BRAZIL - RS
Equilibrated Ordinary Chondrite L4.
The meteorite exhibits a well-defined chondritic texture, with easily discernible chondules in the middle of the matrix, which in turn is microcrystalline, granular and transparent, that is, no longer opaque like glass. In some areas of the matrix, however, it is possible to find cloudy glass. Chodrules vary considerably in internal texture (porphyritic, poikilitic, barred and radial). Source: Gomes & Keil (1980).
According to Berkley et al. (1978b) the meteorite consists mainly of Fa24.6 olivine, low Ca pyroxene (bronzite) Fs20.6 and FeNi metal. As an accessory mineral there is pyroxene with high Ca (diopside) En51.3 Fs10.4 Wo38.3, microcrystalline plagioclase Ab84.8 An10.0 Or5.2, chromite and glassy material. Source: Gomes & Keil (1980).
The chemical composition of the constituents suggests the classification for the chemical L group. The type 4 as petrographic classification, according to Van Schmus & Wood (1967), is due to textural evidence with abundance of geminated low Ca clinopyroxenes, well-defined chondrules, presence of regions still with turbid glass in the matrix and rare occurrence of plagioclase microcrystals. Source: Gomes & Keil (1980).
Not reported by the Meteoritical Bulletin Database. According to Gomes & Keil (1980), a detailed description of the meteorite was given by Berkey et al. (1978b).
The Santa Bárbara meteorite fell on September 26, 1873, at about 1:00 pm, in a town called Santa Bárbara, in the German colony of Leonerhof ½ league of São Leopoldo and 5-6 leagues from SW of Santa Catarina do Pine forest. The meteorite was apparently traveling from N to S, having been observed by several people. The fall was accompanied by sound effects, three loud bangs, followed by a detonation, ending with a long hiss. Several fragments of the meteorite fell (a shower of meteorites), however only one fragment was recovered by Mr. Cristiano Valentin who had witnessed the fall. He located the meteorite buried about two feet apart, and leaning against a root, it was the size of an orange. Mr. Pohlman, who had been commissioned by the then President of the province of Rio Grande do Sul, Mr. Dr. João Pedro Carvalho de Moraes, paid $ 5000 for the stone and divided it. He gave Guilherme Kowdorry a part, taking the other part where he took a piece that he handed to the sub-delegate, who sent it to the president, who in turn, sent it to the National Museum through the Ministry of Agriculture. One of the pieces weighing 49,415g was donated to Princess Isabel and the Príncipe do Grão Pará collection was attached. Possibly the third fragment with 41,265g ended up in Rua da Ajuda, because according to Derby, this meteorite had the same characteristics as Santa Bárbara , mainly the density and shape making it suspect that it was the same meteorite. Today, at the National Museum there is no more sample of this meteorite. The Rua da Ajuda fragment was exchanged with the Monnig Collection and the authentic sample is on loan to Dr. Celso de Barros Gomes at the USP museum. That of Grão Pará was exchanged with the Field Museum of Natural History in Chicago. 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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