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Drusy vugs in an iron meteorite |
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| Albion, IVA, iron, fine octahedrite. |
| Drusy vugs are small
cavities within iron meteorites, a feature well-known in terrestrial geology
where they occur in igneous, sedimentary, and metamorphic rocks. On Earth,
these irregular cavities typically form from cracks and fissures. In iron
meteorites, however, vugs are rare. The Albion iron meteorite stands out as
exceptional: it is the only known iron meteorite with vugs lined internally by
masses of spheroidal drusy mineralogy. A key question is whether these vugs are primary or secondary in origin. The Albion iron did not form as part of a planetary core. Instead, it contains cracks, voids, and possibly imperfectly sealed grain boundaries. These features likely allowed hot fluids or gaseous vapors to flow through, mobilizing troilite, fractionating nickel, and depositing drusy spheroids on the vug interiors. This scenario-more plausible than shock-melting-suggests a primary origin tied to the meteorite's initial formation. In contrast, a shock-induced origin would imply secondary vugs formed after solidification. Such a process would likely leave evidence of shock effects, such as deformation or damage in the kamacite and taenite lamellae of the surrounding Widmanstätten structure. However, studies show no such shock features in Albion's kamacite/taenite lamellae (1) (2). Without evidence of shock or further analysis suggesting otherwise, the vugs in the Albion iron are classified as primary. 1. Marvin, U.B., Petaev, M.I., Kempton, R.W. (1996) LPS XXVII, 821 2. Kempton, R.W. (1995) Meteorite!, November Issue |
Figure 1. Scale bar 2.6 mm. |
| Albion, IVA, iron, fine octahedrite. |
| Vug lined with drusy mineralogy. |
Figure 1. Scale bar 1.5 mm. |
| Albion, IVA, iron, fine octahedrite. |
| Vug interior. Daubreelite occures in blocky, euhedral grains in the spheroids. A new phosphide mineral occuring in rounded euhedral to subhedral grains was also found in the spheroids. (1). |
Figure 3. Scale bar 2.6 mm. |
| Albion, IVA, iron, fine octahedrite. |
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