Sample Petrographic Description
Sample Number | GRO 95505 |
Newsletter | 20,1 |
Location | Grosvenor Mountains |
Field Number | 7696 |
Dimensions (cm) | 14.0 x 10.5 x 9.5 |
Weight (g) | 2031.00 |
Original Classification | L3.6 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%): 11-26;Ferrosilite (mol%): 15-24 | |
Weathering | |
B | |
Fracturing | |
A | |
Macroscopic Description - Cecilia Satterwhite | |
The exterior of this ordinary chondrite is covered with black fractured fusion crust on most of its surfaces. Areas without fusion crust are yellow brown and oxidation is heavy in areas. Many inclusions and chondrules are visible. The interior reveals a gray brown matrix with abundant light and dark inclusions ranging in size from 1 - 5 mm. Minor metal and weathering are present. | |
Thin Section Description (,2) - Brian Mason | |
The section shows a close-packed aggregate of chondrules (up to 2.4 mm across), chondrule fragments, and mineral grains in a dark matrix containing small amounts of nickel-iron and troilite. The meteorite is considerably weathered, with brown limonitic staining throughout the section. Microprobe analyses show olivine and pyroxene of variable compositions; olivine, Fa11-26; pyroxene, Fs15-24. The meteorite is classified as an L3 chondrite (estimated L3.6). | |
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. |
Antarctic Meteorite Images for Sample GRO 95505 | ||||
Lab Photo(s) : | ||||
Antarctic Meteorite Images for Sample GRO 95505 | ||||
Thin Section Photo(s) : | ||||
References for Sample GRO95505 | |
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. | |
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. | |
Needham, A. W., Porcelli, D., Russell, S. S., 2009, An Fe isotope study of ordinary chondrites. Geochimica et Cosmochimica Acta, 73 Issue 24, 15-Dec-09, 7399-7413, ISSN 0016-7037, http://dx.doi.org/10.1016/j.gca.2009.08.034. | |
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. | |
Schultz, L., Franke, L., 2004, Helium, neon, and argon in meteorites: A data collection. Meteoritics & Planetary Science, 39, 1889-1890, http://dx.doi.org/10.1111/j.1945-5100.2004.tb00083.x. | |
RELAB, , Reflectance Experiment Lab , catalogue of samples. |