A lag deposit is the deposition of material winnowed by physical action.

Aeolian processes Aeolian processes, also spelled eolian, pertain to wind activity in the study of geology and weather and specifically to the wind's ability to shape the surface of the Earth (or other planets). Winds may erode, transport, and deposit mate ...

fluvial processes In geography and geology, fluvial processes are associated with rivers and streams and the deposits and landforms created by them. When the stream or rivers are associated with glaciers, ice sheets, or ice caps, the term glaciofluvial or fluvio ...

, and tidal processes can remove the finer portion of a sedimentary deposit leaving the coarser material behind. Lag deposits are found in processes such as central island formation in streams and rivers. One theory of

desert pavement A desert pavement, also called reg (in the western Sahara), serir (eastern Sahara), gibber (in Australia), or saï (central Asia) is a desert surface covered with closely packed, interlocking angular or rounded rock fragments of pebble and cob ...

formation is that they are an aeolian lag deposit. Armored beaches and inlets can be composed in part by lag deposits of shells or cobbles created when tidal forces strip away the finer

sand Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural class o ...

and

silt Silt is granular material of a size between sand and clay and composed mostly of broken grains of quartz. Silt may occur as a soil (often mixed with sand or clay) or as sediment mixed in suspension with water. Silt usually has a floury feel ...

References

{{geology-stub Deposition (geology)