Lunar Meteorite: Oued Awlitis 001

Western Sahara

Oued Awlitis 001, large piece. Photo credit: Mohamed Aid

Oued Awlitis 001, with the small piece positioned on the right. Photo credit: Mohamed Aid

Sawn slice of Oued Awlitis 001. Photo credit: Tony Irving

Thin section of Oued Awlitis 001. Width of rock section: 2.5 cm. The meteorite is highly feldspathic (31% Al2O3). Photo credit: Randy Korotev

Lab samples of Oued Awlitis 001. Photo credit: Randy Korotev

from The Meteoritical Bulletin, No. 103

Oued Awlitis 001 (OA 001)

Western Sahara
Found: 2014 Jan 15
Mass: 432.5 g  (2 pieces)

Classification: Lunar meteorite

History: (A. Irving and M. Aid) In January 2014 a group of eight people traveling in two cars were returning northward after an unsuccessful meteorite hunting trip to southern Morocco, when they stopped near Oued Awlitis to cook dinner by the roadside. During a search for firewood, Mr. Zaid Oussaid found a buried piece of dead tree trunk, but he could not excavate it by hand. With the use of a pickaxe he was able to pull the wood out of the ground, but he then noticed beside it in the cavity a flat ellipsoidal, brownish gray rock coated by glossy translucent crust with anastomozing wrinkle ridges. Upon returning to his home (at Dwar Ait Gazo, 30 km west of Tagounite), Mr. Oussaid showed the 382 g specimen to Mr. Mohamed Aid, who organized a return trip to the find site on February 21, 2014, and after a search of the area an additional 50.5 g piece which fits exactly onto the main stone was found about 50 m away.

Physical characteristics: (A. Wittmann, WUSL, and A. Irving, UWS) A very fresh specimen (total weight 432.5 g, approximate dimensions 7.7 × 6.6 × 3.5 cm) with a pale yellow-brown, translucent fusion crust exhibiting a darker network of anastomozing wrinkle ridges on the surface. Small, yellow-white components are visible through the fusion crust, and chipped parts of the stone reveal a whitish-gray interior. A cut sample surface exhibits a fine-grained, wavy texture of gray mineral phases in a groundmass consisting of intergrown domains of anhedral, grayish-white minerals. Rare rounded, up to 2 mm, white domains occur that appear homogeneous, and represent possible vesicle fills of secondary minerals.

Petrography: (A. Wittmann, WUSL; A. Irving, UWS) Crystallized, clast-rich melt rock with a poikilitic texture of intensely fractured olivine and pyroxene crystals that fill interstitial spaces between 5 to 50 µm, euhedral plagioclase phenocrysts. This crystallized melt groundmass envelops partly assimilated, strongly undulous, <1 mm plagioclase clasts that are distinguished by irregular and sub-planar fractures in lensoid, relict domains. In places, these plagioclase clasts contain 10 µm, euhedral domains of silica polymorph and commonly contain planar deformation features. Up to 10 µm kamacite and taenite crystals, and up to 70 µm troilite crystals that are in places intergrown, occur in the plagioclase clasts and in the poikilitic groundmass. Euhedral, <10 µm grains of ilmenite and Ti-Fe rich spinel are in some regions intergrown and contain <<1 µm domains of FeNi metal. Small shock melt pockets occur as <0.1 mm pods, or as <10 µm thick veins that offset the crystal fabric. Light brown, vesicular fusion crust (up to 150 µm thick on one side of the studied thin section and 0.5 mm thick on the other side) is composed of glass containing sparse whisker phenocrysts. A single ~10 µm wide, irregular fracture is filled with brown clay minerals, but no other terrestrial alteration phases were observed in the thin section.

