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The amino acid and hydrocarbon contents of the Paris meteorite: Insights into the most primitive CM chondrite
Author(s) -
Martins Zita,
Modica Paola,
Zanda Brigitte,
d'Hendecourt Louis Le Sergeant
Publication year - 2015
Publication title -
meteoritics and planetary science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.09
H-Index - 100
eISSN - 1945-5100
pISSN - 1086-9379
DOI - 10.1111/maps.12442
Subject(s) - chondrite , meteorite , chemistry , parent body , carbonaceous chondrite , aqueous solution , hydrocarbon , mass spectrometry , astrobiology , organic chemistry , chromatography , physics
Abstract The Paris meteorite is one of the most primitive carbonaceous chondrites. It is reported to be the least aqueously altered CM chondrite, and to have experienced only weak thermal metamorphism. We have analyzed for the first time the amino acid and hydrocarbon contents of this pristine meteorite by gas chromatography–mass spectrometry ( GC – MS ). When plotting the relative amino acids abundances of several CM chondrites according to the increasing hydrothermal scale (petrologic subtypes), from the CM 2.7/2.8 Paris to the CM 2.0 MET 01070, Paris has the lowest relative abundance of β‐alanine/glycine (0.15), which fits with the relative abundances of β‐alanine/glycine increasing with increasing aqueous alteration for CM chondrites. These results confirm the influence of aqueous alteration on the amino acid abundances and distribution. The amino acid analysis shows that the isovaline detected in this meteorite is racemic ( d / l = 0.99 ± 0.08; l ‐enantiomer excess = 0.35 ± 0.5%; corrected d / l = 1.03; corrected l ‐enantiomer excess = −1.4 ± 2.6%). The identified hydrocarbons show that Paris has n ‐alkanes ranging from C 16 to C 25 and 3‐ to 5‐ring nonalkylated polycyclic aromatic hydrocarbons ( PAH s). The lack of alkylated PAH s in Paris seems to be also related to this low degree of aqueous alteration on its parent body. The extraterrestrial hydrocarbon content, suggested by the absence of any biomarker, may well have a presolar origin. The chemistry of the Paris meteorite may thus be closely related to the early stages of the solar nebula with a contribution from interstellar (molecular cloud) precursors.