A dunite-norite lunar microbreccia.

An olivine-rich microbreccia with noritic affinities, collected on the Apollo 14 mission to Fra Mauro, is described and analyzed. A photomicrograph (by plain transmitted light) of the microbreccia is discussed. One of three distinct areas on the microbreccia is shown to be a dunite containing over 90% olivine. The other two are more gabbroic in composition, though most of the mineral clasts are olivine. The fine grained matrix material contains significant amounts of K2O and P2O5, suggesting a relation to norites.