At first glance, there seemed no life beyond the few plants that had managed to find a stronghold in the shifting sands. Among the dozens of species, the Indian ricegrass, the soaptree yucca , and the Rio Grande cottonwood.
Life is more implied than obvious in the dunes. Burrows, mounds and the occasional footprints are testaments to the adaptation (and essentially nocturnal activity) that begets life for the hardy few, including the camel cricket, the Apache pocket mouse, and the bleached earless lizard.
Despite our best intentions, it was close to noon (not a good time to be in the relentless desert sun) when Jimmy and I arrived at New Mexico’s Tularosa Basin, where 4.5 billion tons of gypsum sand had collected since . . .
The short answer? Wind and water.
Geologists would speak about a shallow inland sea covering most of the Southwest United States 250 million years ago, a sea rich in gypsum minerals. They'd go on to make mention of one Ice Age and 70 million more years of geological magic resulting in the surrounding mountain ranges and the ancient lake bed on which today’s white sands have found a home. Both mountain range and ancient lake bed are continued sources of gypsum today via rainwater, evaporation, and prevailing winds.
Those prevailing winds grind the large gypsum selenite crystals that emerge from the protective mud surface of what was once Lake Otero 7 to 10 thousand years ago, eroding the soft mineral into smaller shards. When the shards are small enough to be picked up by the wind, the “cornflakes” bounce along the surface and leap-frog over one another, becoming scuffed and buffed until snowy white; kind of like my face after a facial.
More gypsum is sloughed off from the mountains on either side of Tularosa Basin via rainfall during intense but brief thunderstorms from July to September. Broader frontal systems deliver the remainder of the rainfall from October to May.
Did you know gypsum is the basis for plaster of Paris? Yes, the French got bragging rights for discovering that the large deposits of gypsum in Paris were rather handy when it came to making plaster, although the word gypsum is derived from the Greek word gypsos, meaning ‘chalk’ or ‘plaster’. I guess plaster of Athens didn’t come to mind back in the day. Anyhoo, add a little water, and voila!; gypsum becomes hard as stone. Gotta love the circle of life, even when tiny grains of sand are at the center of that circle.
History buffs may remember White Sands as the site of the world’s first atomic bomb, detonated on July 16, 1945 at Trinity Site, 70 miles to the north on the other side of the San Andres Mountains in the distance. The 75-mile-long mountain range lies almost entirely within the restricted White Sands Missile Range, the largest military installation in the United States. More than half of the remarkably nimble and active White Sands dunes are located inside the restricted government property. Visits to Trinity Site are limited to the first Saturday in April and October.
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