The beds have been eroded out horizontally on the shore, J.Thomson / GNS Science
These sandstone and mudstone strata where laid down under the sea in a subsiding basin about 20,000,000 years ago. It is thought that the folding occurred when the sediments were still soft, by sliding of the sea floor. Geologists use the term anticline for an up-fold, and syncline for when the rocks are folded downwards.