All sedimentary rocks are horizontal when first laid down. In instable regions of crust, the stratas have been folded, squeezed and fractured, processes collectively called deformation. The way in which rocks deform under stress is determined by their composition, the temperature and pressure under which they are confined, the pressure of water contained in pores in the rock and strain, that is the amount by which the rock is compressed in a given time.

Place : La Mort Anglaise’s upfold in Camaret