Sample Petrographic Description
Sample Number | EET 90018 |
Newsletter | 14,2 |
Location | Elephant Moraine |
Field Number | 6497 |
Dimensions (cm) | 5.0 x 3.5 x 1.4 |
Weight (g) | 31.38 |
Original Classification | Carbonaceous C4 |
Updated Classification | CK5 Chondrite |
Pairing | EET 87507; EET 16006; EET 16029; EET 16048; EET 16049; EET 16170; EET 16172; EET 16201; EET 16203; EET 87508; EET 87514; EET 87519; EET 87525; EET 87526; EET 87527; EET 87529; EET 90001; EET 90002; EET 90003; EET 90004; EET 90005; EET 90006; EET 90007; EET 90008; EET 90009; EET 90010; EET 90013; EET 90014; EET 90015; EET 90016; EET 90017; EET 90018; EET 90022; EET 90023; EET 90025; EET 90026; EET 90027; EET 90028; EET 90035; EET 90036; EET 90038; EET 90039; EET 90040; EET 90041; EET 90042; EET 90044; EET 90045; EET 90046; EET 90048; EET 90049; EET 90050; EET 90052; EET 90234; EET 90428; EET 90991; EET 92002; |
Mineral Composition (%Fa & %Fs) | |
Fayalite (mol%): 29 | |
Weathering | |
Be | |
Fracturing | |
A | |
Macroscopic Description - Robbie Marlow | |
Dull brown or black fusion crust covers approximately half of all 5 specimens. Evaporite deposits are present on all. EET90015, and 90018 have white deposit; 90004 and 90007 have more abundant light green colored deposit; and 90022 has abundant thick, fluffy looking deposit with euhedral crystals. The original hydrated color of the deposit on 90022 was turquoise which turned to a lighter green after it was dried. The interior of all specimens is medium gray with minor amounts of metal and a few white inclusions. Weathering of the interior is minimal. | |
Thin Section Description (,3) - Brian Mason | |
The sections of these meteorites are all very similar and a single description applies to all. They show an aggregate of small (average about 0.02 mm) olivine grains and minor opaque material; some of the opaque material is finely dispersed and gives the sections a gray color. Occasional chondrules, up to 1.2 mm across, are present. Fusion crust is present on 90007, 90015, and 90022. Olivine composition is Fa29; a little plagioclase of variable composition, An33-45, is present; one grain of diopside, Wo40Fs11, was analyzed. The opaque material is mainly magnetite with a little troilite and pentlandite. The meteorites are 04 chondrites; they are very similar in texture and mineral compositions to the EET 87507 group of C4 chondrites, and the possibility of pairing should be considered. | |
Reclassification Notes (AMN 17,1) | |
Re-classified to CK5 according to Kallemeyn, G. W., Rubin, A. E., Wasson, J. T., 1991, The compositional classification of chondrites: V. The Karoonda (CK) group of carbonaceous chondrites. Geochimica et Cosmochimica Acta, 55, 881-892. |
Antarctic Meteorite Images for Sample EET 90018 | ||||
Thin Section Photo(s) : | ||||