Locality	Layer
	Great Britain, England,Devonshire, Barnstaple, near Mount Standford	Pilton Beds
	Great Britain, England,Devonshire, Codden Hill, Barnstaple	Codden Hill Chert
	Great Britain, England,Devonshire, Kersdown quarry, Bampton	Codden Hill Chert
	Great Britain, England,Devonshire, Park gate quarry	Codden Hill Chert
	Great Britain, England,Yorkshire, Skipton, Haw Bank Tunnel	Visean