Kaibab Limestone

The Kaibab is a geologic formation that is spread across the U.S. states of northern Arizona, southern Utah, east central Nevada and southeast California. This geologic unit is part of the Park City Group in Nevada and Utah and is sometimes locally classified as a geologic group in Utah. It is called the Kaibab Marble in California, the Kaibab Formation in Arizona, Nevada and Utah and the Kaibab Limestone everywhere the unit is represented except for California. Part of the Colorado Plateau and Basin and Range, this formation was laid down in the Early Permian during the Leonardian stage.

Asterisks (*) indicate usage by the U.S. Geological Survey. Other usages by state geological surveys.

History of investigation
There is no type locality designated for this formation. It was named by Darton in 1910 for the Kaibab Plateau, which is on the north side of Grand Canyon in Coconino County, Arizona. Darton also named it as the upper formation of Aubrey Group in 1910 (group name no longer used). Bassler and Reeside revised Darton's work and assigned the Harrisburg Member in 1921. Areal extent limits were set by Gilluly and Reeside in 1928 and again by Gregory and Moore in 1931. Its lower contact was revised and the unit was informally divided into (ascending) alpha, beta, and gamma units by McKee in 1938. Blakey revised its upper contact in 1974. Welsh and others attempted to raise the formation to group rank and divide it into several formations in 1979 (not recognized by the USGS). In 1982 Hamilton redescribed it as the as Kaibab Marble in California and set its areal limits there. The Kaibab was divided into (ascending) Fossil Mountain Member (new) and Harrisburg Member by Sorauf and Billingsley in 1991. Areal limits were set again by Anderson and Hintze in 1993.

Subunits
Formation rank (alphabetical):
 * Fossil Mountain Member (AZ,NV*,UT),
 * Harrisburg Member (AZ*,NV*,UT*).

Places found
Geologic Province:
 * Basin and Range province*
 * Black Mesa Basin*
 * Great Basin province*
 * Paradox Basin*
 * Plateau sedimentary province*
 * Salton Basin*

Parklands (incomplete list):
 * Capitol Reef National Park - See Geology of the Capitol Reef area
 * Grand Canyon - See Geology of the Grand Canyon area
 * Zion National Park - See Geology of the Zion and Kolob canyons area
 * Grand Staircase-Escalante National Monument