Wind can erode the landscape through a number of processes. There are two major methods of wind erosion.
- Deflation: Deflation refers to wind blowing across loose sediment and picking up the finer smaller particles on top, called topsoil. The topsoil is blown away resulting in a lowering of the land surface. Shallow depressions known as deflation hollows often remain after the topsoil has blown away. These deflation hollows vary in diameter from a few meters (about ten feet) up to several kilometers (several miles). In many areas, deflation removes the lighter soil particles and leaves behind stones and rocks that are too heavy. This gravelly surface is called a desert pavement.
Deflation has eroded material under this vegetation cap at White Sands National Monument in New Mexico. A deflation hollow is also visible around the base.
This photo of desert pavement in the Mojave Desert in California illustrates its hard-packed, gravelly appearance.
- Abrasion: Wind abrasion is the process whereby windblown sediment rubs and scrapes against other rock and with time slowly wears the rock surface away. Windblown sand, in particular, is quite active in the abrasion process because it is often made of quartz, a very hard mineral that can easily wear away softer rock. The process of abrasion is also active in water erosion and in glacial erosion.
Abrasion of the softer rock under the harder upper rock in the Cappadocia region of Turkey resulted in the formation of these rock columns known as hoodoos.
Word Link
Deflation: This word is a combination of the Latin prefix de meaning away and the Latin word flare which means blow. Deflation, in the geologic sense, literally means to blow away.
Abrasion: This word stems from 1656 and is based on the Latin word abradere which means to scrape away.
History Link
What Do You Think?
Delicate Arch, the most famous landmark in Arches National Park, is also depicted on the Utah license plate.
Erosion at Fiery Furnace
Arches National Park in Utah is well-known for its dramatic sandstone arches formed by erosion.
Less well known is that Arches National Park also possesses several other unusual landforms that have also been formed by erosion. Prominent among these is the landform known as Fiery Furnace.
- Click here to see Fiery Furnace.
Geologists consider wind erosion to have been a major factor in the formation of the parallel ridge-like structure of Fiery Furnace.
Part of the ridge-like structure of Fiery Furnace.
What evidence is visible in the main view panel to the right that wind erosion was, and continues to be, a major factor in the formation of Fiery Furnace? What do you think?
(Note: You may wish to zoom in, and change your view of Fiery Furnace to assist you in answering this question.)
Geologists do believe, however, that water had a significant role in the formation of Fiery Furnace. They believe that water initially seeped into cracks in the sandstone. Repeated freezing and thawing of this water/ice lead to the widening of cracks and the breakdown of rock into smaller sandstone fragments. The scouring action of the wind over time (i.e. wind abrasion) then served to clear out and further erode these cracks over time resulting in the parallel, ridge-like formations that we see today.