STUDY OF EXTRA-SOLAR MATERIALS ON THE VIEW OF OXYGEN ISOTOPES

本项目研究了阿连德陨石中富Ca、Al包裹体的日外物质。主要内容如下：（1）利用电子探针分析仪对CAI矿物进行了浓度分布图的绘制。结果显示了矿物的结晶顺序。(2)A研制了一种用于二次离子质谱（西姆斯）的新型负金属离子源（BLAKE-V），用于CAI矿物氧同位素的精确分析。(3)A利用BLAKE-V离子源产生的Au-初级束，对CAI矿物进行了精确的氧同位素分析。（4）CAI矿物内氧同位素分布均匀，矿物间氧同位素分布不均匀。这种关系不能用矿物间的化学平衡来解释。（5）CAI的成因可以解释为：（a）CAI中的尖晶石晶粒是超新星遗迹中结晶形成的。（B）辉石颗粒产生于太阳星云和太阳星云最外缘的残骸之间的混合气体中。(c)In太阳星云过冷液析出，黄长石和钙长石在过冷液中结晶。

Extra-solar materials in Ca, Al-rich inclusions (CAIs) from Allende meteorite have been investigated in this projects. The project may be summarized as follows:(1)Concentration mapping of CAI minerals has been generated by electron micro probe analyzer. The results show crystallization sequences of the minerals.(2)A novel negative-metal ion source (BLAKE-V) for secondary ion mass spectrometry (SIMS) was developed for precise oxygen isotope analyses of CAI minerals.(3)A precise oxygen isotope analysis in CAI minerals was developed using the Au^- primary beam from the BLAKE-V ion source.(4)Oxygen isotope distribution was homogeneous in intra-mineral in CAI, whereas was quite heterogeneous among minerals. Such relationship cannot be interpreted by chemical equilibrium among minerals.(5)The origin of CAI may be interpreted as follows: (a)Spinel grains in CAIs ware crystallized in super novae remnant. (b)pyroxene grains were generated in the mixing gas between the solar nebula and the remnant at the most outer rim of the solar nebulae. (c)In the solar nebulae super cooling liquid was precipitated, and melilite and anorthite grains were crystallized in the liquid.