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Coral Pink Sand Dunes
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Stop 26 Coral Pink Sand Dunes
Location: 12 miles west of Kanab, UT.
Date: March 12, 2007

Coral Pink Sand Dunes State Park lies in southwestern Kane County, Utah.  The sparse vegetation, semiarid-desert climate, prevailing southerly winds, and large sand supply from Navajo Sandstone creates a very susceptible area for sand dune formation.  The Coral Pink Sand Dunes is one of the largest “freely migrating” dune fields in the Colorado Plateau. The dunes here owe its unique color to iron-oxide stains on the surface of the sand.  The sand is mainly derived from the nearby Navajo Sandstone cliffs which are exposed near and around the park.

 


A view of the Coral dunes

 

The dunes themselves are composed of transverse ridges, barchanoid ridges, and a single star dune. The formation of a dune field here is thought be largely due to the Sevier Faults activity (mentioned later) which caused a large break in the Vermillion Cliffs to the south of the park.  As the strong southerly winds reached this gap they would accelerate and entrain more sediment.  As the gap widens and the winds reach the bedrock scarp, created by the Sevier Fault, the velocity of the wind would then decrease allowing for deposition of sediment.  The dunes at the southern end of the park have north-south trending characteristics that would represent the prevailing winds blowing in from the south of the park.  Further north the dunes characteristics change to a south-west-north-east trending field.  This could represent prevailing winds coming from Rosy Canyon, another nearby gap in the Vermillion Cliffs.  In both cases the widening valley and bedrock escarpment serve as an ideal place for deposition.

 


A map of the Coral Pink dune field

 

The geology and tectonics exposed in the park is quite striking. Coral Pink Sand Dunes lies on the boundary between the Colorado Plateau and Great Basin of the basin and range province and so lies in an area of once active tectonic activity.  The bedrock escarpment that forms the eastern boundary of the dune field were created by the north-south trending Sevier Fault, which cuts the park into two (almost equal) halves.  This large normal fault extends from the Grand Canyon to central Utah as a series of braided faults and began movement apprx. 12-15 Ma.  The eastern side of the fault has been thrust upward revealing members of the Moenave Formation, much higher than the younger Navajo Sandstone, which appears on the down-drop side.  The formations of bedrock exposed in the park can easily by described by using figure below.  Various depositional environments occurred in the area over millions of years.  These paleo-environments left their distinct footprint in the bedrock exposed throughout the region.

 


Geologic formation

 


A look at the faulting in the valley

 

 

By Phillip Larson