Raman characterization of carbonaceous matter in CONCORDIA Antarctic micrometeorites
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 a function of their degree of thermal alteration developed during the deceleration in the atmosphere. These samples r...
Published in: | Meteoritics & Planetary Science |
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Main Authors: | , , , , |
Other Authors: | , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
HAL CCSD
2011
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Subjects: | |
Online Access: | https://hal.in2p3.fr/in2p3-00634834 https://doi.org/10.1111/j.1945-5100.2011.01235.x |
Summary: | 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 a function of their degree of thermal alteration developed during the deceleration in the atmosphere. These samples range from unmelted (fine-grained-Fg; ultracarbonaceous-UCAMMs) to partially melted AMMs (scorias-Sc) and completely melted particles (cosmic spherules-CS). More than half of the analyzed AMMs contain a substantial amount of polyaromatic carbonaceous matter with a high degree of disorder. The proportion of particles where carbon is not detected increase from the Fg to the Fg-Sc and to the Sc-AMMs, and no carbon is detected in CS. In addition, the spectral characteristics of the G and D bands of the carbonaceous matter in Sc-AMMs plot apart from the trend formed by the data from Fg-AMMs and UCAMMs. These results suggest that oxidation processes occurred during the deceleration of the particles in the atmosphere. In Fg-AMMs and UCAMMs, the spectral characteristics of the G and D bands reveal the high degree of disorder of the carbonaceous matter, precluding a long duration thermal metamorphism on the parent body and suggesting that AMMs have a connection with C1-C2 chondrites. The Raman parameters of the deuterium-rich carbonaceous matter of UCAMMs do not differ from that of Fg-AMMs. Using a 244 nm excitation, we detected the cyanide (-CN) functional group for the first time in a UCAMM, reinforcing the likely cometary origin of this type of micrometeorites. |
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