کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1775088 | 1021183 | 2008 | 11 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: A refractory Ca–SiO–H2–O2 vapor condensation experiment with implications for calciosilica dust transforming to silicate and carbonate minerals A refractory Ca–SiO–H2–O2 vapor condensation experiment with implications for calciosilica dust transforming to silicate and carbonate minerals](/preview/png/1775088.png)
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.
Journal: Icarus - Volume 195, Issue 1, May 2008, Pages 493–503