Geochemistry: (A. Wittmann, P. Carpenter and R. Korotev, WUSL; S. Kuehner, UWS) Plagioclase phenocrysts in crystallized melt groundmass, An95–97Or0–0.2, n=13; plagioclase in relict clasts, An88–97Or0–0.3, n=18; olivine, Fa30–44, molar Fe/Mn=81–151, n=13; pigeonite, Fs26–40Wo6–19, molar Fe/Mn=45–74, n=10; subcalcic augite, Fs20–24Wo25–34, molar Fe/Mn=41–61, n=5; spinel, (Mg0.07–0.11 Mn0.01 Fe2+0.87–0.92) (Fe3+0.73-0.88 Al0.13–0.22 Si0.01-0.05 Ti0.65–0.8 Cr0.16–0.34), n=5; ilmenite, 2.1 wt% MgO, n=2; troilite, 0.08–0.1 wt% Ni, n=3; kamacite, 6.8–7.6 wt% Ni, 0.8–0.9 wt% Co, n=3; taenite, 11.5–24.1 wt% Ni, 0.7–1.2 wt% Co, n=5.

Classification: Lunar (anorthositic melt rock).

Specimens: 20.1 g including one polished thin section at UWB. The remaining material is held by M. Aid.

Randy Says…

Oued Awlitis 001 is a typical feldspathic lunar meteorite. The circumstance of its discovery is a good story. 

More Information

Meteoritical Bulletin Database

OA 001

References

Ferrière L., Meier M. M. M., Assis Fernandes V., Fritz J., Greshake A., Barrat J.-A., Böttger U., Bouvier A., Brandstätter F., Busemann H., Korotev R. L., Maden C., Magna T., SchmittKopplin Ph., Schrader D. L., and Wadhwa M. (2017) The unique crowdfunded Oued Awlitis 001 lunar meteorite – A consortium overview. 47th Lunar and Planetary Science Conference, abstract no. 1621.

Fritz J., Greshake A., Klementova M., Wirth R., Palatinus L., Trønnes R. G., Fernandes V. A., Böttger U., and Ferrière L. (2020) Donwilhelmsite, [CaAl4Si2O11], a new lunar high-pressure Ca-Al-silicate with relevance for subducted terrestrial sediments. American Mineralogist 105, 1704–1711.

Klementova M., Palatinus L., Fritz J., Greshake A., Wirth R., Fernandez V. A., and Ferrière L. (2019) Structure determination of donwilhelmsite by electron diffraction tomographyMicroscopy and Microanalysis S2, 2450-2451.

Korotev R. L. and Irving A. J. (2017) Still not keeping up with the lunar meteorites – 2017Lunar and Planetary Science XLVIII, abstract no. 1498.

Miyawaki R, Hålenius U., Hatert F., Pasero M., and Mills S. J. (2019) New minerals and nomenclature modifications approved in 2018 and 2019. Mineralogical Magazine. 83, 143–147. [New mineral: donwilhelmsite (CaAl4Si2O11) in Oued Awlitis 001]

Wittmann A., Korotev R. L., Jolliff B. L., Chennaoui-Aoudjehane H., and Irving A. J. (2014) Petrology and chemistry of a lunar feldspathic impact melt rock meteorite from Oued Awlitis, Morocco. 77th Annual Meeting of the Meteoritical Society, abstract no. 5352.

Wittmann A., Korotev R. L., Jolliff B. L., and Irving A. J. (2015) Petrogenesis of Lunar Poikilitic Impact Melt Meteorite Oued Awlitis 001. 46th Lunar and Planetary Science Conference, abstract no. 1141.

Wittmann A., Korotev R. L., Jolliff B. L., Zanetti M., Nishiizumi K., Jull A. J. T., Caffee M. W., and Irving A. J. (2017) Who launched lunar meteorite Oued Awlitis 001? Lunar and Planetary Science XLVIII, abstract no. 2482.

Wittmann A., Korotev R. L., Jolliff B. L, Nishiizumi K., Jull A. J. T., Caffee M. W., Zanetti M., and Irving A. J. (2019) Petrogenesis of lunar impact melt rock meteorite Oued Awlitis 001Meteoritics & Planetary Science Meteoritics & Planetary Science 54, 2167-2188.

Zhang B., Reger P. M., Gannoun A., Boyet M., Schrader D. L., Wadhwa M., Ferrière L., Bouvier A. (2019) Pb-Pb chronometry of impact melts from lunar meteorite Oued Awlitis 001. 82nd Annual Meeting of the Meteoritical Society, abstract no. 6479.

Lunar Meteorites | List of Lunar meteorites