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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 150 m (490 ft) to 244 m (801 ft).
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.
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]
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]
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. The Redwall Limestone cliff section in ...
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.
This is a list of Supai Group prominences in the Grand Canyon.Landforms with up to 4 units of Supai Group, as prominences.. The rock unit sequences are as follows: Coconino Sandstone, (prominence, Permian unit)
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.