A bajada consists of a series of coalescing
alluvial fans along a mountain front. These fan-shaped deposits form by the deposition of sediment within a stream onto flat land at the base of a mountain.
[Desert Processes Working Grou]
"Summary: Alluvial Features, Bajadas"
, ''Knowledge Sciences, Inc.''. Retrieved on 9 October 2012 The usage of the term in landscape description or
geomorphology derives from the
Spanish word ''bajada'', generally having the sense of "descent" or "inclination".
Formation and occurrence
When a stream flows downhill, it picks up sediment along with other materials. As this stream emerges from a mountain front, the sediment carried begins to be deposited, such that coarser sediment is deposited closest to the base and the finer sediment grades outwards and deposits in a fan-shape away from the mountain face.
[National Geographic Society]
"Alluvial Fan"
''National Geographic''. Retrieved on 9 October 2012 The sediment is transported across a
pediment
Pediments are gables, usually of a triangular shape.
Pediments are placed above the horizontal structure of the lintel, or entablature, if supported by columns. Pediments can contain an overdoor and are usually topped by hood moulds.
A pedim ...
into a closed basin where the bajadas grade back into a pediment, making the boundary difficult to distinguish. Bajadas frequently contain
playa lakes.
[Easterbrook, Don. Surface Processes and Landforms. Upper Saddle River: Prentice Hall, 1999. Print. P. 162. Accessed 9 October 2012.] Bajadas are common in dry climates (e.g., the Southwestern US) where flash floods deposit sediment over time, although they are also common in wetter climates where streams are nearly continuously depositing sediment.
References
{{reflist
Sedimentology
Fluvial landforms