Kaibab Limestone 800 Late Grand Gray limestone formed in the
Carboniferous Canyon sea, as indicated by many
Carboniferous fossil shells.
At the Grand Canyon it is the
surface rock. In the Plateau
Country to the north, it lies
at the bottom of the series.
Coconino 300 Carboniferous ″ Very massive, cross-bedded
yellow sandstone.
Supai Formation 1100 Carboniferous ″ Alternating red shale and red
and brown sandstone, the
latter forming low cliffs.
This constitutes the greatest
red body of the Canyon wall.
Redwall Limestone 600 Carboniferous ″ Extremely hard blue or gray
limestone, forming the
greatest cliff of the Grand
Canyon. It is stained a vivid
red by the wash of the red
Supai shales above. The cliff
is a conspicuous feature of
the Canyon everywhere.
Missing Strata Devonian ″ During Devonian, Silurian and
Silurian Ordovician times, extensive
Ordovician strata were deposited upon
the Cambrian rocks below, but
were wholly eroded away
during a long uplift period
and the limestone known as
the Red Wall was deposited on
the Tonto during a succeeding
period.
Tonto Group 950 Cambrian ″ Olive green shale and
limestone, forming the broad
green floor of the Grand
Canyon, through which winds
the Granite Gorge.
Unkar and Chuar Algonkian ″ Greenish sandstones, fine
Groups known as quartzites and vividly red
the Grand shales, once 13,000 feet
Canyon Series thick, but here eroded away
till they appear only in
places.
Granite Gorge 1200 Archean ″ Schists metamorphosed from
sedentary rocks, and intruded
igneous rocks.
[Illustration: _Utah Parks Co. Automobile Specially Designed for
Southern Utah Travel_]