A fold consist of two limbs, which are divided by an imaginary surface called axial plane. Will look like a rainbow (convex side up) Youngest rocks will be on the top. If you erode it, the outside are the youngest rocks, the middle is the oldest rocks. When you walk in a syncline and rocks are repeating. The oldest rocks are now on the outside and the youngest rocks are in the inside. Sometimes you have so much compression things get turned upside down. The simplest way, when you dissect, the axial plane can tilt. If it gets squished against something hard, it will flip over. In cordiara, you have that formation but it"s all tilted in the same direction. Folds often occur as alternating synclines and anticlines. They take up less horizontal space, you have crumpled. The top you have anticline on all sides. The middle is oldest cline in anticline structural dome.