Which term describes the broad apron formed by the coalescence of several alluvial fans?

Which term describes the broad apron formed by the coalescence of several alluvial fans?

• A. Bajada
• B. Pediment
• C. Alluvial fan
• D. Dune field

Answer: (A)

A bajada is the broad apron formed when several alluvial fans merge their deposits downslope along the base of a mountain range. Each fan is a fan-shaped deposit created where a mountain stream loses energy at the canyon mouth, dropping sediment. When multiple fans grow and overlap, their aprons combine into a continuous, gentle slope along the piedmont, producing a bajada. This differs from a pediment, which is a broad, gently sloping platform of bedrock or weathered material at the mountain front formed by erosion rather than by stacked fan deposits. An alluvial fan refers to a single such deposit, not the merged apron along the mountain front. A dune field is made by wind-blown sand, not water-laid fan deposits.

A bajada is the broad apron formed when several alluvial fans merge their deposits downslope along the base of a mountain range. Each fan is a fan-shaped deposit created where a mountain stream loses energy at the canyon mouth, dropping sediment. When multiple fans grow and overlap, their aprons combine into a continuous, gentle slope along the piedmont, producing a bajada. This differs from a pediment, which is a broad, gently sloping platform of bedrock or weathered material at the mountain front formed by erosion rather than by stacked fan deposits. An alluvial fan refers to a single such deposit, not the merged apron along the mountain front. A dune field is made by wind-blown sand, not water-laid fan deposits.