Where does all the sand in the desert come from?

What causes a desert to form? How is the sand created and how does it get there? read more

a large question. We start with the formation of the Earth; by chance the chief crustal elements are O, Si and Al- which have to be incorporated into the first crustal rocks. The main crustal rocks are granites; the main minerals in the granites are feldspars and quartz. read more

The Sahara’s sand is actually all that is left of soil that lost its moisture. The Sahara area was much wetter about a million years ago, with rivers, trees, and grass. But when the Ice Age ended about a half- million years ago, the climate in the Sahara grew hotter and drier. read more

All of this levels the land over millions of years. The sediment is gradually broken down into finer and finer particles from boulders to silt over millenia to form sand. In a desert situation, it is a combination of erosion of both surrounding landforms, climate change and erosion of soil. read more

But we now know that the Sahara’s sand is much newer than that. The Sahara’s sand is actually all that is left of soil that lost its moisture. The Sahara area was much wetter about a million years ago, with rivers, trees, and grass. read more

Nearly all sand in deserts came from somewhere else – sometimes hundreds of kilometers away. Sand consists of small particles of larger rock that’s been eroded. But erosion doesn’t happen fast enough in arid environments to be the only cause of desert sand. read more