Sample Petrographic Description
Sample Number | GRO 95581 |
Newsletter | 20,1 |
Location | Grosvenor Mountains |
Field Number | 7603 |
Dimensions (cm) | 4.0 x 2.0 x 2.5 |
Weight (g) | 49.39 |
Original Classification | Howardite |
Pairing | GRO 95534; GRO 95535; GRO 95574; GRO 95581; |
Mineral Composition (%Fa & %Fs) | |
Ferrosilite (mol%): 21-54 | |
Weathering | |
A | |
Fracturing | |
A | |
Macroscopic Description - Kathleen McBride | |
Ninety percent of this achondrite's exterior surface is covered with shiny, glassy brown/black fusion crust. The interior is light gray with clasts up to 3 cm in diameter. Plagioclase and pyroxene grains are numerous. Minor amount of weathering is visible. | |
Thin Section Description (,4 ,6) - Brian Mason | |
The sections show a groundmass of comminuted pyroxene (orthopyroxene and pigeonite) and plagioclase (grains up to 0.3 mm) with a few larger plagioclase clasts (up to 3 mm). Microprobe analyses show a wide composition range in low -calcium pyroxene, from Wo2Fs21 to Wo7Fs54; one grain of augite, Wo28Fs25 was analyzed. Plagioclase composition is An89-93. The meteorite is a howardite; it is very similar to GRO95534, and 95535, with which it is probably paired. | |
Notes | |
GRO 95602 was initially paired with four other GRO howardites – GRO 95534, GRO 95535, GRO 95574, and GRO 95581. The relations between these five howardites have been re-evaluated by Mittlefehldt et al. (2013), Cartwright et al. (2014) and Lunning et al. (2016). Based on petrography, mineralogy, petrology, and bulk composition, GRO 95534, GRO 95535, GRO 95574, and GRO 95581 are paired together; GRO 95602 has been removed from this pairing group and is unpaired. AMN 45, no. 2. |
Antarctic Meteorite Images for Sample GRO 95581 | ||||
Lab Photo(s) : | ||||
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Antarctic Meteorite Images for Sample GRO 95581 | ||||
Thin Section Photo(s) : | ||||
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References for Sample GRO95581 | |
Hahn, T. M., Lunning, N. G., McSween, H. Y., Bodnar, R. J., and Taylor, L. A., 2018, Mg-rich harzburgites from Vesta: Mantle residua or cumulates from planetary differentiation. Meteoritics & Planetary Science, 53, 514-546, doi: 10.111/maps.13036. | |
Moriarty, D. P., Pieters, C. M., 2016, Complexities in pyroxene compositions derived from absorption band centers: Examples from Apollo samples, HED meteorites, synthetic pure pyroxenes, and remote sensing data. Meteoritics & Planetary Science, 51(2), 207-234. | |
Lunning, N. G., Welten, K. C., McSween, H. Y., Caffee, M. W., Beck, A. W., 2016, Grosvenor Mountains 95 howardite pairing group: Insights into the surface regolith of asteroid 4 Vesta. Meteoritics & Planetary Science, 51(1), 167-194. | |
Mittlefehldt, D. W., 2015, Asteroid (4) Vesta: I. The howardite-eucrite-diogenite (HED) clan of meteorites. Chemie der Erde - Geochemistry, 75 Issue 2, Jun-15, 155-183, ISSN 0009-2819, http://dx.doi.org/10.1016/j.chemer.2014.08.002. | |
Lunning, N. G., Mcsween Jr., H. Y., Tenner, T. J., Kita, N. T., Bodnar, R. J., 2015, Olivine and pyroxene from the mantle of asteroid 4 Vesta. Earth and Planetary Science Letters, 418, 15-May-15, 126-135, ISSN 0012-821X, http://dx.doi.org/10.1016/j.epsl.2015.02.043. | |
Mittlefehldt, D. W., Herrin, J. S., Quinn, J. E., Mertzman, S. A., Cartwright, J. A., Mertzman, K. R., Peng, Z. X., 2013, Composition and petrology of HED polymict breccias: The regolith of (4) Vesta. Meteoritics & Planetary Science, 48, 2105-2134, http://dx.doi.org/10.1111/maps.12182. | |
Warren, P. H., Kallemeyn, G. W., Huber, H., Ulff-Møller, F., Choe, W., 2009, Siderophile and other geochemical constraints on mixing relationships among HED-meteoritic breccias. Geochimica et Cosmochimica Acta, 73 Issue 19, 1-Oct-09, 5918-5943, ISSN 0016-7037, http://dx.doi.org/10.1016/j.gca.2009.06.030. | |
RELAB, , Reflectance Experiment Lab , catalogue of samples. |