Ooldea 015        30°31’53.5"S, 131°50’15.7"E

South Australia, Australia

Find: 23 Apr 2013

Classification: HED achondrite (Howardite)

History: Single non-magnetic stone found by A. Tomkins

Physical characteristics: A brown flatish stone with sparse patches (5%) of black fusion crust.

Petrography: (S. Alkemade) This meteorite is an achondrite polymict breccia, containing clasts of eucrite and diogenite with sizes ranging from 0.2-5 mm in a clastic matrix. Mineralogy consists of orthopyroxene (>10%), clinopyroxene, plagioclase and minor olivine. A few dark angular clasts (0.5-2 mm) are fragments of carbonaceous chondrite material with mineralogy including amphibole, mg-spinel, and clinopyroxene. Accessory minerals are troilite, FeNi metal, chromite, ilmenite and olivine. The sample is highly shocked with most clasts exhibiting mosaic extinction and planar deformation features. Oxidation of metal and troilite is slight.

Geochemistry: (S. Alkemade) Orthopyroxene (Fs_42.1±11.9, n=10), pigeonite (Fs_22.1Wo_11.0), augite (Fs_25.8Wo_47.1), plagioclase (An₈₇, n=4), and rare olivine (Fa_6.65, n=1). Oxygen isotope analysis completed at UNM by Karen Ziegler, samples acid treated. δ¹⁷O’=1.586 (per mil, ±0.190) , δ¹⁸O’=3.644 (per mil, ±0.387), Δ¹⁷O’=-0.338 (per mil, ±0.043).

Classification: Howardite. Oxygen isotopes plot slightly below the eucrite/diogenite fractionation line, suggesting material from the carbonaceous chondrite clasts was included in the analyses.