Newsletter |
11,2 |
Location |
Elephant Moraine |
Field Number |
4369 |
Dimensions (cm) |
2.5 x 2.0 x 1.5 |
Weight (g) |
15.20 |
Original Classification |
Iron w/Silicate Inclusions |
Updated Classification |
Iron-IAB (Anomalous) |
Pairing |
EET 87504;
EET 87505;
EET 87506;
EET 96009;
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Fayalite (mol%): 3;Ferrosilite (mol%): 6 |
B/C |
B/C |
All three specimens are weathered to a deep red-brown color with no fusion crust remaining. Oxidation haloes are obvious on the exterior surfaces as is gold-colored metal. Fractures penetrate the interior of the three specimens. Chipping revealed somewhat less weathered metal, lots of oxidation, and some colorless crystals. A minute amount of salt deposit is present. All three fragments are obviously paired.
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Thin Section (87504,4; 87505,3; 87506,4) Description: Brian Mason and Roy S. Clarke, Jr.
These specimens are so similar in all respects that they must be pieces of a single meteorite. The sections are made up largely of nickel-iron, which includes numerous anhedral grains and aggregates of silicate minerals (grain size 0.3-3.1 mm), dominantly pyroxene, with minor olivine and a little plagioclase. One large grain of apatite was noted in 87504,4. Weathering is extensive, the sections being seamed with brown limonite. Microprobe analyses give the following compositions: olivine, Fa3; pyroxene, Wo2Fs6 (CaO content varies slightly, 0.7-1.2%); plagioclase somewhat variable, average An3 (CaO 0.1-1.6%, K2O 0.2-2.2%). Metal areas of 87504,4 consist of kamacite in contact with large amounts of plessite. The association within the plessite areas is: clear taenite borders (probably tetrataenite), cloudy taenite, clear taenite, and comparatively large areas of martensite. Areas of troilite in the mm size range are present, several containing well developed (0.1 mm) crystals of radiating graphite. The meteorites are irons with silicate inclusions.
Reclassified to IAB anomalous in AMN 13, no. 1. |
EET 87506 was re-classified to IAB iron (anomalous) according to information published in Wasson, J. T., Kallemeyn, G. W., 2002, the IAB iron-meteorite complex: A group, five subgroups, numerous grouplets, closely related, mainly formed by crystal segregation in rapidly cooling melts. Geochimica et Cosmochimica Acta 66, 2445-2473. |