Aeolian processes and erosive landforms
427
Great deflation basins (Figure 16.9), such as the Quattara depression, commonly have a
polygenic origin, although deflation plays the fundamental role. Albritton et al. (1990)
show that this depression was initially a fluvial valley that was later split by karstic
processes during Upper Miocene, and later it was deepened by deflation. Moreover, mass
movements and fluvial processes modified it somewhat. In addition, saline weathering
prepared materials for subsequent deflation. We should also consider the role that
Quaternary climatic oscillations played, modifying the geomorphological processes and,
as a consequence the genesis of depressions. We can conclude that great deflation basins
have a long and complex history. In smaller deflation basins deflation is dominant,
although other processes are also present, as we previously indicated.
427
Great deflation basins (Figure 16.9), such as the Quattara depression, commonly have a
polygenic origin, although deflation plays the fundamental role. Albritton et al. (1990)
show that this depression was initially a fluvial valley that was later split by karstic
processes during Upper Miocene, and later it was deepened by deflation. Moreover, mass
movements and fluvial processes modified it somewhat. In addition, saline weathering
prepared materials for subsequent deflation. We should also consider the role that
Quaternary climatic oscillations played, modifying the geomorphological processes and,
as a consequence the genesis of depressions. We can conclude that great deflation basins
have a long and complex history. In smaller deflation basins deflation is dominant,
although other processes are also present, as we previously indicated.