Stretching from Exmouth in Devon to Studland Bay in Dorset, the 96-mile patch of gorgeous south-coast coastline might, at first blush, look little more than a lovely place to spend an afternoon walking, relaxing and dining, but looking closer reveals more – much more.
It reveals the Jurassic Coast, a World Heritage Site which, in its fossil deposits, tells a story of 185 million years of geological history.
Thanks to coastal erosion, today those who visit the coast can see an almost continuous sequence of rock formations, covering three crucial eras of world history – the Triassic, Jurassic and Cretaceous periods. These three periods make up the Mesozoic Era, the age of giant reptiles and dinosaurs – roughly 66 million years ago.
At different times in history, the stone shows the area has been desert, tropical sea and marsh, before becoming the startlingly beautiful coastline it is today, but what happened to the area during the Triassic, Jurassic and Cretaceous periods? Join us as we share an extremely truncated history of the Jurassic Coast.
The Triassic Period – 252-201 million years ago
During the Triassic period, all of the land on earth was lumped together into one single mega-continent called Pangea. It was an arid landscape, for the most part, and most of Pangea was covered in unforgiving desert.
It’s for this reason that along the Jurassic coast you can see red rocks exposed on the East Devon cliffs – they were formed in those deserts! The Jurassic coast is one of the key sites worldwide for fossils from this period.
The Jurassic Period – 201-145 million years ago
At the beginning of the Jurassic period sea levels rose and the desert that had existed where the Jurassic coast now stands was transformed into a shallow tropical sea, encouraging a rich marine ecosystem to develop. This ecosystem supported everything from lobsters, starfish and sharks to long extinct creatures like Ichthyosaurs and Pliosaurs – the gigantic sea predators.
Today, you’ll find evidence of this shift in the grey clay, yellow sandstone and limestone in the Jurassic coast cliffs. These stones were laid in shallow seas during the start and middle of the period, and are a globally renowned source for ammonites, fish and giant marine reptile fossils.
The Cretaceous Period – 145-66 million years ago
Not so long ago, historically, was the Cretaceous period. It began with low sea levels, coastal forests and swamps and ended with the Chalk sea, with sea levels which were over 200m higher than they are today!
It’s during this period that the dinosaurs we know and love walked the earth, including the terrifying Tyrannosaurus Rex!
Along the Jurassic coast, we find examples of this period. Specifically, Purbeck reveals the history of the Cretaceous period, with limestones from swamps and lagoons clearly visible, alongside that iconic white chalk, which was the last rock to be laid down during the whole Mesozoic era.
With regular tours across the Jurassic Coast and a host of museums along its length, there’s no better place to explore the history of the world than the Jurassic coast. From your Lyme Bay Holidays base, you can go out and explore every inch, so don’t delay – you’ve got so much to see.