pebbly mudstone

例句：

1. 1.The riverbed is covered in pebbly mudstone.
   河床覆盖着砾石泥岩。
2. 2. This fossilized rock is a rare find in the region.
   这种化石岩石是该地区罕见的发现。
3. 3. The geologists are studying the properties of this pebbly mudstone.
   地质学家正在研究这种砾石泥岩的性质。