January 6, 2012
This view of the canyon reveals the layers of limestones and sandstones that testify to vanished seas and deserts. Note the strong, narrow white layer of Coconino Sandstone near the top, composed of 260-million year-old sand dunes. Also note in the center of the photo the 500-foot-tall cliff of Redwall Limestone formed on a seabottom 300-400 million years ago.
Stories this photo appears in:
I took a step — a long step — a million years step. Then I stopped, turned and faced north. Perched on the jagged edge of my life, I looked down deep into the shadowed layers of lost worlds — terrible deaths, fractured continents, vanished seas, mass extinctions. Taking a breath, I took another step — a long step — another million years. Curiously, I felt better — my troubles for the moment shrunk to no more than a ledge of Tapeats Sandstone in the wall of the Grand Canyon opposite. A layer of fossilized beach sand laid down 570 million years ago, the Tapeats Sandstone lies atop a mystery of missing stone — dubbed the “Great Unconformity.”