Area: 0.76 hectares.

Description and Reasons for Notification: 

This disused quarry exposes a succession through the Devonian Plymouth Limestone, typically yielding a coral-stromatoporoid fauna of late Givetian age. Associated conodonts confirm this correlation. 

At two main levels in the quarry unusual beds of limestone conglomerate are developed and at least one of these passes laterally into the neighbouring quarry to the north of the Fisons quarry itself. The lower conglomerate horizon has been termed the “Fisons Quarry Conglomerate” and is the best developed. Exposures show rounded limestone blocks in an argillaceous limestone matrix overlain by a localised band of shale. The matrix has yielded a mid-Frasnian conodont fauna and is therefore significantly younger than the enclosing Plymouth Limestone. 

Interpretation of the conglomeratic horizons is problematic and an origin as slumps or crevasse/fissure infills has been speculated. This is an important site in the interpretation of the stratigraphy and geological evolution of the Plymouth Limestone mass.