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Lunar Meteorite

Paired* stones Anoual and Northwest Africa 773, 2700, 2727, 2977, 3160, 3170, 3333, 6950, 7007, 8127, 10656

northwestern Africa

 

*The reported find and purchase locations of the NWA 773 clan of lunar meteorite stones are far too dispersed for all the stones to be terrestrially paired, that is, all fragments from a single fall. Anoual and Dchira are separated by 1160 km, for example. Compositionally and mineralogically, these stones are clearly all related and none like them have been found outside the area of this map. So either we must accept the coincidence of launch pairings - one impact on the Moon launched several stones that all happened to land in Northwest Africa - or that some of the reported find locations are inaccurate.

(Map courtesy of Google Earth.)

 

lm_nwa773l.jpg

Photo of a sawn face of Northwest Africa 773.  As with Dhofar 287, the stone appears to be a portion of a regolith breccia that contains a large clast of olivine gabbro and many small clasts.

(photo credit: Marvin Killgore; from Fagan et al., 2003)

 

A slice of NWA 2977, which, like NWA 773, is a olivine gabbro.

Tick marks on the scale are spaced at 1 mm intervals.

(photo credit: Randy Korotev)

 

Sawn face of NWA 2727 showing three lithologies: (1) basalt (right) and (2) breccia (left) containing (3) two gabbro clasts including a very coarse-grained one.

(photo credit: Stan Turecki and Tony Irving)

 

lm_nwa2727_4423m.jpg

NWA 2727, a breccia that is dominated by mare basalt.

Tick marks on scale are spaced at 1-mm intervals.

(photo credit: Randy Korotev)

 

A slice of NWA 3160, which is mostly basalt, with breccia along top and right edge.

(photo credit: Randy Korotev)

 

NWA 3170 consists subequally of olivine gabbro and brecciated basalt.

(photo credit: Stefan Ralew and Martin Altmann)

 

A slice of NWA 3333, a breccia (lower left of center), with a olivine gabbro clast (left) and olivine-phyric basalt clast (right).

(photo credit: Randy Korotev)

 

False color x-ray map of the interior portion of the NWA 3333 section above. Red represents aluminum, green, magnesium, and blue, iron. In this scheme, red grains are plagioclase, green are mostly olivine and some magnesian pyroxene, and purple to blue colors are Fe-rich pyroxene, glass, and ilmenite. A glassy impact-melt vein with several large vesicles cuts through the breccia on the right side.

(photo credit: Katherine Gibson)

 

A large slice NWA 3170 showing the ferrogabbro breccia (middle top) and magnesian olivine gabbro (left, right, bottom. Click on image for enlargement (big).

(photo credit: Randy Korotev)

 

NWA 6950

(photo credit: ?)

 

NWA 7007

(photo credit: Greg Hupé)

 

A polished face of NWA 7007 (width = ~3 cm). Click on image for enlargement (big).

(photo credit: Randy Korotev)

 

Two views of of NWA 8127. Click on image for enlargement.

(photo credit: Peter Marmet)

 

lm_nwa10656_DP_m.jpg 

Sawn face of NWA 10656. Click on image for enlargement.

(photo credit: Darryl Pitt)

 

from The Meteoritical Bulletin, No. 93, Meteoritics & Planetary Science 43, 571–632 (2007)

Anoual

Anoual, Morocco
Find: 2006 May 3
Mass: 5.92 g

Achondrite (Lunar, mare basalt/gabbro breccia)

History: Nomads from near Anoual (a village located in the East of Morocco between Bouarfa and Talsint; about 40 km E-N-E of the latter) learned that the small odd stones that had been found close to their settlement in June and July of 2005 was indeed a meteorite from the Moon (NWA 2727). After extensive searching and screening of the soil, Mr. Boujena recovered 12 pieces for a total mass of 5.92 g, over a small area of about 5 m in diameter. The small size of the pieces can be explained by the brecciated character of the stone. Ph. Thomas visited the place in May 2006 and May 2007, participated in the search, took pictures, in particular of the investigated soil and registered the GPS coordinates.

Physical characteristics: Tan greenish stones devoid of fusion crust.

Petrography: (A. Jambon, O. Boudouma and D. Badia. UPVI). Breccia composed dominantly of two lithologies: A phyric basalt and a gabbro. Basalt with subhedral olivine phenocrysts (<1mm; 20 vol%) slightly resorbed in a finely crystallized groundmass. Highly fractured gabbro clasts. Small doleritic clasts with zoned pyroxenes. Mafic areas of once molten rock with olivine needles. One clast of quenched basaltic melt with numerous zirconolite needles (0.7 vol%; 0.1 mm) silica and celsian K-spar. Ilmenite, troilite, chromite. Plagioclase and clinopyroxene. Carbonate fills the largest fractures.

Geochemistry: (EMPA) Olivine (Fa45-28, with few crystals >Fa45; FeO/MnO = 97). Pyroxene: from (Mg#= 0.80) pigeonite (Wo10) and augite (Wo45) to pyroxferroite (Fs70Wo25; FeO/MnO = 70). Plagioclase (An91-83). Spinel (Cr66Sp25Us3Mt6).

Classification: Lunar mare basalt/gabbro breccia. Paired with NWA 2727/3160 (and potentially NWA 3333)

Type specimens: A total of 1.205 g of sample (one polished section) is on deposit at UPVI. Thomas holds the main mass.

