火成岩和变质岩比较致密,通常是结晶性的,颗粒之间很少有空隙。
However, even igneous and metamorphic rocks may act as groundwater reservoirs if extensive fracturing occurs in such rocks and if the fracture system is interconnected.然而,如果火成岩和变质岩中发生大规模的断裂,并且断裂系统相互连通,那么它们也可以作为地下水储集层。
Some very ancient sediments were no longer recognizable, having been converted to igneous and metamorphic rocks in the course of mountain building.在造山的过程中,一些非常古老的沉积物已被转化为火成岩和变质岩,已经无法辨认了。