Sample Petrographic Description
Sample Number | GRO 95546 |
Newsletter | 20,2 |
Location | Grosvenor Mountains |
Field Number | 10991 |
Dimensions (cm) | 7.0 x 3.0 x 4.0 |
Weight (g) | 200.84 |
Original Classification | L3.8 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%): 9-25;Ferrosilite (mol%): 12-27 | |
Weathering | |
B/Ce | |
Fracturing | |
A | |
Macroscopic Description - Kathleen McBride | |
The exterior of this ordinary chondrite has some patches of black fusion crust. Most of the fusion crust has weathered away. Iridescent oxidation halos and some evaporites are present on the exterior surface. The interior is gray with light chondrules ~ 1 mm in size. Rust is abundant especially around the edges and forms an oxidation rind. Some metal is visible. | |
Thin Section Description (,2) - Brian Mason | |
The section shows an aggregate of chondrules, chondrule fragments and silicate grains with minor amounts of nickel-iron and troilite. Minor weathering is indicated by some limonitic staining around metal grains. Microprobe analyses show olivine and pyroxene of variable compositions: olivine, Fa9-25, mean Fa19; pyroxene, Fs12-27. The meteorite is classified as an L3 chondrite (estimated L3.8). | |
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 95546 | ||||
Lab Photo(s) : | ||||
Antarctic Meteorite Images for Sample GRO 95546 | ||||
Thin Section Photo(s) : | ||||
References for Sample GRO95546 | |
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. | |
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. | |
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. |