 

from The Meteoritical Bulletin, No. 85, Meteoritics & Planetary Science 36, A293–A322 (2001)

Northwest Africa 773

Western Sahara 
Found: 2000 September
Mass: 633 g

Lunar Meteorite (cumulate olivine norite with regolith breccia)

[see discussion below regarding classification]

Three stones of 359 g, 224 g and 50 g, totaling 633 g were sold to Marvin Killgore (SWML) by nomads who showed him the place of find on a flat dry desert plain near Dchira, Western Sahara.

Mineralogy and classification (T. Fagan, UHaw, M. Killgore, SWML): consists of two distinct lithologies, cumulate rock and regolith breccia; weathering grade, W1; shock stage, S5. Cumulate portion: modes (vol%) are olivine = 54.7, pigeonite = 24.2, augite = 5, feldspar (including minor K-feldspar) = 15.6, opaques (troilite, chromite, Fe-metal) = 0.5; olivine, Fa28-97, mean Fa31, FeO/MnO = 99±11 g/g; pigeonite, En64Wo11, FeO/MnO = 53±6 g/g; augite, En49Wo36, FeO/MnO = 46±6 g/g; plagioclase, An88-91; Ba-rich K-feldspar, An3Ab4Or93 with average BaO = 2.2 wt.%. Breccia portion: contains fragments of cumulate portion as well as silica glass, hedenbergitic pyroxene, volcanic rocks, and unusual lithic clasts with fayalite + Ba-rich K- feldspar + silica + plagioclase; olivine and pyroxene in the breccia have a slightly wider compositional range towards lower Mg/(Mg+Fe) than in the cumulate portion of the rock.

Chemical composition (D. Mittlefehldt, JSC): KREEP-rich with strong negative Eu-anomaly. Noble gases (O. Eugster, Physikalisches Institut, Bern): high solar wind component, 4He/20Ne = 9, indicative of regolith material.

Specimens: type specimen, 15 g, NHM; main mass SWML.

 

from The Meteoritical Bulletin, No. 90, Meteoritics & Planetary Science 41, 1383–1418 (2006)

Northwest Africa 2700

Morocco
Find: 2004
Mass: 31.7 g

Achondrite (lunar, olivine gabbro with regolith breccia)

History: A light green to dark complete stone of 31.7 g was purchased in Erfoud, Morocco, in November 2004.

Petrography and Geochemistry: (T. Bunch and J. Wittke, NAU) The specimen consists of olivine gabbro and regolith breccia lithologies. The cumulate olivine gabbro contains ~50 vol% olivine (Fa29.3-34.7; FeO/MnO = 94), pigeonite (Fs22-28.3Wo5.6-10; FeO/MnO = 52), augite (Fs13.2Wo38.5), plagioclase and minor maskelynite (An89), Ba-rich alkali feldspar (Or92An4; BaO = 8.9 wt%), Cr-spinel, ilmenite, phosphate, and troilite. The breccia lithology is dominated by small olivine gabbro fragments and also contains subvariolitic basalt clasts with zoned pyroxenes (Fs44Wo29 to Fs58Wo23; FeO/MnO = 57); plagioclase (An90); ilmenite, and Fe-rich, low-Ca pyroxene (Fs80.8Wo14); symplectites of fayalite (Fa91); hedenbergite (Fs60.3Wo32.7); silica; clear to yellow glass spherules; agglutinates, high silica fayalitic rocks (Fa95.6); ulvöspinel; K2O-rich glass (K2O = 8.8; SiO2 = 77 [both wt%]), and pure SiO2.

Classification: Achondrite (lunar, olivine gabbro with regolith breccia) where the olivine gabbro is moderately shocked and minimally weathered. Note: This sample may be paired with NWA 773.

Specimens: A 6.8 g type specimen and two thin sections are on deposit at NAU. An anonymous finder holds the main mass.

 

from The Meteoritical Bulletin, No. 90, Meteoritics & Planetary Science 41, 1383–1418 (2006)

Northwest Africa 2727

Morocco or Algeria
Find: June/July 2005
Mass: 191.2 g

Achondrite (Lunar mare basalt/gabbro breccia)

History: Four stones of 30.6 g, 11.6 g, 64 g and 85 g were purchased from Moroccan dealers in Erfoud for a consortium of North American collectors in June and July of 2005.

Petrography and Geochemistry: (T. Bunch and J. Wittke, NAU; A. Irving and S. Kuehner, UWS; R. Korotev, WUSL) All stones are very similar and consist of a clast-dominated polymict breccias composed of >80 vol% olivine-phyric basalt and gabbroic/diabasic clasts (0.2 cm to several cm across) within a finer breccia matrix. The basalt clasts show a wide range in mineral compositions, but all contain phenocrysts of olivine Fa 28-99 FeO/MnO = 98.9 and some also have phenocrysts of pyroxferroite or chromite all in a rapidly quenched, fine-grained matrix consisting of intergrown pigeonite, pyroxferroite, K-Ba-feldspar, ilmenite, merrillite, baddeleyite, troilite, silica and glass. The gabbroic clasts range in texture from coarser grained (>3 mm) hypidiomorphic gabbro to finer grained (~1 mm) diabasic clasts. Both types of gabbroic lithologies consist mainly of pigeonite Fs23.3-31.3Wo8.7-11.5, FeO/MnO = 60-69 and subhedral to anhedral olivine Fa34.1-41 FeO/MnO = 85-99 with less abundant augite Fs24.1-47.5 Wo24.4-32.1 and partly maskelynitized, blocky to tabular plagioclase An81-94. The breccia matrix consists mainly of gabbroic debris with fragments of basalt, silica polymorph, symplectites, subparallel intergrowths of anorthite + pyroxferroite+ilmenite and shock-melted material.

