Sample Petrographic Description
Sample Number | ALH 90411 |
Newsletter | 14,2 |
Location | Allan Hills |
Field Number | 6609 |
Dimensions (cm) | 28.0 x 16.5 x 7.5 |
Weight (g) | 5836.50 |
Original Classification | L3 Chondrite |
Updated Classification | L3.7 Chondrite |
Mineral Composition (%Fa & %Fs) | |
Fayalite (mol%): 4-24;Ferrosilite (mol%): 5-14 | |
Weathering | |
Be | |
Fracturing | |
B/C | |
Macroscopic Description - Robbie Marlow | |
Exterior is ~90% covered with dull black fusion crust. Evaporite deposit is visible on one exterior surface. Fractures penetrate deeply into the interior in several locations. Interior matrix is light gray and oxidation is scattered throughout. Numerous millimeter-sized chondrules are present. | |
Thin Section Description (,6) - Brian Mason | |
The section shows a close-packed aggregate of chondrules and chondrule fragments, up to 2.4 mm across, in a matrix of fine-grained olivine and pyroxene with a minor amount of nickel-iron and troilite. Some weathering is indicated by brown limonitic staining around metal grains. Microprobe analyses show olivine and pyroxene of variable composition: olivine, Fa4-24, mean Fa21 (CV FeO is 34); pyroxene, Fs5-14. The amount of nickel-iron suggests L group, and the variability of olivine and pyroxene compositions type 3, hence the meteorite is classified as an L3 chondrite (estimated L3.6). | |
Reclassification Notes (AMN OUTSIDE) | |
Classification updated to L3.7 in Meteoritical Bulletin 76. |
Antarctic Meteorite Images for Sample ALH 90411 | ||||
Lab Photo(s) : | ||||
Antarctic Meteorite Images for Sample ALH 90411 | ||||
Thin Section Photo(s) : | ||||
References for Sample ALH90411 | |
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. | |
Sears, D. W. G., Yozzo, J., Ragland, C., 2011, The natural thermoluminescence of Antarctic meteorites and their terrestrial ages and orbits: A 2010 update. Meteoritics & Planetary Science, 46, 79-91, http://dx.doi.org/10.1111/j.1945-5100.2010.01139.x. | |
Menzies, O. N., Bland, P. A., Berry, F. J., Cressey, G., 2005, A M”ssbauer spectroscopy and X-ray diffraction study of ordinary chondrites: Quantification of modal mineralogy and implications for redox conditions during metamorphism. Meteoritics & Planetary Science, 40, 1023-1042, http://dx.doi.org/10.1111/j.1945-5100.2005.tb00171.x. | |
Benoit, P. H., Akridge, G. A., Ninagawa, K., Sears, D. W. G., 2002, Thermoluminescence sensitivity and thermal history of type 3 ordinary chondrites: Eleven new type 3.0-3.1 chondrites and possible explanations for differences among H, L, and LL chondrites. Meteoritics & Planetary Science, 37, 793-805. | |
Sugiura, N., Kiyota, K., Hashizume, K., 1998, Nitrogen components in primitive ordinary chondrites. Meteoritics & Planetary Science, 33, 463-482. | |
RELAB, , Reflectance Experiment Lab , catalogue of samples. |