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Date of visit:
March 17, 2000
For location of this site in NM, click on the map:
We rate this site a:
Site Highlights:
 Very popular
Seems uncrowded
Modest entry fee
Bring sunglasses
Bring sunblock SPF30
Bring camera
Many hiking trails
Evening tours
Learn source of sand
Walk alkali flats
Is it snow or sand?
Many picnic sites
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At the White Sands
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At the northern end of the Chihuahuan Desert lies a mountain-ringed valley, the Tularosa Basin. Rising from the heart of this basin is one of the world's great natural wonders - the glistening white sands of New Mexico. Here, great wave-like dunes of gypsum sand have engulfed 275 square miles of desert and have created the world's largest gypsum dune field.
The brilliant white dunes are ever changing: growing, cresting, then slumping, but always advancing. Slowly but relentlessly the sand, driven by strong southwest winds, covers everything in its path. Within the extremely harsh environment of the dune field, even plants and animals adapted to desert conditions struggle to survive.
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| Only a few species of plants grow rapidly enough to survive burial by moving dunes, but several types of small animals have evolved a white coloration that camouflages them in the gypsum sand.
White Sands National Monument preserves a major portion of this gypsum dune field along with the plants and animals that have successfully adapted to this constantly changing environment.
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| How the dunes formed |
How the Tularosa Basin was formed.
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The Tularosa Basin: The gypsum that forms the white sands was deposited at the bottom of a shallow sea that covered this area 250 million years ago. Eventually turned into stone, these gypsum-bearing marine deposits were uplifted into a giant dome 70 million years ago when the Rocky Mountains were formed. Beginning 10 million years ago, the center of this dome began to collapse and create the Tularosa Basin.
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The remaining sides of the original dome formation now form the San Andres and Sacramento mountain ranges that ring the basin.
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| A rare form of sand |
A dapper visitor
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The common mineral gypsum, a hydrous form of calcium sulfate (CaS04-2H20), is rarely found in the form of sand because it is soluble in water.
Rain and snow that fall in the surrounding mountains dissolve gypsum from the rocks and carry it into the Tularosa Basin.
Normally, rivers would carry dissolved gypsum to the sea. But no river drains the Tularosa Basin.
The water, along with the gypsum and other sediments it contains, is trapped within the basin.
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| Lake Lucero |
Prevailing winds of White Sands
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With no outlet to the sea, water flowing into the Tularosa Basin either sinks into the ground or pools up in low spots. One of the lowest points in the basin is a large playa called Lake Lucero. Occasionally, this dry lakebed fills with water. As the water evaporates, the dissolved gypsum is deposited on the surface. Even more gypsum deposition occurred during the last Ice Age when a larger lake, Lake Otero, covered much of the basin.
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Crystal beds: In wet periods, water evaporating slowly on the playa floor causes gypsum to be deposited in a crystalline form called selenite. Along Lake Lucero's shore and in the Alkali Flat, beds of selenite crystals-some three feet long-cover the ground. The forces of nature - freezing and thawing, wetting and drying-eventually break down the crystals into sand-size particles light enough to be moved by the wind.
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| Four types of dunes at White Sands |
Dome dunes
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The first dunes to form downwind of Lake Lucero are low mounds of sand that move up to 30 feet a year.
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Barchan dunes
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Crescent-shaped dunes form in areas with strong winds but a limited supply of sand.
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Transverse dunes
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In areas with ample sand, barchan dunes join together into long ridges of sand
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Parabolic dunes
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On the dune field edges, plants anchor the arms of barchans and invert their shape..
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Sand verbena |
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Claret cup cactus |
Cactus wren |
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Bleached earless lizard |
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| Site Gallery - White Sands
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