Spectral nature of CO2 adsorption onto meteorites

Autor: Driss Takir, Genesis Berlanga, Elizabeth C. Sklute, Charles A. Hibbitts, M. Darby Dyar
Rok vydání: 2016
Předmět:
Zdroj: Icarus. 280:366-377
ISSN: 0019-1035
DOI: 10.1016/j.icarus.2016.06.020
Popis: Previous studies have identified carbon dioxide (CO 2 ) on the surfaces of jovian and Galilean satellites in regions of non-ice material that are too warm for CO 2 ice to exist. CO 2 ice would quickly sublimate if not retained by a less-volatile material. To ascertain what non-ice species may be responsible for stabilizing this CO 2 , we performed CO 2 gas adsorption experiments on thirteen powdered CM, CI, and CV carbonaceous chondrite meteorites. Reflectance spectra of the ν 3 feature associated with adsorbed CO 2 near 4.27 µm were recorded. Results show that many meteorites adsorbed some amount of CO 2 , as evidenced by an absorption feature that was stable over several hours at ultra-high vacuum (UHV) and high vacuum, (1.0 × 10 −8 and 1.0 × 10 −7 Torr, respectively). Ivuna, the only CI chondrite studied, adsorbed significantly more CO 2 than the others. We found that CO 2 abundance did not vary with ‘water’ abundance, organics, or carbonates as inferred from the area of the 3-µm band, the 3.2–3.4 µm C–H feature, and the ∼3.8-µm band respectively, but did correlate with hydrous/anhydrous phyllosilicate ratios. Furthermore, we did not observe CO 2 ice because the position of the CO 2 feature was generally shifted 3–10 nm from that of the 4.27 µm absorption characteristic of ice. The strongest compositional relationship observed was a possible affinity of CO 2 for total FeO abundance and complex clay minerals, which make up the bulk of the CI chondrite matrix. This finding implies that the most primitive refractory materials in the Solar System may also act as reservoirs of CO 2 , and possibly other volatiles, delivering them to parts of the Solar System where their ices would not be stable.
Databáze: OpenAIRE
Externí odkaz: