Article

Analytical results for the material of the Chelyabinsk meteorite

Geochemistry International (Impact Factor: 0.58). 07/2013; 51(7). DOI: 10.1134/S0016702913070100

ABSTRACT

This paper presents the results of the mineralogical, petrographic, elemental, and isotopic analysis of the Chelyabinsk meteorite and their geochemical interpretation. It was shown that the meteorite can be assigned to LL5-group ordinary chondrites and underwent moderate shock metamorphism (stage S4). The Chelyabinsk meteorite contains a significant fraction (approximately one-third by volume) of shock-melted material similar in composition to the main volume of the meteorite. The results of isotopic analysis suggest that the history of meteorite formation included an impact event approximately 290 Ma ago.

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Available from: M. A. Nazarov
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    • "The chemistry of Chelyabinsk chromite is typical for LL chondrites (Wlotzka 2005). Other details on petrography and mineralogy of the Chelyabinsk meteorite can be found in Galimov et al. (2013). Preliminary mineralogical studies indicate that taenite/ kamacite ratio in the metallic phase of the Chelyabinsk chondrite is approximately 4 (e.g., 20 wt% kamacite versus 80 wt% taenite). "

    Full-text · Dataset · Dec 2015
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    • "sure, and x Оl , x Рx , x Рl , x Тr , and x Мe are the weight fracc tions of these phases in the Chelyabinsk meteorite, which were borrowed from (Galimov et al., 2013). In our calculations, we have used the Hugoniots of nickelliron Fe 90 Ni 10 , pyrrhotite, olivine Fo 92 (Ahrens and Johnson, 1995a, 1995b), enstatite (Marsh, 1980), and oligoclase (Ahrens et al., 1969). "
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    ABSTRACT: The Chelyabinsk meteorite (which fell on February 15, 2013) is a LL5 chondrite of shock stage S4, whose fragments are classified into light and dark lithologies. According to the intensity of their shock metamorphism, light lithology fragments are subdivided into two groups, which were affected by peak pressures within the ranges of 20-25 and 25-30 GPa, respectively. The material of the dark lithology was shocked at 25-30 GPa but was then annealed, which resulted in a decrease in the discernible degree of shock metamorphism. Black veins cutting across both the light and the dark lithologies and impact melt dikes in the dark lithology were produced by friction melting along boundaries of blocks that had been generated by fragmentation in a shock wave. The impact melt of the dikes is slightly enriched in Si, Al, Ca, Na, and K and has an oxygen isotopic composition similar to the chondrite matrix. It is thought that black vein melt started to crystallize in a rarefaction wave. Melt in the dikes and the central portions of the black veins crystallized after total pressure release. Heating of material hosting the melt dikes resulted in its blackening and annealing of its shock metamorphic features. The Hugoniot obtained for the Chelyabinsk meteorite was utilized to calculate the post-shock and shock temperatures within a broad pressure range. According to these evaluations, the meteorite was heated for 65-135 degrees during the impact event. The melting of the LL chondrite started at a load of approximately 100 GPa because of the high “equilibrium” post-shock temperatures, and a pressure of 140 GPa resulted in the complete melting of the material.
    Full-text · Article · Mar 2015 · Petrology
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    • "It is natural to assume that a larger parent body could have been disrupted at Sun-grazing conditions. The recovered fragments of the Chelyabinsk meteorite contain significant portions of shock blackened material and melt veins (Galimov et al., 2013; Kohout et al., 2014; Ozawa et al., 2014) that could be produced in the Sun atmosphere (a temperature of the shock-melt vein matrix formation is estimated over 1700-2000º C in (Ozawa et al., 2014)). "
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    ABSTRACT: The orbit of the Chelyabinsk object is calculated, applying the least-squares method directly to astrometric positions. The dynamical evolution of this object in the past is studied by integrating equations of motion for particles with orbits from the confidence region. It is found that the majority of the Chelyabinsk clones reach the near-Sun state. Sixty-seven percent of these objects have collisions with the Sun for 15 Myr in our numerical simulations. The distribution of minimum solar distances shows that the most probable time for the encounters of the Chelyabinsk object with the Sun lies in the interval from −0.8 Myr to −2 Myr. This is consistent with the estimate of a cosmic ray exposure age of 1.2 Myr (Popova et al. 2013). A parent body of the Chelyabinsk object should experience strong tidal and thermal effects at this time. The possible association of the Chelyabinsk object with 86039 (1999 NC43) and 2008 DJ is discussed.
    Full-text · Article · Nov 2014
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