JOHN HESELTINE / SCIENCE PHOTO LIBRARY JOHN HESELTINE / SCIENCE PHOTO LIBRARY
Chalk cliffs, with a sandy beach in the background. Chalk was laid down between approximately 100 million and 65 million years ago, during the second half of the Cretaceous period. It is composed chiefly of the remnants of coccoliths, unicellular lime-secreting algae, and covers a wide area in Europe. Cliffs such as these are a rich source of fossils.
Model release not required. Property release not required.