Sample Petrographic Description
Sample Number | LEW 87248 |
Newsletter | 12,1 |
Location | Lewis Cliff |
Field Number | 4748 |
Dimensions (cm) | 2.0 x 2.0 x 1.5 |
Weight (g) | 13.85 |
Original Classification | L3 Chondrite |
Updated Classification | L3.15 Chondrite |
Pairing | LEW 85434; LEW 85437; LEW 87248; LEW 87284; LEW 88254; LEW 88462; |
Mineral Composition (%Fa & %Fs) | |
Fayalite (mol%): 0-18;Ferrosilite (mol%): 1-22 | |
Weathering | |
A/B | |
Fracturing | |
A | |
Macroscopic Description - René Martinez | |
This small specimen shows abundant light and dark colored sharply defined chondrules in a dark gray matrix. It is 95% covered with fusion crust and appears relatively unweathered. | |
Thin Section Description (,3) - Brian Mason | |
The section shows abundant chondrules and chondrule fragments, up to 1.5 mm across, in a dark matrix containing a few grains of nickel-iron and sulfide. A variety of chondrule types is present, including granular and porphyritic olivine and olivine-pyroxene, barred olivine, and cryptocrystalline pyroxene. Much of the pyroxene is polysynthetically twinned clinobronzite. Microprobe analyses show olivine and pyroxene of variable composition: olivine, Fa0-18, mean Fa14 (CV FeO is 49); pyroxene, Fs1-22. The small amount of nickel-iron suggests L group, and the variability of olivine and pyroxene compositions type 3; hence the meteorite is classified as an L3 chondrite (estimated L3.5). | |
Reclassification Notes (AMN 44,2) | |
Reclassified as an L3.15 Chondrite based on Cr contents of Type II chondrule olivine. Pairing groups adjusted based on olivine composition and recovery location. Righter, K., Schutt, J., Lunning, N., Harvey, R., & Karner, J. (2021a) Identification and pairing reassessment of unequilibrated ordinary chondrites from four Antarctic dense collection areas. Meteoritics & Planetary Science 56, 1556-1578. | |
Notes | |
Righter et al. (2021) proposed that LEW 85434, LEW 85437, LEW 87248, LEW 87284, LEW 88254, and LEW 88462 are all paired and type L3.15. |
Antarctic Meteorite Images for Sample LEW 87248 | ||||
Lab Photo(s) : | ||||
Antarctic Meteorite Images for Sample LEW 87248 | ||||
Thin Section Photo(s) : | ||||
References for Sample LEW87248 | |
Eschrig, J., Bonal, L., Mahlke, M., Carry,B., Beck, P., Gattacceca, J., 2022, Investigating S-type asteroid surfaces through reflectance spectra of ordinary chondrites, Icarus, 381. | |
Righter, K., Schutt, J., Lunning, N., Harvey, R, and Karner, J., 2021, Identification and pairing reassessment of unequilibrated ordinary chondrites from four Antarctic dense collection areas. Meteoritics & Planetary Science, 56, 1556-1573, doi: 10.1111/maps.13707. | |
Eschrig, J., Bonal, L., Beck, P., Prestgard, T.J., 2021, Spectral reflectance analysis of type 3 carbonaceous chondrites and search for their asteroidal parent bodies. Icarus, 354, 114034, https://doi.org/10.1016/j.icarus.2020.114034. | |
Bonal, L., Quirico, E., Flandinet, L., Montagnac, G., 2016, Thermal history of type 3 chondrites from the Antarctic meteorite collection determined by Raman spectroscopy of their polyaromatic carbonaceous matter. Geochimica et Cosmochimica Acta, 189, 312-337. | |
Wang, M. S., Lipschutz, M. E., 2007, Trace elements in primitive meteorites-VII Antarctic unequilibrated ordinary chondrites. Geochimica et Cosmochimica Acta, 71 Issue 4, 15-Feb-07, 1062-1073, ISSN 0016-7037, http://dx.doi.org/10.1016/j.gca.2006.10.009. | |
Krot, A. N., Zolensky, M. E., Wasson, J. T., Scott, E. R. D., Keil, K., Ohsumi, K., 1997, Carbide-magnetite assemblages in type-3 ordinary chondrites. Geochimica et Cosmochimica Acta, 61 Issue 1, Jan-97, 219-237, ISSN 0016-7037, http://dx.doi.org/10.1016/S0016-7037(96)00336-5. | |
Sears, D. W. G., Hasan, F. A., Batchelor, J. D., Lu, J., 1991, Chemical and physical studies of type 3 chondrites. XI-Metamorphism, pairing, and brecciation of ordinary chondrites. Proceedings Lunar and Planetary Science Conference, 21, 493-512. |