Calvert, Warren L.Scale 1:500 000.by Warren L. Calvert.Includes legend.TIFFhttps://hdl.handle.net/1811/63fb4d86-a73d-41be-85b2-ea1afb9305d0engOhio. Division of Geological SurveyPublicGeologyGeology, StructuralGeology, StratigraphicSubcrop and thickness of Sauk sequence Knox uniformity to PrecambrianMapsOhio--Butler CountyOhioThe Ohio State University