The influence of sample thickness on results of Mössbauer spectroscopy of ordinary chondrites and their classification

Ordinary chondrites are the most frequently found type of meteorites (about 85% of all meteorites found). There are three types of ordinary chondrites: H, L and LL. They contain various amounts of iron (type H - high amount of iron, type L– low amount of iron, type LL– low amount of iron and low amount of metal). Typical Mӧssbauer spectrum of ordinary chondrite is composed of doublets associated with olivines and pyroxenes and sextets associated with troilite and FeNi alloy (such as kamacite and taenite). In 2019 Warsaw group elaborated a new method of classification of ordinary chondrites using the results of Mössbauer spectroscopy. This method, called 4M method, consists in calculating the similarity of the investigated sample to particular types of ordinary chondrites based on percentage of Mӧssbauer spectroscopy areas of four basic mineral phases: olivines, pyroxenes, metallic components, and troilites. The aim of our current study was to verify the hypothesis that the thickness of the investigated sample of ordinary chondrite has no effect on percentages of Mӧssbauer spectral areas associated with four main mineral phases present in ordinary chondrites. The results of our experimental study confirmed this hypothesis.