Chuar Group
Usage of Geologic Unit Name:
Chuar Group*
Age:
Precambrian*
Proterozoic, Late*

Early Proterozoic - 770 to 740 million years (age used by National Park Service; Mathis and Bowman, 2005)
Geologic Province:
Southern Rocky Mountain region*
Areal Extent:
AZ(n)*
Type Locality:
Not designated (Walcott, 1883).
Unit Name History:
First used as Chuar Group (Walcott, 1883). Age modified (Elston, 1989b). Overview (Elston, 1989b, 1993a, 1993b). Revised--assigned to Grand Canyon Series (Walcott, 1894); divided into Galeros, Kwagunt, and Sixty Mile Formations (Ford, Breed, 1973); assigned to Grand Canyon Supergroup (Elston, Scott, 1976); spelling changed to Sixtymile (Elston, 1979); Sixtymile Formation removed (Elston, McKee, 1982).

References

Walcott, C.D., 1883, Pre-Carboniferous strata in the Grand [Canyon] of the Colorado, Arizona: American Journal of Science, 3rd series, v. 26, p. 437-442.

Walcott, C.D., 1894, Pre-Cambrian igneous rocks of the Unkar terrane, Grand Canyon of the Colorado, Arizona: U.S. Geological Survey Annual Report, 14, pt. 2, p. 503-519.

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. and McKee, E.H., 1982, Age and correlation of the late Proterozoic Grand Canyon disturbance, northern Arizona: Geological Society of America Bulletin, v. 93, no. 8, p. 681-699.

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., Link, P.K., Winston, Don and Horodyski, R.J., 1993, Correlations of Middle and Late Proterozoic successions, 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. 468-487.

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.

Dodson, Crystal L., Crossey, Laura J., Bloch, John D., Dehler, Carol
M., 2002, Major element geochemistry of the Neoproterozoic Chuar Group,
Grand Canyon: New Mexico Geology, v. 24, no. 2, p. 64.

Uphoff, Thomas L., 1997, Precambrian Chuar source rock play., an exploration case history in
southern Utah: AAPG Bulletin, v. 81, no. 1, p. 1-15.

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:
http://ngmdb.usgs.gov/Geolex/geolex_qs.html.
The URL is: https://gotbooks.miracosta.edu/gonp/coloradoplateau/lexicon/chuar_group.htm
Last modified: 1/7/2011