Nankoweap Formation

Usage of Geologic Unit Name:
Nankoweap Formation* of Grand Canyon Supergroup
Proterozoic, Middle*

Early Proterozoic - 900 million years (age used by National Park Service; Mathis and Bowman, 2005)
Geologic Province:
Southern Rocky Mountain region*
Areal Extent:
Type Locality:
Type section: Basalt Canyon, north side Colorado River south of intersecton with Little Colorado River, Grand Canyon National Park, Coconino Co, AZ (Van Gundy, 1951).
Unit Name History:
Overview of Nankoweap Group (Van Gundy, 1951). Revised (Ford, Breed, 1973; Elston, Scott, 1976). Age modified (Elston, 1989b). Overview (Elston, 1993b).


Van Gundy, C.E., 1951, Nankoweap Group of the Grand Canyon Algonkian of Arizona: Geological Society of America Bulletin, v. 62, no. 8, p. 953-959.

Ford, T.D. and Breed, W.J., 1973, Late Precambrian Chuar Group, Grand Canyon, Arizona: Geological Society of America Bulletin, v. 84, no. 4, p. 1243-1260.

Elston, D.P. and Scott, G.R., 1976, Unconformity at the Cardenas-Nankoweap contact (Precambrian), Grand Canyon Supergroup, northern Arizona: Geological Society of America Bulletin, v. 87, no. 12, p. 1763-1772.

Elston, D.P., 1989, Grand Canyon Supergroup, northern Arizona; stratigraphic summary and preliminary paleomagnetic correlations with parts of other North American Proterozoic successions, IN Jenney, J.P., and Reynolds, S.J., editors, Geologic evolution of Arizona: Arizona Geological Society Digest, v. 17, p. 259-272.

Ford, T.D., 1990, Grand Canyon Supergroup: Nankoweap Formation, Chuar Group, And Sixtymile Formation. In: Beus, S.S., Morales, M., editors, Grand Canyon Geology, Oxford University Press, New York, p. 49-70.

Elston, D.P., 1993, Middle and early Late Proterozoic Grand Canyon Supergroup, northern Arizona, IN Link, P.K., ed., Middle and Late Proterozoic stratified rocks of the western U.S. Cordillera, Colorado Plateau, and Basin and Range province, Chapter 6, OF Reed, J.C., Jr., and others, editors, Precambrian; conterminous U.S.: Geological Society of America, The Geology of North America, The Decade of North American Geology (DNAG), v. C-2, p. 521-529.

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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Note that data on this page contains information that has been partly revised from bibliographic resources available via the National Geologic Map Database GEOLEX:
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Last modified: 1/7/2011