Northwest Africa 4734 & 10597
pieces of Northwest Africa 4734
credit: Albert Jambon)
33-g stone, the one nearest the loupe in the top photo. Thanks to Tim Heitz for the sample.
credit: Randy Korotev)
the similarity of the fusion crust to that of the LAP
basalts from Antarctica
credit: Randy Korotev)
of basalts LAP 04841 (left) and NWA 4734 (right), same scale (millimeter
credit: Randy Korotev)
views of Northwest Africa 10597. Click on image for enlargement.
credit: Weibiao Hsu)
face of NWA 10597. Click on image for enlargement.
credit: Weibiao Hsu)
electron (BSE) image of NWA 10597. Click on image for enlargement.
credit: Weibiao Hsu)
Meteoritical Bulletin, No. 93, Meteoritics
& Planetary Science 43,
Find: October 2006
Mass: 477 g
Two pieces were purchased from nomads in Erfoud, Morocco in October 2006
and February 2007.
characteristics: A. Habibi
purchased two pieces, with a total mass of 477 g, in Rissani,
Morocco, and several other pieces of the same stone totaling 895 g are with
M. Oumama in Rissani,
Morocco. Dull black/brown fusion crust nearly complete and inside slightly
tarnished where absent. It is a gray, coarse grained, pristine magmatic
rock consisting of millimeter-sized phenocrysts, mainly of pyroxene and
(A. Jambon, O. Boudouma and D. Badia, UPVI). The texture
is best described as shergottite-like. Pyroxene grains are highly fractured
while plagioclase laths, partly transformed to maskelynite, are only
affected by a small number of fractures. Silica and silica-feldspar glass
are minor components. A few patches of impact melt are also observed.
Ilmenite, baddeleyite, zirconolite, tranquilityite,
pyrrhotite and metal. Fayalite associated with silica probably results from
the dissociation of iron rich pyroxene. Modal mineralogy (vol %): Cpx 50, Plagioclase +
Kspar 32, silica + glass 7.5, opaques (ilmenite,
Ti-magnetite, pyrrhotite) + fayalite 7, voids + fractures 3.
Mineralogy by EMP and SEM. (Trace and major element analyses ICP-MS and
ICP-AES, J-A Barrat, UBO).
Pyroxene grains are complexly zoned (En65Fs21Wo13
to En2Fs83Wo15; FeO/MnO = 78 [average]). A
few compositions correspond to pyroxferroite. Plagioclase is normally zoned
from An75-91 (average An89) with minor olivine (Fa80-95).
Chondrite normalized REE pattern with an enrichment of 53 (La) to 40 (Yb).
Trace element pattern with negative anomalies of Sr and Eu. Interstitial
glass is high in silica (75 wt%) and contains microcrysts
of K-feldspar with a significant celsian
component. The chemistry, major and trace elements, is identical to NWA
032-479-773 and LAP 02205-02224-02226-02234-02436-03632. The texture is
very similar to that of the LAP specimens. The very low abundance of
olivine and the relative abundance of silica in NWA 4734 are the main
differences beside the grain size and the slightly different composition of
the major phases.
Achondrite (lunar); extensive shock.
specimens: A total
of 20 g of sample and one polished section is on deposit at UPVI.
Elkaid hold the main masses.
The Meteoritical Bulletin, No. 105
Purchased: 2016 Feb
Mass: 350 g
Classification: Lunar meteorite (basalt)
Purchased by Ke Zuokai in
Feb. 2016 at Tucson mineral show from an anonymous Moroccan dealer.
characteristics: A single stone with a complete fresh
The meteorite is a medium-grained unbrecciated basalt composed of elongate,
zoned pyroxene (up to 1 mm) grains and plagioclase (up to 1.2 mm) laths.
Olivine phenocrysts are up to 350 µm, and commonly have inclusions of hercynite, Ti-Al-rich chromite, pigeonite or rarely
augite with intergrowth of Na-rich glass. Most pyroxene grains are
pigeonite with a minor amount of augite. A few pigeonite grains have augite
rims. Plagioclase is partly
converted to maskelynite. Late-stage mesostasis is composed of silica,
Fe-rich olivine, Fe-rich pyroxene, K-rich glass, ilmenite, pyrrhotite,
baddeleyite, and elongate, skeletal apatite and merrillite. Other opaque
phases include chromite, Ti-rich chromite, troilite, ulvöspinel,
tranquillityite, zirconolite and a few FeNi metal. Shock veins and impact
melt pockets are present. Mineral modes (vol%):
olivine = 6, pyroxene =52, plagioclase = 32, silica=3, ilmenite = 4,
mesostasis + impact melt = 3.
