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| Tres Irmaos | |||||||||||||||||||||||||||||||||||||||||
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| Basic information | Name: Tres Irmaos This is an OFFICIAL meteorite name. Abbreviation: There is no official abbreviation for this meteorite. Observed fall: Yes, confirmed fall Year fell: 2017 Country: Brazil Mass:  890 g | ||||||||||||||||||||||||||||||||||||||||
| Classification history: |
This is 1 of 13099 approved meteorites (plus 11 unapproved names) classified as L6. [show all] Search for other: L chondrites, L chondrites (type 4-7), Ordinary chondrites, and Ordinary chondrites (type 4-7) | ||||||||||||||||||||||||||||||||||||||||
| Comments: | Approved 15 Aug 2017 | ||||||||||||||||||||||||||||||||||||||||
| Writeup |
Writeup from MB 106:
Tres Irmaos 14° 7' 1"S, 43° 3' 51"W Bahia, Brazil Confirmed fall: 2017 Classification: Ordinary chondrite (L6) History: On May 26, 2017, about 11:30 am local time, a stone fell in the rural area of Palmas de Monte Alto, Bahia, Brazil. It was a clear sunny day; the residents heard some loud detonations, but thought it might be from a train line construction or a quarry. Mrs. Euzani Pais also heard a whistle and the sound of something hitting the soil. She went to the door and saw a small sand swirl. Her daughter and granddaughter, Sirlene da Silva Pais and Márcia Eduarda Pais, looked around and found a pit on the farm’s sandy road, with a black stone about 6 m away. A history professor, Nilton A. Azevedo, became aware of the fact and, with a broadcaster, published a video on the Internet. Andre L. R. Moutinho, M. E. Zucolotto (MNRJ) and Wilton Carvalho (GPA/UFBA leaded by Debora Rios) went to the site, certified the authenticity of the meteorite and purchased it in a consortium with the City Mayor on June 2. Physical characteristics: Single stone with dimensions 9 × 6 × 5 cm. Nearly completely covered by fusion crust with thickeness of 0.2-1 mm. On one edge, a piece of approx. 7 × 4 cm was sawed off, exposing the light-gray interior. Petrography: (M. E. Zucolotto, MNRJ and C. Villaça, IGEO/UFRJ) Polished thin and microprobe sections show a high degree of recrystallization of the matrix with few recognizable chondrules. Plagioclase grains are abundant and exceed 50 μm in size. Metal grains include kamacite, zoned taenite and zoneless plessite. Monocrystalline chromite. The presence of melt pockets in addiction to irregular fractures in olivine and undulatory extinction of olivine and plagioclase indicate a shock stage of S3. Some thin veins cross the meteorite. No weathering products were observed. Geochemistry: Electron microprobe analysis yielded: olivine Fa25.5±0.7 (Fa24.7-27.4; n=21), pyroxene Fs21.6±0.4Wo1.5±0.7 (Fs21.1-22.6Wo1.0-3.2; n=18). Classification: Ordinary chondrite (L6), shock stage S3, no weathering (W0). Specimens: Palmas de Monte Alto city: 450 g, MNRJ : 50 g. | ||||||||||||||||||||||||||||||||||||||||
| Data from: MB106 Table 0 Line 0: |
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| Institutions and collections |
MNRJ: Museu Nacional, Quinta da Boa Vista, Rio de Janeiro, CEP 20940-040, Brazil (institutional address; updated 26 Dec 2011) |
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| References: | Published in Gattacceca J., Bouvier A., Grossman J., Metzler K., and Uehara M. (2019) Meteoritical Bulletin, no. 106. Meteorit. Planet. Sci. 54 in press.
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Geography:
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Statistics: This is 1 of 6 approved meteorites from Bahia, Brazil (plus 1 unapproved name) This is 1 of 88 approved meteorites from Brazil (plus 6 unapproved names) (plus 7 impact craters) | ||||||||||||||||||||||||||||||||||||||||
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