alum shale

• 明矾页岩,明矾片岩,茂页岩

alum shale的用法和样例：

例句

1. The new process extracts oil from shale.
   这一新过程可从页岩里提炼出石油。
2. Thin layers of sandy shale, and carbonaceous fragments are locally present.
   局部出现砂质页岩薄层和碳质碎屑。