In a syncline the youngest beds, the ones that were originally on top of the rest of the beds, are at the center, along the axis of the fold. Anticlines and synclines form in sections of the crust that are undergoing compression, places where the crust is being pushed together.

How synclines are formed?

Synclines are formed when tectonic plates move toward each other, compressing the crust and forcing it upward.

What causes a syncline?

Anticlines and synclines are caused when tectonic plates move together and compress the earth's crust between them.