It preserves fossils dating back to the Carboniferous period The Brazil Formation was named in 1902 for the city of Brazil, located in Clay County, Indiana.

It originally included rocks between the bottom of the Petersburg Coal and the top of the Mansfield Sandstone.

In 1976, it was amended again to include rocks between the upper part of Minshall Coal Member and the lower part of Lower Block Coal Member.

[3][4] The formation was named by E. R. Cumings to refer to the exposed rocks found near Staunton, Clay County.

The Staunton Formation is made up of sandstone and shale (75 to 150 feet), and coalbeds (up to 8).