Northwest Africa 5153

Morocco

Find: 2007

Achondrite (lunar, feldspathic breccia)

History and physical characteristics: A 50.4 g nearly complete stone was purchased in Erfoud, Morocco, in January 2008. The aeolian-modified fusion crust is dark gray to reddish-brown.

Petrography: (T. Bunch and J. Wittke, NAU; Dolores Hill, UA) Fragmental to melt-matrix breccia that contains an assortment of lunar highland lithologies and Mare basalts and glasses. Highland components include cataclastic gabbro, troctolite, fragments of granophyric intergrowths of K-feldspar, felsic glasses and silica. Mare components include ophitic pigeonite and olivine basalts. Interior is very fresh and lacks alteration veins.

Mineral/phase compositions: Gabbro olivine is Fa_31.7 (FeO/MnO = 99) and pigeonite is Fs_25.7Wo_9.3 (FeO/MnO = 53). Troctolite olivine is Fa_22.3 (FeO/MnO = 80), Ca-pyroxene is Fs_22.1Wo₁₇, chromite Cr/(Cr + Al) = 0.63, and granophyric K-feldspar is An_14.5Or_54.3 with BaO = 2.6 wt%. Mare ophitic pigeonite basalt olivine is Fa_36.7 (FeO/MnO = 106), pigeonite is Fs_7.1Wo_13.3(FeO/MnO = 65) and ilmenite MgO = 5.2 wt%. Olivine basalt olivine is Fa_36.2 (FeO/MnO = 94) and Ca-poor pyroxene is Fs_32.1Wo_13.3 (FeO/MnO = 62).

Bulk chemistry: (R. Korotev, WUSL): Na₂O = 0.476 wt%; Sc = 25.6 ppm; Cr = 1963 ppm; FeO = 12.72 wt%; Ni = 150 ppm; Co = 42.4 ppm and Sr = 132 ppm.

Classification: Achondrite (lunar feldspathic breccia).

Type specimen: 5 g and one thin section are on deposit at NAU and one thin section and 0.3 g are on deposit at UA. DPitt holds the main mass.