How is desert sand formed?
All sand is produced by the removal of the more soluble and easily broken fraction of the original material, Most desert sand is the result of water formed sands in earlier periods. The sands were deposited originally in circumstances very different from the current desert. Wind erosion continues to”purify” the sand by removing the less dense fractions. Chemical reactions during the occasional rainstorm continue to dissolve the soluble part. Particle size and chemistry are good guides to how strong the winds are and the amount of rain that falls. The coarser the grain size the windier the area is, the higher the content of soluble minerals the drier the desert is. Wind by itself can form sand in theory but it is very slow. Again it mostly does so by removal of the less dense fraction of material and by chipping away at the larger pieces of rock.