Sample Petrographic Description
Sample Number | ALH 77033 |
Newsletter | 1,3 |
Location | Allan Hills |
Field Number | 771227 34 |
Dimensions (cm) | ~3.0 cm maximum length |
Weight (g) | 9.34 |
Original Classification | LL3 Chondrite |
Updated Classification | L3.5 Chondrite |
Pairing | ALH 77011; ALH 77015; ALH 77031; ALH 77033; ALH 77034; ALH 77036; ALH 77043; ALH 77047; ALH 77049; ALH 77050; ALH 77052; ALH 77115; ALH 77140; ALH 77160; ALH 77163; ALH 77164; ALH 77165; ALH 77166; ALH 77167; ALH 77170; ALH 77175; ALH 77178; ALH 77185; ALH 77211; ALH 77214; ALH 77241; ALH 77244; ALH 77249; ALH 77260; ALH 77303; ALH 78013; ALH 78015; ALH 78017; ALH 78037; ALH 78038; ALH 78041; ALH 78162; ALH 78170; ALH 78176; ALH 78180; ALH 78186; ALH 78188; ALH 78235; ALH 78236; ALH 78238; ALH 78239; ALH 78243; ALH 79001; ALH 79045; ALH 80133; ALH 81025; ALH 81030; ALH 81031; ALH 81032; ALH 81053; ALH 81060; ALH 81061; ALH 81065; ALH 81066; ALH 81069; ALH 81085; ALH 81087; ALH 81121; ALH 81145; ALH 81156; ALH 81162; ALH 81190; ALH 81191; ALH 81214; ALH 81229; ALH 81243; ALH 81259; ALH 81272; ALH 81280; ALH 81292; ALH 81299; ALH 83038; ALH 85155; |
Mineral Composition (%Fa & %Fs) | |
Fayalite (mol%): 8-38;Ferrosilite (mol%): 8-9 | |
Weathering | |
C | |
Fracturing | |
B | |
Macroscopic Description - | |
Specimen is angular, rough and dark brown. Exterior surfaces do not appear to have fusion crust, but are highly weathered. The stone chipped easily, revealing a highly oxidized broken face. Maximum overall length is ~3.0 cm. | |
Thin Section Description - Brian Mason | |
The section shows a closely packed mass of chondrules (0.3-1.1 mm diameter) and irregular crystalline aggregates, with a little interstitial nickel-iron and troilite (1-2% of each) and a relatively small amount of fine-grained matrix. A considerable variety of chondrules is present, the commonest being granular olivine and olivine/polysynthetically-twinned clinopyroxene, porphyritic olivine, and fine-grained pyroxene. Some chondrules have intergranular transparent pale brown glass, in others the glass is turbid and partly devitrified. Yellow-brown limonitic staining pervades the section, and patches and veinlets of red-brown limonite are common. Microprobe analyses show olivine ranging in composition from Fa8 to Fa38, with a mean of Fa18; the pyroxene is relatively uniform in iron content (Fs8-9) but shows a considerable range in calcium (Wo0.3-8.5). The low content of nickel-iron and troilite suggest L group, and the meteorite is classified L3. | |
Reclassification Notes (AMN OUTSIDE) | |
Classification updated in Meteoritical Bulletin 76. |
Antarctic Meteorite Images for Sample ALH 77033 | ||||
Thin Section Photo(s) : | ||||
References for Sample ALH77033 | |
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. | |
Kimura, M., 1983, Chemical and petrologic relations of the constituent units in ALH-77249 meteorite (L3). Memoirs of National Institute of Polar Research., Special Issue 30, 146-167, http://ci.nii.ac.jp/naid/110000009826/en/. | |
Ikeda, Y., Kimura, M., Mori, H., Takeda, H., 1981, Chemical compositions of matrices of unequilibrated ordinary chondrites. Memoirs of National Institute of Polar Research., Special Issue 20, 124-144, http://ci.nii.ac.jp/naid/110000009438/en/. | |
Marvin, U. B., Mason, B., 1980, Catalog of Antarctic Meteorites 1977-1978. Smithsonian Contributions to the Earth Sciences, Number 23, 50. | |
Nagahara, H., 1980, Petrology of "Equilibrated" Chondrites. 2. Metamorphism and Thermal History. Memoirs of National Institute of Polar Research., Special Issue 17, 32-49, http://ci.nii.ac.jp/naid/110000009333/en/. |