Bulk compositions: (R. Korotev, WUSL) INAA of 11 subsamples show that they vary considerably in bulk composition, with the most Fe-rich subsample nearly indistinguishable from NWA 3160 basalt. All other subsamples are compositionally equivalent to mixtures of NWA 3160 basalt and the regolith breccia lithology of NWA 773, but with slightly lower concentrations of incompatible elements. Note: Based on petrography, mineral compositions, and bulk compositions, these stones are paired with NWA 3160 and may be paired with NWA 773.

Classification: Achondrite (lunar, mare basalt/gabbro breccia).

Specimens: A 20.2 g type specimen and two polished thin sections are on deposit at NAU. A 0.5 g type specimen is on deposit at WUSL. Oakes, Reed, Boswell, and Turecki hold the main masses.

 

from The Meteoritical Bulletin, No. 90, Meteoritics & Planetary Science 41, 1383–1418 (2006)

Northwest Africa 2977

Morocco or Algeria
Find: 2005 November
Mass: 233 g

Achondrite (lunar, gabbro)

History: A single minimally weathered fusion-encrusted stone of 233 g was purchased from a Moroccan dealer in Tagounite, Morocco, by M. Farmer in November 2005.

Petrography and Geochemistry: (J. Wittke and T. Bunch, NAU; A. Irving, UWS) The specimen consists of a single yellow-green, relatively coarse-grained rock traversed by thin, black glass-rich veins. It is an olivine-rich, twopyroxene cumulate gabbro composed of olivine (Fa31.7; FeO/MnO = 96; 52 vol%), (Fs26.6Wo6.7; 23 vol%), augite (Fs16.2Wo29; 9 vol%), and plagioclase (An56; 14 vol%) with minor amounts of Ba-K feldspar, chromite, ilmenite, and merrillite. Larger pigeonite grains commonly enclose equant olivine grains, which contain abundant melt inclusions (0.025–0.125 mm). Plagioclase is partially converted to maskelynite, and pyroxenes and olivine exhibit shock lamellae and undulatory extinction. Note: This specimen is identical in texture and mineral composition to the gabbro clasts in NWA 773 and NWA 2700 and thus appears to be paired with those breccia specimens.

Classification: Achondrite (lunar, gabbro); minimal weathering.

Specimens: A 20.1 g type specimen and one polished thin section are on deposit at NAU. A 0.5 g specimen is on deposit at WUSL. An anonymous owner holds the main mass.

 

from The Meteoritical Bulletin, No. 90, Meteoritics & Planetary Science 41, 1383–1418 (2006)

Northwest Africa 3160

Morocco
Find: 2005 July
Mass: 34 g

Achondrite (lunar mare basalt breccia)

History: In July 2005, A. and G. Hupé purchased three broken stones with a total weight of 34 g from a Moroccan dealer in Erfoud, Morocco.

Physical Characteristics: The largest stone (28 g) has a partial thin weathered fusion crust.

Petrography: (R. Zeigler and R. Korotev, WUSL; A. Irving and S. Kuehner, UWS) The large specimen consists almost entirely of a fine-grained, olivine-phyric basalt clast with minor attached breccia matrix and appears to be part of a larger, coarse-grained, polygenic breccia. The two small stones are pieces of the breccia. The basalt contains phenocrysts of euhedral to subhedral olivine (~0.1–0.9 mm) and minor chromite (<0.1 mm).

Geochemistry: Olivine phenocrysts are zoned, with cores typically Fo55-70 and rims extending to ~Fo40; FeO/MnO ratios are 91-105. The groundmass has spinifex olivine Fo29 and skeletal pyroxene En37-39Wo11-13 FeO/MnO = 71-75 set in a fine-grained matrix of pyroxene En35-39Wo20-23, olivine ~Fo22 and glass. The breccia lithology is a fragmental breccia consisting primarily of olivine Fo6-82 and pyroxene En1-68Wo9-39Fs16-83, with minor amounts of plagioclase An82-97 and trace silica; hedenbergite-fayalite-silica symplectite (after former pyroxferroite), and Fe-Ti-Cr oxides.

Classification: Achondrite (lunar, mare basalt breccia). Note: These samples may be paired with NWA 2727.

Specimens: A 4.8 g type specimen and one polished thin section are on deposit at UWS. A 2.1 g specimen is on deposit at WUSL. A. Hupé holds the main mass.

 

from The Meteoritical Bulletin, No. 101

Northwest Africa 3170

(Northwest Africa)
Purchased: 2007 April
Mass: 60 g

Lunar meteorite (gabbro)

History: Purchased from a Moroccan dealer in 2007 by Stefan Ralew.

Physical characteristics: A single 60 g stone consisting of large clasts of yellowish-green gabbro (containing fine, black shock veinlets) in a darker fragmental matrix.

Petrography: (A. Irving and S. Kuehner, UWS) Monomict breccia consisting of ferroan gabbro clasts and related debris. Predominantly composed of olivine, clinopyroxenes and anorthite with accessory fayalite, silica, ilmenite and minor K-Ba-feldspar. Symplectitic intergrowths of hedenbergite+fayalite+silica are present. No orthopyroxene found.

Geochemistry: Olivine (Fa29.6-39.9, FeO/MnO = 82-116), pigeonite (Fs42.3Wo11.9, FeO/MnO = 79), subcalcic augite (Fs28.7Wo26.2, FeO/MnO = 57), subcalcic ferroaugite (Fs64.4-78.8Wo26.3-26.2, FeO/MnO = 78-93). Bulk composition (R. Korotev, WUSL): mean values from INAA of subsamples are 20.7 wt.% FeO, 40 ppm Sc, 56 ppm Co, 110 ppm Ni, 24.3 ppm La, 11.2 ppm Sm, 0.76 ppm Eu, 8.1 ppm Yb, 4.3 ppm Th.

