BRAZIL - RS
Equilibrated Ordinary Chondrite L6 with textural and mineralogical characteristics of shock events.
The meteorite exhibits a texture with high recrystallization, with only a few discernible chondrules in the middle of the matrix. The visible chondrules vary in shape (round to elongated), size (with an average of 0.8 mm) and internal texture (porphyritic, poikilitic, barred, radial and granular). The meteorite also has textural and mineralogical characteristics from which it suffered shock events, such as the transformation of feldspar into maskelinite and undulating extinction in ferromagnesian minerals. Source: Gomes & Keil (1980).
According to Symes & Hutchison (1970) and Keil et al. (1978b), the meteorite mainly consists of Olivine Fa24.8, low Ca pyroxene (bronzite) Fs21.3 and metallic phases FeNi (kamacite, taenite and plessite), with smaller amounts of chromite and plagioclase. Keil et al. (1978b) observed that the maskelinite plagioclase was transformed into isotropic to slightly anisotropic due to solid-state shock metamorphism. This shock transformation must have occurred after the glass matrix was recrystallized. Maskelinite is an oligoclase in composition Ab81.0 An12.4 Or6.6. Accessory minerals include chromite and whitlockite. Source: Gomes & Keil (1980).
The classification for the chemical L group was first suggested by Symes & Hutchison (1970) and later confirmed by Keil et al. (1978b), through the composition of olivine, pyroxene, plagioclase, chromite and total chemistry. Total chemistry supports the L classification due to the following reasons found by Keil et al. (1978b) and Symes & Hutchison (1970), respectively: Feº / Ni (5.24; 5.50), Fe / SiO2 (0.58; 0.58) and Feº / Fe (0.27; 0.28), as well as the concentration of total Fe in the meteorite ( 22.31%; 23.3%) and total FeNi of 7.25% and 7.86%. The petrographic classification type 6, according to Van Schmus & Wood (1967), is due to the high recrystallization of the matrix, a very poorly defined chondritic texture and the compositional homogeneity of olivines and pyroxenes. Source: Gomes & Keil (1980).
Not reported by the Meteoritical Bulletin Database. A preliminary description was given by Roisenberg (1970). A more detailed study of the meteorite was carried out by Symes & Hutchison (1970) and Keil et al. (1978b). Source: Gomes & Keil (1980).
The meteorite fell in the afternoon (16:30) of August 16, 1937. The whole city of Putinga was gathered to celebrate the day of the city's patron, São Roque, when, suddenly, there were sounds of fireworks fireworks and, at the same time, thunder in the clear sky: "fulmine al cielo sereno", an expression widely used in the region populated by Italian and German settlers. Everyone looked at each other in fright when a dark cloud clouded the sky and a shower of stones fell over the city. A smell of burning, like sulfur, washed over the place. Dr. Vicenzo Guaragna, an Italian doctor residing there, was straightforward, saying that it was certainly a meteorite, in which he was accompanied by the priest. Other witnesses later said they saw large pieces of stone falling from the sky, very close to the city. The next day, about 200kg of stone was removed from holes about 1 to 2 meters deep. The precipitation of thousands of smaller fragments also reached the neighboring municipality of Ilópolis and part of Soledade. The meteorite rain was perhaps the biggest ever in Brazilian territory. A little over 200kg were collected at the time and, by calculations, at least 1000kg are still lost among the pine forests that cover the region. The interest aroused at the time excited the entire state, the subject being published prominently in the newspapers of the following days. The then mayor of Putinga, Demétrio Costi, sent to the newspaper Diário de Notícias, from Porto Alegre, two fragments weighing 45 kg, one, and 55 kg., The other. Both were exposed for a long time in the lobby of the newspaper's headquarters. Subsequently, the 45kg fragment was sent to the Luiz Englert Museum, at UFRGS, where it still exists today. Over time, the event fell by the wayside. The meteorites were disappearing from view, as well as the memory ... Nothing is known today about the 55 kg, which had been taken to the newspaper; neither is there news of another fragment, this one weighing 90kg. In 1963, already knowing the importance of meteorites, Dr. Hardy Grunewaldt, a physician residing in Arroio do Meio, sought to find out about the fact that he had witnessed as a child in the city of Candelária. Returning to the place in the company of Mr. Hermínio Cé, he obtained some fragments, sending them, later, accompanied by an account of his history, to some museums, including the Smithsonian Stitution, of Washington, the Vatican Museum, the Deutsche Museum , the British Museum and the National Museum of Rio de Janeiro. The bolide was seen in several cities in the Taquari River region, in Rio Grande do Sul, following a straight line from SSE to NNW leaving a trail of smoke that remained in the sky until nightfall. The sound effect was heard within a 50km radius and can be observed within a radius of at least 100km. Description obtained in the documents of M. E. Zucolotto.
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