A Mossbauer study on Fe-bearing phases in Almahata sitta meteorite


Abbasher Mahmoud Gismelseed, University of Khartoum, Khartoum, Sudan

A newly fallen Sudanese meteorite named Almahata sitta have been studied using Mossbauer spectroscopy, X-ray diffraction (XRD) and electron microprobe analysis (EMPA). The Mössbauer measurements at 295 K and 78 K are in agreement with the XRD characterizations, showing at least one singlet assigned to taenite, two paramagnetic doublets which are assigned to olivine and pyroxene and magnetic sextet assigned to kamacite (hyperfine field ≈ 33.5 T). Using the Mossbauer data the relative abundance of each Fe-phase in the meteorite is identified and compared with the results obtained by mineralogical and petrographical studies.