Redwall Limestone
| Redwall Limestone | |
|---|---|
| Stratigraphic range: Early and early Late Mississippian[1][2] | |
 Redwall Limestone cliff, and upper platform of cliff extension (resting on very short Muav Limestone cliff), from Tower of Set, central Grand Canyon, adjacent Granite Gorge. The bottom of Redwall cliffs typically rest on sections of Temple Butte Formation-(locally), or attached sections of Muav Limestone cliffs (regionally exposed in Grand Canyon, elsewhere in Arizona, not always with surface exposure). | |
| Type | Geological formation |
| Underlies | Supai Group and locally Surprise Canyon Formation. The Surprise Canyon Formation fills local paleovalleys, caves, and collapse structures cut into the underlying Redwall Limestone. |
| Overlies | Muav Limestone and Temple Butte Formation |
| Thickness | 800 feet (240 m), at maximum |
| Lithology | |
| Primary | fossiliferous limestone |
| Other | dolomite and chert |
| Location | |
| Region | Northern Arizona, southeast California, New Mexico, and southern Utah, Nevada |
| Country | United States of America |
| Type section | |
| Named for | the red appearance of its escarpment on either side of the Grand Canyon[3] |
| Named by | Gilbert (1875)[3] |
The Redwall Limestone is an erosion-resistant, Mississippian age, cliff-forming geological formation that forms prominent, red-stained cliffs in the Grand Canyon. these cliffs range in height from 500 feet (150 m) to 800 feet (240 m).[1][2]
Nomenclature[edit]
In 1875, Gilbert[3] recognized and named the Redwall Limestone for the red coloration of its escarpment on either side of Grand Canyon. As originally defined by him, it included some strata younger and older than as it is currently defined. Later in 1910, Darton[4] selected a canyon that he named the Redwall Canyon in the Shinumo drainage basin, on north side of the Grand Canyon, as the type section of the Redwall Limestone. At this location, it consists mostly of the usual heavily bedded massive limestone and is circa 244 m (801 ft) thick. Noble[5] subsequently redefined the Redwall Limestone in its present definition, which includes all strata of Mississippian age. As a result of studies in Yavapai County, Arizona, Gutschick[6] recognized four informal members within the Redwall Limestone and McKee[7] later formally named them. The most comprehensive study of the Redwall Limestone is the History of the Redwall Limestone of northern Arizona by McKee and Gutschick.[2]
Lithology[edit]
Redwall Limestone consists predominantly of light-olive-gray to light-gray, fine- to coarse-grained, thin- to thick-bedded, often cherty, limestone. Its lower part consists of brownish-gray, interbedded finely crystalline dolomite and fine- to coarse-grained limestone with layers of white chert lenses and yellowish-gray and brownish-gray, cliff-forming, thick-bedded, fine-grained dolomite. It is divided into Horseshoe Mesa Member, Mooney Falls Member, Thunder Springs Member, and Whitmore Wash Member. Its origins date to the Mississippian age.[1][2]
Contacts[edit]
The upper and lower contacts of the Redwall Limestone are both unconformities. Locally, the Redwall Limestone directly overlies the unconformity that forms its lower contact consisting of a basal conglomerate. This basal conglomerate is typically composed of gravel that is locally derived from either the underlying Temple Butte Formation or Muav Limestone. The Temple Butte Formation consists of a thin layer of Devonian strata that fills paleovalleys cut into the underlying Cambrian Muav Limestone. Outside of the paleovalleys, the Redwall Limestone overlies the Muav Limestone.[1]
The upper contact of the Redwall Limestone consists of a deeply eroded disconformity characterized by deeply incised paleovalleys and deep paleokarst depressions that are often filled by sediments of the Surprise Canyon Formation.[1][8]
See also[edit]
References[edit]
- ^ a b c d e Beus, SS (2003) "Redwall Limestone and Surprise Canyon Formation." in: Beus, S.S., Morales, M., eds., pp. 115–134, Grand Canyon Geology, 2nd. Oxford University Press, New York.
- ^ a b c d McKee, E.D., and Gutschick, R.C., eds., 1969. History of the Redwall Limestone of northern Arizona, [with] chapters on paleontology of the Redwall Limestone by B. Skipp, W.J. Sando, H. Duncan, E.L. Yochelson, W.M. Furnish, D.B. Macurda, Jr., and J.C. Brower. Geological Society of America Memoir. 114. Boulder, Colorado, Geological Society of America. 612 pp ISBN 978-08-137-1114-0
- ^ a b c Gilbert, G.K., 1875. Report upon the geology of portions of Nevada, Utah, California, and Arizona, Chapter 6. In Wheeler, G.M., ed., pp. 17-187, Report on the Geographical and Geological Explorations and Surveys West of the One Hundredth Meridian, vol. 3. U.S. Geological and Geographical Survey, Publication of the Wheeler Survey, Washington, D.C., 681 pp.
- ^ Darton, N. H., 1910. A reconnaissance of parts of northwestern New Mexico and northern Arizona. U.S. Geological Survey Bulletin. 435, 88p.
- ^ Noble, LF (1914) The Shinumo quadrangle, Grand Canyon district, Arizona. Bulletin no. 549, US Geological Survey, Reston, Virginia. 42 pp.
- ^ Gutschlck, R. C., 1943. The Redwall Limestone (Mississippian) of Yavapai County, Arizona. Plateau, 16(1), pp. 1-11.
- ^ McKee, E. D., 1963. Nomenclature for lithologic subdivisions of the Redwall Limestone, Arizona. U.S. Geological Survey Professional Paper. 475-C, pp. C21-C23.
- ^ Kenny, R (2010) Continental paleoclimate estimates from the late Mississippian Redwall karst event: northern and north-central Arizona (USA). Carbonates Evaporites. 25(4):297–302
Further reading[edit]
- 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[edit]
- Abbot, W, (2001) Revisiting the Grand Canyon – Through the Eyes of Seismic Sequence Stratigraphy. Search and Discovery Article # 40018, America Association of Petroleum Geologists, Tulsa, Oklahoma.
- Anonymous (nda) The Redwall Limestone Formation. Utah Geology.
- Mathis, A., and C. Bowman (2007) The Grand Age of Rocks: The Numeric Ages for Rocks Exposed within Grand Canyon, Grand Canyon National Park, Arizona, National Park Service, Grand Canyon National Park, Arizona.
- Shur, C., and D. Shur (2008) The Mississippi Redwall Limestone In Northern Arizona. Arizona Fossil Adventures.
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