Classification: Lunar (mare gabbro breccia). This stone is very similar in mineralogy and bulk composition to NWA 7007, and both specimens are likely paired with NWA 773.

Specimens: 12.1 g is on deposit at UWS. The remaining material is held by Ralew.

 

from The Meteoritical Bulletin, No. 94, Meteoritics & Planetary Science 43, 1551–1588 (2008)

Northwest Africa 3333

Morocco
Purchased: 2005 May
Mass: 33 g

Achondrite (lunar basaltic fragmental breccia)

History: Fabien Kuntz purchased a 33 g specimen from a Moroccan dealer. The original main mass was broken into at least 5 pieces and distributed to several dealers..

Physical characteristics: A partially weathered blackish brown fusion crust was present on the specimen. Cut and polished surfaces on two different specimens reveal a coarsely brecciated texture, while a third specimen exhibits three different lithologies.

Petrography: (R. Zeigler, WUSL) The specimen examined consists of one basalt clast (1.5 cm) and one clast of cumulus olivine gabbro (1.2 cm) set in a fragmental breccia matrix. The basalt consists of large phenocrysts of zoned olivine and smaller chromite phenocrysts set in a fine-grained matrix of spinifex olivine, skeletal pyroxene, and glass. The olivine gabbro is 50% olivine, 35% pyroxene, and 15% plagioclase. A vein of black shock melt separates the cumulate clast from the fragmental breccia. The breccia is composed predominantly of pyroxene and olivine clasts, with minor plagioclase, and trace silica, Fe,Ti,Cr oxides, troilite, chromite, ilmenite, FeNi, apatite, and RE-merrillite.

Mineral compositions and geochemistry: Matrix pyroxene and olivine is Fs17-65Wo12-29En8–61 and Fo5-60; plagioclase clasts are An86-95Or<2. Olivine in the basalt is zoned (Fo47-72). Mineral compositions in the olivine cumulate are Fo68, Fs63Wo15 and Fs52Wo32, and An92Or1. Fe/Mn = 85–110 (olivine) and 40–77 (pyroxene).

Bulk composition: (R. Zeigler and R. Korotev, WUSL) The basalt (TiO2 = 0.8%, FeO = 21%, MgO= 14%, Th = 1.4 µg/g) is compositionally similar to that of NWA 3160; the cumulate olivine gabbro (TiO2 = 0.4%, FeO = 20%, MgO = 27%, Th = 1.2 µg/g) is similar to NWA 773 and NWA 2977. All lithologies are characterized by low concentrations of Na2O (= 0.15 ± 0.06 %) and Eu (= 0.4 ± 0.2 ppm) compared to other lunar basalts. The oxygen isotope composition (I. A. Franchi, OU) is consistent with lunar origin (δ17O=2.94, δ18O=5.59, Δ17O = 0.032).

Classification: Achondrite (lunar basaltic fragmental breccia). The specimen is another stone of the NWA 773/2700/2727/2977/3160 pair group.

Type specimens: A mass of 6.55 g is on deposit at DuPont and 0.4 g (neutron irradiated) and one thin section at WUSL.

 

from The Meteoritical Bulletin, No. 100

Northwest Africa 6950

Mali or Algeria
Purchased: 2011 August
Mass: 771 g

Lunar meteorite (gabbro)

History: Reported to be found near the border between Mali and Algeria in June 2011, and purchased from the finder by Adam Aaronson in August 2011.

Physical characteristics: A single yellowish-green stone (771 g) with partial fusion crust. Thin black shock veins are visible in the interior.

Petrography: (A. Irving and S. Kuehner, UWS) Relatively coarse grained with a cumulate igneous texture. Aggregate dominated by olivine, low-Ca pyroxene, pigeonite, and subcalcic augite, with interstitial very calcic plagioclase. Accessory minerals are ilmenite, Ti-chromite, armalcolite, troilite, baddeleyite, taenite and merrillite with rare zirconolite and K-feldspar.

Geochemistry: Olivine (Fa31.9-32.7, Fe/Mn=85-97), low-Ca pyroxene (Fs27.1-28.1Wo4.8-4.5, Fe/Mn=47-55), pigeonite (Fs25.6±0.0 Wo9.2-11.1, Fe/Mn=47-52), subcalcic augite (Fs13.9Wo36.9, Fe/Mn=41), plagioclase (An87.9-93.0Or1.1-0.9).

Classification: Achondrite (lunar, gabbro). This specimen is texturally and mineralogically identical to NWA 2977 and the olivine gabbro clasts in NWA 773, NWA 2700, NWA 2727 and NWA 3333, and evidently is paired with those stones.

Specimens: A total of 20.1 g of sample and one polished thin section are on deposit at UWS. The main mass is held by Aaronson.

 

from The Meteoritical Bulletin, No. 100

Northwest Africa 7007

Western Sahara
Purchased: 2011 October
Mass: 91 g

Lunar meteorite (gabbro)

History: Found near Smara, southern Morocco in September 2011, and purchased from a dealer in Zagora, Morocco by Greg Hupé in October 2011.

Physical characteristics: A single dense, rounded stone (91 g) partially coated with black fusion crust. Dark angular mineral clasts plus sparse white clasts are visible within a finer grained dark matrix. One small polymineralic gabbroic clast is exposed on the surface, and others are revealed in interior slices.

