Experimental study of mineral production in primodal solar nebula

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1. Reproduction experiments of (100) plane defects in olivineSingle crystals of Fa_<100>, Fa_<90>, Fa_<80>, Fa_<70>, and Fa_<60> in Fayalit-Forsterite solid solition were grown by TSFZ method. Thin sections (010) of about 15 mum thickness were hydrothermally altered at condition of 300ﾟC,0.1Kbar and HM buffer using HCl 1N or NaOH 1N solution. Planar precipitates were produced along (001) or (100) of olivine in acidic condition or alkaline condition, respectively. Oriented precipitates complexes were composed of hematite and amorphous silica in acidic condition and hematite and laihunite in alkaline condition. I explaned these results by cation leaching mechanism during olivine is altered in aqueous oxidizing environment. This result means that C chondrite was altered in alkaline oxidizing condition. I gave oral presentaiton on these results at Annual Meeting of Mineralogical Society of Japan and published them in the International Journal of Physics and Chemistry of Minerals.2. Reprodu … More ction experiments of enstatite whiskers which are elongated in a-axisEnstatitet whiskers which are elongated in the crystallogaraphic a-axis were produced only a few, but surely, at 25mmHg, at condensation temperature of 1150 ﾟC-1100 ﾟC and in the duration time of 10 minutes. None was condensated at the temperature higher than 1150 ﾟC,and enstatite whiskers elongated in c-axis was condensated alone at lower temperature than 1100ﾟC.Enstatite whiskers elongated in a-axis can grow in some probability at high supersaturation (high temperature) because crystal can growth at any direction in these conditions. However, enstatite whiskers elongated only in c-axis grow at low supersaturation (low temperature), because only these whiskers which is the highest crystal growth rate at low temperature can grow. On the other hand, inverted twins were found in the enstatite whiskers elongated in a-axis produced in this experiment. Threfore, these enstatite whiskers might be grown in the protoenstatite stable region, while enstatite whiskers found in interplanetary dust are clinoenstatite without inverted twins, which must be grown metastably at low temperature. Less