Sample Petrographic Description
Sample Number | GRO 95504 |
Newsletter | 20,2 |
Location | Grosvenor Mountains |
Field Number | 7643 |
Dimensions (cm) | 19.0 x 13.0 x 14.0 |
Weight (g) | 4018.30 |
Original Classification | L3.5 Chondrite |
Updated Classification | L3.2 Chondrite |
Pairing | GRO 95502; GRO 95504; GRO 95505; GRO 95512; GRO 95539; GRO 95542; GRO 95544; GRO 95545; GRO 95546; GRO 95550; |
Mineral Composition (%Fa & %Fs) | |
Fayalite (mol%): 2-22;Ferrosilite (mol%): 9-23 | |
Weathering | |
A/B | |
Fracturing | |
A | |
Macroscopic Description - Kathleen McBride | |
All three of these ordinary chondrites have a brown/black fusion crusted exterior with chondrules/clasts visible. The interiors reveal a brownish black matrix with abundant chondrules that range in size from mm to 1 cm. All three have minor metal and some rusty areas. | |
Thin Section Description (,2) - Brian Mason | |
The sections are so similar that a single description will suffice; the meteorites are probably paired. The sections show numerous chondrules and chondrule fragments, up to 3.2 mm across, in a black matrix containing small amounts of nickel-iron and troilite. The chondrules are mainly granular and porphyritic olivine and olivine-pyroxene, with a few radiating and cryptocrystalline pyroxene. Microprobe analyses show olivine and pyroxene of variable compositions: olivine, Fa2-24, mean Fa14; pyroxene, Fs1-28. The meteorites are classified as L3 chondrites (estimated L3.5). They are very similar to GRO95505, 95544, 95545, and the possibility of pairing should be considered. | |
Reclassification Notes (AMN 44,2) | |
Reclassified as an L3.2 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) propose that GRO 95502, GRO 95504, GRO 95505, GRO 95512, GRO 95539, GRO 95542, GRO 95544, GRO 95545, GRO 95546, and GRO 95550 are all paired and type L3.2. |
Antarctic Meteorite Images for Sample GRO 95504 | ||||
Lab Photo(s) : | ||||
Antarctic Meteorite Images for Sample GRO 95504 | ||||
Thin Section Photo(s) : | ||||
References for Sample GRO95504 | |
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. | |
Alexander, C. O. D., Cody, G. D., De Gregorio, B. T., Nittler, L. R., & Stroud, R. M., 2017, The nature, origin and modification of insoluble organic matter in chondrites, the major source of Earth’s C and N. Chemie der Erde-Geochemistry, 77, 227-256, http://dx.doi.org/10.1016/j.chemer.2017.01.007. | |
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. | |
Vernazza, P., and M. Lockhart , B. Zanda, R. P. Binzel, T. Hiroi, F. E. DeMeo, M. Birlan, R. Hewins, L. Ricci, P. Barge, 2014, Multiple and fast: The accretion of ordinary chondrite parent bodies. . The Astrophysical Journal , 791, 120-131, https://doi.org/10.1088/0004-637X/791/2/120. | |
Aleon, J., 2010, Multiple origins of nitrogen isotopic anomalies in meteorites and comets. The Astrophysical Journal, 722, 1342–1351, doi:10.1088/0004-637X/722/2/1342. | |
Alexander, C. M. O'D., Fogel, M., Yabuta, H., Cody, G. D., 2007, The origin and evolution of chondrites recorded in the elemental and isotopic compositions of their macromolecular organic matter. Geochimica et Cosmochimica Acta, 71 Issue 17, 1-Sep-07, 4380-4403, ISSN 0016-7037, http://dx.doi.org/10.1016/j.gca.2007.06.052. | |
Benoit, P. H., Akridge, G. A., Ninagawa, K., Sears, D. W. G., 2002, Thermoluminescence sensitivity and thermal history of type 3 ordinary chondrites: Eleven new type 3.0-3.1 chondrites and possible explanations for differences among H, L, and LL chondrites. Meteoritics & Planetary Science, 37, 793-805. | |
RELAB, , Reflectance Experiment Lab , catalogue of samples. |