The current meteorite taxonomy, the result of two centuries of research and meteorite tradition, intertwines with synthetic and genetic terms in a less than consistent manner, with some taxa (such as shergottites) representing diverse lithologies from a single putative main body while others (such as pallasites) accommodate relatively similar organisms of origins different to the solar system.
It is also difficult to empirically determine the familiar concept of a group as representative of a single, primary primary body. It is proposed that the classification become explicitly binary throughout the meteorite spectrum, with categories denoting the primary rock types identified by rocks, while groups retain a genetic meaning, but are no longer associated with any assumption as to the number of parent bodies represented.
Thus, the classification of the meteorite would include both a class and a group, in a two-dimensional manner similar to the way Van Schmeus and Wood separated primary and secondary properties in chondrites. Since the groups will not, initially, differ fundamentally from those currently used de facto, the taxonomic treatment of ordinary meteorites, the category of which will not bring new information, hardly changes.
However, categories combined with high- or low-level groups would provide a unified network for characterizing stony and/or unusual or theoretically anomalous meteorites (which make up the majority of the meteorite parent bodies represented) for example, with respect to the carbon/noncarbon split. In the long term, mergers of genetically related groups, more systematic manipulation of lithology mixtures, and chondrite/chondrite transition can simplify the nomenclature.
Comments: 21 pages, 4 numbers
Topics: Earth and Planetary Astrophysics (astro-ph.EP)
Cited as follows: arXiv: 2209.07377 [astro-ph.EP] (or arXiv: 2209.07377v1 [astro-ph.EP] for this version)
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Journal reference: Jacquet E. (2022). Meteoritics and Planets 57: 1774-1794
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Who: Emmanuel Jacquet
[v1] Thursday, September 15, 2022 15:44:09 UTC (1,181 KB)
Astrobiology, astronomy, astrochemistry