Antarctic Meteorite Newsletter 31,1 - Petrographic Descriptions
| Sample No.: | CMS 04032 |
| Location: | Cumulus Hills |
| Field No.: | 14646 |
| Dimensions (cm): | 4.5 x 3.0 x 2.5 |
| Weight (g): | 84.85 |
| Meteorite Type: | Mesosiderite |
| Pairing: |
Macroscopic Description: Kathleen McBride
40% of the exterior surface has brown/black, fractured fusion crust. The interior is an “odd” combination of fine-grained material and a more coarse grained, dark crystalline material, some weathered to a rusty tan color. Some areas are gray with “holes”. The meteorite has some metal rich inclusions. It is somewhat friable and has a granular texture.
Thin Section (,2) Description: McCoy, Linda Welzenbach and Cari Corrigan
The section shows a groundmass of comminuted pyroxene and plagioclase with abundant metal and sulfide that occur as stringers up to several mm in length and a cm-sized clast containing two pyroxene grains each approaching 5 mm. Orthopyroxene compositions are reasonably homogenous ranging from Fs30-33Wo1-3 (Fe/Mn ~30) and plagioclase is An89Or1. The meteorite is probably a silicate-rich clast from a mesosiderite. Pairing with CMS 04021 is possible given the very similar mineral compositions, although the latter is poorer in metal and sulfide and perhaps more metamorphosed. These differences may be within the expected variation in a single mesosiderite.