Blue Lias
It is part of the Lias Group. The Blue Lias consists of a sequence of limestone and shale layers. It was laid down in late Triassic and early Jurassic times, between 195 and 200 million years ago. The Blue Lias is famous for its fossils, especially ammonites. Also found were remains of a number of dinosaurs, and the pterosaur Dimorphodon.