country rocks

• 围岩

country rocks的用法和样例：

例句

1. Laminated siliceous rocks in country rocks might represent the nature of the Devonian hydrothermal sedimentary rocks.
   围岩中的层纹状硅质岩可能代表了泥盆纪时期的热水沉积岩性质。
2. The dolomite of Upper Sinian Dengying Formation is favorable ore-source rock and useful ore-preserving country rock.
   上震旦统灯影组碎裂状白云岩是有利的矿源层及有利的赋矿围岩。