Natural Features and Formations
The Geology of Sand Dunes
While one-quarter to one-third of the world's deserts are covered with sand, little research has taken place in ergs ...
The Nature of Sand
Sand is defined by its size, although exact quantitative ranges vary with author. ...
Wind-induced Sand Movement
Individual sand grains are moved under the force of the wind in two distinct ways: saltation and surface creep. ...
Two primary factors are necessary for the accumulation of sand into sand sheets and dunes: ...
Small-scale Sand Accumulation Features
Once sand grains have accumulated into relatively large sandy patches, small-scale geomorphic features will often ...
Large-scale Sand Accumulation Features
According to Bagnold (1941), certain conditions must be met for flat sandy areas to build up into true dunes.