Sample Petrographic Description
Sample Number | ALH 83008 |
Newsletter | 9,1 |
Location | Allan Hills |
Field Number | 2516 |
Dimensions (cm) | 8.5 x 5.0 x 3.0 |
Weight (g) | 272.00 |
Original Classification | L3 Chondrite |
Updated Classification | L3.4-3.7 Chondrite |
Mineral Composition (%Fa & %Fs) | |
Fayalite (mol%): 10-24;Ferrosilite (mol%): 5-24 | |
Weathering | |
B | |
Fracturing | |
A | |
Macroscopic Description - Carol Schwarz | |
Shiny black fusion crust with large (<1 cm) oxidation haloes covers nearly all of this specimen. The interior is dark in color and dotted with oxidization. Small (~1 mm) sized clasts/chondrules are barely discernible. | |
Thin Section Description (,3) - Brian Mason | |
The section shows a close-packed aggregate of chondrules, chondrule fragments, and irregular inclusions in a dark matrix which contains minor subequal amounts of nickel-iron and troilite. Chondrules range in size from 0.2-3 mm across, and show a variety of types, the commonest being porphyritic or granular olivine with or without polysynthetically twinned clinopyroxene. Considerable weathering is indicated by brown limonitic staining throughout the section. Microprobe analyses give the following compositions: olivine, Fa10-24, mean Fa17 (CV FeO22); pyroxene, Fs5-24. The variability of olivine and pyroxene compositions indicates type 3, and the amount of nickel-iron suggests L group; hence the meteorite is tentatively classified as an L3 chondrite. It resembles ALHA78046. | |
Reclassification Notes (AMN 33,1) | |
Typo corrected in meteorite type ("-" indicates breccia) |
Antarctic Meteorite Images for Sample ALH 83008 | ||||
Lab Photo(s) : | ||||
Antarctic Meteorite Images for Sample ALH 83008 | ||||
Thin Section Photo(s) : | ||||
References for Sample ALH83008 | |
Eschrig, J., Bonal, L., Mahlke, M., Carry,B., Beck, P., Gattacceca, J., 2022, Investigating S-type asteroid surfaces through reflectance spectra of ordinary chondrites, Icarus, 381. | |
Eschrig, J., Bonal, L., Beck, P., Prestgard, T.J., 2021, Spectral reflectance analysis of type 3 carbonaceous chondrites and search for their asteroidal parent bodies. Icarus, 354, 114034, https://doi.org/10.1016/j.icarus.2020.114034. | |
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., Sears, D. W. G., Akridge, J. M. C., Bland, P. A., Berry, F. J., Pillinger, C. T., 2000, The non-trivial problem of meteorite pairing. Meteoritics & Planetary Science, 35, 393-417. | |
Ebihara, M., Ozaki, H., 1995, Re, Os and Ir in Antarctic unequilibrated ordinary chondrites and implications for the solar system abundance of Re. Geophysical Research Letters, 22, 2167-2170. | |
Sears, D. W. G., Hasan, F. A., Batchelor, J. D., Lu, J., 1991, Chemical and physical studies of type 3 chondrites. XI-Metamorphism, pairing, and brecciation of ordinary chondrites. Proceedings Lunar and Planetary Science Conference, 21, 493-512. | |
RELAB, , Reflectance Experiment Lab , catalogue of samples. |