Name: Larkman Nunatak 12240 This is an OFFICIAL meteorite name. Abbreviation: LAR 12240 Observed fall: No Year found: 2012 Country: Antarctica [Collected by US Antarctic Search for Meteorites program (ANSMET)] Mass: 57.6 g
The exteriors are a rough, fractured texture with brown/black fusion crust and some evaporites. Areas without fusion crust show tan matrix with some olivine grains. The interiors are greyish tan with abundant green mineral grains and some darker grains visible. Minor oxidation is present.
Thin Section Description (,2) - Cari Corrigan and Linda Welzenbach
These meteorites are similar enough that one description will suffice. Each section is composed of a coarse-grained assemblage of pyroxene, olivine and maskelynite. Olivine occurs as phenocrysts with grain sizes up to 3 mm. Olivines have a brown staining probably due to shock. Pyroxene and maskelynite in the matrix are finer grained, typically reaching 0.5 mm. Sulfides and oxides are present, as is one shock melt vein in each section. Olivine is Fa28-42; pyroxenes exhibit a range of compositions from pigeonite to subcalcic augite (Fs25-31Wo8-18; Fe/Mn27-32); feldspar is intermediate in composition (An54-64Or0-1). These meteorites are olivine-phyric shergottites.
JSC: Mailcode XI, 2101 NASA Parkway, NASA Johnson Space Center, Houston, TX 77058, United States; Website (institutional address; updated 28 Jul 2022) SI: Department of Mineral Sciences, NHB-119, National Museum of Natural History, Smithsonian Institution, Washington, DC 20560, United States; Website (institutional address; updated 16 Jan 2012)
Catalogs:
Search for this meteorite in the NASA/JSC database (U.S.):