Petrography: (A. Irving and S. Kuehner, UWS) Crystal-rich regolithic breccia consisting of some larger polymineralic clasts (gabbro and ophitic basalt) and apparently related crystal debris in a sparse glassy, microvesicular matrix. Major components are anorthite, complexly-zoned subcalcic augite, ferropigeonite, and relatively large fragments composed of intergrowths of fayalite+hedenbergite+silica (typical of subsolidus inversion assemblages from primary pyroxferroite). Accessory phases include olivine, ilmenite, fayalite, hedenbergite, silica polymorph, troilite, Ni-free metal and baddeleyite (to 10 µm across within fayalitic rims on pyroxene). Matrix glass contains abundant small, round vesicles (typical of those representing trapped solar wind gases in other lunar regolith breccias).

Geochemistry: Zoned subcalcic augite [(core Fs22.5Wo31.2, Fe/Mn=46), mantles (Fs34.2-50.0Wo29.6-25.9, Fe/Mn=55-65), ferropigeonite rims (Fs66.1Wo19.7, Fe/Mn=66)], olivine (Fa42.0-44.4, Fe/Mn=86-93), fayalite (Fa98.4, Fe/Mn=78-84), plagioclase (An91.4.5-93.2Or0.5-0.3).

Classification: Achondrite (lunar, gabbro breccia). Terrestrial weathering is minimal.

Specimens: A total of 18.2 g of sample and one polished thick section are on deposit at UWS. The main mass is held by an anonymous collector.

 

from The Meteoritical Bulletin, No. 103

Northwest Africa 8127

(Northwest Africa)
Purchased: 2012 March
Mass: 529 g

Classification: Lunar meteorite (gabbro)

History: Purchased by Marc Jost in March 2012 in Brugg, Switzerland from a Moroccan dealer.

Physical characteristics: Fresh, pale green stone (529 g) with cross-cutting thin, black shock veins. Apple green clinopyroxene and glassy maskelynite grains are visible.

Petrography: (A. Irving and S. Kuehner, UWS) Equigranular igneous rock (mean grain size 0.8 mm) consisting of smaller grains of olivine, Ti-bearing chromite and ilmenite (with associated baddeleyite) poikilitically enclosed in clinopyroxene (some containing fine, subparallel exsolution lamellae), with interstitial anorthitic plagioclase. Most plagioclase has been converted to maskelynite, but some grains have patchy birefringence.

Geochemistry: Olivine (Fa30.0-32.1, FeO/MnO = 90-91), pigeonite (Fs21.4-25.1Wo10.6-9.8, FeO/MnO = 46-54), subcalcic augite (Fs14.5-15.4Wo32.6-30.5, FeO/MnO = 39-42). Bulk composition (R. Korotev, WUSL) INAA of subsamples gave (in wt.%) FeO 18.2, Na2O 0.11, and (in ppm) Sc 29.2, La 4.7, Sm 2.59, Eu 0.21, Yb 2.24, Th 0.56.

Classification: Lunar (olivine gabbro). This specimen is paired with NWA 6950 and the gabbroic lithology in NWA 773 and paired stones.

Specimens: 23.7 g, one polished thin section and a polished mount are at UWB. The main mass is held by Space Jewels Switzerland.

 

Modal Mineralogy of Northwest Africa 773 Cumulate Portion
(values in percent)

 

Met.Bull.

Fagan et al.

Jolliff et al.

Bridges et al.

olivine

55

55.5

48

66

augite

5

8.7

12

26

pigeonite

24

18.9

28

hypersthene

 

 

2

plagioclase

15

14.2

10

8

alkali feldspar

minor

1.6

trace

 

ilmenite, chromite, alkali feldspar, phosphates, troilite, FeNi metal

<1

<1.5

<1

<1

The cumulate is coarse grained and the thin sections are small, so the modal mineral proportions obtained from different sections do not agree well.  Because augite and pigeonite, both clinopyroxenes, dominate over orthopyroxene, which is at most "minor" (Korotev et al., 2002), the cumulate is a gabbro, not a norite.  Specifically, it is an olivine gabbro because olivine exceeds 10%. If plagioclase is actually <10%, then it's a peridotite.

After Stöffler et al. (1980)

 

More Information

Meteoritical Bulletin Database

Anoual | NWA 773 | NWA 2700 | NWA 2727 | NWA 2977 | NWA 3160 | | NWA 3170 | NWA 3333 | NWA 6950 | NWA 7007 | NWA 8127 | NWA 10656

References

Borg L. E., Shearer C. K., Asmerom Y., and Papike J. J. (2004) Prolonged KREEP magmatism on the Moon indicated by the youngest dated lunar igneous rock. Nature 432, 209–211.

Borg L. E., Shearer C. K., Asmerom Y., and Papike J. J. (2005) Geochemical and isotopic systematics of the youngest dated lunar igneous rock, Northwest Africa 773 (abstract). In Lunar and Planetary Science XXXVI, abstract no. 1026.

Borg L. E., Gaffney A. M., Shearer C. K., DePaolo D. J., Hutcheon I. D., Owens T. L., Ramon E., and Brennecka G. (2009) Mechanisms for incompatible-element enrichment on the Moon deduced from the lunar basaltic meteorite Northwest Africa 032. Geochimica et Cosmochimica Acta 73, 3963–3980.

Bridges J. C., Jeffries T. E.,  and Grady M. M. (2002) Trace element signatures of trapped KREEP in olivine- rich clasts within lunar meteorite NWA773, 65th Meteoritical Society Meeting, no. 5137.

