A very pure limestone from the Upper Cretaceous. Related Articles: Real ‘Southend Rock’Field trip to the building stones of CanterburyGeology museums of Britain: Whitby Museum, YorkshireCoccoliths: Tiny fossils with immense paleontological importanceBook review: The Isle of Wight (Geologists’ Association Guide No 60), by Andy Gale« Back to Glossary Index