Lithograph City Formation Explained

Lithograph City Formation
Type:	Formation
Age:	Devonian
Period:	Devonian
Country:	United States
Unitof:	Cedar Valley Group
Extent:	Iowa and Minnesota

The Lithograph City Formation is a geologic formation in Iowa, part of the Cedar Valley Group. It preserves fossils dating back to the Devonian period. The formation is composed of dolomite and limestone, with many fossils and vugs in the lower part, while the upper part contains few fossils.^{[1] [2]}

The formation is named after exposures in the former company town of Lithograph City, where quarries were opened to exploit the high-quality lithographic limestone found in parts of this formation.^[3]

See also

• List of fossiliferous stratigraphic units in Iowa
• Paleontology in Iowa

Notes and References

1. Bill J. Bunker, Brian J. Witzke and Jed Day, Upper Cedar Valley Stratigraphy North Central Iowa Lithograph City Formation, Guidebook 44, Geological Society of Iowa, Apr. 27, 1986.
2. Web site: Fossilworks: Gateway to the Paleobiology Database. ((Various Contributors to the Paleobiology Database)). 17 December 2021. dmy-all.
3. A. B. Hoen, Discussion of the Requisite Qualities of Lithographic Limestone, with Report on Tests of the Lithographic Stone of Mitchell County, Iowa, Iowa Geological Survey Annual Report, 1902, Des Moines, 1903; pages 339-352.