Bunch T. E., Wittke J. H., Korotev R. L., and Irving A. J. (2006) Lunar meteorites NWA 2700, NWA 2727 and NWA 2977: Mare basalt/gabbro breccias with affinities to NWA 773 (abstract). In Lunar and Planetary Science XXVII, abstract no. 1375.

Burgess R., Fernandes V. A., Irving A. J., and Bunch T. E. (2007) Ar-Ar ages of NWA 2977 and NWA 3160 – lunar meteorites paired with NWA 773 (abstract). In Lunar and Planetary Science XXXVIII, abstract no. 1603, 38th Lunar and Planetary Science Conference.

Calzada-Diaz A., Joy K. H., Crawford I. A., and Nordheim T. A. (2015) Constraining the source regions of lunar meteorites using orbital geochemical data. Meteoritics & Planetary Science 50, 214-228.

Fagan T. J. (2006) A record of extreme FeO/(MgO+FeO) enrichment during igneous crystallization on the Moon preserved in lunar meteorite Northwest Africa 773 (abstract). In Antarctic Meteorites XXX, 9-10, National Institute of Polar Research, Tokyo.

Fagan T. J. (2007) Formation of symplectite-like inclusions by direct quenching from igneous liquid in lunar meteorite NWA 773 (abstract). 70th Annual Meeting of the Meteoritical Society, abstract no. 5204.

Fagan T. (2007) Formation of symplectite inclusions by direct quenching of a high-FeO/(FeO+MgO) silicate liquid on the Moon (abstract). Antarctic Meteorites XXXI, p. 15-16, National Institute of Polar Research, Tokyo.

Fagan T. J., Keil K., Taylor G. J., Hicks T. L., Killgore M., Bunch T. E., Wittke J. H., Eugster O., Lorenzetti S., Mittlefehldt D.W., Clayton R.N., and  Mayeda T. (2001) New lunar meteorite Northwest Africa 773: Dual origin by cumulate crystallization and impact brecciation (abstract), 64th Meteoritical Society Meeting, no. 5149.

Fagan T. J. (2014) Effect of titanium abundance on silica vs. iron enrichment in lunar basalts: Modeling and comparisons with Northwest Africa 773 (abstract). 45th Lunar and Planetary Science Conference, abstract no. 1599.

Fagan T. J., Taylor J. G., Keil K., Hicks T. L., Killgore M., Bunch T. E., Wittke J. H., Mittlefehldt D. W., Clayton R. N., Mayeda T. K., Eugster O., Lorenzetti S., and Norman M. D. (2003) Northwest Africa 773: Lunar origin and iron-enrichment trend. Meteoritics & Planetary Science 38, 529–554.

Fagan T. J., Hayakawa S., Kodama S., Kataoka Y., and Sasamoto A. (2008) Late-stage crystallization products in NWA 773 group lunar meteorites (abstract). In Lunar and Planetary Science XXXIX, abstract no. 1854, 39th Lunar and Planetary Science Conference.

Fagan T. J., Suginohara A., and Kashima D. (2010) Effect of initial Ti-abundance on Si-enrichment during magmatic evolution of lunar basalts: Initial modeling results (abstract). The 33rd Symposium on Antarctic Meteorites, Tokyo.

Fagan T. J., Wakabayashi Y., Suginohara A., and Kashima D. (2012) Do high Ti abundances in lunar basalts lead to silica-enrichment? Yes and no (abstract). 75th Annual Meeting of the Meteoritical Society, abstract no. 5110.

Fagan T. J., Wakabayashi Y., Suginohara A., and Kashima D. (2013) Controls and constraints on tholeiite-like and calc-alkaline-like igneous trends on the Moon from Northwest Africa 773 and Apollo 15405 (abstract). In 44th Lunar and Planetary Science Conference, abstract no. 1812.

Fagan T. J., Kashima D., Wakabayashi Y., and Suginohara A. (2014) Case study of magmatic differentiation trends on the Moon based on lunar meteorite Northwest Africa 773 and comparison with Apollo 15 quartz monzodiorite. Geochimica et Cosmochimica Acta, http://dx.doi.org/10.1016/j.gca.2014.02.025.

Fernandes V. A., Burgess R. and Turner G. (2002) North West Africa 773 (NWA773): Ar-Ar studies of breccia and cumulate lithologies (abstract). In The Moon Beyond 2002: Next Steps in Lunar Science and Exploration, p. 16, abstract no. 3033, LPI Contribution No. 1128, Lunar and Planetary Institute.

Fernandes V. A., Burgess R. and Turner G. (2003) 40Ar-39Ar chronology of lunar meteorites Northwest Africa 032 and 773. Meteoritics & Planetary Science 38, 555–564.

Fernandes V.A., Burgess R., Bischoff A., Sokol A. K., and Haloda J. (2007) Kalahari 009 and North East Africa 003: Young (<2.5 ga) lunar mare basalts (abstract). In Lunar and Planetary Science XXXVIII, abstract no. 1611, 38th Lunar and Planetary Science Conference.

Fernandes V. A. S. M., Fritz J. P., Wünnemann K., and Hornemann U. (2010) K-Ar ages and shock effects in lunar meteorites (abstract). EPSC Abstracts, Vol. 5, EPSC2010-237.

Gaffney A. and Borg L. (2008) What we are learning about the Moon from lunar meteorites. Goldschmidt Conference Abstracts 2008, Geochimica et Cosmochimica Acta 72, 12S, p. A287.

Gibson K. E., Jolliff B. L., Zeigler R. A., and Korotev R. L. (2010) Testing petrogenetic relationships of the lunar nwa773 meteorite clan with nickel & cobalt in olivine? (abstract). In Lunar and Planetary Science XLI, abstract no. 2593, 41st Lunar and Planetary Science Conference.

