| Popis: |
The thermal, adsorption, and, in particular, the water-bearing properties of the CI-type meteorite Orgueil as an example of early preplanetary matter have been studied by quantitative sorption experiments with H 2 O, CO 2 , N 2 , and n -heptane, thermogravimetry/differential scanning calorimetry as well as by coupled thermogravimetry/mass spectroscopy. The study contributes to a detailed examination of the behavior of volatile species in carbonaceous chondrites and could support future surface missions on asteroids. The results confirm the presence of phyllosilicates, sulfates, carbonates, and presumably carbon in Orgueil. The decomposition fragments observed during the thermoanalytical experiment indicate somewhat lower temperatures of decomposition for the sulfates. The nature of the distinct partial step around 970 K interpreted in terms of a carbon release remains uncertain. The adsorption measurements and thermogravimetric investigations suggest the presence of water-bearing Earth-like minerals such as phyllosilicates. The specific N 2 BET surface area is 30 m 2 /g. The total water quantity present in Orgueil may exceed 10 wt%. At least half of this amount (as a minimum) is very strongly bonded in the water/OH bearing phases of Orgueil. |
Full Text from ScienceDirect