Harrisburg Member of Kaibab Formation

Usage of Geologic Unit Name:
Harrisburg Member of Kaibab Formation (AZ*,NV*,UT*)
Permian, Early*
Geologic Province:
Great Basin province*
Plateau sedimentary province*
Basin and Range province*
Areal Extent:
Type Locality:
Not designated. Named for occurrence in the Harrisburg dome, 8 mi east of St. George, Washington Co., UT (Bassler and Reeside, 1921); these exposures designated type locality (Sorauf and Billingsley, 1991).
Unit Name History:
Named Harrisburg Gypsiferous Member, upper member of Kaibab Limestone (Bassler and Reeside, 1921). Redescribed as Harrisburg Member Kaibab Formation; Reference section; Overview (Sorauf and Billingsley, 1991). Areal limits (Anderson and Hintze, 1993).
Description from Grand Canyon Area ( from Billingsley, George H., 2000)

Harrisburg Member—Reddish-gray and brownish-gray, slope-forming gypsum, siltstone, sandstone, and limestone. Informally subdivided, in descending order, into three units forming an upper slope, middle cliff, and lower slope. Upper slope unit is interbedded red and gray gypsum, sandstone, and siltstone, and yellowish-gray fossiliferous sandy limestone. Middle cliff unit is gray, thin-bedded, fossiliferous cherty limestone and sandy limestone. Lower slope unit is (1) yellowish-gray to pale-red gypsifereous siltstone and calcareous sandstone, (2) gray, thin-bedded sandy limestone, and (3) gray to white, thick-bedded gypsum. Upper, middle, and lower units become inseparable on the Kaibab Plateau, northeastern quarter of map area. Solution weathering within gypsum beds of lower slope unit has resulted in warping and bending of limestone of middle cliff unit, especially in or near local drainages on Kanab and Coconino Plateaus where middle cliff unit forms surface bedrock. Gypsum solutioning is responsible for several sinkhole depressions within Harrisburg Member. Contact with underlying Fossil Mountain Member is gradational and arbitrarily marked at top of cherty limestone cliff of the Fossil Mountain. About 260 ft (80 m) thick in western half of map area, thinning eastward to about 120 ft (36 m) in northeastern quarter of map area. Average thickness about 165 ft (50 m).


Bassler, Harvey and Reeside, J.B., Jr., 1921, Oil prospects in Washington County, Utah, IN Contributions to economic geology, 1921; Part 2, Mineral fuels: U.S. Geological Survey Bulletin, 726-C, p. C87-C107.

Sorauf, J.E. and Billingsley, G.H., 1991, Members of the Toroweap and Kaibab Formations, Lower Permian, northern Arizona and southwestern Utah: The Mountain Geologist, v. 28, no. 1, p. 9-24.

Anderson, R.E. and Hintze, L.F., 1993, Geologic map of the Dodge Spring quadrangle, Washington County, Utah and Lincoln County, Nevada: U.S. Geological Survey Geologic Quadrangle Map, GQ-1721, 1 sheet, scale 1:24,000.

Billingsley, George H., 2000, Geologic Map of the Grand Canyon 30' by 60' Quadrangle, Coconino and Mohave Counties, Northwestern Arizona: U.S. Geological Survey Geologic Investigation Series I-2688, Available on-line at: http://pubs.usgs.gov/imap/i-2688/.).

Mathis, A. and Bowman, C., 2005, What's in a number? Numeric ages for rocks exposed within the Grand Canyon, Part 2: Nature Notes ( Grand Canyon National Park ), v. 21, no. 2, p. 1-5.

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* show accepted USGS usage.
Note that data on this page contains information that has been partly revised from bibliographic resources available via the National Geologic Map Database GEOLEX:
The URL is: https://gotbooks.miracosta.edu/gonp/coloradoplateau/lexicon/kaibab_harrisburg.htm
Last modified: 1/7/2011