Experimental Simulation of Planetary Formation Processes

为了研究地球和其他行星的早期历史，我们于1991年在东京理工学院地球和行星科学系安装了一台单轴多砧式高压装置(SPI-1000)。用SPI-1000对地幔橄榄岩进行了非常详细的实验熔融研究。测定了17 Gpa和2300℃以下的液固相线。这相当于大约500公里深的陆地岩浆海洋。这项研究得到了世界各国科学家的高度评价。在1992年8月京都国际地质大会、1992年3月伦敦皇家学会专题讨论会和1993年秋季美国地球物理联合会上发表了应邀论文。用SPI-1000研究了金属氢化铁(FeH)的熔化温度，最高可达10 GPa.在5 Gpa下的最高温度被确定为1200℃。这与Fukai等人(1993)的原位X射线观测结果符合得很好。此外，我们还发现，熔化温度随着压力的增加而降低(即800℃。C.在10 GPA下)。我们的实验表明，如果有大量的铁原子参与，地球中心的温度可能会比正常情况下低得多。

In order to study the early history of the Earth and other planets, we have installed an uniaxial multi-anvil type high pressure apparatur (SPI-1000) at the Earth and Planetary Sciences Department, Tokyo Institute of Technol ogy using the above grant in 1991.A very detailed experimental melting study on earth's mantle peridotite has been carried out with SPI-1000. Liqui dus and solidus curves were determined up to 17 GPa and 2300 deg. C which is equivalent ot approximately 500 km depth of the terrestrial magma ocean. This study has been highly appreci at ed from the world scientists. Invited papers were present ed at the International Geological Congress, Kyoto Autust 1992, at the Royal Society of London Special Symposium, March 1992 and at the American Geophysical Union, 1993 Fall Meting.Melting temperature of iron metal hydride (FeH) was studied using the SPI-1000 up to 10 GPa. The metig temperatre at 5 GPa was determined to be 1200 deg. C.which is in well accordance with the insitu-X-ray observation by Fukai et al (1993). In addition, we discovered that the melting temperature lowers with increasing pressure (i.e., 800 deg. C.at 10 GPa). Our experiments imply that the temperature f the earth's cre might be much lower than revusly thught if substantial amount of FeHis incororated.