Sample Petrographic Description
Sample Number | PRA 04402 |
Newsletter | 30,1 |
Location | Mt. Pratt |
Field Number | 15703 |
Dimensions (cm) | 4.5 x 3.5 x 2.0 |
Weight (g) | 37.76 |
Original Classification | Howardite |
Pairing | PRA 04401; PRA 04402; |
Mineral Composition (%Fa & %Fs) | |
Ferrosilite (mol%): 16-60 | |
Weathering | |
B | |
Fracturing | |
B | |
Macroscopic Description - Kathleen McBride | |
20-50% of the exteriors have thin, shiny patches of black fusion crust. The interiors are charcoal gray to black matrix with no metal visible. | |
Thin Section Description (,2) - Tim McCoy, Valerie Reynolds | |
The meteorites are so similar that a single description suffices. The sections show a groundmass of comminuted pyroxene and plagioclase (up to 0.5 mm) with fine- to coarse-grained basaltic clasts ranging up to 5 mm. PRA 04401 contains particularly abundant CM2 clasts. Orthopyroxene compositions span a range of Fs16-60Wo1-3, although a single grain of Fs1 was observed, presumably from the CM2 clast. The Fe/Mn ratio is ~30 and feldspar is anorthitic (An87-90). The meteorites are howardites. | |
Astromaterials 3D Link(s) | |
https://ares.jsc.nasa.gov/astromaterials3d/sample-details.htm?sample=PRA04402-23 |
Antarctic Meteorite Images for Sample PRA 04402 | ||||
Lab Photo(s) : | ||||
Antarctic Meteorite Images for Sample PRA 04402 | ||||
Thin Section Photo(s) : | ||||
References for Sample PRA04402 | |
Righter, K., Holmwood, A.P., 2020, Mineralogy and petrology of dark clasts in the Allan Hills 76005 polymict eucrite pairing group. Meteoritics & Planetary Science, 55, 781-799, doi: 10.1111/maps.13465. | |
Visser, R., John, T., Whitehouse, M. J., Patzek, M., & Bischoff, A., 2020, A short-lived 26Al induced hydrothermal alteration event in the outer solar system: Constraints from Mn/Cr ages of carbonates. Earth and Planetary Science Letters, 547, 116440. | |
Visser, R., John, T., Patzek, M., Bischoff, A., & Whitehouse, M. J., 2019, Sulfur isotope study of sulfides in CI, CM, C2ung chondrites and volatile-rich clasts–Evidence for different generations and reservoirs of sulfide formation. Geochimica et Cosmochimica Acta, 261, 210-223. | |
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. | |
RELAB, , Reflectance Experiment Lab , catalogue of samples. |