Hallis L. H. Joy K. H. Anand M., and Russell S. S. (2007) Compositional analysis of the very-low-Ti mare basalt component of NWA 773 and comparison with low-Ti basalts, LAP 03632 & 02436 (abstract). In Lunar and Planetary Science XXXVIII, abstract no. 1703, 38th Lunar and Planetary Science Conference.

Jolliff B. L., Korotev R. L., Zeigler R. A., Floss C., and Haskin L. A. (2003) Northwest Africa 773: Lunar mare breccia with a shallow-formed olivine-cumulate component, very-low-ti heritage, and a KREEP connection (abstract), Lunar and Planetary Science 34, abstract #1935.

Jolliff B. L., Korotev R. L., Zeigler R. A., Floss C., and Haskin L. A. (2003) Northwest Africa 773: Lunar mare breccia with a shallow-formed olivine-cumulate component, very-low-Ti (VLT) heritage, and a KREEP connection. Geochimica et Cosmochimica Acta 67, 4857–4879.

Jolliff B. L., Zeigler R. A., and Korotev R. L. (2007) Compositional characteristics and petrogenetic relationships among the NWA 773 clan of lunar meteorites (abstract). In Lunar and Planetary Science XXXVIII, abstract no. 1489, 38th Lunar and Planetary Science Conference.

Kayama M., Nakashima S., Tomioka N., Ohtani E., Seto Y., Nagaoka H., Ozawa S., Sekine T., Miyahara M.,  Miyake A., Götze J., and Tomeoka K. (2016) Water in olivine, clinopyroxene, and plagioclase of lunar meteorites of the NWA 773 clan by IR micro-spectroscopy (abstract). 79th Annual Meeting of the Meteoritical Society, abstract no. 6127.

Korotev R. L. (2005) Lunar geochemistry as told by lunar meteorites. Chemie der Erde 65, 297-346.

Korotev R. L and Irving A. J. (2013) Keeping up with the lunar meteorites - 2013 (abstract). In 44th Lunar and Planetary Science Conference, abstract no. 1216.

Korotev R. L. and Zeigler R. A. (2007) Keeping up with the lunar meteorites (abstract). In Lunar and Planetary Science XXXVIII, abstract no. 1340.

Korotev R. L., Zeigler R. A., Jolliff B. L., and Haskin L. A. (2002) Northwest Africa 773 - An unusual rock from the lunar maria, 65th Meteoritical Society Meeting, no. 5259.

Korotev R. L., Irving A. J., and Bunch T. E. (2012) Keeping Up With the Lunar Meteorites — 2012 (abstract). In Lunar and Planetary Science XLIII, abstract no. 1152, 43rd Lunar and Planetary Science Conference.

Korotev R. L. and Irving A. J. (2014) Keeping up with the lunar meteorites — 2014 (abstract). 45th Lunar and Planetary Science Conference, abstract no. 1405.

Kuehner S. M., Irving A. J., and Korotev R. L. (2012) Petrology and composition of lunar mare ferroan gabbro breccia Northwest Africa 7007: New insights into the complex petrogenesis of Northwest Africa 773 and siblings (abstract). In Lunar and Planetary Science XLIII, abstract no. 1519, 43rd Lunar and Planetary Science Conference.

Lorenzetti S., Busemann H., and Eugster O. (2005) Regolith history of lunar meteorites. Meteoritics & Planetary Science 40, 315-327.

Macke R. J., Kiefer W. S., Britt D. T., and Consolmagno G. J. (2010) Density, porosity and magnetic susceptibility of lunar rocks (abstract). In Lunar and Planetary Science XLI, abstract no. 1252.

Macke R. J., Kiefer W. S., Britt D. T., Irving A. J., and Consolmagno G. J. (2011) Densities, porosities and magnetic susceptibilities of meteoritic lunar samples: Early results (abstract). In Lunar and Planetary Science XLII, abstract no. 1986.

Macke R. J., Britt D. T., and Consolmagno G. J. (2011) Density, porosity and magnetic susceptibility of achondritic meteorites. Meteoritics & Planetary Science 46, 311-326.

McCubbin F. M., Steele A., Hauri E. H., Nekvasil H., Yamashita S., and Hemley R. J. (2010) Nominally hydrous magmatism on the Moon. Proceedings of the National Academy of Sciences, doi: 10.1073/pnas.1006677107.

Nagaoka H. Karouji Y., Takeda H, Ebihara M., and Hasebe N. (2010) Chemical signatures in bulk element composition for Northwest Africa 2977 (abstract). 73th Annual Meeting of the Meteoritical Society, abstract no. 5182.

Nagaoka H., Karouji Y., Takeda H. (2015) Mineralogy and petrology of lunar meteorite Northwest Africa 2977 consisting of olivine cumulate gabbro including inverted pigeonite. Earth, Planets, Space 67, 200: DOI 10.1186/s40623-015-0368-y.

Nishiizumi K. and Caffee M. W. (2006) Constraining the number of lunar and martian meteorite falls (abstract). In Meteorit. Planet. Sci. 41, p. A133, 69th Annual Meeting, Meteoritical Society.

Nishiizumi K., Hillegonds D. J., McHargue L. R., and Jull A. J. T. (2004) Exposure and terrestrial histories of new lunar and martian meteorites (abstract), In Lunar and Planetary Science XXXV, abstract no. 1130.

