Northwest Africa 10603 (NWA 10603)

Mauritania

Purchased: April 2015

Classification: HED achondrite (Eucrite, melt breccia)

History: The sample was purchased by the main mass holder in Morocco but is believed to originate from Mauritania.

Petrography: (R. Greenwood, OU) The meteorite has a clastic texture, comprising angular, fine to medium-grained basaltic fragments, up to about 4 mm diameter, enclosed in a dark, flow-banded matrix. Plagioclase grains, are up to 1 mm long, show complex deformation twinning and are often cloudy and partially altered. Pyroxene grains show mosaicism. Numerous, distinct, sub-mm sized oval vesicles are present in the matrix.

Geochemistry: Mineral compositions and geochemistry: Pyroxene consists of a low-Ca pyroxene host, Fs_59.4±1.0Wo_5.4±1.1En_35.2±0.1(±1σ, n=2), with well-developed exsolution lamellae of augite, Fs_29.3±2.6Wo_41.5±2.5En_29.2±0.2 (±1σ, n=3)). Plagioclase compositions are in the range An_88.3-91.5 (n=6). Accessory minerals include silica, chromite, zircon and ilmenite. Oxygen isotopes: (Laser-assisted fluorination) δ¹⁷O = 1.865‰; δ¹⁸O = 4.030‰; Δ¹⁷O = -0.247‰ (Δ¹⁷O calculated using method of Miller (2002), GCA 66, 1881-1889.

Classification: This meteorite is a brecciated eucrite with a significant impact melt component. It shows moderate weathering May be paired with NWA 10602. However, the texture observed in polished section is fairly distinct from that of NWA 10602.

Specimens: A type specimen mass of 21.86 g is held at OU. The main mass is held by Mohammed Hmani.