Characterization of Kemer L4 meteorite using Raman spectroscopy, X-ray diffraction, magnetization measurements and Mossbauer spectroscopy
Özet
The bulk interior of Kemer L4 ordinary chondrite was characterized for the first time by means of optical microscopy, scanning electron microscopy with energy dispersive spectroscopy, Raman spectroscopy, X-ray diffraction, magnetization measurements and Mossbauer spectroscopy with a high velocity resolution. The main and minor iron-bearing phases were found as well as ferrihydrite as a result of weathering. The Fe2+ partitioning among the M1 and M2 sites in olivine, orthopyroxene and clinopyroxene was determined from the X-ray diffraction. The ratios of Fe2+ occupancies for these crystals were estimated from both X-ray diffraction and Mossbauer spectroscopy data and appeared to be in a good agreement. The distribution coefficients K-D and the temperatures of equilibrium cation distribution T-eq were also evaluated for olivine and orthopyroxene from two independent techniques and were in a good consistence: K-D = 1.77, T-eq = 441 K (X-ray diffraction) and K-D = 1.77, T-eq = 439 K (Mossbauer spectroscopy) for olivine and K-D = 0.10, T-eq = 806 K (X-ray diffraction) and K-D = 0.09, T-eq = 787 K (Mossbauer spectroscopy) for orthopyroxene. The fusion crust of Kemer L4 was studied using X-ray diffraction. magnetization measurements and Mossbauer spectroscopy. Magnesioferrite and probably maghemite were found in the fusion crust in addition to other phases observed in the bulk interior. (C) 2020 Elsevier B.V. All rights reserved.
