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Kamacite Globules in Gujba |
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| Meteorite - Gujba, CBa, Bencubbinite. |
| The physical characteristics of
the CB subgroup of carbonaceous chondrites are prominent, 0.4 to 0.6 cm-sized
metal and other chondrule-like structures, i.e., silicate globules, kamacite
nodules, and cryptocrystalline spherules. The kamacite nodules have minor accessory troilite, while the silicates are barred olivine and pyroxenes. Cambell et al. (2002) and Rubin et al. (2003) proposed that the metal and silicate structures may have formed as liquid droplets either from condensation in an impact-generated vapor plume (asteroid) or by evaporation of preexisting metal particles in a plume. The image is of a prepared section of the coarse-grained CBa, Gujba. |
| Figure 1. Scale bar 1.3 mm. |
| Prepared section of Gujba. Kamacite globules are light grey. The large structure, upper right, is a cryptocrystalline silicate spherule. There are a lot of structures in Gujba i.e., fragmented breccias, mineralogy altered by heat/shock, terrestrial weathering byproducts, large-sized kamacite globules of unknown formation, etc. A determination of primary/secondary structures is left to others. Any input is welcome. |
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