Sample Petrographic Description
Sample Number | QUE 94484 |
Newsletter | 19,1 |
Location | Queen Alexandra Range |
Field Number | 5107 |
Dimensions (cm) | 2.5 x 2.0 x 0.8 |
Weight (g) | 5.56 |
Original Classification | Eucrite (Unbrecciated) |
Mineral Composition (%Fa & %Fs) | |
Ferrosilite (mol%): 25-49 | |
Weathering | |
B | |
Fracturing | |
B | |
Macroscopic Description - Kathleen McBride | |
QUE94484 is a complete button-shaped stone. The fusion crust is dull brownish-black. The interior consists of dark gray crystalline material, some appearing as laths. Patches of heavy rust are present. | |
Thin Section Description (,2) - Brian Mason | |
The section shows an aggregate of plagioclase laths (up to 1.3 mm long) and anhedral pale brown pyroxene grains; interstitial to the plagioclase and pyroxene are angular areas of fine-grained black material. The section is partly rimmed with fusion crust. Microprobe analyses show that most of the pyroxene is low-Ca: Wo5-10, Fs28-49, but a few Ca-rich grains are present, up to Wo43Fs25. Plagioclase compositions are An82-87. The fine-grained black areas consist largely of troilite and tridymite, suggestive of a quenched residual liquid. The composition of the fusion crust, probably similar to that of the bulk meteorite, is (weight percent): SiO2 50, Al2O3 13, FeO 17, MgO 6.5, CaO 11, TiO2 1.0, MnO 0.55, Na2O 0.80, K2O less than 0.1. The meteorite is an unbrecciated eucrite. |
Antarctic Meteorite Images for Sample QUE 94484 | ||||
Thin Section Photo(s) : | ||||
References for Sample QUE94484 | |
Mittlefehldt, D.W., Greenwood, R.C., Berger, E.L., Le, L., Peng, Z.X., and Ross, D.K., 2022, Eucrite-type achondrites: Petrology and oxygen isotope compositions, Meteoritics & Planetary Science, 57, 484-526, doi:10.1111/maps.13730. | |
McCubbin, F.M., Lewis, J.A., Barnes, J.J., Elardo, S.M., and Boyce, J.W., 2021, The abundances of F, Cl, and H2O in eucrites: Implications for the origin of volatile depletion in the asteroid 4 Vesta. Geochimica et Cosmochimica Acta, 314, 270–293, https://doi.org/10.1016/j.gca.2021.08.021. | |
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. | |
Mayne, R. G., Mcsween Jr., H. Y, Mccoy, T. J., Gale, A., 2009, Petrology of the unbrecciated eucrites. Geochimica et Cosmochimica Acta, 73 Issue 3, 1-Feb-09, 794-819, ISSN 0016-7037, http://dx.doi.org/10.1016/j.gca.2008.10.035. |