Canal Quarry, Frome Road
Bradford on Avon, Wiltshire
.
The quarry stretched along the canal bank from the lock-keeper’s house (now Canal Trust café) as far as Moulton Drive, a place called Clay Farm on old maps. The pale grey clay was used for puddling -lining and water-proofing- the bed of the Kennet & Avon Canal. What was left of it was infilled in the 1990s and houses and a car park occupy the space.
The interest in the fossils of the Bradford Clay largely revolved around perfect specimens of the sea lily Apiocrinites that were collected there by Joseph Chaning Pearce and others. It was a member of the Crinoidea, a group of animals that are related to the sea urchin and starfish, but mostly live attached to the sea bed by a ‘root’ and a long stem of articulated rings. The body has a crown of fan-like tentacles which help filter minute food from the sea water. In the 1820s there was much worldwide debate about these animals. The pair of specimens on display in the Museum are from Chaning Pearce’s collection and belong to Bristol City Museum & Art Gallery.
The other interest in the Bradford Clay has been in how a rich fauna which was mostly living attached to a rocky sea bed became killed off when environmental conditions were dramatically changed by an influx of mud, which buried the creatures and preserved them. This thin sequence of rocks demonstrated that environments in the distant geological past had been changing and the rocks were not just a fixed part of the landscape.
A small area has been dug out (at grid reference ST 825 603) to show what was the hard limestone sea bed and a layer of the Bradford Clay above it. The Wiltshire Geology Group has provided an interpretation panel there to explain its significance. The Group has published a Landscape and Geology Trail guide to Bradford’s geology.