bajada

(geology) An alluvial plain formed as a result of lateral growth of adjacent alluvial fans until they finally coalesce to form a continuous inclined deposit along a mountain front. Also spelled bahada.

A series of alluvial fans, typically laid down by ephemeral streams, which has coalesced along the foot of the mountains to form a gently sloping plain of unconsolidated sediments. The weathering of the mountain front may also supply debris. A bajada may also consist of alluvium on the lower part of a pediment. The bajada in the San Sanquin valley of California is some 20 km wide, with gradients from 1 : 35 to 1 : 530.