Saturday, January 7, 2012
The condition of the rocks in Bryce National Park is absolutely perfect for the formation of hoodoos, that is unconnected rock spires. The spaces in between the rocks is filled with an unconsolidated clay. The colors come from the mineralization of the iron in the clay between the rock ledges. You can see the same forces at work in a sandbox or sand pile with different layers of wet and dry sand. The slopes below the cliffs lie at the angle of repose, that is the optimal angle for particles in an unconsolidated pile. What is surprising about Bryce is the color and extent of the eroded surfaces.