Why is there sand in deserts and no dirt? Why isn’t there sand anywhere else?

Question

I figured it was something to do with sand being light enough to be carried by wind, but that wouldn’t explain why the rest of the world lacks sand.

In: 327

Answer 1

Sand is broken down rock with bits that are “sand” size but rocks can also break down to smaller bits, clay and silt, in a desert the processes that make clay and silt aren’t present, specifically water erosion. Dirt is made up of sand, silt, clay and “natural” fertilizer. In some deserts especially dry ones many of those components will be missing so you are just left with sand.