Bright Angel Shale
Usage of Geologic Unit Name:
Bright Angel Shale (CA*,NV*,UT*)
Bright Angel Schist (CA*)
Bright Angel Shale of Tonto Group (AZ*)

 Bright Angel Shale
View of the Bright Angel Shale (shale slope with sandstone ledges below cliff-forming Muav Limestone) along Grand Canyon's South Kaibab Trail.

Age:
Cambrian, Early* (local)
Cambrian, Middle*

Middle Cambrian - 515 million years
(age used by National Park Service;
Mathis and Bowman, 2005)
Geologic Province:
Plateau sedimentary province*
Salton basin*
Areal Extent:
AZ(n)*
CA(se)*
NV(s)*
UT(sc)*
Type Locality:
Not designated. Named for Bright Angel Canyon, Bright Angel quad, Coconino Co., AZ (Noble, 1914).
Subunits:
(alphabetical): Flour Sack Member (AZ*), Meriwitica Member (AZ) or Meriwitica Tongue (AZ*), Tincanebits Tongue (AZ*).

Unit Name History:
Named as middle formation of Tonto Group (Noble, 1914, [Noble, 1922]). Revised to include Tincanebits, Meriwitica, Elves Chasm, Garnet Canyon, Lava Falls, Parashant, and Boucher Tongues, and Flour Sack Member (McKee, 1945). Age modified (Stewart, 1970). Areal limits (Peterson and Barnum, 1973). Redescribed, Revised; Areal limits (Hamilton, 1982).
Description from Grand Canyon Area (from Billingsley, George H., 2000)

Bright Angel Shale (Middle Cambrian)—Green and purple-red, slope-forming siltstone and shale, and interbeds of red-brown to brown sandstone of Tapeats Sandstone lithology. Includes ledge-forming red-brown sandstone member of McKee and Resser (1945). Consists of green and purple-red, fine-grained, micaceous, ripple-laminated, fossiliferous siltstone and shale; dark-green, medium- to coarse-grained, thin-bedded, glauconitic sandstone; and interbedded purplish-red and brown, thin-bedded, fine- to coarse-grained, ripple-laminated sandstone. Includes gray, thin-bedded, fine-grained, micaceous silty dolomite in upper part of unit in western quarter of map area. Intertonguing and facies change relationships with the underlying Tapeats produce variable thickness trends. Contact with the Tapeats is arbitrarily marked at lithologic vertical and lateral transition from predominantly green siltstone and shale to predominantly brown sandstone in slope above the Tapeats cliff. Thickness is about 350 ft (107 m) in eastern quarter of map area, thickening to about 500 ft (150 m) in western quarter.

References

Noble, L.F., 1914, The Shinumo quadrangle, Grand Canyon district, Arizona: U.S. Geological Survey Bulletin, 549, 100 p., (incl. geologic map, scale 1:48,000).

Noble, L.F., 1922, A section of the Paleozoic formations of the Grand Canyon at the Bass Trail: U.S. Geological Survey Professional Paper 131-B, p. 23-73.

McKee, E.D., 1945, Stratigraphy and ecology of the Grand Canyon Cambrian, Part 1; Cambrian history of the Grand Canyon region: Carnegie Institution of Washington Publication, no. 563, p.
1-170.

McKee, E.D., and Resser, C.E., 1945, Cambrian history of the Grand Canyon region: Carnegie Institution of Washington Publication 563, 232 p.

Stewart, J.H., 1970, Upper Precambrian and Lower Cambrian strata in the southern Great Basin, California and Nevada: U.S. Geological Survey Professional Paper, 620, 206 p.

Peterson, Fred and Barnum, B.E., 1973, Geologic map and coal resources of the northeast quarter of the Cummings Mesa quadrangle, Kane County, Utah: U.S. Geological Survey Coal Investigations Map, C-63, 2 sheets, scale 1:24,000.

