PATOS DE MINAS (Octaedrito)

Iron

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ACHONDRITE

COMPLEX OCTAHEDRITE

IAB

BRAZIL - MG

1925

Iron Meteorite - Complex Octahedrite IAB.

PETROGRAPHY:

Polished sections display a poor medium Widmanstätten structure of irregular kamacite lamellae 1.1 ± 0.2 mm (max. 2.4 mm), with the Widmanstätten pattern not very obvious. Aspect ratios (length/width) of individual lamellae range from 1 to 8, most being 4-6. Terrestrial corrosion penetrates to a depth of 5 cm. Troilite nodules are very common. The structure is identical to Patos de Minas (octahedrite) so the two masses are considered to be paired..

GEOCHEMISTRY:

(John T. Wasson, UCLA, data obtained by INAA). Bulk composition: Co = 4.8, Ni = 83 (both mg/g); Ga = 67, Cu = 240, As = 15.4, Ir = 1.3 and Au = 1.7 (all in µg/g).

CLASSIFICATION:

Iron (IAB complex) very weathered.

CLASSIFIERS:

M. E. Zucolotto and J. T. Wasson

HISTORY:

A small (18.4 g) end piece of a badly oxidized octahedrite was found in 1925 at the collection of the Escola de Minas Ouro Preto. In 1960 it was donated to Museu Nacional of Rio de Janeiro. The meteorite was mentioned in the British Museum catalog and the Handbook of iron meteorites of Buchwald, when it was named Patos de Minas (octahedrite), or Patos II, to distinguish it from Corrego do Areado, or Patos de Minas (hexahedrite). In 2002, a mass of about 200 kg was found by Paulo Garcia when plowing the land with a tractor.

All information that does not have a specific source was extracted from the Meteoritical Bulletin Database.

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