from The Meteoritical Bulletin, No. 109
Classification: Lunar meteorite (anorthosite)
History: This stone was found by vacationers on January 7, 2020, near Lake Gaberoun, Libya.
Physical characteristics: Single stone covered in pale-green, glassy fusion crust; oriented shape with a broad rollover lip. One side of the stone is broken and the interior is exposed, however this is not recent fracture as the surface is slightly weathered and smoothed. A freshly fractured surface shows a sugary, shiny texture of white to light gray grains.
Petrography: (C. Agee, UNM) Microprobe and SEM reveals an anorthitic plagioclase host without visible grain boundaries making up ~92% of this meteorite. Poikiolitically enclosed in the plagioclase are olivine and pyroxene grains, most in the size range 100-300 μm, making up a total of ~7% of this meteorite. Olivine grains are very homogeneous, some with resorbed rims. Pyroxene grains have exsolution lamellae with coarser bands of low-Ca pyroxene and finer bands of augite. Accessory chromite was observed throughout. Fusion crust is ~75 μm thick.
Geochemistry: (C. Agee, UNM) Plagioclase An98.1±0.8Ab1.8±0.3Or0.0±0.0, n=4; pyroxene Fs30.5±6.2Wo12.7±11.4, Fe/Mn=52±8, n=9; olivine Fa40.9±0.3, Fe/Mn=88±3, n=6; fusion crust SiO2=43.1±0.2, Al2O3=31.0±0.1, FeO=3.7±0.2, MgO=3.3±0.1, MnO=0.05±0.03, CaO=17.0±0.1, Na2O=0.19±0.02 all wt%, n=5. Oxygen isotopes (K. Ziegler, UNM): 3 acid-washed fragments analyzed by laser fluorination gave δ18O= 5.810, 6.152, 5.852; δ17O= 3.038, 3.198, 3.042; Δ17O= -0.029, -0.050, -0.047 (linearized, all per mil, TFL slope=0.528).
Classification: Lunar ferroan anorthosite, unbrecciated. Olivine, pyroxene and plagioclase compositional values plot within the FAN suite field (after Warren, 1993).
Specimens: 20.6 g on deposit at UNM, Abdelhadi Aithiba holds the main mass.
This meteorites is the first unbrecciated anorthosite from the lunar highlands.
Meteoritical Bulletin Database
Agee C. B., Ross A.J., Ziegler K., and Spilde M. N. (2021) Ghadduwah 001: Uniquely unbrecciated ferroan anorthosite lunar meteorite. 52nd Lunar and Planetary Science Conference, abstract no. 2314.Warren P. H. (2022) Ferroan anorthosite: A widespread and distinctive, high-olivine/pyroxene, lunar rock type. 85th Annual Meeting of The Meteoritical Society, abstract no. 6047.