Undercutting ... Hermits Rest...Grand Canyon

Undercutting ... Hermits Rest...Grand Canyon

The broad layer of rock near the center of the photo, with vertical cliff faces, is Coconino Sandstone. It is a relatively hard layer of rock that is sometimes described as 'petrified dunes'. Below it, the layer with sloping walls is Hermit Shale, a much softer layer that was deposited in ancient swamps and by rivers and streams.

The Hermit Shales erodes more rapidly than the Coconino Sandstone. I chose this photo because it shows clearly areas of undercutting at the boundary between the two layers. Each of these areas is a site for future collapse of the overriding sandstone.

I also liked the view of the sun-brightened rim of the next side canyon to the west showing above the cloud-shaded rim at Hermits Rest. It reminds the viewer that the Colorado Plateau is far from being a flat, level region. It varies significantly in elevation as you move along the rim.

Location: Hermits Rest, south rim, Grand Canyon NP, Arizona, USA