White Sands, the world's largest gypsum dunefield, formed over millions of years through a fascinating process involving ancient seas, mineral deposits, and wind erosion.
The Permian Sea and Gypsum Deposits
The story begins approximately 280 million years ago with the Permian Sea covering the area now known as White Sands. As the sea evaporated, vast quantities of gypsum, a soft mineral (hydrous calcium sulfate), were deposited on the seafloor. This process was repeated over time as sea levels rose and fell, building up significant layers of gypsum. [Source: NPS, various articles]
Lake Evaporation and Crystal Formation
Further warming and drying led to the evaporation of lakes in the Tularosa Basin, where White Sands is located. This evaporation concentrated the gypsum, resulting in the formation of selenite crystals. [Source: Wikipedia] The gypsum originated from the nearby San Andres Mountains and washed into the basin. [Source: NASA]
Wind Erosion and Dune Formation
Strong winds then played a crucial role. They broke up the selenite crystals, transporting them eastward and accumulating them into the massive dunes we see today. This ongoing process of erosion and renewal continues to shape the landscape. [Source: NPS, various articles] The pure gypsum forms dunes originating from an ephemeral lake or playa in the western portion of the monument. [Source: New Mexico Tourism] The gypsum concentrates and forms crystals when the lake dries. Wind then blows the crystals into piles forming dunes. [Source: Quora]
In summary, the unique white sands of White Sands National Park are the result of a long geological history involving:
- Ancient Sea: The Permian Sea deposited layers of gypsum.
- Lake Evaporation: Evaporation of lakes concentrated gypsum, forming crystals.
- Wind Erosion: Wind transported and shaped the gypsum crystals into dunes.
