Sample Petrographic Description
| Sample Number | LAR 12011 |
| Newsletter | 36,2 |
| Location | Larkman Nunatak |
| Field Number | 23233 |
| Dimensions (cm) | 14.5 x 6.0 x 6.0 |
| Weight (g) | 701.17 |
| Original Classification | Shergottite |
| Pairing | LAR 06319; LAR 12011 |
| Mineral Composition (%Fa & %Fs) | |
| Fayalite (mol%): 23-58;Ferrosilite (mol%): 24-44 | |
| Weathering | |
| A | |
| Fracturing | |
| A | |
| Macroscopic Description - Kathleen McBride | |
| 95% of the exterior surface has shiny black fusion crust with a rough, ropey texture. The interior matrix is a gray with black, white and transparent mineral grains. This shergottite is very similar in appearance to LAR 06319. | |
| Thin Section Description (,2) - Cari Corrigan, Linda Welzenbach | |
| This meteorite is composed of a fine-grained assemblage of pyroxene, olivine and maskelynite. Olivine occurs as phenocrysts with grain sizes up to 1 mm (smaller and more abundant than 12095 and 12240). Olivines have a brown staining probably due to shock. Pyroxene and maskelynite in the matrix are 200-400 microns in size. The maskelynites appear foliated in this section. Olivine is Fa23-58; pyroxenes exhibit a range of compositions from pigeonite to subcalcic augite (Fs24-44Wo3-27; Fe/Mn 26-35); plagioclase feldspar is intermediate in composition (An49-52Or3). This meteorite is an olivine-phyric shergottite but is different enough from LAR 12095 and LAR 12240 that it is not being paired here. It does, however, look very similar to LAR 06319. | |
| Antarctic Meteorite Images for Sample LAR 12011 | ||||
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| Field photo image(s) courtesy of the ANSMET (ANtarctic Search for METeorites) Program, Case Western Reserve University and the University of Utah | ||||
| Antarctic Meteorite Images for Sample LAR 12011 | ||||
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| Antarctic Meteorite Images for Sample LAR 12011 | ||||
| Thin Section Photo(s) : | ||||
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| References for Sample LAR12011 | |
| Nicklas, R.W., Day, J.M.D., Vaci, Z., Udry, A., Liu, Y., and Tait, K.T., 2021, Uniform oxygen fugacity of shergottite mantle sources and an oxidized martian lithosphere. , Earth and Planetary Science Letters, 564 , 116876 , https://doi.org/10.1016/j.epsl.2021.116876 . | |
| Ramsey, S.R., Howarth, G.H., Arya Udry, A., and Juliane Gross, J., 2021, Nickel–manganese variability in olivine and Al-in-olivine thermometry for olivine-phyric shergottites. , Meteoritics & Planetary Science, 56 , 1597–1618 , doi: 10.1111/maps.13721 . | |
| Clay, P.L., Strekopytov, S., and Ballentine, C.J., Joy, K.H., O'Driscoll, B., Busemann, H., Ruzié-Hamilton, L., Burgess, R., Fellowes, J., Joachim-Mrosko, B., Pernet-Fisher, J., 2020, Heavy halogen geochemistry of martian shergottite meteorites and implications for the halogen composition of the depleted shergottite mantle source. , American Mineralogist, 105 , 289–306 . | |
| Bellucci, J.J., Nemchin, A. A., Whitehouse, M. J., Snape, J. F., Bland, P. , Benedix, G.K. , & Roszjar, J. , 2018, Pb evolution in the Martian mantle. , Earth and Planetary Science Letters, 485 , 79-87 , https://doi.org/10.1016/j.epsl.2017.12.039 . | |
| Bellucci, J. J., Whitehouse, M. J., John, T., Nemchin, A. A., Snape, J. F., Bland, P. A., & Benedix, G. K. , 2017, Halogen and Cl isotopic systematics in Martian phosphates: Implications for the Cl cycle and surface halogen reservoirs on Mars. , Earth and Planetary Science Letters, 458 , 192-202 , https://doi.org/10.1016/j.epsl.2016.10.028 . | |
| Howarth, G. H., Liu, Y., Chen, Y., Pernet-Fisher, J. F., Taylor, L. A., 2016, Postcrystallization metasomatism in shergottites: Evidence from the paired meteorites LAR 06319 and LAR 12011. , Meteoritics & Planetary Science, 11 , 2061-2072 . | |