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Lunar Meteorite: Northwest Africa (NWA) 2995, 2996, 3190, 4503, 5151, 5152, and other unnamed paired stonesAlgeria |
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See photos of NWA 2996 | NWA
3190 | NWA
4503 | others
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from The
Meteoritical Bulletin, no. 90, Meteoritics & Planetary Science
41, 1383-1418 (2006)Northwest Africa 2995AlgeriaFound 2005 Achondrite (lunar feldspathic breccia) History: A 538 g, fully crusted and minimally weathered stone was purchased in Morocco by A. Aaronson in November 2005. Petrography and Geochemistry: (T. Bunch and J. Wittke, NAU): The feldspathic fragmental breccia contains many highlands fine-grained lithologies including norite (orthopyroxene, Fs26.4Wo4, FeO/MnO = 66); olivine basalt (olivine, Fa87.2 FeO/MnO = 95; plagioclase, An84.7); subophitic basalt (Ca-pyroxene, Fs25-48Wo37.1-25.9; pigeonite, Fs27.8-31.7Wo15.4-9.3 FeO/MnO = 53; olivine Fa36.3 FeO/MnO = 90; plagioclase, An97); gabbro (olivine Fa34.7 FeO/MnO = 95; pigeonite Fs28.2Wo8.9 FeO/MnO = 67; plagioclase An94); KREEPy-like basalt (plagioclase, Ab50Or17.4; K-feldspar, Ab14.3Or83.6 in addition to silica, phosphate and Fe-rich pyroxenes); troctolite (Fa30.8 FeO/MnO = 94; plagioclase An94.7); granulitic impact melts (Fa31; orthopyroxene, Fs25.2Wo3.4; plagioclase An95); anorthosite (An92.7-96.8); glassy impact melts, coarse-grained mineral fragments, and a 0.350 mm sized grain of meteoritic Ni, Fe metal (Ni = 6.3 Co = 1.0, both wt %). In addition, the assemblage appears to be characterized by large amounts of breccias within breccias: at least 4 generations of brecciation were observed in one cm-sized breccia clast. Numerous shock-induced melt veins are present along large breccia clast margins as well as isolated melt pockets within clasts. Interior weathering grade is very low, all glasses are fresh and no apparent terrestrial alteration veins were noted. Classification: Achondrite (Lunar feldspathic breccia). Specimens: A 21.2 g specimen is on deposit at NAU. Aaronson holds the main mass. |
from The Meteoritical Bulletin, no. 95, Meteoritics & Planetary
Science 44, 429-462 (2009).Northwest Africa 2996AlgeriaFind: 2006 Achondrite (lunar, feldspathic breccia) History and physical characteristics: A 968 g, partially crusted stone, was purchased in Morocco in November 2006 by Adam Aaronson and sold to a private collector in 2007. The weathered crust shows a color range of vermillion to dark brown to black. Several anorthositic clasts exposed on broken surfaces are as large as 3 cm. Petrography (T. Bunch and J. Wittke, NAU): This feldspathic breccia has an extensive melt matrix with prominent entrainments of tiny bubbles. Lithologies include anorthosite, medium-grained gabbros, anorthositic norites and troctolites, in addition to mineral fragments, shocked clasts, and devitrified glassy clasts. Mineral compositions: A medium-grained gabbroic clast contains plagioclase (An92.1), olivine (Fa32.4, FeO/MnO = 110), Ca pyroxene (Fs22.4Wo19.1), chromite (cr# = 61) and ilmenite (MgO = 5.3 wt%). Anorthositic norite low-Ca pyroxene is Fs28.6Wo3.1 (FeO/MnO = 64), troctolitic olivine is Fa31.9, FeO/MnO = 104 and plagioclase clasts range from An91.8 to An97.4. Bulk chemistry (R. Korotev, WUSL): TiO2 = 0.68 wt%, Al2O3 = 20.7 wt%, FeO = 9.7 wt%, MgO = 8.0 wt%, Ni = 184 ppm, Sm = 4.6 ppm and Th = 1.6 ppm. Classification: Lunar (feldspathic breccia). Type specimen: A total of 20.3 g is on deposit at NAU. The main mass holder is anonymous. |
from The
Meteoritical Bulletin,
no. 93, Meteoritics & Planetary Science 43,
571-632 (2007)Northwest Africa 3190Northwest AfricaFind: 2006 Achondrite (lunar, mingled breccia) History and physical characteristics: A. Aaronson purchased a 40.7 g partially crusted, complete stone in Rissani, Morocco in December 2006. The hand specimen exhibits an abundance of large (between 0.6 and 2.1 mm in dia.) anorthositic clasts. The weathered portion of the crust is pale vermillion to light brown, fresher crust is dark gray to black. Petrography (T. Bunch and J. Wittke, NAU; A. Irving, UWS): This mingled breccia contains anorthositic lithologies that include anorthosite, anorthositic norites, gabbros and troctolites, in addition to variolitic and subophitic basalt clasts, breccia-within-breccia clasts, and an abundance of olivine and plagioclase fragments. Melt and fragmental matrices are heterogeneously distributed. The interior shows very low weathering effects. Mineral compositions and geochemistry: Anorthositic norite orthopyroxene (Fs28.5Wo3.8; FeO/MnO = 65). Olivine gabbro contains olivine (Fa26.2; FeO/MnO = 96), plagioclase (An92.3), subcalcic pyroxene (Fs21.6Wo14.4; FeO/MnO = 48), and ilmenite with MgO = 6.5 wt%. Variolitic basalt has olivine (Fa35.7; FeO/MnO = 103), pigeonite (Fs24.6Wo8.7) and plagioclase (An95.5). Bulk composition (R. Korotev, WUSL): FeO = 9.6 wt.%, Sm = 3.9 ppm, Th = 1.4 ppm, Ir = 6.5 ppb. Classification: Achondrite (lunar, mingled breccia). Probably paired with NWA 2995, based on essentially identical bulk compositions. Type specimen: A total of 8.8 g is on deposit at NAU. The main mass holder is anonymous. |
