II.--FROM THE GRAND CANYON RIM TO THE GRANITE GORGE
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_]
[1]_A table of the geological formations is on pages 45 and 46._
[2]_These accommodations are not operated by the Utah Parks Company and the information given is subject to change._
Representatives of the Union Pacific System