岩层

例句：

1. 1. The geologist is analyzing therock layers in the area.
   地质学家正在分析该地区的岩石层。
2. 2. Themineral deposits are foundwithin the upper strata ofthe earth's crust.
   矿物矿床位于地球地壳上层。
3. 3. Theerosion process has removed many of theolder rock layers from the mountainside.
   侵蚀过程已经从山体上移除了许多较老的岩石层。