The other is concave upward with younger rocks of Silurian shale and siltstone toward the center of curvature. The former is called anticline and the latter syncline. The sides of the folds are known as limbs,
英
美
- 而另一個(gè)褶曲向上凹，較新的志留系頁(yè)巖和砂巖位于彎曲的中心部位，前者被稱(chēng)為背斜，后者則稱(chēng)之為向斜，褶皺核部?jì)蓚冉凶鲴薨櫟囊聿俊?/strong>
