[Geography Notes] on Bajada Pdf for Exam

Bajada (Spanish: slope), also spelled as bahada, consists of a series of coalescing alluvial fans along a mountain front. Such fan-shaped deposits are formed by the deposition of sediments within a stream resting on the flat land at the base of the mountain. The term “ Bajada” is widely used to detail the landscape of geomorphology. 

What are Bajadas?

Bajadas are the shallow slopes that lie at the base of the rocky mountains, where the material gets accumulated from the weathering of the rocks. The bajadas typically have a mixture of sand, gravels, boulders, and silt particles, forming a  deep and complex soil structure that holds water and supports rich vegetation. 

Bajada Formation

When a stream slopes downwards, it picks up sediments along with the other material. As the stream comes up from a mountain front, the sediments that are carried begin to be deposited, such that the rough deposits are deposited at the base and the finer deposits arranged outwards in a fan – shape away from the mountain base. The sediments are further transferred to the opposite side of pediments into a close basin where the bajadas are arranged back into the pediments, making the boundary difficult to observe. 

Bajada Occurrence

Bajadas are moderately sloping depositional plains located between playa and pediments. They are commonly found in dry climates ( for example the Southwest US) where the flash flood deposits remain over time. Bajada is also commonly found in wetter climates where streams are almost constantly depositing sediments. 

Did You Know?

• Bajadas below the Hexie Mountains can be seen from Joshua Tree National park.

• Bajadas are found on both sides of Death valley (north of Stopevilles Wells), more well developed on the Panamint Range side.

• A bajada is generally composed of gravel alluvium and even has larger rocks interbedded in it.

• Pyara lake is found between the Bajadas and pediments.

• The Spanish term Bajada means inclination or descent is often used to describe a landscape or geomorphology.  

• When many alluvial fans come together at one place, or deposits in the same area it forms bajada. Due to the gathering of all the fans, it implies that there is much more water and sediments than usual, and is quite evenly spread out to the whole bajada.