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The lower contact of the Redwall Limestone is a disconformity that rests either on upon the Devonian Temple Butte Formation or, where it is missing in the eastern Grand Canyon, strata of Cambrian Tonto Group. Often, the Redwall Limestone immediately overlying this disconformity contains a basal conglomerate.
The Muav Limestone is a Cambrian geologic formation within the 5-member Tonto Group.It is a thin-bedded, gray, medium to fine-grained, mottled dolomite; coarse- to medium-grained, grayish-white, sandy dolomite and grayish-white, mottled, fine-grained limestone.
Vertical erosion in cliff of Redwall Limestone, upon horizontal Muav Limestone cliff. [19] The Tapeats Sandstone sits in foreground on Granite Gorge , and is seen as thinly-bedded. The slope-former above is the (dull-greenish)-Bright Angel Shale with thin, inter-bedding, as well as one resistant cliff unit.
Redwall is composed of thick-bedded, dark brown to bluish gray limestone and dolomite with white chert nodules mixed in. [34] It was laid down in a retreating shallow tropical sea near the equator during 40 million years of the early-to-middle Mississippian. [39]
Muav Limestone – (dark or light 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.
As relative sea level dropped the westward retreat of the sea, a marine regression, subaerially exposed the seafloor in which the Redwall Limestone had accumulated. This left the former seafloor and upper surface of the Redwall Limestone subaerially exposed as a tropical sinkhole plain drained by west-trending, low-gradient rivers.
The disconformity between the Redwall Limestone and the Supai Group records a time of regional uplift, in which the Grand Canyon area was elevated by at least several hundred feet. Erosion carved channels in the Redwall Limestone that reach a maximum depth of 400 feet (120 m) in the western Grand Canyon. [10]
The Red Wall, the nickname given to supporters of the Wales National Football Team; Redwall Limestone or Redwall Formation, rock layer that forms prominent, red-stained cliffs in the Grand Canyon, Arizona; Redwalls, The Homestead, Sandiway, Cheshire, England, UK; a listed building on the Homestead estate