Grand Canyon Poster 4820 Black

The Colorado River from the East Rim of Grand Canyon National Park at Moran Point (elevation at 7,160 feet above sea level). In the foreground, the tan rock is Coconino Sandstone formed 275 million years ago. The black rock layer at river level includes Vishnu Basement Rocks (formed 2 billion years ago) which resulted from the North American tectonic plate colliding with the Juan de Fuca tectonic plate. This created heat and pressure that melted the rock into dark metamorphic rock and squeezed it up through the cracks in the earth to become the basement of the Grand Canyon. The Colorado River (elevation at 2,450 feet) started carving the Grand Canyon 5 or 6 million years ago. The river's blue-green color is from the minerals of calcium-carbonate and copper-sulfate.