Northwest Africa 11596 (NWA 11596)

Algeria

Purchased: 2016 May 1

Classification: HED achondrite (Eucrite)

History: Purchased by Miao Bing-an in 2016 in Morocco.

Physical characteristics: A black fusion crust coveres the surface of the stone. The meteorite is a polymict breccia consisting of fragments of medium- to coarse-grained metamorphosed gabbroic rocks and medium- to fine-grained subophitic basaltic rocks. Dimensions: 3.5 × 5.0 × 5.4 cm.

Petrography (L. Huang, B. Miao, H. Chen, GUT): Breccia containing a variety of basaltic lithologies, with <10 vol% cumulate lithologies. Cumulate eucrite lithologies are coarse grained (~0.3-1 mm) gabbros composed principally of low-Ca zoned clinopyroxene and calcic plagioclase. Basaltic breccia lithologies are fine- to medium-grained, have textures that are mostly subophitic, and contain very fine-grained vitrophyric textured basaltic lithologies. A silica phase is commonly present. Accessories are ilmenite, chromite, troilite and rare iron metal.

Geochemistry (L. Huang, B. Miao, H. Chen, GUT): Bulk pyroxene: Fe/Mn=36.6. Low-Ca pyroxene of cumulate lithologies: median compositions are Mg#=51.3, Fs_46.7Wo_4.2 (n=10). Low-Ca pyroxene of basaltic lithologies: median compositions are Mg#=45.1, Fs_52.9Wo_3.8 (n=8). High-Ca pyroxene of basaltic lithologies: median compositions are Mg#=43.8, Fs_47.5Wo_16.0 (n=18). Plagioclase: An_79.8-89.0Or_0.5-1.9, median An_85.1Or_1.1 (n=11).

Classification: Basaltic polymict brecciated eucrite

Specimens: 16.9 g and polished thin section are deposited in GUT