Eolian

Eolian, also spelled aeolian, refers to processes, landforms, and deposits created or shaped by the action of the wind. The term derives from Aeolus, the Greek god of winds, and is used in geology, geomorphology, and sedimentology to distinguish wind-driven phenomena from those produced by water, ice, or gravity.

Wind transports sediments through saltation, suspension, and surface creep. In saltation, grains are lifted and then bounce along the surface; suspension carries finer particles high into the air; surface creep involves larger grains rolling or sliding along the ground. Eolian erosion occurs by abrasion as windblown particles wear surfaces, while deposition happens when wind velocity decreases or topography slows the flow, leading to sorted sediments and characteristic landforms.

Common eolian sediments include sands and silts, often forming well-sorted deposits. Dune fields are prominent eolian features, with varieties such as barchan dunes (crescent-shaped with horns downwind), transverse dunes (perpendicular to prevailing winds), longitudinal or seif dunes (linear ridges aligned with wind flow), star dunes (radial arms from multi-directional winds), and parabolic dunes (horns upwind, stabilized by vegetation). Another widespread sediment type is loess, a thick blanket of wind-blown silt that forms extensive, highly fertile soils in many regions.

Eolian landforms also include yardangs, streamlined ridges carved from bedrock by persistent wind erosion, and ventifacts, surface rocks shaped by wind-driven abrasion. Eolian soils, such as psamments in sandy terrains and loess-derived soils, reflect pedogenic processes in wind-blown deposits.

Eolian processes are most active in arid and semi-arid regions but influence landscapes worldwide and play a key role in planetary geology, evident on the surfaces of Mars and other bodies where wind shapes the terrain.