The cliffs of chalk which line French Manche belong to the Cretaceous time and more exactly to the geological floors:

  • Cénomanien,
  • Turonien,
  • Coniacien,
  • Santonien,
  • Campanien.

These floors and their sub-floors are defined by the paleontology, that is by the fossil sorts which they contain.

Other methods of spatiotemporal cuttings are used:

  • The sequential stratigraphy,
  • The cyclostratigraphie,
  • The chemo-physical stratigraphy.