Plagioclase, An85.1±2.3Or0.4±0.3 (An78.5-87.8Or0.2-0.8,
n=20); olivine zoned from Fo58.2-49.9 (cores) to Fo36.6-40.7
(rims) (Fa46.5-93.1, n=13; FeO/MnO = 81.9-106.8, average: 91±7);
zoned pigeonite, core En57.7-51.6Wo8.9-16.8, rim En7.2-22Wo20.2-31.5
(Fs28.5-79.6Wo10.1-25.5, n=23), and augite, Fs21.3-52.5Wo28.4-39.3
(Wo32.9-36.2 En11.9-38.8, n=9), with pyroxene FeO/MnO
= 30.8-81.9, average: 60±10; mesostasis olivine and pyroxene, Fo2.3-13.5
and En1-3Wo14-17. Chemical compositions (wt.%) of
fusion crust: MgO 7.0, FeO 23.5, Al2O3 7.9, SiO2
47.4, CaO 10.6, TiO2 3.5.
4734/10597 is one of the few unbrecciated basalts. The meteorite is compositionally and texturally
identical to LAP basalts from Antarctica and
likely launch paired. NWA 10597 is probably one of the “several other
pieces of the same stone [NWA 4734] totaling 895 g…”
4734 | 10597
Chennaoui Aoudjehane H. and Jambon A. (2008) First
evidence of high pressure silica: Stishovite and seifertite in lunar meteorite Northwest Africa 4734
(abstract). 71st Annual Meeting of the Meteoritical Society, abstract no. 5058,
& Planetary Science 43, A32.
S. M., Shearer C. K. Jr., Fagan A. L., Neal C. R., Burger P. V., and Borg
L. E. (2012) Diversity in
low-Ti mare magmatism and mantle sources: A Perspective from lunar
meteorites NWA 4734, NWA 032, and LAP 02205 (abstract). In Lunar and Planetary
Science XLIII, abstract no. 2648, 43rd Lunar and Planetary
S. M., Shearer C. K., Fagan A. L., Borg L. E., Gaffney A. M., Burger P. V.,
Neal C. R., and McCubbin F. M. (2013) The origin of
young mare basalts inferred from lunar meteorites NWA 4734, NWA 032, and
LAP 02205 (abstract). In 44th
Lunar and Planetary Science Conference, abstract no. 2762.
S. M., Shearer C. K. Jr., Fagan A. L., Borg L. E., Gaffney A. M., Burger P.
V., Neal C. R., Fernandes V. A., and McCubbin F. M. (2013) The
origin of young mare basalts inferred from lunar meteorites Northwest
Africa 4734, 032, and LaPaz Icefield 02205. Meteoritics & Planetary Science
49, 261–291. doi: 10.1111/maps.12239
V. A., Korotev R. L., and Renne P. R. (2009) 40Ar-39Ar
ages and chemical composition for lunar mare basalts: NWA 4734 and NWA 4898
(abstract). In Lunar
and Planetary Science XL, abstract no. 1045, 40th Lunar and
Planetary Science Conference.
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.
W. and Wu Y. (2016) NWA 10597 — A new
unbrecciated mare basalt (abstract). 79th Annual
Meeting of the Meteoritical Society, abstract no. 6042.
A. and Devidal J.-L. (2009) Monazite
dating of lunar meteorite NWA 4734 (abstract). 72th Annual Meeting of
the Meteoritical Society, number 5006.
R. L., Irving A. J., and Bunch T. E. (2008) Keeping up
with the lunar meteorites – 2008 (abstract). In Lunar and Planetary
Science XXXIX, abstract no. 1209, 39th Lunar and Planetary
R. L., Zeigler R. A., Irving A. J., and Bunch T. E. (2009) Keeping up
with the Lunar Meteorites — 2009 (abstract). In Lunar and Planetary
Science XL, abstract no. 1137, 40th Lunar and Planetary Science
M., Kaneko S., Ohtani E., Sakai T., Nagase T.,
Kayama M., Hishido H., and Hirao
N. (2013) High-pressure
polymorphs of silica in NWA 4734. Antarctic
Meteorites XXXVI, Papers Presented to the Thirty-Sixth
Symposium on Antarctic Meteorites, p. 52, Tokyo.
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.
Planet. Sci. Lett., doi:10.1016/j.epsl.2010.02.007.
Xu L., Lin Y. T.,
Hofmann B. A., Gnos E., and Ouyang Z. Y. (2012) The origin
of metal particles in lunar meteorites (abstract). 75th Annual Meeting
of the Meteoritical Society, abstract no. 5247.
Y. and Hsu W. (2010) SIMS Pb/Pb
dating of Zr-rich minerals from NWA 4734 and LAP 02205/02224: Evidence for
the same crater on the Moon (abstract). 73th Annual Meeting of the Meteoritical
Society, abstract no. 5024. Lunar and Planetary Institute.
Y. and Hsu W. (2016) Shock-induced
metamorphism in the lunar meteorite Northwest Africa 4734 (abstract). 79th Annual Meeting of the Meteoritical Society, abstract no. 6337.
Y., Hsu W., Guan Y., Li X., Li Q., Liu Y., and Tang G. (2012) Petrogenesis of
the Northwest Africa 4734 basaltic lunar meteorite. Geochimica et
Cosmochimica Acta 92,
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