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。
3
Both, they found, are capable of fracturing a skull.