Evaporation Experiments on Planetary Materials.

行星材料的蒸发实验。

基本信息

批准号：
07454132
负责人：
TSUCHIYAMA Akira
金额：
$ 4.48万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07454132/
关键词：
evaporation condensation metallic iron troilite solicate melts chondrules primordial solar nebula kinetics 鉱物脱水

项目摘要

It has been believed that evaporation and condensation processes playd important roles in differentiation of materials during the formation of the solar system. The following results were obtained in the present project in relation to the above topics.(1) Experimental techniques for exactly obtaining time variation in the amounts of evaporation and condensation by using ultra-high temperature thermal balance to discuss their kinetics strictly were developed. First of all, dehydration experiments on hydrous silicate minerals and glass were carried out, and it was confirmed that kinetics of dehydration, wthich is regarded as incongruent evaporation of water, can be discussed by time variation in the amouts of dehydration. Evaporation experiments of alkalies (Na and K) on silicate melts were carried out at low pressures, and the evaporation rates were successfully obtained.(2) A new model on evaporation of Na from silicate melts and origin of chondrules was proposed. It was shown that chondrule formation is possible not only by open-system flash heating mechanism which has been proposed previously but by closed-system gradual heating. This gave a new viewpoint on the chondrule formation issue.(3) Evaporation experiments on Fe-S minerals (metallic iron and troilite) were done, and their kinetics (modes and rates) were obtained. Evaporation rates of these minerals in the primordial solar nebula were estimated based on the present results, and the Fe/S fractionation in the primordial solar nebula was discussed by combining a model for formation of a protoplanetary disk with the evaporation data.

人们认为，在太阳系形成过程中，蒸发和凝结过程在材料的区分中发挥了重要作用。（1）通过使用超高温度热平衡严格地讨论其动力学的实验技术，在本项目中获得了以下结果。首先，对硅酸盐矿物质和玻璃进行了脱水实验，并证实，可以通过脱水的时间变化来讨论脱水的动力学。在低压下进行了硅酸盐熔体上碱（Na和k）的蒸发实验，并成功获得了蒸发速率。（2）提出了一种新的关于Na蒸发从硅酸盐熔体蒸发的模型，并提出了软骨的起源。结果表明，软骨形成不仅可以通过先前提出的开放系统闪光加热机制，而且可以通过闭合系统逐渐加热来形成。这给出了关于软骨形成问题的新观点。（3）完成了Fe-S矿物质（金属铁和Trolite）的蒸发实验，并获得了它们的动力学（模式和速率）。根据目前的结果估算了原始太阳星云中这些矿物质的蒸发率，并通过结合形成原行星磁盘的模型与蒸发数据来讨论原始太阳星云中的Fe/S分馏。