Sample Petrographic Description
| Sample Number | EET 99430 |
| Newsletter | 24,1 |
| Location | Elephant Moraine |
| Field Number | 12395 |
| Dimensions (cm) | 4.0 x 3.0 x 1.5 |
| Weight (g) | 27.07 |
| Original Classification | CK4 Chondrite |
| Mineral Composition (%Fa & %Fs) | |
| Fayalite (mol%): 30-33 | |
| Weathering | |
| C | |
| Fracturing | |
| A/B | |
| Macroscopic Description - Kathleen McBride | |
| The entire exterior surface of this carbonaceous chondrite is covered with thick black fusion crust with polygonal fractures. The interior is black, earthy material with a sulfurous odor. This meteorite has an oxidation rind and rust halos. | |
| Thin Section Description (,4) - Tim McCoy, Linda Welzenbach | |
| The section consists of large (up to 2 mm), well-defined chondrules in a matrix of finer-grained silicates, sulfides and abundant magnetite. The meteorite is extensively shocked and brecciated. Olivine is relatively homogeneous Fa30-33. In this section, we observed a 1.5 by 2 mm CAI consisting of anorthite, fassaite and pleonaste spinel. A very unusual feature of this meteorite is the presence of FeO-rich phyllosilicates, which occur as veins and patches. The phyllosilicates also appear to cross cut the brecciated texture and are sometimes associated with magnetite. The origin of these phyllosilicates (terrestrial vs. extraterrestrial; timing relative to metamorphism and brecciation) is uncertain. The meteorite is a CK4 chondrite. However, phyllosilicates have not been previously reported in CK chondrites and large CAIs are very rare. This specimen is clearly very unusual. | |
| Antarctic Meteorite Images for Sample EET 99430 | ||||
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| Field photo image(s) courtesy of the ANSMET (ANtarctic Search for METeorites) Program, Case Western Reserve University and the University of Utah | ||||
| Antarctic Meteorite Images for Sample EET 99430 | ||||
| Lab Photo(s) : | ||||
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| Antarctic Meteorite Images for Sample EET 99430 | ||||
| Thin Section Photo(s) : | ||||
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| References for Sample EET99430 | |
| Rochette, P., Kohout, T., Pesonen, L., Quirico, E., Sagnotti, L., Skripnik, A., Gattacceca, J., Bonal, L., Bourot-Denise, M., Chevrier, V., Clerc, J. P., Consolmagno, G., Folco, L., Gounelle, M., 2008, Magnetic classification of stony meteorites: 2. Non-ordinary chondrites. Meteoritics & Planetary Science, 43, 959-980, http://dx.doi.org/10.1111/j.1945-5100.2008.tb01092.x. | |
| Righter, K., Neff, K. E., 2007, Temperature and oxygen fugacity constraints on CK and R chondrites and implications for water and oxidation in the early solar system. Polar Science, 1 Issue 1, Aug-07, 25-44, ISSN 1873-9652, http://dx.doi.org/10.1016/j.polar.2007.04.002. | |
| Huber, H., Rubin, A. E., Kallemeyn, G. W., Wasson, J. T., 2006, Siderophile-element anomalies in CK carbonaceous chondrites: Implications for parent-body aqueous alteration and terrestrial weathering of sulfides. Geochimica et Cosmochimica Acta, 70 Issue 15, 1-Aug-06, 4019-4037, ISSN 0016-7037, http://dx.doi.org/10.1016/j.gca.2006.06.001. | |
| Rubin, A. E., Huber, H., 2005, A weathering index for CK and R chondrites. Meteoritics & Planetary Science, 40, 1123-1130, http://dx.doi.org/10.1111/j.1945-5100.2005.tb00178.x. | |
| Oura, Y., Takahashi, C., Ebihara, M., 2004, Boron and chlorine abundances in Antarctic chondrites: A PGA study. Antarctic meteorite research, 17, 172-184, http://ci.nii.ac.jp/naid/110001052380/en/. | |