"When rock is compressed and folded, the folds are anticlines and synclines. They are much like the components of the letter S. Roll an S forward on its nose and you have to the left a syncline ...

but the strata are folded into a subsidiary syncline (the Gwesyn syncline) and anticline (the Rhiwnant anticline), with their axes parallel to that of the main structure; that is, from south-west ...

Rocks that have been bent are what geologists call folded. Examples of a fold is a syncline and an anticline. Rocks that have been shifted upward, downward or against each other is known as a ...