Fort Riley Limestone

The Fort Riley Limestone is a Kansas Permian stratigraphic unit of member rank and historic building stone, sold commercially as fine-grained Silverdale, having at one time been quarried at Silverdale, Kansas. This limestone outcrops in east-central Kansas, extending into northeast-central Oklahoma and southeastern Nebraska, in the Midwestern United States. Its conspicuous "rim rock" marker horizon outcrop caps the bluffs overlooking the original buildings of Fort Riley, as well as the Marshall Army Airfield opposite the Kansas River.