|
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.)
|
|
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)
|
|
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)
|
|
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., Tomioka N., Seto Y., Ohtani E., H Nagaoka., Fagan
T. J., Ozawa Sekine S., T., Miyahara M., Miyake
A., and Tomeoka K. (2016) Formation process of high-pressure
silica polymorphs in lunar meteorites of the NWA 773 clan
(abstract). 79th Annual Meeting of the Meteoritical Society, abstract no.
6102.
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.
|
Back to: Lunar
Meteorites | List of Lunar
Meteorites | Top of Page
|
