The Tertiary deposits of an area in Shannon County, South Dakota (Fig. 1), were mapped by Harksen for the State Geological Survey in the summer of 1959. This work corroborated Macdonald’s view that a distinctive new stratigraphic unit (herein named the Sharps formation) is present between the Brule formation of the Oligocene White River group below, and the Monroe Creek formation of the Miocene Arikaree group, above.

The Sharps formation is named for exposures near Sharps Corner in Shannon County, South Dakota, and consists of 390 feet of massive tan silt and volcanic ash.

The Sharps formation includes...

First Page Preview

First page PDF preview
You do not currently have access to this article.