still under construction
The Vicência meteorite fall: A new unshocked (S1) weakly metamorphosed (3.2) LL chondrite
Keil, K., Zucolotto, M. E., Krot, A. N., Doyle, P. M., Telus, M., Krot, T. V., Greenwood, R. C., Franchi, I. A., Wasson, J. T., Welten, K. C., Caffee, M. W., Sears, D. W. G., Riebe, M., Wieler, R., dos Santos, E., Scorzelli, R. B., Gattacceca, J., Lagroix, F., Laubenstein, M., Mendes, J. C., Schmitt-Kopplin, P., Harir, M. and Moutinho, A. L. R. (2015),
Meteoritics & Planetary Science. doi: 10.1111/maps.12456
Article first published online: 25 MAY 2015
Entry in the Meteoritical Bulletin Database (30 August 2014):
Fell: 21 Sept 2013
Classification: Ordinary chondrite (LL3.2)
History: Fell, September 21, 2013, ~15:00 hours local time (18:00 UTC), village Borracha near Vicência, Pernambuco, Brazil. Landed <1 m from Mr. Adeildo Silva. Mr. Adeildo Silva claims that when he picked up the meteorite immediately after the fall, one side was warm, whereas the other was cold. Purchased by Maria E. Zucolotto and Andre Moutinho on September 30, 2013.
Physical characteristics: Single stone of 1.547 kg and ~13.7 × 12 × 8.5 cm. Pronounced chondritic texture, with abundant chondrules up to ~7 mm in diameter. Bulk density 3.13 g/cm3; grain density 3.28 g/cm3, porosity of 4.75%.
Petrography: Unshocked (S1), well-developed chondritic texture and mineralogy and mineral compositions of a highly unequilibrated ordinary chondrite. Major minerals olivine (Fa0.4-58.9), low-Ca pyroxene (Fs0.4-29.8). Mean Cr2O3 ferroan olivine 0.14±0.09 wt.%, n=115.
Geochemistry: R. Greenwood and I. Franchi, OU. Bulk oxygen isotopic composition is δ17O = 3.768 ± 0.042‰, δ18O = 5.359 ± 0.042‰, Δ17O = 0.981 ±0.020 ‰.
Classification: LL group based on chondrule mean apparent diameter (0.9 mm), bulk oxygen isotopic composition, content of metallic Fe,Ni (1.8 vol%), Co content of kamacite (1.73 wt%), ratios of metallic FeO/total iron (0.105) vs. total Fe/Mg (1.164), and of Ni/Mg (0.057) vs. total Fe/Mg. Petrologic type 3.2 classification is based on chondritic texture, plot of the standard deviation (0.09) vs the mean Cr2O3 content (0.14 wt. %) of ferroan olivine, trapped 132Xe of ~32×10-10cm3STP/g consistent with petrologic type 3.2.