Glaciers are found in snow-capped mountain ranges at great heights and are basically rivers of ice. The glaciers pick up and carry soil and loose stones along with ice which exposes the solid rock below. The forced movement of these materials with the glacier cause deep scratches and large holes to be carved in the bedrock.
As the ice melts, these holes get filled with water, and form picturesque lakes in the mountainside. When the materials carried by the glacier get deposited, they accumulate and form glacial moraines. Wind blowing in a desert carries and deposited sand from one place to another, in the form of low hill-like structures, called sand dunes, mushroom rocks and loess.
Winds carrying heavy, thick grains grind against the lower section of the rock while the upper portions of these rocks are less exposed to erosion and remain wide. The erosion hence gives it the shape resembling a mushroom.
When the sand grains are very fine and light, the wind carries it over very long distances. When such sand is deposited in large areas, it is called loess.