prize9-5, Exercise 1: Anticline and syncline

Model answer (check the details):

An anticline is an arch: the layers dip away from a central line (the axis). A syncline is a trough: the layers dip toward the axis.

On a map, where erosion has cut across the folds, an anticline normally shows the oldest rocks along the middle, with progressively younger rocks outward on both sides. A syncline shows the youngest rocks in the middle, with older rocks outward. Dip symbols point away from the axis in an anticline and toward it in a syncline.

Care: in overturned folds the age order can be reversed, so check with other evidence such as fossils or sedimentary features that show which way was up.