This is an electron microscope image of a dust particle rounded by eolian transport. It originated in the Sahara desert and was found in 7.2 million year old sediments in Greece. Disclaimer ...

Eolian (windblown) sandstone deposits can form excellent oil and gas reservoirs. Wind is a very effective agent for sorting sand-size, silt-size, and clay-size grains, both vertically within the air ...