BRAZIL - SP
Chondritic texture and mineral composition of an unequilibrated ordinary chondrite of the chemical and petrographic type LL3.2. Shock stage S3 and weathering W1.
Weakly shocked (S3), well-developed chondritic texture with mineralogy and mineral compositions consistent with an unequilibrated ordinary chondrite. All principal types of chondrules are present, including porphyritic olivine, porphyritic pyroxene, radial pyroxene and well-developed barred olivine. Many metal grains are composed of kamacite with inclusions of tetrataenite. Several chondrules are Al-rich; one of them shows a dust-rich rim with glass and Al-rich minerals. The major minerals are forsterite, enstatite and clinoenstatite. The meteorite is a genomict breccia.
Microprobe analysis shows ferromagnesian minerals with unequilibrated composition. Olivine (Fa29.8±13.6; n=48) and low-Ca pyroxene (Fs25.3±16.7Wo1.5±1.1, n=16). Metallic Fe,Ni is composed of kamacite (93 wt% Fe) tetrataenite (47 wt% Fe), taenite (62 wt% Fe) and troillite (61 wt% Fe; 35 wt% S). The rims of dust-laden shells have an average: Al2O3=21.1, MgO=6.7, SiO2=63.7, FeO=4.1, CaO=3.3, Cr2O3=4.4, all in wt%. The genomict breccia has in average: Al2O3=6.5, MgO=14.6, Na2O=0.07, CaO=4.6, SiO2=54.8, FeO=16.4, Cr2O3=0.6, all in wt%.
LL group classification based on: bulk density (3.3 g/cm3), chondrule mean apparent diameter (0.8 mm), content of metallic Fe,Ni (2 vol%), Co content of kamacite (1.3 wt%), 20.88 total iron (wt%), a low magnetic susceptibility (log χ (× 10-9 m3/kg) = 4.47) with a low weathering meteorite (W1) and Fs25.3, Fa29.8 = LL . Petrologic type 3.2 classification based on the texture and highly unequilibrated minerals: mean Cr2O3 content of ferroan olivine is ~0.22±0.19 wt%; PMD of Fa content of olivine = 45, PMD of Fs content of pyroxene = 65; absence of albite in mesostasis chondrules type I and II; matrix <20% recrecrystallized; Ni content of troilite (0.09 wt%); Ni heterogeneity of kamacite (16.2%); and, cathodoluminesnce (CL) analysis shows rare yellow CL, common blue CL, present red CL and a low matrix CL.
R.N. Salaverry, M.E. Zucolotto,K. Keil, J.C. Mendes, A. Zanardo, J. Gattacceca and A. Tosi RJ
On August 14, 1967, at 03:40 AM (local time), many residents of São Simão and Buritizal witnessed a big explosion in the sky and a light so bright that it turned the sky as bright as day. Hearing about it, reporter Saulo Gomes, working at TV Tupi, went to Buritizal to investigate the fall and write a newspaper report. He confirmed the reports and found three fragments of the meteorite in the stable of a small farm in Buritizal owned by Mr. Almir Canc. The event was well documented at the time. Years later, in 2014, Saulo Gomes donated one of the meteorite fragments to MNRJ.
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