用仪器中子活化分析研究岩庄陨石元素宇宙化学特征

A Preliminary Study on the Cosmochemical Characteristics of Elements in the Yanzhuang Meteorites by INAA

用中子活化分析测定了新陨岩庄陨石的主量和微量元素含量。陨石浅灰色相的微量元素化学特征与Ｈ６型相似。金属粒子中稀土元素相对富集，有非常明显的Ｅｕ正异常，与Ｈ６型比较以低的Ｂｒ，Ｚｎ含量和高的Ｆｅ、Ｎｉ、Ｉｒ、Ａｕ丰度为其特征。讨论了岩庄陨石在微重力影响下，微量元素宇宙化学特征与太空八面体Ｆｅ－Ｎｉ金属四同心环微晶体结构生长可能的内在联系。

The contents of the major and trace elements in the Yanzhuang meteorites have been determined by instrumental neutron activation analysis(INAA).The grey phase of the Yanzhuang meteorites and the H6-type meteorites have extremely similar trace element characteristics.In the Fe-Ni metallic phase, the rare-earth elements are enriched with significantly positive anomalies. As compared with the H6 type,the Yanzhuang meteorites are characterised by their lower content of Br & Zn and their higher abundance of Fe, Ni, Ir & Au. All these characteristics suggest that the four concentric-ring micro-crystallites growth patterns in the octahedron Fe-Ni metal phase might have some possible connection with the cosmochemical characteristics of the trace elements concerned during the nucleation and crystallisation processes under the micro gravity in space.