Cuatro Ciénegas Gypsum Dunes.
Cuatro Ciénegas Dune Fields are among the largest known gypsum sand-dune accumulations on Planet Earth. The sulfate that forms the white sand is evaporite strata of Cretaceous age.
An unrepeatable landscape in our planet by Nicolás Sánchez-Mejorada GiraultCuatro Ciénegas- Genesis 4C Museum and Laboratory
Gypsum composition.
Gypsum is a soft sulfate mineral mainly composed of calcium sulfate dihydrate (CaSO42H20.), widely used as a fertilizer and as the main constituent of plaster.
It's naturally formed from calcium carbonate and sulfur.
How is gypsum formed?
The sulfur comes from hydrothermal vents on the seafloor and calcium carbonate from the shells of marine invertebrates; after a very complex chemical reaction, these two components bound together to form calcium sulfate.
Evaporite deposit by Nicolás Sánchez-Mejorada GiraultCuatro Ciénegas- Genesis 4C Museum and Laboratory
Calcium sulfate accumulation.
Gypsum occurs commonly in nature on evaporite beds; these types of deposits come from the evaporation of seawater, lakes, and hot springs but are extremely rare in the form of dunes such as those found in Cuatro Ciénegas, Coahuila México.
The mountains once were part of the ocean floor.
Different environmental factors must happen to create gypsum dunes. When the carbonate-rich seafloor emerged to the surface in the Cretaceous, the range mountains surrounding the Cuatro Ciénegas valley were formed.
Cloud covered mountains by Nicolás Sánchez-Mejorada GiraultCuatro Ciénegas- Genesis 4C Museum and Laboratory
The mountains in the valley are the gypsum source.
This particular place is located in the Chihuahuan Desert; so there is very little rain and, when it rains, the gypsum content in the mountains dissolves and flows with the water until it reaches the aquifers that feed the ponds.
Gypsum crystals accumulation by Nicolás Sánchez-Mejorada GiraultCuatro Ciénegas- Genesis 4C Museum and Laboratory
Some of the ponds are shallow and when the water evaporates, the gypsum is exposed on the surface.
Gypsum crystals by Nicolás Sánchez-Mejorada GiraultCuatro Ciénegas- Genesis 4C Museum and Laboratory
Once exposed, the gypsum begins a very long and gradual erosion process into smaller pieces forming sparkling crystals.
Dunes formation by Nicolás Sánchez-Mejorada GiraultCuatro Ciénegas- Genesis 4C Museum and Laboratory
The wind forms the dunes.
When the gypsum crystals become small enough are carried out by the wind to a specific area within Cuatro Ciénegas valley where the currents converge, depositing them in an area covering 8 km2 of land, creating an incredible landscape with dunes that rise meters as white as snow.
Plant species diversity by Nicolás Sánchez-Mejorada GiraultCuatro Ciénegas- Genesis 4C Museum and Laboratory
The world's second-largest gypsum dunes field.
Cuatro Cienega's Gypsum Dunes, known by de locals as "The Arenales," are composed of 98% calcium sulfate, making them the purest gypsum dunes on the Planet Earth. Home of 15 endemic species of plants and multiple animals that surprisingly exist nowhere else on Earth.
Breathtaking sunrise by Nicolás Sánchez-Mejorada GiraultCuatro Ciénegas- Genesis 4C Museum and Laboratory
An unrepeatable scenario.
Walking through "Los Arenales" is like being transported to the past, with sand generated from marine fossil remains.
It´s a place that awakens all the senses, with unrepeatable sunsets that take your breath away.
Ph.D. Héctor Fernando Arocha Garza, Genesis 4C.
Acknowledgments to Desuvalle, A.C. for the access granted to get the photographs.
