粘土层

例句：

1. 1. The engineer carefully excavated the clay layer to reveal the underlying structure.
   工程师小心翼翼地挖掘了粘土层，以揭示其下的结构。
2. 2. The construction crew was working on the clay layer, which was difficult to dig due toits compactness.
   建筑工人正在处理粘土层，由于其紧密性，挖掘起来很困难。
3. 3. The scientists used a drill to remove the clay layer and expose the mineral deposits underneath.
   科学家们使用钻机移除了粘土层，露出了下面的矿物沉积物。