恐龙蛋壳化石微区的元素组成与分布的质子探针研究

Trace element composition and distribution in micron area of dinosaur eggshell fossils determined by proton microprobe

使用扫描质子微探针及微束ＰＩＸＥ定量分析技术对我国广东南雄盆地晚白垩系地层中的病态恐龙蛋壳化石样品的微米区域内元素成分进行了测定和研究。结果表明，恐龙蛋壳微区内主要由Ｔｉ、Ｖ、Ｃｒ、Ｍｎ、Ｃｏ、Ｎｉ、Ｃｕ、Ｚｎ、Ａｓ、Ｒｂ、Ｓｒ、Ｙ、Ｚｒ、Ｓｂ、Ｂａ和Ｐｂ等微量元素组成，而它们的分布特征则不相同。其中，Ｃｒ、Ｍｎ、Ｎｉ、Ｃｏ、Ｃｕ、Ｚｎ、Ａｓ、Ｒｂ、Ｙ、Ｚｒ和Ｂａ的分布形式基本一致，主要分布在蛋壳的锥体层（近内表层）中；而Ｓｒ元素则主要分布在蛋壳的柱状层（近外表层）中。根据这些微量元素的含量及分布特征。

The scanning proton microprobe and micro-PIXE quantitative analysis technique have been used to determine composition and distribution of the trace elements in micron areas of dinosaur eggshell fossils from the stratum of Upper Cretaceous system at Nanxiong Basin in Guangdong Province, China. The study shows that the trace elements mainly include Ti, V, Cr, Mn, Co, Ni, Cu, Zn, As, Rb, Sr, Y, Zr, Sb, Ba and Pb in the micron area, but they present different distributions. While the element Sr is mainly enriched in the near surface layer, others mainly reside in the near inner layer. A preliminary discussion on the reason of the dinosaur extinction is given based on the above study.