¹Martyna Jakubowska,¹Jolanta Gałązka-Friedman,²Marek Woźniak,³Krzysztof Szopa,⁴Katarzyna Brzózka,⁵Barbora Pospíšilová,⁶Agnieszka Grabias
Meteoritics & Planetary Science (in Press) Link to Article [https://doi.org/10.1111/maps.70122]
¹Faculty of Physics, Warsaw University of Technology, Warsaw, Poland
²Faculty of Biology, University of Warsaw, Warsaw, Poland
³Faculty of Natural Sciences, University of Silesia, Sosnowiec, Poland
⁴Faculty of Mechanical Engineering, Casimir Pulaski Radom University, Radom, Poland
⁵Faculty of Science, Palack´y University Olomouc, Olomouc, Czech Republic
⁶Łukasiewicz Research Network—Institute of Microelectronics and Photonics, Warsaw, Poland
Published by arrangement with John Wiley & Sons

The paper presents a modified version of the 4M method, which is the latest method of classifying ordinary chondrites, based on their Mössbauer spectra measured at room temperature. The proposed changes, including the introduction of a new criterion for assessing which group (H, L, or LL) the meteorite being tested belong to, are expected to improve the plausibility of classification by the 4M method. The modification makes use of the Bayesian analysis and the maximum a posteriori probability. This modified version of the 4M method was tested by attempting to classify 20 samples of ordinary chondrites: 8 of type H, 7 of type L, and 5 of type LL. The results were compared with those obtained by the classical method of ordinary chondrite classification. The vast majority of classification tests performed using the new version of the 4M method were consistent with the classical method for group assignment, except for one L-type sample that was classified differently. It was also shown that the introduction of a new criterion resulted in a significantly better agreement with the established classification than in the case of the level of similarity criterion used in the previous version of the 4M method.