结果表明其由核心和叠层石包壳组成，具有核形石特有的结构和构造。

The structure and texture found in these nodules are characteristic of oncolite.

youdao

结果表明其由核心和叠层石包壳组成，具有核形石特有的结构和构造。

The structure and texture found in these nodules are characteristic of oncolite.

youdao