BIR OUNANE 005

The Dark Side of the Moon.

BIR OUNANE 005 is a small meteorite, but very important at a scientific level. It is a rock from the lunar soil, brecciated, and constitutes an authentic collection of minerals and rocks from the lunar surface. It is made up of up to 13 different lithologies, among which there are orange spherules.

When I received this rock, and performed the first analysis, it was clear that it was a meteorite from the lunar soil, and that this type of rock is not the classic feldspathic breccia that we are used to seeing. It is an extremely rare specimen that I have never seen before. I wanted to keep the main mass in the laboratory.

Petrography

Sample is a polymict breccia comprised of mm-sized lithic and mineral clasts/fragments, and impact glass spherules, set within a fine-grained matrix. Lithic clast lithologies identified include: anorthosites, basalts, impact melt clasts, noritic anorthosites, norites, and high-Fe clasts; mineral clast fragments of irregularly zoned pyroxenes, fayalitic olivine, pleonaste spinel, and silica are also present. Accessory phases identified include Ca-phosphates and troilite.

Geochemistry

Olivine (Fa67.7±29.2, range Fa14.0-97.8, Fe/Mn=82±6, n=14), Pigeonite (Fs47.2±12.3Wo17.8±3.9, range Fs30.0-83.3Wo9.9-24.5, Fe/Mn=54±6, n=20), High-Ca Pyroxene (Fs35.7±11.8Wo33.2±4.9, range Fs11.8-55.2Wo25.2-41.1, Fe/Mn=53±8, n=16), Calcic Plagioclase (An94.3±2.2, range An90.0-97.1, n=21).