color photo of oolite sample

Oolites are sedimentary rocks made up of ooids cemented together. An ooid is a small spherical grain of sedimentary material that forms when a particle of sand or other nucleus is coated with concentric layers of calcite or other minerals. Ooids most often form in shallow, wave-agitated marine water. Oolitic limestones, particularly of Pennsylvanian age, are found at or near the surface in the eastern third of Kansas.

Read more about oolites in Rocks and Minerals of the Osage Cuestas.

small drawing of Kansas map with Reno County highlighted in red

The sample pictured above is from Reno County, Kansas


Buchanan, Rex C., Tolsted, Laura L., and Swineford, Ada, 1986, Kansas Rocks and Minerals: Kansas Geological Survey, Educational Series 2, 60 p.

Klein, Cornelis, 1993, Manual of Mineralogy (after James D. Dana), 21st Edition: New York, Wiley, 681 p.

Unless noted otherwise, illustrations by Jennifer Sims, Kansas Geological Survey; photographs by John Charlton, Kansas Geological Survey; text by Liz Brosius, Kansas Geological Survey.

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