The Fort Riley Limestone is a Kansas

Permian The Permian ( ) is a geologic period and System (stratigraphy), stratigraphic system which spans 47 million years, from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.902 Mya. It is the s ...

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 Kansas ( ) is a landlocked U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders Nebraska to the north; Missouri to the east; Oklahoma to the south; and Colorado to the west. Kansas is named a ...

, extending into northeast-central

Oklahoma Oklahoma ( ; Choctaw language, Choctaw: , ) is a landlocked U.S. state, state in the South Central United States, South Central region of the United States. It borders Texas to the south and west, Kansas to the north, Missouri to the northea ...

and southeastern

Nebraska Nebraska ( ) is a landlocked U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders South Dakota to the north; Iowa to the east and Missouri to the southeast, both across the Missouri River; Ka ...

, in the

Midwestern United States The Midwestern United States (also referred to as the Midwest, the Heartland or the American Midwest) is one of the four census regions defined by the United States Census Bureau. It occupies the northern central part of the United States. It ...

. Its conspicuous "rim rock"

marker horizon Marker horizons (also referred to as chronohorizons, key beds or marker beds) are stratigraphic units of the same age and of such distinctive composition and appearance, that, despite their presence in separate geographic locations, there is no do ...

outcrop caps the bluffs overlooking the original buildings of

Fort Riley Fort Riley is a United States Army installation located in North Central Kansas, on the Kansas River, also known as the Kaw, between Junction City and Manhattan. The Fort Riley Military Reservation covers 101,733 acres (41,170 ha) in Ge ...

, as well as the

Marshall Army Airfield Marshall Army Airfield (MAAF) is a military airfield located on Fort Riley, Kansas, United States. It was opened in 1921. The primary mission of MAAF is to provide fully integrated fixed base helicopter operations for the Combat Aviation Brig ...

opposite the

Kansas River The Kansas River, also known as the Kaw, is a meandering river in northeastern Kansas in the United States. It is potentially the southwestern most part of the Missouri River drainage, which is sometimes in turn the northwesternmost portion of ...

. ap legendbr/>''Note the

below the blue-line Pb marker bed.''

References

Permian Kansas Permian geology of Nebraska Stratigraphy of Oklahoma Limestone formations of the United States Building stone Geologic members of the United States Geologic members of Kansas {{Kansas-geologic-formation-stub

See also

References