photo by Randy Korotev)  A different slice on NWA 4881 (photo by Randy Korotev)  Slice of NWA 4483. (photo by Randy Korotev) |
from The
Meteoritical Bulletin, no. 90, Meteoritics & Planetary Science
41, 1383-1418 (2006)
Northwest Africa 3163Mauritania or AlgeriaFind: August 2005 Achondrite (lunar, feldspathic granulitic impactite) History: In August 2005, G. Hupé purchased a 1634 g stone from a Moroccan dealer in Ouarzazate. Petrography and Geochemistry: (A. Irving and S. Kuehner, UWS) The exterior is almost completely coated by a thin, transparent, greenish fusion crust. The pale gray interior has multiple shock fractures (with very minor calcite coatings) and some thin glass veins. Poikiloblastic recrystallized breccia, with larger grains of plagioclase (~70 vol%) enclosing much smaller grains (less than 100 µm across) of pyroxenes (~20 vol%), olivine (~10 vol%), and accessory Ti-chromite (Cr/(Cr+Al) = 0.714–0.736; Mg/(Mg+Fe) = 0.121– 0.143; TiO2 = 9.1–18.4 wt%), ilmenite, troilite, and metal (Ni = ~15 wt%). Anorthitic plagioclase (An97.4-98.2) has been converted by shock almost entirely to maskelynite (although domains of birefringent, less-shocked feldspar remain). Pigeonitic pyroxene grains have very fine-scale exsolution lamellae of augite (Fs14.5-16.1 Wo40.2-40.5; FeO/MnO = 41.7– 43.8) within orthopyroxene Fs32.0-33.9 Wo4.4-5.8; FeO/MnO = 55.5–61.2). Olivine (Fa38.0-40.9; FeO/MnO = 91.7–110). Classification: Achondrite (lunar, feldspathic granulitic impactite). Specimens: A 20.1 g type specimen and one polished thin section are on deposit at UWS. G. Hupé holds the main mass. |
from The
Meteoritical Bulletin,
no. 93, Meteoritics & Planetary Science 43,
571-632 (2007)
Northwest Africa 4881Mauritania or AlgeriaFind: 2005 Achondrite (lunar, granulitic breccia) History: Found in 2005 and purchased by Stefan Ralew in January 2007 from a dealer in Ouarzazate, Morocco. Physical characteristics: A single, broken, irregular conical stone (606 g) partially covered by translucent, pale greenish fusion crust and with a pale grey-brown interior. Petrography: (A. Irving and S. Kuehner, UWS) Fine grained recrystallized breccia composed of larger plagioclase grains (converted partially to maskelynite) poikilitically enclosing very small grains (mostly 30-80 microns) of low-Ca pyroxenes, olivine, Ti-chromite, ilmenite, troilite and metal. Mineral compositions and geochemistry: Olivine (Fa40.4-58.8, FeO/MnO = 91-100), plagioclase (An96.1-98Or<0.1), pigeonite (Fs32.0-64.5Wo9.5-13.1, FeO/MnO = 51.1-62). Classification: Achondrite (lunar, granulitic breccia). This stone is paired with Northwest Africa 3163 (Irving et al., 2006) and Northwest Africa 4483; in combination these specimens evidently represent naturally broken pieces from a crusted lunar meteorite weighing at least 2448 g. Specimens: A total of 20 g of sample and one polished mount are on deposit at UWS. Ralew holds the main mass. |
from The
Meteoritical Bulletin, No. 94, September 2008. Meteoritics & Planetary
Science 43, 1551–1588 (2008)
Northwest Africa 4483AlgeriaFind: July 2006 Achondrite (lunar, granulitic breccia) History: Purchased by Stefan Ralew in July 2006 from a dealer in Erfoud, Morocco. Physical characteristics: Twelve broken fragments of very fine-grained, pale grey rock with a combined weight of 208 g. Petrography (A. Irving and S. Kuehner, UWS): Fine grained recrystallized breccia composed of larger plagioclase grains (converted mainly to maskelynite) poikilitically enclosing very small grains (mostly 30-80 microns) of low-Ca pyroxene (some with very fine augite exsolution lamellae), olivine, Ti-chromite, ilmenite, troilite and metal. Geochemistry: Olivine (Fa30.9-60.8, FeO/MnO = 88.1- 106), plagioclase (An96.2-98Or<0.1), orthopyroxene(Fs14.3Wo2.0, FeO/MnO = 52.6), pigeonite (Fs36.4- 75.1Wo6.3-13.5, FeO/MnO = 62.9-66.5). Classification: Achondrite (lunar, granulitic breccia). Possibly paired with Northwest Africa 3163 (Irving et al., 2006). Specimens: A total of 20 g and one polished mount are on deposit at UWS. Ralew holds the main mass. |
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