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L73 Fossilized sand dunes, Navajo Sandstone, Zion National Park,
Utah, USA
Position:
N37° 13.815'
W112° 52.721'
Elevation:
4700'/1737m
Image format:
MF & 35mm
FOSSILIZED SAND DUNES
Ancient sand dunes from the Permian Period some 250 million years
ago are preserved in this cliff. Look for the diagonal lines running
left-right. These are the buried surface of former sand dune back-slopes.
By studying the orientation of the slopes it would be possible
to calculate the wind directions at the time of deposition. Of
course allowance would have to be made for CONTINETAL DRIFT and
POLAR WANDERING since the time of deposition. The dune structures
of this famous Navajo rock formation can be traced over large
areas of the American South West. The vertical lines have been
eroded by running water during rain storms.
Less detail
Image Trail:
L23, L35, L46.
Links:
www.geology.uvm.edu/vtlandforms/gl_rippl.htm
www.geology.sdsu.edu/visualgeology/geology101/riplmrks.htm
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