Host: The Japanese Society for Planetary Sciences: Local Organizing Committee for 2006 Fall Meeting
Some Antarctic Micrometeorites (AMMs) were studied non-destructively by infrared (IR) microspectroscopy for characterizing organic and hydrous components in these particles. Their IR spectra showed absorption peaks of OH (molecular water) at 3400 cm−1, aliphatic carbonaceous components at 2960 cm−1 for CH3 and 2925 and 2860 cm−1 for CH2. By using peak height ratios of CH3/CH2 (2960 cm−1/2925 cm−1) and OH/CH2 (3400 cm−1/2925 cm−1), aliphatic and hydrous component characters of AMMs can be quantitatively investigated. The CH3/CH2 and OH/CH2 ratios of AMMs are ranging 0.6-0.9 and 1-3, respectively. These ratios of AMMs are smaller than those of carbonaceous chondrites. In order to study effects of heating, an AMM was heated in-situ under the IR microscope in atmosphere at temperatures from room temperature (RT) to 600˚C. The peak height ratio of CH3/CH2 remained mostly unchanged from RT to 210˚C and increased from 210˚C to 300˚C. The OH/CH2 ratio decreased from RT to 210˚C and then increased greatly from 210˚C to 300˚C. Effects of aqueous altaeration on micrometeorites are now being studied by hydrothermal experiments on simulated mineral-organic compounds.
