The Landscape - paulsmit
[USA.UTAH 28261
'Sunset at Monument Valley.’

	A last ray of sunlight illuminates the plain at Monument Valley.
Soft shales at the base of the buttes crumble under the influence of water and frost erosion, undermining the more resistant overlying sandstone which forms vertical cliffs when it collapses. The shales and sandstone date from the Permian period. Photo Mick Palarczyk.