Study of Chelyabinsk LL5 meteorite fragment with a light lithology and its fusion crust using Mössbauer spectroscopy with a high velocity resolution

Abstract

Abstract. Study of Chelyabinsk LL5 ordinary chondrite fragment with a light lithology and its fusion crust, fallen on February 15, 2013, in Russian Federation, was carried out using Mössbauer spectroscopy with a high velocity resolution. The Mössbauer spectra of the internal matter and fusion crust were fitted and all components were related to iron-bearing phases such as olivine, pyroxene, troilite, Fe-Ni-Co alloy, and chromite in the internal matter and olivine, pyroxene, troilite, Fe-Ni-Co alloy, and magnesioferrite in the fusion crust. A comparison of the content of different phases in the internal matter and in the fusion crust of this fragment showed that ferric compounds resulted from olivine, pyroxene, and troilite combustion in the atmosphere.Keywords: Chelyabinsk LL5 ordinary chondrite, fragment with a light lithology, fusion crust, Mössbauer spectroscopy with a high velocity resolution. PACS: 76.80.+y, 91.65.Sn.

Mineralogy, petrology, chronology, and exposure history of the Chelyabinsk meteorite and parent body

“…These two areas indicate that the vein was entirely molten or superliquidus upon formation, and then quenched to multiple phases during the cooling. Maksimova et al (2014) and data for other unaltered or weakly altered LL ordinary chondrites (Fe 3+ /Fe ≤7%) are also plotted (Menzies et al 2005;Oshtrakh et al 2008Oshtrakh et al , 2014. close to their respective isochrons corresponding to young Ar-Ar plateau ages of 28.6 Ma ) and 312 Ma (plagioclase in this study).…”

“…Datum for Chelyabinsk light‐toned lithology from Maksimova et al. () and data for other unaltered or weakly altered LL ordinary chondrites (Fe 3+ /Fe ≤7%) are also plotted (Menzies et al. ; Oshtrakh et al.…”

Spinels in Meteorites: Observation Using Mössbauer Spectroscopy

“…Additionally, the fusion crust from Chelyabinsk LL5 fragment No 1a and the massive troilite inclusion from the Sikhote-Alin iron meteorite were removed and prepared as a powder for the study. Details of different samples preparation and characterization were described in [9][10][11][12][13][14][15].…”

“…The Mössbauer spectra were measured in transmission geometry with moving absorber in the cryostat and recorded in 4096 channels. To increase the signal-to-noise ratio in the complex spectra with the minor components, they were converted into 1024 channels by consequent summation of four neighboring channels to reach higher statistics and larger signal-to-noise ratio (details for each sample study are given in [9][10][11][12][13][14][15]).…”

“…Various studies of meteorite fusion crusts showed formation of magnetite Fe 3 O 4 , a spinel resulting from iron oxidation during combustion of the Fe-Ni-Co alloy [38,39]. We studied the fusion crust removed from ordinary chondrite Chelyabinsk LL5 fragment No 1a [10]. The XRD pattern of the fusion crust from Chelyabinsk LL5 fragment No 1a is shown in Figure 12a.…”