|
|||||
|
|
A refractory Ca-SiO-H2-O2 vapor condensation experiment with implications for calciosilica dust transforming to silicate and carbonate minerals |
|
| Authors: | Frans JM Rietmeijer Aurora Pun Joseph A Nuth III |
| Institution: | a Department of Earth and Planetary Sciences, MSC03-2040, University of New Mexico, Albuquerque, NM 87131-0001, USA b Laboratory for Nano-Structure Science, Department of Physics, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu-shi, Shiga, 525-8577, Japan c Astrochemistry Laboratory, Solar System Exploration Division, Code 691, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA |
| Abstract: | Condensates produced in a laboratory condensation experiment of a refractory Ca-SiO-H2-O2 vapor define four specific and predictable deep metastable eutectic calciosilica compositions. The condensed nanograins are amorphous solids, including those with the stoichiometric CaSiO3 pyroxene composition. In evolving dust-condensing astronomical environments they will be highly suitable precursors for thermally supported, dust-aging reactions whereby the condensates form more complex refractory silicates, e.g., diopside and wollastonite, and calcite and dolomite carbonates. This kinetically controlled condensation experiment shows how the aging of amorphous refractory condensates could produce the same minerals that are thought to require high-temperature equilibrium condensation. We submit that evidence for this thermal annealing of dust will be the astronomical detection of silica (amorphous or crystalline) that is the common, predicted, by-product of most of these reactions. |
| Keywords: | Comets dust Disks Mineralogy Experimental techniques |
| 本文献已被 ScienceDirect 等数据库收录！ | |