Deflation basins, called blowouts, are hollows formed by the removal of particles by wind. Blowouts are generally small, but may be up to several kilometers in diameter. (cartage.org)

Slopes protected from the prevailing winds have had negligible wind erosion except in areas where severe erosion created deflation basins. These blowout basins are limited to small interfluve areas, a few square miles in size, which probably had a thick layer of loose, sand-size fissile-shale fragments that winds could erode. (Soil Science Society of America)

Wind erosion removes and redistributes soil. Small blowout areas may be associated with adjacent areas of deposition at the base of plants or behind obstacles, such as rocks, shrubs, fence rows, and roadbanks. (United States Department of Agriculture)