Dhofar 489

Oman

Found 2001 August 11

Lunar meteorite (feldspathic crystalline matrix breccia)

One 34.4 g stone was found in the Dhofar region of Oman. Mineralogy and classification (H. Takeda, Chiba; T. Ishii and M. Ohtsuki, UTok): A feldspathic fragmental breccia consisting of clasts of various lithologies embedded into a fine-grained crystalline matrix (crystals up to 0.04 mm in length). Clasts include cataclastic feldspars up to 1.8 × 0.6 mm in size, plus dark fine-grained impact melt breccia 3.3 × 2.3 mm in size with feldspar fragments. Plagioclase compositions of An_95–97 are within the range of lunar anorthites. Pyroxene crystals in plagioclase and crystalline matrix range from En₇₅Fs₂₁Wo₄ to En₈₅Fs₁₀Wo₅ with FeO/MnO (wt%) = 57. Olivine: Fa₁₅ to Fa₂₄ with FeO/MnO (wt%) = 78. Fine Ca carbonate veins penetrate into the specimen. Unlike known lunar meteorites, this lunar rock is a feldspathic crystalline matrix breccia. The most Mg-­rich pyroxene is more Mg-rich than those of common lunar regolith breccias and similar to those of 60019, an Apollo 16 breccia containing poikilitic clasts. This lunar meteorite differs from other known lunar meteorites from the Dhofar region, which are either feldspathic regolith breccias or fragmental breccias. Specimens: type specimen, 6 g, NSMT; 0.42 g plus two polished thin sections, Chiba; main mass with anonymous finder.