Non-destructive deep-UV Raman mapping of C ≡ N-bearing functional-group bands in Tagish Lake meteorite: Implications for a new primitive class of meteorites
Josephine C. Di Maurizio, Elizabeth A. Lymer, Michael G. Daly, Kim Tait, Haley M. Sapers, Joseph Razzell Hollis, Emmanuel A. Lalla
Icarus, available online 5 November 2026
“Highlights
- UV Raman spectroscopy detects C ≡ N-bearing functional groups in the Tagish Lake meteorite using a non-destructive, cryogenic, inert-gas analytical setup.
- C ≡ N-region Raman bands exhibit spatial heterogeneity, appearing as localized hotspots within individual pixels rather than uniformly across the fragment.
- Representative spectra (e.g., pixel P135) show true co-location of C ≡ N bands with carbon D/G and Csingle bondH features, confirming pixel-scale chemical associations.
- Deep-UV Raman mapping reveals complex organic signatures in Tagish Lake consistent with previously reported low amino acid abundances and heterogeneous aqueous alteration.
- The approach demonstrates the feasibility of non-destructive UV Raman mapping for identifying C ≡ N-bearing functional groups in fragile carbonaceous meteorites and supports future application to returned asteroid samples.”
“The detection of C ≡ N functional groups in the Tagish Lake meteorite suggests the previously ungrouped carbonaceous chondrite may provide additional context for understanding the primitive nature of this ungrouped carbonaceous chondrite. Cyano-bearing molecules are one of the most important precursors for the synthesis of amino acids, and a critical step in furthering our understanding of early Earth conditions prior to widespread biological activity. The presence of cyano-molecules within 2D Raman maps is consistent with previously reported low amino acid abundances in Tagish Lake relative to other carbonaceous chondrites, suggesting the parent body did not undergo extensive amino acid-generating reactions and therefore most likely represents a uniquely primitive member among type-2 meteorites, indicative of limited aqueous alteration. Here, we describe the first spatial analysis and mapping of Raman bands consistent with C ≡ N-bearing functional groups in the Tagish Lake meteorite. This research provides a potential criterion for identifying the primitive feedstock for molecular synthesis on early Earth and insight into the earliest geochemical conditions in our Solar System capable of producing the important functional groups relevant to prebiotic chemistry. Finally, these qualitative, non-destructive 2D Raman maps show that C ≡ N bearing bands exhibit spatial heterogeneity within the Tagish Lake fragment.”
