VITÓRIA DA CONQUISTA
BRAZIL - BA
Iron Meteorite - IVA Fine Octahedrite.
The polished and etched sample with 2% nital exhibits a Widmanstätten pattern with narrow lamellae (width 0.35mm ± 0.05) and long with a length-to-width ratio of approximately 20. The lamellae of kamacite are stained upon attack and they are of the crosshatched type due to shocks above 130 kbar or presenting Neumann lines in some directions, indicative of shocks below 130 kbar. Taenite and plessite cover approximately 50% of the examined area and are common in duplex, black and fingerprint types. Plessite fields with transitional zone from the edge to the interior and altered plessite fields were also observed, possibly due to annealing. Many lamellae and plessite fields, as well as taenite and kamacite lamellae, have distorted edges, possibly as a result of cosmic shocks. Small vermicular bodies of the schreibersite phosphide were also found, apparently linking taenite lamellae. Description obtained in the documents of National Museum.
Co = 0.41, Ni = 9.4 (both in wt.%); Ga = 2.4, As = 13, Ir = 0.84, Au = 2.37 (all in ppm).
By the characteristics described, the meteorite is classified as belonging to the fine octahedrite structural group (Of). Chemically, through analysis by INAA (analysis by atomic activation of neutrons) to determine the trace elements present, Vitória da Conquista fits into the chemical group IVA.
M. E. Zucolotto
The meteorite do not have resemblance to any other Brazilian meteorite, and this is certainly a new finding. Unfortunately, no information about the place of origin and date of collection, not even the collector, was preserved, which makes it impossible to relate this specimen to any historical record. It was during research dedicated to the study of the Palmas de Monte Alto meteorite, the paleontologist Prof. Douglas Riff and the archelogue Joaquim Perfeito were informed by Prof. Eduardo Bernarde of the existence of a meteorite among the rocks and minerals in the collection of the Geology Laboratory of UESB / Vitória da Conquista where they taught. They were able to recognize the meteorite, however they were unable to find out where, when, or who found the meteorite. Chemical and structural analyzes show that it was a new Brazilian meteorite. It is a metallic body, with a weight of 10.5 kg and dimensions of 25 X 14 X 13 cm. Its identification as a meteorite occurred in December 2007. In the absence of any information that identifies the precise origin of the meteorite, the epithet Vitória da Conquista was proposed to name it in reference to the municipality where it was found. Source: www.meteorito.com.br
All information that does not have a specific source was extracted from the Meteoritical Bulletin Database.
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