Leave the sand on the beaches
Do you know what is the composition of sand and how did it appear on the coast? Explanations in detail.
What is the composition of the sand?
Beach sand is a moving sedimentary rock made up of debris, small particles from minerals such as granite, quartz, iron oxides and carbonate fragments. The grains are of different sizes. The beaches were formed by the erosion of continental rocks, also ancient. Common sand, therefore made up of quartz grains, is formed by the erosion of rocks under the effect of water and temperature and carried by rivers and wind. During the ice age, 2 million years ago, sand accumulated for a very long time in dunes or fossil beaches, here is an example: The cliff of Corréjou in Brittany. During storms, the sand came together and washed up on the beaches.
The colors of the sand
Of organic origin, composed of fragments of corals, shells and skeletons of organisms, white sand covers paradisiacal atolls (coral islands in tropical oceans). Black sands, on the other hand, come from a volcanic rock like basalt. Other colors of sand exist, such as pink, red, garnet or even green.
Leave the sand on the beach
You should know that more and more sand is being extracted from the beaches. It is used for construction and dams. The fight against the erosion of banks and dunes as well as the melting of glaciers and the rising waters are not helping.
The people of the dunes in Trégor explain the fight to you because the beaches are receding and gradually disappearing.
What happened in Aquitaine
In the Middle Ages, the accumulating water gave birth to the coastal ponds that we know today on the coast of the Gironde and Landes.
The beach regime
In winter, between the tip of Brittany and that of the Pyrenees, the beaches get thinner and during strong storms, the sand is drawn towards the sea. It can be stirred up to 5 to 15 m deep and up to 40 meters background. In summer, the beaches progress. The small waves bring the sand back to the beach but the evolution of this phenomenon is very slow and far from over, the curve taking shape perfectly.
Today, we take full advantage of the world's beaches, but they are fragile and risk disappearing if we do not leave the sand on the beaches.