from The
Meteoritical Bulletin,
no. 93, Meteoritics & Planetary Science 43,
571-632 (2007)Northwest Africa 4503Northwest AfricaFind: 2007 Achondrite (lunar, anorthositic breccia) History and physical characteristics: A 70 g partially crusted stone was purchased in January 2007 by A. Aaronson and sold to a collector in July 2007. The fusion crust is dark to light brown and vermillion in translucent areas. Petrography (T. Bunch, J. Wittke, NAU; A. Irving, UWS): This feldspathic melt breccia is dominated by very fine to medium-grained anorthositic lithologies that are typically enriched in olivine (anorthositic troctolites and gabbros) together with a large fraction of plagioclase, olivine, and exsolution-textured pyroxene fragments. Shock-melt clasts, K-, Ba-rich glasses, and fayalite-pyroxene-quartz igneous lithologies are also present. One granophyre clast shows a granophyric or micrographic texture of oriented quartz inclusions in alkali feldspar surrounded by shock-melted plagioclase. Most of the matrix is glassy and vesicular with included mineral fragments. Weathering effects are minimal. Mineral compositions and geochemistry: Gabbro: olivine (Fa34.8; FeO/MnO = 88), augite (Fs14.6Wo41.8; FeO/MnO = 42), plagioclase (An97.6), chromite (cr# = 74). Troctolite: olivine (Fa27.9; FeO/MnO = 83). Norite: orthopyroxene (Fs24.8Wo2.5; FeO/MnO = 55), augite (Fs20.4Wo38.9). Basaltic pyroxene fragments, host = Fs46.9Wo2.4, exsolution lamellae = Fs19.8Wo43.4. Granophyre K-feldspar (Or72Ab18.3). Classification: Achondrite (lunar, anorthositic breccia). Type specimen: A total of 14 g is on deposit at NAU. The main mass holder is anonymous. |
from The
Meteoritical Bulletin, No. 94, September 2008. Meteoritics & Planetary
Science 43, 1551–1588 (2008)Northwest Africa 5151AlgeriaFind: 2007 Achondrite (lunar, feldspathic breccia) History and physical characteristics: A 289 g stone was purchased in Rissani, Morocco in 2007. The exterior is reddish-brown to dark gray with minor, translucent residual fusion crust. Petrography (J. Wittke and T. Bunch, NAU): The fragmental to melt matrix contains abundant brecciawithin- breccia clasts together with typical highlands lithic components that mostly include anorthosites, noritic and troctolitic anorthosites, troctolites (olivine > 40 vol. %), gabbros, granulites, cataclastic breccias, shock melt clasts, in addition to mare basalt clasts and mineral fragments. Several small to mm-size metal globules are scattered throughout the matrix. Numerous dark brown, shock-melt veins are present along large clast margins. Interior weathering grade is very low with no apparent alteration veins. Mineral compositions: Noritic anorthosite orthopyroxene is Fs24.4Wo3.8 (FeO/MnO = 60), plagioclase = An94.2. Gabbro olivine is Fa34.1 (FeO/MnO = 97), plagioclase is An88.1, pigeonite is Fs27.9Wo9.2 (FeO/MnO = 55), chromite Cr/(Cr+Al) = 0.65 and Ni in metal is 5.8 to 6.6 wt %. Bulk chemistry (R. Korotev, WUSL): Na2O = 0.478 wt %; Sc = 16.7 ppm, Cr = 1440 ppm; FeO = 8.52 wt %; Ni = 171 ppm; Ba = 183 ppm; Th = 1.76 ppm. Classification: Achondrite (lunar feldspathic breccia). Type specimen: A total of 20.3 g is on deposit at NAU. The main mass holder is anonymous. |
from The
Meteoritical Bulletin, No. 94, September 2008. Meteoritics & Planetary
Science 43, 1551–1588 (2008)Northwest Africa 5152MoroccoFind: 2006 Achondrite (lunar, feldspathic breccia) History and physical characteristics: A 38 g complete stone was purchased in Rissani Morocco in 2007. The dark gray fusion crust is mostly eroded away by wind ablation. Petrography (J. Wittke and T. Bunch, NAU): The vesiculated melt matrix regolith breccia contains an abundance of typical anorthositic lithologies that include anorthosites, anorthositic norites, troctolitic anorthosites, granulites, devitrified shock melts, breccia-in-breccias, in addition to mare basalts and mineral fragments. Interior weathering effects are minimal. Mineral compositions: Troctolite olivine, Fa27.6 (FeO/MnO = 95); maskelynitized plagioclase fragments, An91.2-97.6, norite orthopyroxene, Fs25.5Wo3.8 (FeO/MnO = 62); subophitic basalt pigeonite, Fs29.7Wo7.8. Bulk chemistry (R. Korotev, WUSL): Sc = 16.8 ppm; Cr = 1460 ppm; FeO = 9.03 wt %; Ni = 210 ppm; Ir = 210 ppm. Classification: Achondrite (lunar feldspathic breccia). Type specimen: A total of 7.7 g is on deposit at NAU. The main mass holder is anonymous. |
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