Shock wave-induced interaction between meteoritic iron and silicates

The possibility of shock wave-induced interaction between meteoritic iron was estimated based on the results of experiments on the shock wave loading of mixtures of kamacite from the Sikhote Alin iron meteorite with quartz, albite, oligoclase, enstatite, olivine, and serpentine. The experimental samples were then examined with the application of optical microscopy, microprobe analysis, and Mössbauer spectroscopy. As a result of shock wave load, the metal was proved to become enriched in Si, while the quartz, albite, and oligoclase melted glasses acquired bivalent Fe ions. The products of our experiments with quartz and feldspar mixtures with kamacite were determined to contain paramagnetic metallic iron, and the surroundings of iron atoms in the silicate constituent of the olivine and enstatite mixtures with kamacite become locally more heterogeneous. Our results indicate that shock waves induce redox reactions between Fe and silicates according to the scheme 2Fe+2 + Si+4 = 2Fe+2 + Si0, where Fe0 and Si0 are iron and silicon in metal and Fe+2 and Si+4 are iron and silicon in the sillimanite matrix.