Study Of Petrology And Mineralogy Of Seymchan Meteorite From Russia

Seymchan meteorites, which contain high degree of crystallinity olivine and Fe- Ni metal, are typical palasites, and it is one of the most beautiful meteorites varieties. There are few current domestic researches on palasites. And this essay discuss the structure and composition characteristics of iron metal and olivine in Seymchan meteorites by using electron microprobe, scanning electron microscopy(SEM), LA-ICP-MS, X-ray powder diffraction. And this essay also discuss the thermal evolution history of Seymchan meteorite’s parent body and how to identify Seymchan meteorite.Through the gemological research, the hardness of olivine in Seymchan meteorites is average 8-9. Filament-like inclusions in olivine and pyrrhotite inclusions suggests the peridot formed in the environment of high temperature and relatively saturated. And this infers that the formation of filament-like inclusion is the experience of the meteorite’s parent body impact event.The microstructure of kamacite is similar to the arranged cloud layer, and it is tightly packed between layer and layer. The microstructure of taenite is similar to strip of metal particles in non-directional accumulation.Through study on mineral composition, the main mineral in Seymchan meteorites are olivine, kamacite and taenite. Olivine in Seymchan meteorites is peridot, its chemical characteristics and the olivine from fresh lithospheric mantle is consistent. Olivine in meteorites is influenced by sulfide solution, the content of NiO % is negatively related with the value of Fo, and this is not the same with peridot from the earth’s mantle.Using the LA-ICP-MS, we can test the trace elements from metal parts in Seymchan meteorites. We can conclude the distribution of Cr in Seymchan meteorites is uneven. We measured concentration range of Ga and Ge, and found that the formation of metal parts in Symchan meteorites is the experience of magma or fire into the role of iron meteorite.The identification of the meteorite are observing the appearance characteristics, using scientific instrument to determine the mineral composition, and coupled with the structure between minerals.