GeologyRocks

• Location: Speeton, North Yorkshire, UK
• Date Taken (dd-mm-yy): 8-6-07

The Speeton clay is the Lower Creteceous deposit on the Yorkshire coast. It lies unconformably on the Kimmeridge clay (Upper Jurassic) and below the red chalk, which ultimately leads to the white chalk of the Upper Cretaceous. In this shot you can see two "marker horizons" in what would otherwise be an homogenous (at least to the casual observer) clay. The top layer is a thin layer of volcanic ash that weathers into a slightly thicker, yellow layer. This is known as Bed C7E. The lower red/brown bed is a more silty layer and is bed C7F. There are more of these silty red/brown layer labelled D to A as you move up the succession. The Speeton clay is heavily folded, which is not really visible in this shot, but the yellow layer can be seen zig-zagging across the formation.