ferruginous limestone

例句：

1. 1. The ancient city is covered with a layer of ferruginous limestone that dates back to the Neolithic period.
   这个古城被一层覆盖着的赤铁矿石灰石所覆盖，可以追溯到新石器时代。
2. 2. The construction site was littered with large blocks of ferruginous limestone, which were difficult to move.
   施工现场到处都是大块的赤铁矿石灰石，很难移动。
3. 3. The local geologists are studying the ferruginous limestone formations in hopes of discovering newminerals.
   当地的地质学家正在研究赤铁矿石灰石的形成，希望发现新的矿物。