The Phoenix Fold Those folded rocks consist of sandstones or mudstones. As you know, they are formed by sands and muds that flowed form a river mouth to deep sea ground and piled up with taking long-long times to be firm, and finally become rocks. Those rocks are called sedimentary rocks and they are normally flat unless they are having something strong pressure. This Phoenix Fold shows us unusual shape. Why? Because they had enormous pressure by submarine volcanic activity and crustal activity, before they have been firm in the deep sea and they forced to bend like present shapes. It is said that a incident occured about 30 million years ago. This bed has gradually lifted up by the tectonic movement and come up to the surface. This site is very famous for us to observe beautiful shape of the fold. Please imagine how the earth has made dynamic activity, seeing this Phoenix Fold.