CASIMIRO DE ABREU
BRAZIL - RJ
Iron Meteorite - IIIAB Medium Octahedrite.
It is a medium octahedrite siderite from IIIAB group. Displays Widmänstatten pattern with widths 1.30 +/- 0.20 mm and Neumann lines. The kamacite was recrystallized showing 100-50microns ferrite grains replacing the pre-existing lamellae. Taenite and plessite edges have rounded outlines, indicating possibly cosmic reheating. Subangular bodies of the schreibersite phosphide are commonly found centralized in the kamacite lamellae, showing no signs of recrystallization. No rabdite was found, despite the existence of some precipitated phosphides in the shape of a wedge along the grain boundaries. Description obtained in the documents of National Museum.
8.43% Ni, 0.52% Co, 0.23% P, 20.9 ppm Ga, 41.0 ppm Ge, 0.25 ppm Br. Source: Buchwald 1975.
Casimiro de Abreu is an average octahedrite typical of the IIIAB group, which probably underwent reheating by a cosmic source at a temperature between 500 and 750oC. It does not show traces of the area affected by the heat (alpha2) by the atmospheric passage, indicating that it is a very old fall. Description obtained in the documents of M. E. Zucolotto. For more information on the Casimiro de Abreu meteorite, access the following link http://evols.library.manoa.hawaii.edu/bitstream/handle/10524/35668/vol2-Car-Ced(LO).pdf#page= 11
Not reported by the Meteoritical Bulletin Database. According to Buchwald (1975), the Casimiro de Abreu meteorite was first described and classified by Curvello (1950c).
The 24.2 kg iron meteorite Casimiro de Abreu was found on September 7, 1947 at the Andorinhas farm near Casimiro de Abreu. Farmers in the region thought it was iron ore and were curious to undermine a "lawrencite" liquid on rainy days. It was recognized as a meteorite by chemist Joaquim Seixas, who bought it and donated it to the National Museum. Description obtained in the documents of National Museum.
Todas as informações que não possuírem fonte especifica, foram extraídas do Meteoritical Bulletin Database.
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