Raman characterization of carbonaceous matter in CONCORDIA Antarctic micrometeorites

摘要: We report a multi-wavelength Raman spectroscopy study of carbonaceous matter in 38 Antarctic micrometeorites (AMMs) from the 2006 CONCORDIA collection. The particles were selected as function their degree thermal alteration developed during deceleration atmosphere. These samples range unmelted (fine-grained-Fg; ultracarbonaceous-UCAMMs) to partially melted AMMs (scorias-Sc) and completely (cosmic spherules-CS). More than half analyzed contain substantial amount polyaromatic with high disorder. proportion where carbon is not detected increase Fg Fg-Sc Sc-AMMs, no CS. In addition, spectral characteristics G D bands Sc-AMMs plot apart trend formed by data Fg-AMMs UCAMMs. results suggest that oxidation processes occurred UCAMMs, reveal disorder matter, precluding long duration metamorphism on parent body suggesting have connection C1-C2 chondrites. parameters deuterium-rich UCAMMs do differ Fg-AMMs. Using 244 nm excitation, we cyanide (-CN) functional group for first time UCAMM, reinforcing likely cometary origin this type micrometeorites.