Black Mesa
       7 ½’ quadrangle: Kenton, OK-CO
       Cimarron County
       Black Mesa State Park
       High Plains

Igneous Volcanic
4,973 ft (1,516m)

Bedrock: Basalt

Late Tertiary ~30 Ma

Remnant of a huge olivine basalt flow that covered the Ogallala Formation, derived from volcanic vents in adjacent Colorado. Black Mesa continues as a narrow mesa about ten miles diagonally across New Mexico, gradually getting higher, until it crosses into Colorado at about 5240 feet elevation, and broadens out to connect with Mesa de Maya and eventually Seven L Buttes, apparently the source of the flow. In Oklahoma, the lower parts of Black Mesa expose the underlying Cretaceous Dakota Sandstone and Purgatoire Formation. These units in turn lie above the Morrison Formation, which contains Jurassic dinosaur trackways within Black Mesa State Park, and Triassic red beds, exposed at the Cimarron River.

For a discussion of all the volcanic highpoints, see http://www.unh.edu/esci/volcanic_highpoints03.pdf.

Soil Series: Apache stony clay loam: Gently sloping, grayish-brown, limy soil developed from weathered basalt at depths of 15 to 20 inches. Native cover: side-oats grama, blue grama, buffalo grass, and other short-grass prairie plants.

Selected References:

• Miser, H.D., 1954, Geologic Map of Oklahoma : U.S. Geological Survey, 1:500,000.
• Mulvany, Patrick S. and Judith O. Mulvany, 1989, Geologic map revision of the Black Mesa region, Cimarron County, Oklahoma: Oklahoma Geology Notes v.49, no.1, p.4-10.
• Murphy, Ralph S. and others, 1960, Soil Survey of Cimarron County, Oklahoma : U.S. Soil Conservation Service.
• Trimble, D. E., 1980, The Geologic Story of the Great Plains: A nontechnical description of the origin and evolution of the landscape of the Great Plains : U.S. Geological Survey Bulletin 1493.

Other suggested sources of information:

• Glossary: http://www2.nature.nps.gov/geology/usgsnps/misc/glossaryAtoC.html
• Time scale: http://www.ucmp.berkeley.edu/help/timeform.html
• Oklahoma Geological Survey: http://www.ogs.ou.edu/