Sand wedge

Position: Floodplain

 

Form

Sandy deposits with wedge-shaped cross-section at channel margins in non-levee settings. Typically have a scoured basal contact. Cross-beds are transitional to finer-grained flood cycle interbeds.

 

Process description

Sand wedges reflect bedload deposition, thereby differentiating them from levees. They form atop the proximal floodplain in moderate-high energy environments. As flows go overbank, velocity is sufficient to carry relatively coarse material. Energy is spread outward onto a wedge shaped area of the floodplain, depositing sand.