- See also: Dinosaurs of the Isle of Wight
The Isle of Wight is made up of a wide variety of different rock types ranging from Early Cretaceous times (around 127 million years ago) to the middle of the Palaeogene (around 30 million years ago). All the rocks found on the island are sedimentary, made up of mineral grains from previously existing rocks. These are all consolidated to form the rocks that can be seen on the island today, such as limestone, mudstone and sandstone. Rocks on the island are very rich in fossils and many of these can be seen exposed on the beaches as the cliffs erode.
Cretaceous rocks on the island, usually red, show that the climate was previously hot and dry. This provided suitable living conditions for dinosaurs. Dinosaur bones and footprints can be seen in and on the rocks exposed around the island's beaches, especially at Yaverland and Compton Bay.
Along the northern coast of the island there is a rich source of fossilised shellfish, crocodiles, turtles and mammal bones. The youngest of these dates back to around 30 million years ago.
The island is mainly made up of Tertiary clays, in most of the northern parts of the island, limestone, upper and lower greensands, wealden and chalk.