A spectacular section through a fossilised dune system in the Navajo sandstone. The overlapping dunes are clearly visible the vertical lines appear to be stress structures. Similar (but not as dramatic) dune systems can be seen in the cuttings at Liverpool Lime Street and Frodsham.
Web information:
Checkerboard Mesa lies at the entrance to Zion National Park. This feature is composed of the Jurassic ages (180 MYA) Navajo Sandstone. The Navajo Sandstone is composed of lithified sand dunes whose source material originates from the ancestral Rocky Mountains. Because the Navajo is made up of lithified sand dunes, distinctive cross bedding (lines that represent ancient sand dunes) are found along the rock face. This rock unit represents the worlds largest Eolian environment (desert) in earth’s history.
The checkerboard pattern stems from the combination of cross bedding and joints created by frost wedging. Frost wedging occurs as water penetrates the Navajo sandstone and freezes. The expansion of water during freezing (8X its liquid volume) the ice pushes apart the rock to create joints. These joints run perpendicular to the cross bedding marks to create the checkerboard pattern after which this feature is named.