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Formation of the Grand Canyon By Jeff Bratman And Daniel Gallenson History in Rocks An exposed rock layer of any type is called an out crop The bottom and oldest rock in the canyon is the Vishnu schist The Tapeats sandstone, the Bright Angel shale, and the Muav limestone
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Formation of the Grand Canyon By Jeff Bratman And Daniel Gallenson
History in Rocks • An exposed rock layer of any type is called an out crop • The bottom and oldest rock in the canyon is the Vishnu schist • The Tapeats sandstone, the Bright Angel shale, and the Muav limestone • The Mississippianperiod is represented in the Redwall limestone • The Supai formation was deposited during the Pennsylvanian Period • The Permian Period is represented by several deposits- the Hermit shale, the Coconino sandstone, the Toroweap formation, and the Kaibab limestone
History in Fossils • Limestone and shale, for example often contain fossils of marine organisms such as clams, fishes, and corals. • The bright angel shale contains many trilobites, marine invertebrates, and brachiopods. • The fossils show that a distinctive group of plants and animals lived during each period of layers • Analysis of the fossils found in lower, older rock layers though the younger, upper simple suggest a sequence of events. These fossils indicate that early/simple life-forms gradually either become extinct or changed into more complex life forms
Formationof the Grand Canyon • The Grand Canyon must have begun as a small valley cut by the Colorado River. Slowly the land was uplifted to form a high plateau. • This new uplifted region is now called the Colorado Plateau. • The Colorado has probably taken 10 million years erode through the slowly rising plateau.
Vocabulary • Vishnu Schist: The bottom and the oldest rock layer • Tapeats Sandstone: Rock layer of the Grand Canyon deposited during the Cambrian Period. • Bright Angel Shale: Same definition as Tapeats Sandstone. • Muav Limestone: Same definition • Redwall limestone: Rock layer of the Grand Canyon deposited during the Mississippian Period. • Supai Formation: Rock layers of the Grand Canyon deposited during the Pennsylvanian Period.
Vocabulary (cont.) • Hermit Shale, Coconino Sandstone, Toroweap formation, and Kaibab Limestone: Rock layers of the Grand Canyon deposited during the Permian Period
Facts and Statistics • The shortest distance by road between the South Rim and the North Rim of the Grand Canyon is 215 miles. • The Grand Canyon is 1,904 square miles. For comparison, the size of the English county of Northumberland is 1,944 square miles. • Depth: One mile. The world's tallest skyscrapers would fit inside the inner gorge of the canyon.