Lawrence, D. J. D. 1990. Limestone Landscapes — a geodiversity audit and action plan for the Durham Magnesian Limestone Plateau. British Geological Survey open report OR/09/007.
Middridge Quarry [NZ 252 252]
Disused Quarry
Ownership not known
One of the most significant geodiversity sites in the area. Exposes rocks from the basal unconformity and breccia with the overlying Marl Slate Formation up to Ford Formation; here the Marl Slate Formation is world famous for fossil vertebrates, fish and plants.
Proposed action Prepare interpretation. Consider re-exposing unconformity.
Would be a good site to feature on the importance of the area for fossils of international importance.
Existing designations SSSI GCR
Existing on site interpretation None
Major geodiversity interest Geological succession from Coal measures to Ford Formation exposed in the site. A key site with the richest and most diverse Permian flora in Britain. Its conifer dominated flora compares with the Kupferschiefer flora of Germany and Hungary. The assemblage at Middridge is of great interest for yielding the oldest British ginkgo. Middridge quarry is the best British Permian tetrapod locality. Three species of fossil reptile were collected from the vicinity in the last century: two species of Proterosaurus and a Lepidotosaurus. Finds of bone indicate the potential of the site.
Biodiversity interest None
Other heritage links None
Additional comment Displays a very good sequence of basal Permian breccia beds which differs somewhat from the sequence in Thickley Quarry 1 km to NNW. The basal muddy conglomerate bed (0.34m) passes upwards directly into the Marl Slate Formation.
Date of photography 2003