Recent photograph of Grand Canyon from Walhalla Plateau ... the metamorphic Proterozoic basement complex and the Paleozoic sediment strata. "There's more than a billion years that's gone ...

Located in the state of Arizona, it cuts across the Grand Canyon National Park. Its horizontal strata retrace the geological history ... The Precambrian and Paleozoic portions of this record are ...

the youngest of the rock formations found in the Grand Canyon, having been laid down under shallow ancient seas some 270 million years ago toward the end of the Paleozoic Era. This is the grayish ...