Jurassic Clays

The Oxford, Ampthill and Kimmeridge clay sequence reveals a deepening of the Jurassic sea from 175 to 150 million years ago. As the waters of the Oxford Clay deepened the sea became unstable, with frequent algal blooms. When great numbers of algae died, sometimes the mass of organic matter collected on the sea floor where little or no oxygen was available, decaying to form muds rich in organic compounds. These compounds are the reason for the excellent firing quality of these brick-making clays. The very flat landscape of the clays makes it impossible to see where one clay ends and another begins, but most of northern Bedfordshire, surrounding the town of Bedford, is composed of these clays.

These clays are rich in fossils including Ammonites, Belemnites (such as the one forming our menu buttons on the left), wood and marine reptiles. Occasionally a dinosaur is found!

Bedfordshire then became dry land once more, and lost rocks to erosion.

Amoebocerus found in the Ampthill Clay