Friday, January 22, 2010

Fossils in Indiana Limestone

Microfossils of the Salem Limestone (aka Indiana Limestone) that existed in the Middle Mississippian Period (340-335 million years ago). Sections of this limestone quarried near Bloomington and Bedford Indiana were used as material for famous buildings around the United States. Buildings such as New York City's Empire State Building & Rockefeller Center and Washington's Pentagon & National Cathedral.  One can learn more about the role of Salem Limestone in the building of the United States in Chapter 6 of the book Stories in Stone: Travels Through Urban Geology by David B. Williams.

This fossil is some sort of bryozoan.  Using its picture it might be a Fenestella or Hemitrypa.

Fossils found in Washington County, Indiana.

Thanks to Herb for the Salem Limestone sand material to study.


David B. Williams said...

Michael, Fun reading about the microfossils of the Salem, which, as you know, is one of my favorite building stones. If I remember correctly, didn't many of the early geologists/paleontologists who studied the Salem, refer to the fauna as "dwarf" or "dwarfed" because of the diminutive size?

Kentuckiana Mike said...

Hi David,
I enjoy reading your blog at

Yes, Fauna of the Salem Limestone of Indiana section written by E.R. Cumings, J.W. Beede, E.B. Branson, and Essie A. Smith in the Indiana Department of Geology and Natural Resources Thirtieth Annual Report from 1905 refer to fossils in the Salem Limestone as "stunted".

In the book Roadside Geology of Indiana by Mark J. Camp and Graham T. Richardson they refer to fossils in the Salem limestone on page 117, "specimens were tiny examples of their kind and were then interpreted as dwarf animals".

The abundance of small fossils is now thought to have been sorted by the wave action in the shallow Mississippian Period sea.

David B. Williams said...

Thanks. I like the use of the word "stunted."