Hamilton, Warren, 1982, Structural evolution of the Big Maria Mountains, northeastern Riverside County, southeastern California, IN Frost, E.G., and Martin, D.L., editors, Mesozoic-Cenozoic tectonic evolution of the Colorado River region, California, Arizona, and Nevada; Anderson-Hamilton volume: San Diego, CA, Cordilleran Publishers, p. 1-27, Published in conjunction with the Geological Society of America symposium and field trip, April, 1982.

Osleger, David A., Montanez, Isabel P., Martin Chivelet, Javier, Lehmann, Christoph, 1999, Cycle and sequence stratigraphy of Middle to Upper Cambrian carbonates, Bonanza King Formation, southern Great Basin: In, Abbott, Patrick L; Cooper, John D., editors, Field Trip Guidebook (American Association of Petroleum Geologists. Eastern Section), v. 80, p. 55-84.

Montanez, Isabel P., Osleger, David A., 1996, Contrasting sequence boundary zones developed within cyclic carbonates of the Bonanza King Formation, Middle to Late Cambrian, southern Great Basin: In, Paleozoic sequence stratigraphy; views from the North American Craton, Witzke, Brian J., Ludvigson, Greg A; Day, and Jed, S., editors, Geological Society of America, Special Paper v. 306, p. 7-21.

Palmer, Allison Ralph, and Hazzard, John Charles, 1956, Age and correlation of Cornfield Springs and Bonanza King formations in southeastern California and southern Nevada: Bulletin of the American Association of Petroleum Geologists, v. 40, no. 10, p. 2494-2499.

Elliott, David K., and Martin, Daryl L., 1987, A new trace fossil from the Cambrian Bright Angel Shale, Grand Canyon, Arizona: Journal of Paleontology, v. 61, no. 4, p. 641-648.

Shoemaker, E M; Squires, R L; Abrams, M J., 1978, Bright Angel and Mesa Butte fault systems of northern Arizona: In, Cenozoic tectonics and regional geophysics of the Western Cordillera,
Smith, R. B., and Eaton, G. P. editors, Geological Society of America, Memoir no. 152, p. 341-367.

Osleger, David A., Montanez, Isabel P., Martin Chivelet, Javier, Lehmann, Christoph, 1999, Cycle and sequence stratigraphy of Middle to Upper Cambrian carbonates, Bonanza King Formation, southern Great Basin:In, Abbott, Patrick L; Cooper, John D., editors, Field Trip Guidebook (American Association of Petroleum Geologists. Eastern Section), v. 80, p. 55-84.

Montanez, Isabel P., Osleger, David A., 1996, Contrasting sequence boundary zones developed within cyclic carbonates of the Bonanza King Formation, Middle to Late Cambrian, southern Great Basin: In, Paleozoic sequence stratigraphy; views from the North American Craton, Witzke, Brian J., Ludvigson, Greg A; Day, and Jed, S., editors, Geological Society of America, Special Paper v. 306, p. 7-21.

Montanez, Isabel P., and Osleger, David A., 1993, Parasequence stacking patterns, third-order accommodation events, and sequence stratigraphy of Middle to Upper Cambrian platform carbonates, Bonanza King Formation, southern Great Basin
In, Carbonate sequence stratigraphy; recent developments and applications, Loucks, Robert G, and Sarg, J. Frederick (eds): AAPG Memoir, v. 57, p. 305-326.

Palmer, Allison Ralph, and Hazzard, John Charles, 1956, Age and correlation of Cornfield Springs and Bonanza King formations in southeastern California and southern Nevada: Bulletin of the American Association of Petroleum Geologists, v. 40, no. 10, p. 2494-2499.

Elliott, David K., and Martin, Daryl L., 1987, A new trace fossil from the Cambrian Bright Angel Shale, Grand Canyon, Arizona: Journal of Paleontology, v. 61, no. 4, p. 641-648.

Shoemaker, E M; Squires, R L; Abrams, M J., 1978, Bright Angel and Mesa Butte fault systems of northern Arizona: In, Cenozoic tectonics and regional geophysics of the Western Cordillera,
Smith, R. B., and Eaton, G. P. editors, Geological Society of America, Memoir no. 152, p. 341-367.
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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/.htm
Last modified: 1/7/2011