Comparison of bulk interior and fusion crust of Chelyabinsk LL5, Ozerki L6 and Kemer L4 ordinary chondrite fragments using X-ray diffraction and Mössbauer spectroscopy

Fragments of Chelyabinsk LL5 No 1a and 2a, Kemer L4 and Ozerki L6 ordinary chondrites covered with the fusion crust were studied by X-ray diffraction (XRD) and Mössbauer spectroscopy. In addition, Kemer L4 and Ozerki L6 were studied by magnetization measurements. These results were analyzed for comparison of the bulk interior and the fusion crust in these meteorites. XRD showed the main and minor iron-bearing phases variations between both the bulk interior and the fusion crust in these meteorite fragments. Magnetization measurements of the bulk interior showed the magnetic phase transitions in chromite and hercynite in Ozerki L6 and Kemer L4 and different saturation magnetization moments for two meteorites as well as its decrease for the fusion crust from both fragments. Mössbauer spectra of the bulk interior and the fusion crust from Chelyabinsk LL5 No 1a and 2a, Kemer L4 and Ozerki L6 showed some differences in the numbers and contents of iron-bearing phases, small variations in the 57 Fe hyperfine parameters in the same iron-bearing phases from different ordinary chondrites. Some differences in the Fe 2+ occupations of the M1 and M2 sites in silicate crystals as well as variations in the temperatures of cation equilibrium distribution between these sites in olivine and orthopyroxene in the bulk interior were determined based on XRD and Mössbauer data.