Bright Angel Shale: Difference between revisions

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* Anonymous (2011c) [http://3dparks.wr.usgs.gov/coloradoplateau/lexicon/muav.htm ''Muav Limestone''], [http://3dparks.wr.usgs.gov/coloradoplateau/index.html Stratigraphy of the Parks of the Colorado Plateau]. U.S. Geological Survey, Reston, Virginia.
* Anonymous (2011c) [http://3dparks.wr.usgs.gov/coloradoplateau/lexicon/muav.htm ''Muav Limestone''], [http://3dparks.wr.usgs.gov/coloradoplateau/index.html Stratigraphy of the Parks of the Colorado Plateau]. U.S. Geological Survey, Reston, Virginia.
*Brandriss, M. (2004) [http://www.geodil.com/image.asp?ImageID=3091&history=0&categoryid=57 ''Angular unconformity between Proterozoic and Cambrian rocks, Grand Canyon, Arizona.''] [http://www.geodil.com/index.asp GeoDIL, A Geoscience Digital Image Library], University of North Dakota, Grand Forks, North Dakota.
*Brandriss, M. (2004) [http://www.geodil.com/image.asp?ImageID=3091&history=0&categoryid=57 ''Angular unconformity between Proterozoic and Cambrian rocks, Grand Canyon, Arizona.''] [http://www.geodil.com/index.asp GeoDIL, A Geoscience Digital Image Library], University of North Dakota, Grand Forks, North Dakota.
* Mathis, A., and C. Bowman (2007) [http://www2.nature.nps.gov/geology/parks/grca/age/index.cfm ''The Grand Age of Rocks: The Numeric Ages for Rocks Exposed within Grand Canyon''], [http://www2.nature.nps.gov/geology/parks/grca/age/index.cfm Grand Canyon National Park, Arizona], National Park Service, Grand Canyon National Park, Arizona.
* Mathis, A., and C. Bowman (2007) [https://web.archive.org/web/20121220094947/http://www.nature.nps.gov/geology/parks/grca/age/index.cfm ''The Grand Age of Rocks: The Numeric Ages for Rocks Exposed within Grand Canyon''], [https://web.archive.org/web/20121220094947/http://www.nature.nps.gov/geology/parks/grca/age/index.cfm Grand Canyon National Park, Arizona], National Park Service, Grand Canyon National Park, Arizona.
*Rowland, S. (nda) [http://geoscience.unlv.edu/pub/rowland/Virtual/virtualfm.html ''Frenchman Mountain Great Unconformity site.''] [http://geoscience.unlv.edu/ Department of Geoscience], University of Nevada, Las Vegas, Nevada.
*Rowland, S. (nda) [http://geoscience.unlv.edu/pub/rowland/Virtual/virtualfm.html ''Frenchman Mountain Great Unconformity site.''] [http://geoscience.unlv.edu/ Department of Geoscience], University of Nevada, Las Vegas, Nevada.
*Rowland, S. (ndb) [http://geoscience.unlv.edu/pub/rowland/Virtual/geomap.html ''Geologic Map of Frenchman Mountain.''] [http://geoscience.unlv.edu/ Department of Geoscience], University of Nevada, Las Vegas, Nevada.
*Rowland, S. (ndb) [http://geoscience.unlv.edu/pub/rowland/Virtual/geomap.html ''Geologic Map of Frenchman Mountain.''] [http://geoscience.unlv.edu/ Department of Geoscience], University of Nevada, Las Vegas, Nevada.

Revision as of 20:14, 25 July 2017

Bright Angel Shale
Stratigraphic range: Middle Cambrian[1][2]
Muav Limestone-(dk or lt gray, brown, or orange-red subcliff at base of Redwall Limestone cliff) and Bright Angel Shale (greenish slope-former), resting on Tapeats Sandstone (short, dp brown vertical cliff) (Tapeats forms the "Tonto Platform"), inner canyon, Granite Gorge. (The 3 units–Muav, Bright Angel, and Tapeats, are easily seen below the red-stained Redwall Limestone (550 ft thick))
TypeGeological formation
Unit ofTonto Group
UnderliesMuav Limestone
OverliesTapeats Sandstone
Thickness500 feet (150 m) at its maximum
Lithology
Primarymicaceous siltstone and shale
Othersandstone and glauconitic sandstone
Location
Regionnorthern Arizona, southeast California, southern Nevada, and southcentral Utah
CountryUnited States of America
Type section
Named forBright Angel Canyon, Bright Angel quadrangle, Coconino Co., Arizona[3]
Named byNoble (1914)[3]

The Cambrian Bright Angel Shale is the middle member of the 3-member Tonto Group. It is about 500 feet (152 m) thick at its maximum.[4] It is a nonresistant slope-forming unit. The Bright Angel Shale consists of green and purple-red, siltstone and shale which is interbedded with red-brown to brown sandstone that is similar in lithology to the underlying Tapeats.[5] The Bright Angel Shale underlies and interfingers with Muav Limestone. The Bright Angel Shale is located in the lower elevations of the Grand Canyon, Arizona.[6]

Geologic sequence

The units of the Tonto Group:[4]

See also

References

  1. ^ Rose, E (2006) "Nonmarine aspects of the Cambrian Tonto Group of the Grand Canyon, USA, and broader implications." Palaeoworld. 15:223–241.
  2. ^ Rose, E (2011) Modification of the nomenclature and a revised deposition model for the Cambrian Tonto Group of the Grand Canyon, Arizona. in JS Hollingsworth, FA Sundberg, and JR Foster, eds., pp 77-98, Cambrian Stratigraphy and Paleontology of Northern Arizona and Southern Nevada: Museum of Northern Arizona Bulletin 67, 321 p.
  3. ^ a b Noble, LF (1914) The Shinumo quadrangle, Grand Canyon district, Arizona. Bulletin no. 549, US Geological Survey, Reston, Virginia.
  4. ^ a b Chronic, H (1983) Roadside Geology of Arizona. The Mountaineers Books, Seattle, Washington. (softcover, ISBN 978-0-87842-147-3)
  5. ^ Anonymous (2006c) Bright Angel Shale, Stratigraphy of the Parks of the Colorado Plateau. U.S. Geological Survey, Reston, Virginia.
  6. ^ Hampton, HM (1998) Geologic Map of the Grand Canyon in the Vicinity of the South Rim Visitor Center. in Kamilli, RJ, and SM Richard, eds., Geologic Highway Map of Arizona, Arizona Geological Society and Arizona Geological Survey, 1 sheet, scale 1:62,500.

Popular Publications

  • Blakey, Ron and Wayne Ranney, Ancient Landscapes of the Colorado Plateau, Grand Canyon Association (publisher), 2008, 176 pages, ISBN 978-1934656037
  • Chronic, Halka. Roadside Geology of Arizona, Mountain Press Publishing Co., 1983, 23rd printing, pp. 229–232, ISBN 978-0-87842-147-3
  • Lucchitta, Ivo, Hiking Arizona's Geology, 2001, Mountaineers's Books, ISBN 0-89886-730-4

External links