摘要
在30kbar压力下进行了肇东陨石的加热-熔融实验。实验结果表明。从840℃至2050℃,陨石中的金属-硫化物相经历了熔融—两相混溶的过程,最终形成一种Fe、Ni、Co、S之比不相等的多相混合物。而陨石中的硅酸盐相经历了热变质—熔融—熔融分异的过程。初熔温度为1610℃,2050℃时熔体发生分异,有富Si、Al的硅酸盐新相分离出来。以上述结果为依据,本文对类地行星早期层圈构造的形成机制进行了探讨和推论。
The heating-melting experiments of Zhaodong chondrite were carried at 30 kbar and various temperature from 840℃ to 2050℃. A YJ-3000 ton press fitted with a wedge-type cubic anvil was employed for all experiments. The experimental products show that this chondrite heated, at first metal and sulphide melt and form aggregate with eutectic texture. When temperature going up 1610℃,the eutectic texture disappears and element-exchange occurs in the two phases. At last, metal and sulphide form a mixture of polyphase with different proportion of Fe, Co, Ni and S. At the same time, silicate of sample suffered a process of thermal-metamorphism, melting to melting-fractionation. The melting temperature of silicate phase is 1610℃. At 2050℃, fractionation occurs in melt of silicate and a new Si-Al-rich phase separates from original melt. Based on above result, the differentiation and evolution of early terrestriaI planets may be inferred. The initial stage of primitive terrestrial planets heated,melting metal-sulphide separated from silicate phase and sinked into the center of planets. When reaching the core of planets, the metal-sulphide became into miscible state in macrocosm. The immiscibility of two different types of silicate phase suggests that Si-and Al-rich magma could derived from original mantle of terrestrial planets and formed initial crust. The result of experiment shows the temperature of melting fractionation of their crust-mantle at least is-higher than 2000℃.
出处
《岩石学报》
SCIE
EI
CAS
CSCD
北大核心
1989年第2期1-8,共8页
Acta Petrologica Sinica
基金
国家自然科学基金
关键词
球粒陨石
高温高压
熔融实验
Chondrite
High pressure and high temperature
Meltingexperiment
Terrestrial planet
