Much has been learned about the geology of the Grand Canyon and about ... layer was deposited not by the sea, but by wind, which blew in sand across the region. Fossils found in these layers ...

the topmost layer of rock in the Grand Canyon, was formed at the ocean's bottom. However, it is now located up to 9,000 feet ...

At the time the Tonto Group was being laid down, sea levels were rising ... "The Tonto Group of Grand Canyon holds a treasure trove of sedimentary layers and fossils chronicling the Cambrian ...

The Department of Conservation and Natural Resources is offering the Canyon Waterfall Geology Hike on April 12.