Lunar Meteorite: Shişr 161

from The Meteoritical Bulletin, No. 95

Shişr 161

Oman
Find: January 2008
Mass: 57.2 g

Achondrite (lunar, feldspathic fragmental breccia)

History: One stone of 57.2 g found by Michael Farmer and later sold to Philip Mani.

Physical characteristics: The meteorite lacks an obvious fusion crust but has the frosted, ablated exterior typical of Omani lunar stones. The interior is light brown with few fractures, and terrestrial weathering is negligible.

Petrography (A. Foreman, WUSL; A. Irving and S. Kuehner, UWS): The meteorite is a fragmental breccia composed of a variety of lithic clasts (3–7 mm) and mineral fragments (0.3–0.4 mm) of olivine, plagioclase, augite, and pigeonite set in a fine-grained matrix with some glass veins. Lithic clasts include feldspathic granulitic breccia (plagioclase matrix with interstitial grains of granoblastic olivine), spherulitic basalt consisting of dominantly lath-shaped plagioclase and
pyroxene, fragmental breccia with 0.3–0.4 mm clasts of plagioclase, olivine, augite, and pigeonite set in a fine-grained light-brown/gray matrix, and a granophyre composed of plagioclase, pigeonite, chromite, and ilmenite. No regolith components (glass spherules) have been identified. Very minor FeNi metal.

Geochemistry (A. Foreman, WUSL): Feldspathic granulitic breccia: olivine (Fa_20.9–37.2, FeO/MnO = 73–115), plagioclase (An_94.5–97.7 Or_0.0–0.3); basaltic clast: 60.0% plagioclase (An_94.5–96.7 Or_0.2–0.5), 34.8% orthopyroxene (Fs_41.7–47.1 Wo_2.5–3.9, FeO/MnO = 55.2–59.4), 3.9% augite (Fs_14.9–26.6 Wo_30.7–41.9, FeO/MnO = 46.3–62.5), 0.3% ilmenite, fragmental-breccia clast: plagioclase (An_96.6 Or_0.4), olivine (Fa_35.4–39.3, FeO/MnO = 82–95), augite (Fs_16.4–16.9 Wo_38.9–39.8, FeO/MnO = 40.6–41.0); mineral fragments: plagioclase (An_93.9–98.6 Or_0.0–0.6), olivine (Fa_17.4–62.5, FeO/MnO =75–101), augite (Fs_10.3–51.4 Wo_21.4–42.4, FeO/MnO = 29.5–88.2), pigeonite (Fs_27.6–47.3 Wo_8.1–19.5, FeO/MnO = 49.9–63.1).

Bulk composition (R. Korotev, WUSL): FeO 5.6 wt%, Sc 13 ppm, Ni 90 ppm, Sm 0.64 ppm, Th 0.16 ppm.

Classification: Achondrite (lunar, feldspathic fragmental breccia).

Specimens: A total of 11.5 g is on deposit at UWS. Thin section at WUSL. The main mass is held by Mr. P. Mani.

Randy Says…

Compositionally,  Shişr 161 is a basalt-bearing feldspathic lunar meteorite. None of the four Shişr lunar meteorites are paired with another.

More Information

Meteoritical Bulletin Database

Shişr 161

Map

Schematic Map of  Find Locations of  Lunar Meteorite from Oman

References

Foreman A. B., Korotev R. L., Zeigler R. A., Wittmann A., Kring D. A., Irving A. J., and Kuehner S. M. (2009) Petrographic and geochemical analysis of feldspathic lunar meteorite Shisr 161. 40th Lunar and Planetary Science Conference, abstract no. 2304.

Korotev R. L. (2012) Lunar meteorites from Oman. Meteoritics & Planetary Science 47, 1365-1402.

Korotev R. L. (2017) Update (2012–2017) on lunar meteorites from Oman. Meteoritics & Planetary Science 52, 1251-1256.

All Korotev data on Omani lunar meteorites.Korotev R. L., Zeigler R. A., Irving A. J., and Bunch T. E. (2009) Keeping up with the Lunar Meteorites – 2009. 40th Lunar and Planetary Science Conference, abstract no. 1137.

Korotev R. L., Jolliff B. L., and Zeigler R. A. (2010) On the origin of the moon’s feldspathic highlands, pure anorthosite, and the feldspathic lunar meteorites. 41st Lunar and Planetary Science Conference, abstract no. 1440.

Wittmann A. and Korotev R. L. (2013) Iron-nickel(-cobalt) metal in lunar rocks revisited. 44th Lunar and Planetary Science Conference, abstract no. 3035.

Wittman A., Korotev R. L., Jolliff B. L., and Irving A. J. (2012) Spherules and glasses in lunaite Shisr 161 record reworked regolith and a magnesian component of the Feldspathic Highlands Terrane. Second Conference on the Lunar Highlands Crust, abstract no. 9019.

Wittmann A., Korotev R. L., and Jolliff B. L. (2013) Feldspathic granulite clasts in lunar meteorite Shisr 161 — Cumulates from a differentiated basin melt sheet?. 44th Lunar and Planetary Science Conference, abstract no. 2061.

Wittmann A., Korotev R. L., Jolliff B. L., and Lapen T. J. (2013) Trace element composition of impact melts in lunar meteorite Shisr 161. 76th Annual Meeting of the Meteoritical Society, abstract no. 5262.

Wittmann A., Korotev R. L., Jolliff B. L., Lapen T. J., and Irving A. J. (2014) The petrogenesis of impact basin melt rocks in lunar meteorite Shisr 161. American Mineralogist 99, 1626–1647.