Carbonaceous-chondrite inclusions in the Kapoeta achondritic meteorite studied by Mössbauer spectroscopy

Yassir A. Abdu

Hyperfine Interactions, Volume 242, Article number: 5 (2021)
Published: 13 October 2021


“Kapoeta is an achondrite meteorite containing mm-sized carbonaceous-chondrite inclusions that are thought to have been incorporated into its parent body by carbonaceous-chondrite impactors (mainly CM “Mighei-type” material). Two different samples (A and B) of the Kapoeta carbonaceous-chondrite materials are studied by Mössbauer spectroscopy at room temperature. The Mössbauer spectra are fitted with a combination of Fe2+ and Fe3+ quadrupole doublets using a Voigt-based function. The spectrum of sample A shows two Fe2+ doublets and one Fe3+ doublet, with Fe3+ accounting for 64% of the total spectral area, and are ascribed to hydrated phyllosilicates. Sample-B spectrum, on the other hand, shows three doublets that are due to Fe2+ only, and are attributed mainly to amorphous silicates (predominantly dehydrated amorphous phyllosilicates) and presence of small amounts of olivine. The results are compared with published Mössbauer data on carbonaceous chondrites, and discussed in relation to aqueous alteration that occurred in their parent bodies and the thermal history the Kapoeta meteorite.”