North S. N., Jolliff B. L., and Korotev R. L. (2013) Pyroxene composition in lunar meteorite NWA 2727 and comparison to NWA 7007 (abstract). In 44th Lunar and Planetary Science Conference, abstract no. 3013.

North-Valencia S. N., Jolliff B. L., and Korotev R. L. (2014) Ferroan gabbro and leucogabbro lithologies in NWA 3170, possible petrogenetic link and comparison to NWA 2727 (abstract). 45th Lunar and Planetary Science Conference, abstract no. 2858.

Nyquist L. E., Shih C.-Y., Reese Y. D., and Irving A. J. (2009) Sm-Nd and Rb-Sr ages for Northwest Africa 2977, a young lunar gabbro from the PKT (abstract). 72th Annual Meeting of the Meteoritical Society, number 5347.

Rochette P., Gattacceca J., Ivanov A. V., Nazarov M. A., and Bezaeva N. S. (2010) Magnetic properties of lunar materials: Meteorites, Luna and Apollo returned samples. Earth Planet. Sci. Lett., doi:10.1016/j.epsl.2010.02.007.

Seddio S. M. and Valencia S. N. (2015) Comparing WDS analyses of minerals in lunar meteorite NWA 2727 Acquired using an electron microprobe and a scanning electron microscope. 46th Lunar and Planetary Science Conference, abstract no. 2992.

Shaulis B. J., Righter M., Lapen T. J., and Irving A. J. (2013) 3.1 Ga crystallization age of magnesian and ferroan gabbro lithologies in lunar meteorites Northwest Africa 773, 3170, 6950 and 7007 and evidence for 3.95 Ga components in NWA 773 polymict breccia (abstract). In 44th Lunar and Planetary Science Conference, abstract no. 1781.

Shearer C. K., Borg L. E., and Papike J. J. (2005) A view of KREEP-rich lunar basaltic magmatism through the eyes of NWA 773 (abstract). In Lunar and Planetary Science XXXVI, abstract no. 1191.

Stöffler D., Knöll H.-D., Marvin U. B., Simonds C. H., and Warren P. H. (1980) Recommended classification and nomenclature of lunar highlands rocks - a committee report. In Proc. Conf. Lunar Highlands Crust (eds. J. J. Papike and R. B. Merrill,), pp. 51-70, Pergamon Press.

Tartese R., Anand M., Joy K. H., Franchi I. A. (2014) H and Cl isotope characteristics of apatite in brecciated lunar meteorites NWA 4472, NWA 773, SaU 169 and Kalahari 009 (abstract). 77th Annual Meeting of the Meteoritical Society, abstract no. 5085.

Wakabayashi Y., Fagan T. J., Hayakawa S., Sasamoto A. (2011) Evolution of trapped vs. main liquids during crystallization of Northwest Africa 773 olivine cumulate (abstract). Thirty-Fourth Symposium on Antarctic Meteorites, p. 85-86. National Institute of Polar Research, Tokyo.

Wang Y., Guan Y., Hsu W., and Eiler J. M. (2012) Water content, chlorine and hydrogen isotope compositions of lunar apatite (abstract). 75th Annual Meeting of the Meteoritical Society, abstract no. 5170.

Zeigler R. A., Korotev R. L., Irving A. J., Jolliff B. L., Kuehner S. M., and Hupé A. C. (2006) Petrography and composition of lunar basaltic meteorite NWA 3160 (abstract). In Lunar and Planetary Science XXXVII, number 1804.

Zeigler R. A., Korotev R. L., Jolliff B. L., Bunch T. E., and Irving A. J. (2006) Pairing relationships among Northwest African basaltic lunar meteorites based on compositional and petrographic characteristics (abstract). In Antarctic Meteorites XXX, 125-126, National Institute of Polar Research, Tokyo.

Zeigler R. A., Korotev R. L., Jolliff B. L., Bunch T. E., and Irving A. J. (2006) Pairing and petrogenetic relationships among basaltic lunar meteorites from northwest Africa (abstract). Meteoritics & Planetary Science 41, A197. 69th Annual Meeting of the Meteoritical Society, abstract no. 5235.

Zeigler R. A., Korotev R. L., and Jolliff B. L. (2007) Petrography, geochemistry, and pairing relationships of basaltic lunar meteorite stones NWA 773, NWA 2700, NWA 2727, NWA 2977, and NWA 3160 (abstract). In Lunar and Planetary Science XXXVIII, abstract no. 2109, 38th Lunar and Planetary Science Conference.

Zhang A. and Hsu W. (2008) Mineralogical and Raman spectroscopic studies of Northwestern Africa 2977 lunar meteorite (abstract). 71st Annual Meeting of the Meteoritical Society, abstract no. 5122.

Zhang A. C., Taylor L. A., Hsu W. B., Floss C., Li X. H., and Liu Y. (2010) Petrogenesis of lunar meteorite Northwestern Africa 2977: Rare earth element geochemistry and baddeleyite Pb/Pb dating (abstract). In Lunar and Planetary Science XLI, abstract no. 1052, 41st Lunar and Planetary Science Conference.

Zhang A.-C., Hsu W.-B., Floss C., Li X.-H., Qiu-Li Li, Liu Y. and Taylor L. A. (2010) Petrogenesis of lunar meteorite Northwest Africa 2977: Constraints from in situ microprobe results. Meteoritics and Planetary Science 45, 1929-1947.

 

 

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Prepared by
: Randy L. Korotev
 
Department of Earth and Planetary Sciences
Washington University in St. Louis

Please don't contact me about the meteorite you think you've found until you read this and this.


e-mail
korotev@wustl.edu

Last revised: 28-June-2016