Characterization of Kemer L4 meteorite using Raman spectroscopy, X-ray diffraction, magnetization measurements and Mössbauer spectroscopy
A. A. Maksimova, E. V. Petrova, A. V. Chukin, M. S. Karabanalov, B.A. Nogueira, R. Fausto, M. Yesiltas, I. Felner, M. I. Oshtrakh
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy
Available online 20 July 2020, 118723
“Highlights
• Raman spectra of orthopyroxene in Kemer L4 indicate 13–20 mol% of ferrosilite.
• Kemer L4 ZFC curve shows two magnetic phase transitions for chromite at 62 and 52 K.
• Fe2+ occupancies of the M1 and M2 sites in silicates agree for XRD and Mössbauer data.”
“The bulk interior of Kemer L4 ordinary chondrite was characterized for the first time by means of optical spectroscopy, scanning electron microscopy with energy dispersive spectroscopy, Raman spectroscopy, X-ray diffraction, magnetization measurements and Mössbauer 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 Mössbauer spectroscopy data and appeared to be in a good agreement. The distribution coefficients KD and the temperatures of equilibrium cation distribution Teq were also evaluated for olivine and orthopyroxene from two independent techniques and were in a good consistence: KD = 1.77, Teq = 441 K (X-ray diffraction) and KD = 1.77, Teq = 439 K (Mössbauer spectroscopy) for olivine and KD = 0.10, Teq = 806 K (X-ray diffraction) and KD = 0.09, Teq = 787 K (Mössbauer spectroscopy) for orthopyroxene. The fusion crust of Kemer L4 was studied using X-ray diffraction, magnetization measurements and Mössbauer spectroscopy. Magnesioferrite and probably maghemite were found in the fusion crust in addition to other phases observed in the bulk interior.”
