Gadamis 004        30.284°N, 11.005°E

Ghadamis, Libya

Purchased: 2022

Classification: Lunar meteorite (anorth)

History: This meteorite was found in Libya at the same location as Gadamis 002 and 003, purchased by Mark Lyon in 2022.

Physical characteristics: Single stone with patches of dark fusion crust and smooth, light green-colored patches. One side is more irregular with a weathered surface that was fractured at some time in the past. Polished sawcut surfaces reveal cm-size clasts of anorthosite bounded by darker, fine-grained, cataclastic zones.

Petrography: (C. Agee, UNM) Microprobe analysis reveals a significantly brecciated, cataclastic anorthitic plagioclase host making up 98-99% of this meteorite. Poikiolitically enclosed in the plagioclase are sparse, very small olivine and pyroxene blebs (most in the range 5-10 μm). Larger pyroxene grains are scarce with two larger grains in size range of 300 μm observed in the microprobe mount. Together, olivine and pyroxene make up a total of ~1-2% of this meteorite.

Geochemistry: (C. Agee, UNM) Plagioclase An_96.0±0.1Ab_3.8±0.1Or_0.2±0.1, n=4; olivine Fa_38.9±1.0, Fe/Mn=105±3, n=4; pigeonite Fs_34.0±4.8Wo_5.4±2.3, Fe/Mn=60±3, n=4; augite Fs_5.7Wo_46.1, Fe/Mn=32.

Classification: Lunar ferroan anorthosite, cataclastic. Olivine, pigeonite and plagioclase compositional values plot within the FAN suite field (after Warren, 1993). The very high anorthite content (98-99%) and cataclastic texture is similar to Apollo 16 cataclastic FANs. Paired with Gadamis 002 and Gadamis 003.

Specimens: 21 g on deposit at UNM, Mark Lyon holds the main mass.