Bass Islands Dolomite outcrop with stalactites in a cave on South Bass Island, Put-In-Bay Township, Ottawa County, Ohio. This area has dolomite, anhydrite, gypsum, salt and shale lithologies. Bedrock is from the Silurian Geologic Period. The slide image was created in 1952 by Philip M. Smith for the Ohio Cave Survey Project. The Ohio Cave Survey Project was formalized in 1952. The Central Ohio Grotto of the National Speleological Society in cooperation with the Ohio Geological Survey established a comprehensive survey of Ohio caves and caverns. The location is approximate to the center of the island.
