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Lunar Meteorite: Northwest Africa (NWA) 4936, 5406, 6221, 6355, 6470, 6570, & 6687 (paired stones)Morocco |
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from The
Meteoritical Bulletin, No. 95, Meteoritics & Planetary Science
44, 429–462 (2009)Northwest Africa 4936MoroccoFind: September 2007 Achondrite (lunar, feldspathic breccia) History: Purchased by an anonymous dealer in Siksou, Morocco, in September 2007. Physical characteristics: Two dark gray, mostly very fine grained stones (72 g and 107 g) exhibiting hackly fracture and lacking obvious fusion crust. The interior is very dark gray, and resembles devitrified glass with dispersed small white clasts. Petrography (A. Irving and S. Kuehner, UWS): Both specimens are composed of small mineral clasts and sparse lithic clasts in a very fine-grained matrix (which has heterogeneous glass). Mineral clasts include anorthitic plagioclase, pigeonite, augite, sparse olivine, Mg-bearing ilmenite, kamacitic metal and troilite. Lithic clasts include troctolite and probable mare basalt. Geochemistry: Low-Ca pyroxene (Fs25.7Wo4.6, FeO/MnO = 56.8), pigeonite (Fs42.0Wo10.2, FeO/MnO = 63.1), olivine (Fa29.1, FeO/MnO = 75.2), plagioclase (An95.4–98.2Or0.2–0.0). Bulk composition (R. Korotev, WUSL): FeO 6.1 wt%, Th 1.85 ppm. Classification: Achondrite (lunar, feldspathic breccia). Specimens: A total of 20.1 g, one polished thin section and one polished mount are on deposit at UWS; a further 20 g sample is on deposit at UAz. The main mass is held by Schrader. |
from The
Meteoritical Bulletin, No. 95, Meteoritics & Planetary Science
44, 429–462 (2009)Northwest Africa 5406MoroccoFind: July 2008 Achondrite (lunar, feldspathic breccia) History: Purchased by Greg Hupé in July 2008 from a dealer in Ouarzazate, Morocco, who reported that these stones were found in the same area as NWA 4936 near Siksou Mountain in southern Morocco. Physical characteristics: Six, dark gray, mostly very finegrained stones (total weight 281 g) with hackly fracture and lacking obvious fusion crust. The interior of each stone resembles devitrified glass with dispersed small white clasts. Petrography: (A. Irving and S. Kuehner, UWS) All specimens are composed of small mineral clasts and sparse lithic clasts in a very fine-grained matrix (which has the texture of an impact melt with heterogeneous, “swirly” glass). Mineral clasts include anorthite, olivine, pigeonite, subcalcic augite, ilmenite, troilite, and irregular-shaped grains of kamacite. Geochemistry: Pigeonite (Fs34.7Wo9.8, FeO/MnO = 59.9), augite (Fs55.8Wo26.4, FeO/MnO = 72.6), olivine (Fa25.7–27.0, FeO/MnO = 85.3–120), plagioclase (An96.2–97.2Or0.0). Bulk composition (R. Korotev, WUSL): FeO 5.8 wt%, Th 2.0 ppm, Sc 9.1 ppm, Ni 520 ppm, Sm 6.3 ppm. Classification: Achondrite (lunar, feldspathic breccia). These stones have essentially the same distinctive textures, mineral compositions and bulk composition as NWA 4936, and are almost certainly paired with the latter stones. Specimens: A total of 20.0 g of is on deposit at UWS. The main masses are held by Mr. G. M. Hupé. |
from The Meteoritical Bulletin, No. 100.Northwest Africa 6221(Northwest Africa)Purchased: Apr 2010 Classification: Lunar meteorite (feldspathic breccia) History: Purchased by P. Thomas in April 2010 from a dealer who reported that this stone was found near Geltat Zemmour. Physical characteristics: One single stone, dark gray with white clasts. Petrography: (A. Jambon, O. Boudouma, D. Badia) Small mineral clasts in a fine-grained matrix with some heterogeneous glass (impact melt glass). Contains plagioclase, pigeonite, augite, ilmenite, olivine, merrilite. Rare lithic clasts. Geochemistry: Feldspar An96-89. Augite (Fs27-22Wo40-30, Fe/Mn=60). Olivine (Fa=12-29, Fe/Mn=60). Ilmenite with 6% MgO. Bulk composition (R. Korotev, WUSL): FeO 6.6 wt%, Sc 9.7 ppm, Ni 1120 ppm, Sm 5.7 ppm, Th 1.7 ppm. Classification: Lunar (feldspathic breccia). Probably paired with NWA 4936 and NWA 5406. |
from The Meteoritical Bulletin, No. 99.Northwest Africa 6355MoroccoFind: June 2009 Achondrite (lunar, feldspathic breccia) History: Found in southern Morocco in June 2009 and purchased by a consortium led by Matt Morgan from a Moroccan dealer in September 2010. Physical characteristics: A single fine grained, brittle stone (760 g) with no obvious fusion crust. The interior is dark gray and resembles devitrified glass with dispersed small white clasts. Petrography: Clast-laden vitric breccia consisting of fine grained mineral debris (mostly pyroxenes, olivine and anorthite) and sparse polycrystalline igneous clasts in a heterogeneous, "swirly" glassy matrix (in part vesicular). Mineral clasts include anorthitic plagioclase, low-Ca pyroxene, pigeonite, olivine, Mg-bearing ilmenite, kamacitic metal and troilite. Lithic clasts include microgabbronorite (composed of subcalcic augite, orthopyroxene, anorthite, Mg-bearing merrillite, silica polymorph, ilmenite, troilite and baddeleyite). Geochemistry: Low-Ca pyroxene (Fs37.5-61.2Wo2.4-5.2, FeO/MnO = 65-88), pigeonite (Fs23.5-45.5Wo10.3-11.1, FeO/MnO = 48-76), subcalcic augite (Fs13.0Wo37.0, Fs17.6Wo30.1, Fs25.7Wo35.0, FeO/MnO = 55-59), augite (Fs11.3Wo41.8; FeO/MnO = 49), olivine (Fa29.5-33.9, FeO/MnO = 81-104), plagioclase (An91.6-96.1Or0.5-0.1). Bulk composition (R. Korotev, WUSL): FeO 5.8 wt%, La 13.0 ppm, Sm 6.1 ppm, Yb 3.95 ppm, Th 1.87 ppm. Classification: Achondrite (lunar, feldspathic breccia). This stone is almost identical in texture, mineral compositions and bulk composition to NWA 4936, NWA 5406 and NWA 6221. It is possibly paired with those stones and is reportedly from the same find location. Specimens: A total of 20.1 g of sample and one polished thin section are on deposit at UWS. The main mass is held jointly by Morgan, Abraham, Rose, Curtiss and an anonymous collector. |
from The Meteoritical Bulletin, No. 99.Northwest Africa 6470MoroccoFind: 2009 Lunar meteorite (feldspathic breccia) History: Found in southern Morocco in 2009 and purchased by Jason Utas in April 2010 from a dealer in Ouarzazate, Morocco. Physical characteristics: A fine-grained, dark gray, 96 g stone containing dispersed small white clasts. Petrography: The specimen consists of small mineral clasts and sparse lithic clasts (some with ophitic textures) in a very fine grained, heterogeneous, partly glassy and in places vesicular matrix. Mineral clasts include anorthitic plagioclase, subcalcic augite, pigeonite, olivine, Mg-bearing ilmenite, kamacite, baddeleyite and troilite. Geochemistry: Pigeonite (Fs23.6-26.9Wo16.2-7.0, FeO/MnO = 51-59), subcalcic augite (Fs21.0Wo36.1, FeO/MnO = 58), olivine (Fa21.9-29.3, FeO/MnO = 84-107), plagioclase (An91.6-95.2Or0.5-0.2). Bulk composition (R. Korotev, WUSL): FeO 5.6 wt%, La 11.1 ppm, Sm 5.0 ppm, Yb 3.24 ppm, Th 1.63 ppm. Classification: Achondrite (lunar, feldspathic breccia). This stone is very similar in texture, mineral compositions and bulk composition to NWA 4936, NWA 5406, NWA 6221 and NWA 6355. It apparently is paired with those stones and is reportedly from the same find location. Specimens: A total of 19.2 g of sample are on deposit at UWS. The main mass is held by Utas. |
from The Meteoritical Bulletin, No. 99.Northwest Africa 6570MoroccoFind: 2010 Lunar meteorite (feldspathic breccia) History: Found in southern Morocco in 2010 and purchased from the finder by Adam Aaronson in December 2010. Physical characteristics: A single fine grained, brittle stone (415 g) lacking fusion crust. The interior is dark gray with dispersed small white clasts. Petrography: (A. Irving and S. Kuehner, UWS) Sparse felsic lithic clasts and mineral debris are enclosed within a dark, partly glassy and vesicular matrix. Mineral clasts include pigeonite, subcalcic augite, anorthitic plagioclase, olivine, ilmenite, kamacite and troilite. Geochemistry: Olivine (Fa29.5-29.6; FeO/MnO = 92-120), pigeonite (Fs26.9-28.5Wo10.0-12.7, Fs43.7Wo5.6; FeO/MnO = 58-70), subcalcic augite (Fs31.6Wo29.6; FeO/MnO = 61), plagioclase (An91.5-95.4Or0.4-0.3). Classification: Achondrite (lunar, feldspathic breccia). This specimen is texturally and mineralogically identical to NWA 4936, NWA 5406, NWA 6221, NWA 6355 and NWA 6470 found in the same area, and evidently is paired with those stones. Specimens: A total of 20.0 g of sample is on deposit at UWS. The main mass is held by Aaronson. |
from The Meteoritical Bulletin, No. 100.Northwest Africa 6587(Northwest Africa)Find: 2010 Lunar (feldspathic breccia) History: Found in Morocco in 2010 and purchased from the finder by G. Tomelleri. Physical characteristics: A single black stone (42.4 g) lacking fusion crust. The interior is dark gray and displays several small white clasts. Petrography: (V. Moggi Cecchi, S. Caporali, G. Pratesi, MSP) The overall texture consists of coarse-grained inclusions set in a fine-grained matrix. The matrix contains isolated mineral clasts, mainly consisting of augite, plagioclase and olivine, and a fine grained mineral debris enclosed within a dark, partly glassy and vesicular matrix. The large coarse grained inclusions consist of elongated plagioclase and clinopyroxene crystals set in a glassy matrix. Opaque phases are represented by ilmenite, ulvospinel and chromite. Geochemistry: Olivine (Fa33.7-49.2, Fe/Mn=108, n=20, Cr=1500 ppm, Mn=3100 ppm), augite (Fs23.8.5-31.2En24.9-30.0Wo27.3-30.0Al-px 13.9-19.5; FeO/MnO mean=65.6; V=400 ppm; Ca=0.61 afu), plagioclase (An83.4Or0.8; K = 0.008 afu); Oxygen isotopes: (I. Franchi, R. Greenwood, OU) δ17O = 3.58, δ18O = 6.84, Δ17O = 0.02 per mil. Classification: Achondrite (lunar, feldspathic breccia). Specimens: 9.5 g sample is on deposit at MSP. |
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