Modifies a noun

• silt: His soil isn't suitable for carrots and parsnips as the alluvial silt has heavy seams running through it which make them bend.

• deposit: Near the Clyde, the soil is an alluvial deposit, bearing very superior crops.

• plain: Much of the country is taken up with a low-lying alluvial plain which covers about 75 % of the country.

• sediment: Subsequently these karstic features may have trapped the alluvial sediments.

• clay: These are generally made from the alluvial clays found around the Humber Estuary.

• soil: The valley floor has a rich, deep alluvial base soil.