The site spans 185 million years of geological history, coastal erosion having exposed an almost continuous sequence of rock formation covering the Triassic, Jurassic and Cretaceous periods. At different times, this area has been desert, shallow tropical sea and marsh, and the fossilised remains of the various creatures that lived here have been preserved in the rocks.

Natural features seen on this stretch of coast include arches, pinnacles and stack rocks. In some places the sea has broken through resistant rocks to produce coves with restricted entrances and, in one place, the Isle of Portland is connected to the land by a barrier beach. In some parts of the coast, landslides are common. These have exposed a wide range of fossils, the different rock types each having its own typical fauna and flora, thus providing evidence of how animals and plants evolved in this region.

The area around Lulworth Cove contains a fossil forest, and 71 different rock strata have been identified at Lyme Regis, each with its own species of ammonite. The fossil collector Mary Anning lived here and her major discoveries of marine reptiles and other fossils were made at a time when the study of palaeontology was just starting to develop. The Charmouth Heritage Coast Centre provides information on the heritage coast, and the whole length of the site can be visited via the South West Coast Path.

What makes the geology here so special?
Earth’s history collectively make up the Mesozoic Era, running from approximately 250 to 65 million years ago. Rocks that offer an almost complete record of that entire time are spread out along the Jurassic Coast, a bit like the pages of a book.

Here’s the short version of their story… 252 million years ago: This area of the Earth’s crust was stretching and sinking. As it sank, layers of sediment piled one on top of the other to form rocks.

First, in baking deserts during the Triassic Period (252 – 201 million years ago)…and then in the Jurassic period (201 – 145 million years ago), sea levels rose and transformed the deserts into a tropical sea.

Finally, as the sea levels fell by the end of Jurassic Period, a forest grew and subsequently died, and were buried beneath the sediments of lagoons, swamps, and rivers. This marked the start of the Cretaceous Period (145 – 66 million years ago).

During this Period, earth movements tilted the rock layers to the east. The top layers of rock that were pushed upwards in the western end of the coast were eroded. Soon, the sea rose again and during the rest of the Cretaceous sandstone and Chalk were laid down across the region, burying the tilted layers of older rock. Since then, erosion has carved this remarkable rock record into the landscape we see today.

Through this coastline’s unique geology, visitors can understand the profound environmental changes that occur across millions of years of time. The fossils of strange and terrifying extinct creatures that tumble from its cliffs have the potential to change the way we see the world. And out of its rock falls, landslides, and storm-battered beaches we gain insights into the creation of the coastline itself.

In short, the Jurassic Coast is a truly outstanding place to explore Earth’s history, the evolution of life and the natural processes that shape our world.